The Musculoskeletal System Flashcards
(226 cards)
1
Q
Function of the Pectoral Girdle
A
Protraction and retraction via the horizontal anticlockwise/clockwise rotation of the clavicles about sternoclavicular joint .
Elevation and depression via the clockwise/anticlockwise of the clavicles about SCJ in the vertical plane.
Superior and inferior rotation- angles the glenoid superiorly and inferiorly. Clockwise and anticlockwise rotation of scapula about acromioclavicular joint.
2
Q
Function of the clavicle
A
Strut between scapula and axial skeleton that prevents tonal contraction of muscles from pushing it hard up against the thorax. This allows free gliding movement. along the ribcage.
3
Q
Pathology of the Fractured Clavicle
A
All force moving up the upper loose limb will eventually be conducted to the clavicles. Since it is a weak bone, it will readily fracture at the midline- FOOSH injury.
Symptoms: sunken upper limb. Palpable raised ledge formed from the fracture.
4
Q
Features of the scapula
A
Three angles: Superior, inferior, and glenoid fossa.
Three edges: thick lateral border, superior border, inferior border.
Three protuberances: Spine, acromion, coracle.
Three fossa: Subscapular fossa (anterior), supraspinous fossa, infraspinous fossa.
5
Q
Features of the sternoclavicular joint
A
Saddle-shaped.
Stabilised by anterior and posterior sternoclavicular lig.
Joint capsule contains a full circular fibrocartilage disc- independent articulation of the two bones of the SCJ.
Stabilised externally by the subclavius m (subclavian groove & manubrium) and costoclavicular lig (coracoclavicular roughened area & first rib)
6
Q
Features of the acromioclavicular joint
A
Arthrodial/plane joint, allowing only gliding.
Stabilised by superior and inferior AC lig. and the tendons of trapezius and deltoids running superior to the lig.
Joint protected by coracoclavicular ligaments, which bear weight of the free limb instead of the ACJ.
7
Q
Features of the conceptual joint
A
Lubricated muscle-on-muscle interface between the subscapular fossa and the posterior surface of the thorax. Allows for smooth gliding movement when needed, but is a point at which the scapula can be braced to lock the girdle.
8
Q
Pectoralis major
A
Anterior.
O: Sternum and clavicle.
I: Lateral lip of the intertubercular groove.
N: Lateral pectoral (clavicular head) and medial pectoral (sternocostal)
F: adduction and internal rotation of humerus. Protraction of unlocked scapula.
9
Q
Pectoralis minor
A
Anterior.
O: Ribs 3-5.
I: Coracoid process.
N: Medial pectoral.
F: Unlocked scapula-depression of scapula.
Locked scapula- Locked scapula- active breathing by moving the ribcage.
10
Q
Subclavius
A
O: Costal cartilage of rib 1.
I: Clavicles.
N: C5
F: Braces arm by resisting dislocating forces.
11
Q
Serratus anterior
A
O: Medial border of the scapula on the anterior side.
I: Ribs 1-9. Sawtooth pattern at the anterior side.
N: Long thoracic nerve.
F: Contraction holds the scapula close to the thoracic. Division between upper and lower fibres.
- Lower: superior rotation at glenoid fossa- only lower section
- Entire: protraction of entire scapula.
12
Q
Trapezius
A
Divided into superior, middle and inferior sections.
O: Sup- Nuchal line, mid- ligamentum nuchae, inf- Spinous processes of lower vertebrae.
I: Sup- Pos. face of clavicles, mid- acromion, pos- spine of scapula.
N: Accessory nerve.
F: Sup- Elevation of scapula. Mid- Retraction of scapula. Inf- Depression of scapula. Sup +inf: Superior rotation of the glenoid.
13
Q
Latissimus dorsi
A
O: Transverse processes of the vertebra of the lower spine and sacrum. Muscle does not connect directly but via a thin, broad, aponeurosis.
I: Floor of intertubercular groove.
N: Thoracodorsal nerve
F: Adduction of humerus. Internal rotation of humerus.
14
Q
Levator Scapulae
A
O: Transverse processes of C1-C4 (four ‘separate’ heads)
I: Superior angle of scapula.
N: Dorsal scapular
F: Elevation of scapula. Flexion of neck when scapula locked.
15
Q
Rhomboid major and minor
A
O: Spinous process of C7-T5.
I: Medial border of the scapula- spine at superiormost point.
N: Dorsal scapular (Direct branch off C4).
F: Active- Retraction of scapula. Passive: Tonal contraction maintains position of scapula.
16
Q
Dura Mater
A
Dense irregular connective tissue. Forms epidural space with vertebral column which is filled with fat and CT for mechanical protection.
17
Q
Arachnoid mater
A
Thin avascular cell layer with network of collagen and elastic fibres. Forms subdural space with dura mater which contain interstitial fluid.
18
Q
Pia mater
A
Highly vascularised inner layer of cuboidal/squamous epithelium. Forms denticulate ligaments with the other meninges which anchor the spinal cord.
Forms subarachnoid space with arachnoid mater- contains CSF.
19
Q
Filum Terminale
A
A fibre of connective tissue made of all three layers of the meninges in order to anchor the spinal cord to the coccyx to avoid unnecessary movement.
Interna: Section inside the central canal of the spinal cord and the middle of the cauda equina.
Externa: Exposed section.
20
Q
Borders of the Axilla Apex
A
Anterior: Clavicles
Medial: First rib.
Posterior: Superior border of the scapula.
21
Q
Anterior wall of the Axilla
Superior to Inferior
A
Clavicle, subclavius, Costocoracoid lig, Pectoralis minor, suspensory ligament of the axilla.
Second layer: Pectoralis major.
22
Q
Posterior wall of the Axilla
A
Supraspinatus, scapula, subscapularis, teres major, latissimus dorsi,
23
Q
Medial wall of the Axilla
A
Serratus anterior and ribs.
24
Q
Division pattern between spinal cord to anterior ramus
A
Nerves leave and enter the spinal cord as roots and converge to form a spinal nerve to leave the intervertebral foramen.
Spinal nerve divides into rami communicans (–> ANS), posterior rami (–> posterior structures), and anterior rami, which enter nerve plexi.
25
Divisions within the Brachial plexus.
Consists of the spinal nerves from C5-T1.
C5 and C6 forms the superior trunk. C7 forms the middle trunk. C8 and T1 forms the inferior trunk.
Superior trunk and middle trunk forms the lateral cord .
All three trunks form the posterior cord. Inferior trunk alone forms the medial cord.
Lateral cord alone forms musculocutaneous nerve.
Posterior cord alone forms the axillary nerve and the radial nerve.
Lateral cord and medial cord forms the median nerve.
Medial cord alone forms the ulnar nerve.
26
Clinical means to identify the nerves of the Axillary Plexus
The musculocutaneous nerve is identifiable as the nerve running between the biceps brachii and brachialis.
Tracing that nerve back will reach a point of division for the lateral cord. Following the other branch will lead to the median nerve.
Tracing the other branch leading to the median nerve will lead to the medial cord.
Tracing the other branch of the medial cord will lead to the ulna nerve.
Posterior cord is found posterior to the large axillary artery and forms a small branch called the axillary nerve which travels posteriorly through the quadrangular space. The rest of the posterior cord continues as the radial nerve.
27
Minor nerves of the Lateral Cord
Lateral pectoral nerve: Innervates clavicular head of pectoralis major.
Suprascapular nerve: Innervates supraspinatus and infraspinatus.
28
Minor nerves of the medial cord
Medial pectoral nerve: Innervates the sternocostal head and pectoralis minor.
Medial cutaneous nerves of the arm and forearm.
29
Minor nerves of the posterior cord
Upper subscapular nerve: Innervates subscapularis.
Thoracodorsal nerve: travels down posterior axillary wall and innervates latissimus dorsi.
Inferior subscapular nerve: Travels down posterior axillary wall and innervates subscapularis.
30
Musculocutaneous Nerve Innervation
Travels along groove between deltoid and pectoralis major.
Penetrates coracobrachialis and moves between Brachialis and biceps brachii. Becomes cutaneous at the lateral epicondyle to form lateral cutaneous nerve of forearm.
31
Median nerve innervation
| List forearm muscles innervated
Moves from median side of humerus to lateral, then innervates 2/3 of muscles in the forearm.
Pronator teres, flexor carpi radialis, palmaris longus, lateral head of flexor digitorum profundus, flexor digitorum superficialis, pronator quadratus, flexor pollicis longus and thenar muscles.
Cutaneous innervation of the first 3.5 digits of the hand via the proper palmar digital nerves of the median nerve.
32
Ulnar nerve innervation
Moves down the medial side of the arm and behind the medial epicondyle. Innervates flexor carpi ulnaris and the ulnar head of the flexor digitorum profundus.
- Dorsal cutaneous branch provides cutaneous innervation to ulnar side of the posterior face of forearm.
- Deep branch ulnar nerve: Supplies 15/20 intrinsic muscles of the hand.
- Proper palmar digital nerves of the ulnar nerve provides cutaneous innervation of the 1.5 digits not innervated by the median nerve.
33
Deltoid Muscle
Ant/pos fibres are unipennate- tendon runs down one side of muscle. Mid fibres are multipennate- unipennate like structure but muscle found on both sides of tendon.
O: The anatomical horseshoe. Ant- clavicle, mid- acromion, pos- Spine of scapular.
I: Deltoid tuberosity of humerus.
N: Axillary nerve
F: Ant- Shoulder flexion. Internal rotation of arm.
Pos: Shoulder extension. External rotation of arm.
Mid: Abduction of arm.
34
Teres major
O: Inferior angle of the scapula in the infraspinous fossa.
I: Medial lip of intertubercular groove.
N: Inferior subscapular.
F: Internal rotation of the arm and extension of shoulder.
35
Teres minor
```
Part of the rotator cuff.
O: Lateral border of the scapula.
I: Inferior facet, greater tubercle.
N: Axillary.
F: Exteral rotation of humerus. Barrier against posterior dislocation of shoulder joint.
```
36
Brachialis
O: Lower half of the anterior face of humerus, including the intermuscular septa.
I: Ulnar tuberosity.
N: Musculocutaneous
F: Flexion of the elbow joint.
37
Biceps brachii
O: Long- Supraglenoid tubercle, after travelling up intertubercular septum and through the glenohumeral joint. Short- Coracoid process.
I: Radial tuberosity on the medial side of radius. Splits to form bicipital aponeuroses to blend with deep fascia of skin.
N: Musculocutaneous
F: Flexion of elbow joint. Supination of hand. Long head tendon provides tension against dislocation of the glenohumeral joint by pulling the humeral head into the glenoid fossa.
Short head can also act as a shunt muscle to reduce unnecessary movement.
38
How is the biceps brachii involved in the supination of the hand.
Pronation causes inserting tendon to wrap around the radius and build up tension. Contraction of biceps will pull on the tendon and 'unwind' it from around the humerus.
39
Coracobrachialis
O: Coracoid process.
I: Tuberosity opposite the deltoid tuberosity on the medial face of humerus.
N: Musculocutaneous
F: Adduction of humerus. Shunt muscle.
40
Mechanism of action of coracobrachialis as a shunt muscle
Role is to reduce unnecessary movement at a joint.
When load is applied to the glenohumeral joint, the there is a downward force pulling on the humerus which can lead to inferior dislocation. Coracobrachialis will contract to maintain the position of the humerus , hence functionally transferring tension to itself.
41
Triceps brachialis
Posterior extensor compartment of forearm.
O: Long- Infraglenoid tubercle. Lateral + Medial- Posterior face of humerous,
I: Olecranon of the ulna.
N: Radial
F: Elbow extensor. Long head is a shunt muscle.
Most of extensor function carried out by the medial head.
42
Axillary nerve innervation and path
Exits the axilla via the quadrangular space. Innervates the deltoid and teres minor. Becomes the lateral cutaneous nerve of the arm.
43
Radial nerve path in the arm
Travels posteriorly alongside the brachial profundus artery. Moves along radial groove of the posterior humerus.
44
Branches of the Axillary artery
Deep artery running medial to the humerus. Becomes brachial artery when inferior to the teres minor.
Forms collaterals which return to the brachial artery at the cubital fossa- backup blood supply via anastomosis.
Anterior and posterior cirumflex: Bends around the surgical neck of the humerus.
The posterior circumflex exits via the quadrangular interval.
Profunda brachii artery runs posteriorly and supplies the posterior of the arm.
45
Parameters of the cubital fossa
Medial border: Lateral border of pronator teres.
Lateral border: Medial border of brachioradialis
Roof: Bicipital aponeuroses.
Floor: Anterior face of brachialis.
Superior border: Arbitrary line between the two epicondyles.
46
Vasculature at the Cubital Fossa
Arteries: Brachial artery splits into ulnar and radial artery.
Veins: Basilic vein runs down the medial side and cephalic vein runs down the lateral side. Basilic vein forms median cubital vein, which moves medially to join the cephalic vein.
Median antebrachial vein form from the median cubital vein.
Venae comitantes: Runs adjacent to the deep brachial artery. Uses rhythmic distension of the arteries to push venous blood up.
47
Clinical significant of Cubital Fossa Veins
Basilic vein is the site of IV injections and where blood is taken from.
Tourniquet is applied above the fossa to limit venous return of blood, without cutting off arterial supply. Leads to accumulation of blood in the veins, which makes them bulge and easily visible.
48
Coracoacromial ligament
Connects coracoid and acromion. Forms roof of the glenohumeral joint to prevent superior dislocation.
Extracapsular ligament
49
Coracohumeral ligament
Capsular ligament connecting the coracoid with the lesser tubercle of the humerus.
Function: Suspension of the humerus in the anatomical position. When the arm is adducted, the ligament stretches over the top of the joint. This tightens it and creates tension in the ligament which holds it up.
50
Transverse humeral ligament
Connects the two lips of the intertubercular groove. Acts as a roof over the long head tendon of biceps brachii.
51
The glenohumeral ligaments
Weak, lateral thickenings found at the anterior of the joint capsule
52
Supraspinatus `
O: Spine of the spine of the scapula.
I: Superior facet of the greater tubercle.
N: Suprascapular nerve of the superior trunk.
F: Initiates humerus abduction.
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Infraspinatus
O: Infraspinous fossa
I: Middle facet of greater tubercle.
N: Suprascapular nerve
F: External rotation of humerus.
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Subscapularis
O: Subscapular fossa.
I: Lesser tubercle.
N: Subscapular nerves
F: Internal rotation of humerus.
55
Function of the Rotator Cuff
Physical barrier against dislocating motion.
| Contracts to pull the head of the humerus medially into the glenoid fossa to prevent dislocation.
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Abductors of Humerus
Supraspinatus. Middle fibres of deltoid.
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Adductors of Humerus
Pectoralis Major, Latissimus Dorsi, Teres major, long head of triceps, anterior and posterior fibres of the deltoid, coracobrachialis.
58
Flexors of Humerus
Anterior fibres of the deltoid, coracobrachialis, clavicular head of pec major. biceps brachii
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Extensors of the Humerus
Posterior deltoid, long head of triceps, teres major, sternocostal head of pec major, latissmus dorsi.
60
Humeroradial joint
Ball and socket like joint formed between the capitulum and the spherical indentation at the head of the humerus. Allows flexion and extension.
Held together by the collateral radial ligament, which attaches to the anular ligament of the radius in order to not limit rotatory movement.
Anular ligament padded from bone by sacciform recess of synovial membrane.
Radial fossa located above capitulum to allow full extent of motion by provide a hole for the head to fit.
61
Humeroulnar joint
Formed between the trochlea of the humerus and the trochlea notch on the head of the ulnar. This notch is formed by the coronoid process inferiorly, and the olecranon posteriorly.
Olecranon fossa located posteriorly above the trochlea . Allows full range of motion by providing a hole for the olecranon to fit into.
Held together by the ulnar collateral ligament/
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Radioulnar joint
Lateral joint formed between the head of the radius and the radial notch on the ulna. Allows rotatory articulation of the radius around the ulna.
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Bursae of the glenohumeral joint
Synovial membranes containing slippery synovial fluid.
Function: Provide interface between ligament and bone to prevent damage and rupture of the ligament by the roughened bone.
Subdeltoid: Protects middle fibres of deltoid from the greater tubercle.
Subacromial: Joined to subdeltoid bursa. Protects supraspinatus and infraspinatus tendons from the acromion.
Subscapular : Protects subscaprularis tendon from the humerus.
Subcoracoid: reduce friction between the tendons of the coracobrachialis, subscapularis and the short head of biceps (ie: any tendons which pass by the coracoid.)
Sacciform synovial membrane: Protects the tendon of the long head against the roughened intertubercular groove.
64
Why is the articular capsule of the glenohumeral joint loose?
Allows for full range of abduction/adducting movements. When abducted, the inferior section of the capsule is loose to provide room for extension.
Loose capsule provides limited resistance against dislocation, hence the need for the rotator cuff.
65
Distal radioulnar joint
Radioulnar notch formed from fibrous cartilage floor and the ulnar notch, Ulna head fits into the notch. Lateral hinge-like joint allowing only pronation/supination motion.
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Pathology of the Elbow Joint
Posterior dislocation: Excessive force exerted on the forearm. If the humerus is locked, the olecranon will act as a lever to lift the humerus out of the trochlear notch.
Damage to olecranon fossa: Force is transmitted around the olecranon fossa, which are narrow strips of bone which will be easily fractured.
67
Interosseous membrane.
Sits between the radius and the ulna and separates the forearm into posterior and anterior compartments.
Fibres are obliquely and inferiorly angled.
Means of force transmission- if force is applied to the radius superiorly, the tension in the sheet of CT will drag the ulna along- hence force transmission occurs and the force applied over a wider area.
Hinge during supination/pronation.
Muscle attachment.
68
Carpal bones- clockwise from scaphoid- anatomical position.
Scaphoid, lunate, triquetrium, pisiform, hamate, capitate, trapezoid, trapezium
69
Anatomy of the Carpal Tunnel and Pathology of the Carpal Tunnel Syndrome
Passage formed over the wrist and positioned at the base of the thenar and hypothenar muscle masses.
Roof: Flexor retinaculum formed between the trapezium and the hook of the hamate.
Floor: Proximal carpals.
Carpal tunnel syndrome is when infection leads to the accumulation of exudate. Exudate accumulation leads to pressure buildup inside the carpal tunnel, which causes impingement on vasculature and innervation.
Retinaculum must be removed to relieve pressure if chronic.
70
Pronator teres
Superficial pronator
O: Medial supraepicondylar ridge. (Humeral head)
Medial side of coronoid process (ulnar head)
I: Lateral surface of the radius
N: Median nerve
F: Pulls the lateral face of the radius medially- internally rotates radius over the 'top' of the ulna.
71
Flexor Carpi Radialis
```
Superficial flexor
O: Common tendon of the anterior compartment- medial epicondyle.
I: Base of the second metacarpal.
N: Median
F: Flexion and abduction of wrist
```
72
Palmaris longus
Superficial flexor
O: Common tendon of the anterior compartment- medial epicondyle.
I: Palmar aponeurosis
N: Median nerve.
F: Flexion of the wrist joint. Tenses the palmar aponeurosis during contraction to resist shearing forces.
73
Flexor Carpi Ulnaris
```
Superficial flexor
O: Common tendon of the anterior compartment- medial epicondyle.
I: Base of the fifth metacarpal.
N: ULNAR nerve
F: Flexion and adduction of the wrist.
```
74
Flexor digitorum superficialis
Intermediate flexor.
O: Medial epicondyle and medial edge of the coronoid process. (Humeroulnar head)
Anterior oblique line of radius (radial head)
I: The end of the middle phalanx of all fingers.
N: Median- anterior interosseous
F: Flexion of the proximal interphalangeal joint and the metacarpophalangeal joint of the fingers.
75
Flexor digitorum profundus
Deep flexor
O: Complex, but stretches obliquely from the interosseous membrane superiorly and posteriorly towards the medial face of the ulnar head.
I: Palmar face of the distal phalanges of the fingers.
N: Lateral half- Anterior interosseous branch of the median nerve
Posterior half- ulnar nerve.
F: Flexion of the DIP joint and the MP joint.
76
Flexor pollicis longus
Deep flexor
O: Anterior surface of the radius and adjacent interosseous membrane- lateral to the FDP on the interosseous membrane.
I: Palmar surface of the distal phalanx of the thumb
N: Median- anterior interosseous
F: Flexion of the thumb at the IPJ and the MPJ.
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Pronator Quadratus
```
Deep pronator
O: Distal anterior surface of the ulna.
I: Distal anterior surface of radius.
N: Median- anterior interosseous
F: Aids pronation.
```
78
Path and branching of the median nerve in the anterior compartment of the forearm
Forms a large branch called the anterior interosseous nerve which runs between the forearm bones, alongside the anterior interosseous artery.
Forms a palmar cutaneous branch just before the retinaculum which passes superficially to the retinaculum to provide cutaneous innervation to the lateral two thirds of the palm.
Past the retinaculum, the median nerve forms the common digital palmar nerves, which further divide into proper digital palmar nerves which innervate the first 3.5 digits.
A recurrent branch is also formed at the same level which innervates the thenar muscle mass.
79
Path and branching of the ulnar nerve in the anterior compartment of the forearm
Runs down the forearm on the medial side. Forms the palmar cutaneous branch halfway down the forearm which passes over the retinaculum to innervate the medial third of the palm.
Superficial ulnar branch forms similar digital divisions which lead to the innervation of the medial 1.5 digits.
Deep ulnar branch moves deeper into the palm via the hypothenar muscle mass.
Dorsal cutaneous branch forms before the retinaclum and provides cutaneous innervation to the medial third of the back of the hand.
80
Vasculature of the Anterior Compartment of the Forearm
Brachial artery branches into radial and ulnar branches after the cubital fossa.
The radial artery runs down the lateral side and joins with the radial recurrent artery. Forms no divisions until at the carpals where it splits into a superficial branch, with the main branch moving deeper .
The ulnar artery runs down the medial side and receives the anterior and posterior ulnar recurrent arteries. Forms a common interosseous branch which receives the interosseous recurrent before splitting coronally into anterior and posterior interosseous ulnar arteries which join posteriorly.
The proper ulnar branch proceeds down the median side until the carpals, where they split into a deep branch and the main superficial branch.
81
Properties of carpometacarpal joints
Fingers: Plane like joints, allowing only limited gliding movement.
Thumb: Saddle joint allowing flex/ext and abd/add, as well as limited rotational.
82
Describe the articulate movements of the thumb
Abduction/Adduction: Raising the thumb above the plane of the palm/ Returning the thumb to the plane of the palm.
Flexion/extension: Movement of the thumb towards/away from the palm.
Opposition: Rotation and adduction of the thumb to reach the other digits.
83
Properties of the metacarpophalangeal joints
Fingers: Condyloid joint that resembles a limited ball-and-socket joint. Allows a wider range of rotational and adduction/abduction.
Thumb: A kind of hinge joint consisting of two condyles. Allows only flexion and extension. Lateral movement further prevented by collateral ligaments.
THE METACARPOPHALANGEAL JOINT OF THE THUMB IS THE SAME AS THE IPJ OF THE FINGERS.
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Ligaments of the phalanges
Collateral ligaments: to limit lateral movement at the IPJs.
Palmar ligaments: Connects collateral ligaments and provides a floor to the fibrous tunnel which houses the flexor ligaments.
Deep transverse metacarpal ligaments: Links the heads of the metacarpals. Prevents the over splaying of the fingers. NOT CONNECTED TO THE THUMB BECAUSE DUH.
85
Interaction between the tendons of the FDS and FDP.
The FPS tendon splits around the FDP tendon at the head of the middle phalanx and reconnects under the FDP tendon.
86
Dorsal interossei muscles.
O: The metacarpals of two adjacent fingers.
I: The base of the proximal phalanx, and the dorsal digital expansion hood of the more medial finger (out of two that the muscle originated from)
N: Deep ulnar branch.
F: Abduction of the digits II, II and IV at the MCPJs.
87
Palmar interossei muscles
O: Sides of the metacarpals.
I: DDEH of the same finger.
N: Deep ulnar branch.
F: Adduction of all digits except III- the third digit always abducts as it is the midline.
88
Adductor Pollicis
O: Lateral head- proximal phalanx of the third digit.
Oblique head- Base of the third metacarpal and the capitate.
I: DDEH of the thumb.
N: Deep ulnar branch.
F: Adduction of the thumb.
89
Lumbricles
O: The tendon of the FDP.
Bipennate (IV/V): Adjacent FDP tendons.
Unipennate (II/III): FDP tendon of the second and third digit.
I: DDEH.
N: Medial- Deep ulnar
Lateral- Digital branches of the median nerve
F: Contracts to extend IP joint in order to achieve a fine grip
90
Anatomy and Functions of the Dorsal digital extension hood
Fibrous sheet formed from the tendons of extensor digitorum and extensor pollicis, and attached to the middle phalanx.
Consists of lateral bands running down the sides up to the base of the distal phalanx, and the central band which runs on the posterior and up to the base of the middle phalanx.
Extensors will pull on the DDEH, which is attached to the phalanges and hence cause extension at the IPJs.
Allows for flexion at the MCPJ but extension at the IPJs to form a fine grip.
91
Thenar muscles
O: Carpals on the lateral side and the flexor retinaculum.
I: Opponens- Lateral and palmar surface of metacarpal I.
Abductor-DDEH
FPB- Proximal phalanx.
N: Recurrent median branch
F: Opposition and other more delicate movements of the thumb.
92
Hypothenar muscles
O: Carpals on the medial side and the flexor retinaculum.
I: Opponens- medial face of metacarpal V.
Abd/flex- proximal phalanx.
N: Deep ulnar branch.
F: Opposition and delicate movements of the little finger.
93
Vasculature of the hand
Superficial branch of the radial artery joins with the superficial ulnar artery to form the superficial palmar arch.
The deep branches of the superficial and ulnar arteries will form a deep palmar loop.
Both palmar arches send out branches to form the common digital arteries, which split to form proper digital arteries.
Independent arteries branch from the deep palmar arch to supply the thumb and index finger.
94
Brachioradialis
Superficial Extensor compartment but not an extensor
O: Proximal face of the supraepicondylar ridge.
I: Base of the radial styloid process (at the wrist joint).
F: Accessory flexor of the elbow joint .
N: Superficial branch of the radial nerve.
95
Anconeous
Superficial Extensor
O: Lateral epicondyle.
I: Olecranon/ proximal posterior region of ulna
F: Accessory elbow extensor.and aids in pronation.
N: Posterior interosseous
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Extensor Carpi Radialis Longus/Brevis
O: ECRL: Lateral supraepicondylar ridge
ECRB: Lateral epicondyle and associated interMUSCULAR septum.
I: Dorsal surface of the second and third metacarpal
N: ECRL- Superficial branch of the radial nerve.
ECRB- Posterior interosseous.
(ECRL superficial to ECRB)
F: Extension and abduction of the wrist. Prevents the flexion of the wrist by powerful flexor pollicis.
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Extensor Carpi Ulnaris
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Superficial extensor
O: Lateral epicondyle and posterior border of ulna.
I: Base of metacarpal V.
N: Posterior interosseous
F: Extension and adduction of the wrist.
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Extensor digitorum and extensor digiti minimi
Superficial extensor
O: Lateral epicondyle and associated intermuscular septum.
I: DDEH of the respective digits, UNDER the extensor retinaculum in their individual tunnels.
N: Posterior interosseous
F: Extension of the IPJ and the wrist.
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Sheaths of the Palm
Synovial sheaths surround the collective bundle of tendons of the FD directed to digits II to V, then again around individual tendons.
FPL tendon has an individual, continuous sheath running along the full length.
Function: Bursa-like. Enables smooth motion of the ligaments without excess friction.
Fibrous digital sheaths run over the palmar side of the synovial sheath- protective function.
100
Collective function of the carpi muscles
All carpi muscle motion consists of a combination of Abd/add and flex/ext.
Simutaneous contractions lead to summation of their actions- if both flexors then lateral components cancel and flexion occurs.
Simultaneous contractions of all four carpi muscles lead to 'locking' of the wrist where the tension in the muscles due to contraction resists externally imposed movements.
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Supinator
Deep extensor
O: Superior- Posterior face of the lateral epicondyle and the annular/collateral ligament of the radius.
Inferior- Supinator crest on the posterolateral surface of the ulna.
I: Anterior face of the radius, superior to pronator teres insertion.
N: Posterior interosseous
F: Supination of the forearm by pulling the radius posteriorly in external rotation.
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Abductor pollicis longus
Deep extensor
O: Proximal posterior surface of the radius and ulna, and the associated interosseous septum.
I: Base of the metacarpal of the thumb.
N: Posterior interosseous
F: Abduction of the thumb by pulling it upwards (in the coronal plane).
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Extensor pollicis longus/brevis
Deep extensor:
O: Longus- Posterior face of ulna and associated interosseous membrane.
Brevis- Posterior face of the radius and associated interosseous membrane.
I: Longus- Base of distal phalanx of thumb.
Brevis- Base of proximal phalanx of the thumb.
N: Posterior interosseous
F: Extension of the thumb at the MCPJ and the IPJ.
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Extensor indicis
Deep extensor
O: Posterior surface of the ulna and associated interosseous membrane inferior to the EPL.
I: Base of the proximal phalanx of digit Ii.
N: Posterior interosseous
F: Extension of digit II. Independent extensor allows for a greater degree of independent movement.
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Anatomical Snuffbox Features and Clinical Significance.
Formed by the tendons of the EPB/APL (lateral border), EPL (medial border) and the scaphoid and trapezium carpals form the floor.
Provides a space for palpitation of the scaphoid to detect fractures.
106
Development of vertebral curves.
During embryonic development there is only the overall C-shaped curve.
Neonatally, there are only two concave curvatures- thoracic and saccral.
Postnatally, the cervical convex curve develops as the baby starts to lift their head.
As the baby learns to walk, the convex lumbar curvature also forms to accommodate the shift in the centre of mass.
The cervical and lumbar curvatures are known as secondary curves.
107
Pathology involving spinal curvature
Scoliosis: Lateral bending and rotation of the spinal cord. Spines tend to be slightly scoliotic due to increased muscle mass on the dominant side.
Kyphosis: Excessively convex thoracic curvature, leading to the head leaning forward. Caused by weakened trapezius. Can lead to formation of wedge-shaped vertebra in osteoporotic patients. Spines are normally mildly kyphotic as the head is positioned anterior to the thoracic spine.
Lordosis: Excess convex curvature in the lumbar region. Caused by increased mass in the abdominal region to shift the centre of mass back onto the spine.
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Positions of the VC relative to body cavities
Cervical: Occupies posterior third to balance out forward leaning mass of skull.
Thoracic: Occupies posterior quarter as thoracic cavity contains lungs and heart, which exert a strong kyphotic force.
Lumbar: Occupies posterior half. Must be large as it bears the load of the entire upper body. As a result, peritoneal viscera is crammed into a small space and some structures will be pushed superficially.
109
The Zygapophoseal joints
These are the joints formed between the articular facets of the superior and inferior articular processes.
The facet is horizontal at the cervical region, but becomes more oblique and inward-facing going down the spinal cord to resist lateral rotatory movement and increased stability.
Acts as a fulcrum to allow load to be transferred from the vertebral bodies to the muscles contracting and pulling downwards on the spinous processes of the vertebra.
110
The Annulus fibrosis
Attached to the vertebral body on both ends.
Concentric rings of collagen arranged orthogonally and becoming more horizontally aligned. Limits rotatory motion and resists overextension of the vertebral column.
111
The nucleus pulposis
Sphere of well hydrated hyaluronic acid and proteoglycans found in the middle of the annulus fibrosis.
Resistant to compression and acts as a pivot between the vertebral bodies.
Dehydration can occur when it is regularly compressed but can be rehydrated during sleep. In elderly this is usually very dehydrated, which reduces range of VC movement and also causes elderly to be shorter.
112
Pathology of the nucleus pulposis
Herniation occurs when there is a gap in the annulus fibrosis which allows the movement of the nucleus pulposis out.
NP will be 'squeezed' out into the intervertebral foramen through a gap between the ligaments and muscles. Causes impingement of nerves and leads to back pain.
113
Ligaments of the vertebral column
Supraspinous: Travels along the tips of the spinous processes of the lower vertebra, and connects with the ligamentum nuchae in the cervical region. Resists excess flexion.
Anterior longitudinal ligament: Travels along anterior face of the vertebral body and prevents excess extension.
Posterior longitudinal ligament: Runs along the posterior face of the vertebral body, inside the vertebral foramen. Resists excess flexion.
Interspinous ligaments: Independent ligaments found between adjacent spinous processes. Blends with the ligamentum flava and supraspinous ligaments. Prevents overflexion.
Ligamentum flava: Lines the lamina inside the vertebral foramen. Very elastic, and stores elastic potential energy as it deforms during flexion. Aids in the return of the spinal column to the anatomical position.
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Erector Spinae
Iliocostalis (lateral-most)
O: Iliac crest of the pelvis via the thoracolumbar fascia.
I: Various insertions onto the ribs.
Longissimus (middle)
O: Common head with iliocostalis
I: Transverse processes of the cervical region.
Spinalis ( Medial)
Connects the spinous processes of adjacent vertebra.
F: Contracts billaterally to reinforce the verticality of the VC. Contracts unilaterally to allow flexion in that direction.
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Multifidus muscle
Originates from a transverse process and moves obliquely and superiorly to attach to a spinous process.
Extends spine when contracting bilaterally and rotates when contracting unilaterally.
116
Organisation of spinal innervation
Intervertebral disc is innervated by sinuvertebral nerve- recurrent branch of the rami communicans.
Rest of rami communicans travels around the vertebral body and supplies the outer layer of the intervertebral disc.
Synapses with the sympathetic ganglia, which can conduct the nerve to another level. Afferent branches form from the sympathetic ganglia to innervate the rest of the periphery of the intervertebral disc.
As nerves are sent to multiple levels via the sympathetic ganglia, sensation detected by them is hard to localise- returns to spinal cord as ONE nerve. The sensation is hence said to be diffuse.
117
Organisation of spinal vasculature
Form similar divisions as the rami of the nervous system.
Posterior branch forms recurrent branch that supplies the structures within the vertebral column.
Main anterior branch forms anastomoses with adjacent anterior branches to ensure blood flow to every level.
LIMITED perfusion to the intervertebral disc as there is no vasculature through the disc.
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Quadrangular interval and what passes through it
Superior border: Teres minor
Inferior border: Teres major
Medial border: Long head triceps brachii.
Lateral border: Humerus
Axillary nerve enters the posterior compartment here.
119
Triangular interval and what passes through it
(This one is the one inferior to the quadrangular interval)
Superior border: Teres major
Medial border: Long head triceps.
Lateral border: Lateral head triceps.
Radial nerve and profunda brachii artery moves posteriorly through here.
120
Triangular space and what passes through it
(This is the one found behind the scapula).
Superior border: Teres major
Inferior border: Teres minor
Lateral border: Long head triceps brachii
Circumflex scapular artery
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Fascia Lata
Deep fascia of the thigh made of Collagen I. Connects along the inguinal ligament between pubic tubercle and the superior anterior iliac spine. Follows the iliac crest and then most posteriorly at the coccyx.
Covers all structures of the thigh except the tensor fascia lata and the gluteus maximus, which the FL forms a sleeve around. Saphenous opening is a hole in the anteromedial region of the FL, near the superior border
Thickening occurs on the lateral face of the fascia lata,- iliotibial band. Connects FL to the tibia across the knee joint which it stabilises. Insertion of TFL and gluteus maximus.
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Iliopsoas
Anterior thigh. Combination of iliacus and psoas major into a shared insertion.
O: Iliacus- Iliac fossa. Psoas major: Transverse processes of L2-L4.
I: Lesser trochanter of the tibia.
N: Iliacus- Femoral. Psoas major- Nerve of L2 and L3.
F: Flexion and external rotation of the thigh.
Identifiable as the lateral side of the floor of the femoral triangle. Visible between sartorius and the femoral triangle structures.
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Pectineus
Anterior-medial compartment.
O: Superior pubic ramus.
I: Space inferior to the lesser trochanter.
N: Mainly femoral nerve but contributions by obturator nerve.
F: Flexion and adduction at the hip joint
Identifiable as the medial floor of the femoral triangle.
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Tensor fascia lata
Gluteal compartment
O: ASIS
I: Lateral condyle of tibia (as it fuses with the FL)
N: Superior gluteal nerve, deep branch.
F: Abduction at the hip joint and stabilises the pelvis.
Identifiable as the lateral-most muscle of the thigh.
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Sartorius
Anterior compartment
O: ASIS.
I: Medial surface of the tibia-pes anserinus
N: Femoral
F: Flexion at the hip and knee. External rotation and abduction of the hip. Pulls leg into cross-legged position.
Most visible muscle. Running anterior to all other muscles.
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Rectus femoris
Anterior compartment
O: Anterior inferior iliac spine and the lateral rim of the acetabulum.
I: Superior pole of the patella, at the common quadriceps tendon.
N: Femoral
F: Extension at the knee.
Visible as the muscle between the two muscles originating from the ASIS.
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Vasti lateralis, medialis and intermedialis.
O: Lateralis- Greater trochanter and linea aspera.
Medialis- Superior 2/3 of the lateral intermuscular septum.
Intermedialis- Medial intermuscular septum.
I: Superior facet of the patella at the common quadriceps tendon.
N: Femoral nerve
F: Extension of the Knee
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How to find the vasti muscles
Medialis: Visible as muscle fibres joining the tendon at an oblique angle.
Intermedialis: Not visible unless RF is reflected.
Lateralis: Not visible unless TSL reflected, but oblique inserting fibres visible at the tendon.
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Adductor Longus
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Medial compartment
O: Body of pubis
I: Linea Aspera
N: Obturator nerve.
Medial border of the femoral triangle.
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Adductor brevis
Medial compartment
O: Inferior pubic ramus
I: Linea aspera, superior to the insertion of adductor longus.
N: Obturator
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Adductor magnus
Medial compartment
O: Inferior pubic ramus. Hamstring head originates from the ischial tuberosity.
I: Along the linea aspera down to the adductor tubercle, with a gap called the adductor hiatus for the femoral artery and vein to move between the anterior and posterior compartments.
Visible after reflection of adductor longus.
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Gracilis
O: Body of the pubis
I: Pes Anserinus
Muscle running along the medial side of the thigh- easily visible.
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Clinical application of the Pes Anserinus tendons
These tendons are not the dominant muscles used for movement at the hip and knee joints Can be harvested for ACL repair.
134
Formation and branching pattern of the Femoral Nerve
Originates from the spinal nerves of L2 -L4, which recombines via the femoral plexus to form the femoral nerve. It passes anteriorly through the pelvis and under the inguinal ligament. It immediately horsetails distal to the inguinal ligament.
- Saphenous nerve. Follows the great saphenous vein and leaves the adductor canal to provide cutaneous innervation to the medial side of the leg.
- Anterior cutaneous branches of the femoral nerve provide innervation to the anterior face of the thigh.
- Various motor branches to innervate muscles.
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Formation and branching pattern of the Obturator Nerve
Arises from the lumbar plexus formed between L2 and L4. Enters anterior compartment via obturator foramen formed between the superior and inferior rami.
Proceeds down the medial compartment via the adductor brevis and provides cutaneous innervation on the medial side of the thigh.
136
Origin and divisions of the femoral artery
Formed from the external branch of the abdominal aorta, which passes under the inguinal ligament and become the femoral artery, located about halfway between the ASIS and the pubic symphysis.
Forms the profunda femoris artery, which form circumflex arteries that supply the hip joint and the head of the femur.
Supplies the posterior compartment via perforating arteries which 'perforate' and move through medial compartment.
137
Boundaries of the Femoral Triangle
Inguinal ligament as superior border. Sartorius as medial border. Iliopsoas and pectineus as the lateral and medial components of the floor.
Fascia lata as the ceiling.
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Structures present within the femoral triangle.
Lateral to medial: Nerve, Artery, Vein, Lymphatics ( the femoral canal).
Artery, vein and canal is surrounded by the femoral sheath. Canal is demarcated by the femoral ring.
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Pathology involved within the femoral triangle
Femoral herniation, where a small loop of small intestine breaches the femoral canal and can become strangled by the canal.
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Adductor Canal Boundaries
Triangular space formed between the sartorius (medial border and roof), vastus medialis (lateral border) and adductor magnus/longus (floor)
Conducts femoral triangle structures into the popliteal fossa.
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Clinical applications related to the femoral canal and triangle
- Femoral block can be applied to the femoral nerve to anaesthetise the head of the femur.
- Femoral vein and artery both useful to access the heart and the artery is useful for taking peripheral samples during shock.
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Compartmental organisation of the leg
Anterior: anything anterolateral of the tibia and the interosseous membrane.
Lateral: anything anterior to the fibula .
Posterior: Everything posterior to the tibia, fibula and the interosseous membrane.
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Compartment syndrome in the anterior compartment
Symptoms: Pain, pallor, paresthesia, paralysis.
Pain during PASSIVE movement of the muscle.
Can be diagnosed by palpating for increased pressure in the compartment as well as using a pressure meter.
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Function of the calcaneus and talus
Talus: Articulates with the end of the tibia to form an ankle joint. Involved in dorsiflexion and plantarflexion.
Calcaneus: found inferior to the talus- articulates at the subtalar joint. Allows eversion and inversion (lateral 'rotatory' movement) of the foot.
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Tibialis Anterior
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Anterior compartment
O: Tibia and interosseous membrane.
I: Medial cuneiform and base of metatarsal I.
N: Deep peroneal
F: Dorsiflexion and inversion of foot.
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Extensor hallucis longus
Anterior compartment
O: Middle to inferior region of the anterior face of the fibula and associated interosseous membrane.
I: Distal phalanx of the hallux (big toe)
N: Deep peroneal.
F: Weak dorsiflexor. Extensor of hallux.
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Extensor digitorum longus of the leg
Anterior compartment
O: Lateral tibial condyle and the superior 3/4 on the anterior face of the fibula as well as associated interosseous membrane.
I: Splits into four and attaches to the distal phalanx.
N: Deep peroneal.
F: Extension of toes. Weak ankle dorsiflexor.
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Peroneus Tertius
Anterior compartment
O: Inferior third of the on anterior fibula and the associated interosseous.
I: Base of metatarsal V.
F: Eversion and dorsiflexion of the foot.
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Lateral compartment muscles of the leg
Innervated by superficial peroneal nerve and act as weak plantarflexors and evertors.
Peroneus longus
O: Superior 2/3 of the lateral face of the fibula.
I: Base of the first metatarsal and the medial cuneiform- reached by forming a transverse tendon which maintains the arch of the foot.
Peroneus brevis:
O: Inferior 2/3 of the lateral face of the fibula.
I: Lateral tubercle on the base of the fifth metacarpal.
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Superior and inferior extensor retinaculum
Superior: Transverse rectangular band that travels from the fibula to the tibia, just superior to the malleoli.
Inferior: Y-shaped ligament with 1 attachment laterally on the lateral face of the calcaneus, one attachments on the medial malleolus and one on the plantar aponeurosis on the sole.
PREVENTS BOWSTRINGING
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Superior and inferior peroneal retinaculum.
Superior: Formed between lateral face of the calcaneus and the lateral malleolus.
Inferior: Formed between the lateral face of the calcaneus (more anterior compared on the SPR) and blends with the inferior extensor retinaculum.
Some fibres attach to the peroneal trochlea to form a septum between the tendons of the two peroneus muscles.
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Formation, Branching and functions of Sciatic Nerve
Formed from the lumbar sacral plexus (L4-S3). Forms a branch in the thigh to innervate hamstring head of the adductor magnus.
Divides into the tibial nerve and the common fibular nerve. Tibial nerve supplies posterior compartment. Common fibular nerve enters anterior compartment between the tendons of the biceps femoris.
Common fibular nerve splits into the superficial and deep peroneal nerves. The common nerve itself also forms branches to innervate the head of the fibula.
Superficial peroneal nerve is located between the peroneus longus and the extensor digitorum longus. Cutaneous innervation to the lateral side of the leg and dorsal aspect of the foot and innervation of lateral compartment muscles.
Deep peroneal nerve found anterior to the interosseous membrane. Innervates anterior compartment muscles and first two dorsal interossei muscles. Very limited cutaneous innervation on the foot.
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Divisions of the Popliteal Artery
Anterior tibial: Enters anterior compartment via the hole in the interosseous membrane at the proximal end of the bones. Sits on the anterior face of the interosseous membrane alongside the deep peroneal nerve and between the EDL/EHL.
Crosses over EHL tendon laterally at the ankle and forms dorsalis pedis. Forms the deep plantar, arcuate and lateral tarsal arteries.
Posterior tibial: Supplies posterior compartment and runs down along the tibial nerve. Forms medial and lateral plantar arteries at the malleolus.
Peroneal: Branch of the posterior tibial artery and remains in the posterior compartment, running laterally to the posterior tibial artery. Supplies lateral compartment via perforating vessels.
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Composition of knee joint and pathology
Consists of the patellofemoral joint and tibiofemoral joints. Allows for flexion and extension only.
Tibiofemoral: Formed between tibial plateau and the condyles of the femur.
Patellofemoral: Posterior surface of the patella forms asymmetrical facets with the femoral condyles. Patella is connected to tibial tuberosity via the patellar ligament.
Misalignment of the acetabulum, knee and ankle joints can lead to varus (apex of joint pointing inward) and valgus alignment (apex of joint pointing outward).
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Collateral Ligaments of the Knee Joint
Connecting the lateral and medial femoral epicondyles to the head of the fibula and medial face of the tibia inferior to the pes anserinus (respectively).
Lateral: Cord like and is independent from the joint capsule.
Medial: Broader, and attached to capsule on posterior side. Forms an anterior division which attaches to the capsule.
156
Anterior and posterior cruciate ligaments
Intracapsular but extrasynovial.
Anterior: Formed between the anterior tibial spine and the lateral condyle of the femur (within the intercondylar fossa)
Posterior: Formed between posterior tibial spine and the medial condyle of the femur. in the intercondylar fossa.
Prevents excess anterior and posterior gliding movement of the
157
Bursae of the knee joint
Prepatellar, subcutaneous and deep infrapatellar: Extracapsular bursae. Prepatellar and subcutaneous bursae allow smooth movement of the skin over the joint.
Deep infrapatellar is found deep to the patellar ligament and allows smooth movement of the ligament.
Suprapatellar: Extension of the synovial articular capsule. Reaches up along the anterior face of the femur superior to the femoral condyle. Does articulate with the knee joint and reduces friction between the quadriceps tendon and the knee joint.
158
Clinical application of knee joint bursae.
Repeated abrasion of the extracapsular bursae will result in damage and inflammation, leading to bursitis.
The suprapatellar bursa allows synovial fluid to be aspirated from the knee joint as a sample or to threat inflammatory arthritis.
159
Menisci of the knee
Two C-shaped fibrocartilaginous discs found within the femoraltibial joint.
Forms a cusp to improve congruency of the femoral condyles with the flat tibial plateau.
Medial meniscus is attached to the capsule and collateral ligament, and hence is more prone to injury as it is subject to the forces applied to the capsule and ligament. The lateral meniscus is not attached.
Both menisci are attached to the the plateau at the ends of the C via ligaments.
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Myotomal organisation of the nerves of the brachial plexus.
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C5- Elbow flexors
C6- Wrist extensors
C7- Elbow extensors
C8- Finger flexors
T1- Finger abductors.
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Unhappy Triad
Caused by valgus force applies to the knee leading to abduction. Leads to rupture of the medial collateral ligament and ACL. Force transmitted to medial meniscus and can lead to rupture.
Adduction can also exert excess compressive force on the lateral meniscus and lead to rupture of the lateral meniscus as well.
162
Bones of the Pelvic Region
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Superior: Ilium
Inferior/posterior: Ischium
Anterior: Pubis
Joined by a cartilaginous suture at birth (triradiate cartilage) which ossifies with age.
Meets at the acetabulum.
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Ligaments of the pelvis
Sacroiliac: Connects the inferior aspect of the sacrum with the ischial spine.
Sacrotuberous: Connects the entire lateral aspect of the sacrum to the ischial tuberosity.
164
Borders of the Sciatic Foramina
Greater sciatic foramen: Greater sciatic notch, sacrospinous ligament, sacrum.
Lesser sciatic foramen: Sacrospinous and sacrotuberous ligaments, lesser sciatic notch.
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Gluteus Maximus
O: Continuous origin along the Iliac crest, sacrum, coccyx,
I: Iliotibial band and gluteal tuberosity
N: Inferior gluteal nerve.
F: Extension of the hip. Stabilisation of hip and knee.
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Gluteus Medius and Minimus
O: Posterior face of the ilium.
I: Greater trochanter
N: Superior gluteal
F: Hip abduction and stabilisation of the pelvis.
- When walking the COM shifts to the side where the foot isn't on the ground. Gmed and Gmin contraction on the contralateral side pulls the pelvis back to normal position.
167
Piriformis
O: Anterior surface of the sacrum.
I: Trochanteric fossa of the greater trochanter.
F: External rotation of the thigh.
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Gemellus superior and inferior
O: Ischial spine and tuberosity respectively.
I: Trochanteric fossa of the greater trochanter
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Obturator internus
O: Obturator fossa
I: Trochanteric fossa of the greater trochanter, forming a right angle.
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Quadratus femoris
O: Ischial tuberosity
I: Intertrochanteric crest
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Biceps femoris
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O: Long- Ischial tuberosity
Short- Linea aspera
I: Head of the fibula
F: Stabilises the lateral side of the knee. Flexes the knee and hip.
N: Long- Sciatic
Short- fibular
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Semimembranosus and semitendinosis
O: Ischial tuberosity
I: SM- Medial tibial condyle. ST- Pes anserinus
F: Flexion of the knee and hip.
N: Sciatic
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Pathology of the Hamstring
Hamstring tears due to sudden and violent stretching. Tear can either occur within the muscle or the muscle can pull the ischial tuberosity off--> hamstring avulsion.
174
Trendelenburg Gait
Caused by degradation of Gmed and Gmin function. Failure to contract in response to the shift in centre of mass--> leads to lurching movement.
175
Gluteal bursitis
Occurs in the ischial bursa, where there is frequent friction between the ischial tuberosity and the bursa- such as in cyclists.
176
Vasculature of the Gluteal Region
Superior gluteal artery leaves the greater sciatic foramen above the piriformis. Runs between gluteus maximus and Gmed/Gmin.
Inferior gluteal artery leaves the greater sciatic foramen under the piriformis and anastomoses with the medial and lateral femoral circumflexes to supply the head of the femur and the hip joint.
The internal pudendal artery leaves the greater sciatic foramen inferior to the piriformis, and then reenters the peroneum via the lesser sciatic foramen.
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Innervation of the gluteal region
Superior gluteal nerve exits above the piriformis.
Inferior gluteal nerve exits under piriformis.
Sciatic nerve is a very large nerve exiting under the piriformis, running alongside the artery of the sciatic nerve.
Internal pudendal nerves exit the peroneum via the greater sciatic foramen, and then reenter at the lesser sciatic foramen.
Posterior cutaneous nerve of the thigh exits and runs alongside the sciatic nerve..
178
Piriformis disorder
Caused when the piriformis muscle impinges on the nerves exiting via the greater sciatic foramen. Leads to pain, tingling and numbness in the buttocks and in the regions innervated by the sciatic nerve down the thigh and leg.
179
Structures within the acetabulum
Lined by a semilunar articular cartilage ring, joined at the ends by the transverse acetabular ligament to form a complete circle, and also to suspend the femoral head in the acetabulum.
Acetabular fossa is the central region that's not covered by articular cartilage, and it is padded by fat and holds the acetabular arch of the obturator artery, which reaches the fovea of the femoral head.
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The femoral head and neck
2/3 of a sphere- ball and socket joint with the acetabulum-stable and flexible. Covered in articular cartilage. More than 50% covered by the acetabulum.
Head is connected to the femur at 120 degrees via the neck, which consists of cancellous bone, which is also more dense on the inferior side of the neck as it bears greater load.
181
Ligaments of the fibrous capsule of the Hip Joint
Iliofemoral: Y-shaped ligament. Corkscrew orientation on the anterior side. Connects the AIIS and the superior section of the acetabulum to the intertrochanteric crest. Prevents overextension.
Pubofemoral: Connects the iliopubic eminence and blends with the fibrous capsule distally. Positioned on the inferior face of the joint. Prevents overabduction and hyperextension.
Ischiofemoral: Connects the ischial component of the acetabular rim and the greater trochanter.
Prevents hyperextension- also corkscrew alignment.
182
Function of the retinacula
Some of the fibres of the ligaments of the hip joint will return to their origin to form a sleeve that sticks to the neck. This holds the retinacular arteries which supply the femoral head close to the neck to ensure supply.
183
Hilton's Law and the Nerves supplying the hip joint
" Any nerve that crosses a joint, or that supplies a muscle that crosses a joint, will supply that joint."
Femoral, obturator superior gluteal, nerve to quadratus femoris.
184
Different types of Femoral Fractures and Associated Pathologies
Caused by trauma, osteoporosis or tumours.
Intracapsular: Capital/subcapital, transcervical. Risk of damaging the retinacular arteries and hence lead to the avascular necrosis of the femoral head. Degradation of bone and collapse of articular surface--> pain.
Repaired by hemiarthroplasty- femoral head replaced with metal hemisphere.
Extracapsular: Intertrochanteric and subtrochanteric. Less risk of avascular necrosis.
Repaired by dynamic hip screw- screw contained in barrel which can transmit force to the femur.
185
Borders of the Popliteal Fossa
Superior medial: Lateral border of SemiM and SemiT.
Superior lateral: Medial border of biceps femoris
Inferior: Heads of the gastrocnemius.
Floor: Popliteus and posterior of the knee joint capsule.
186
Contents of the Popliteal Fossa
Deep to superficial: Popliteal artery, popliteral vein, tibial nerve.
Common fibular nerve tuns along the superior lateral border.
187
Pathology involving the popliteal fossa
Rupture of popliteal structures will occur after an impact injury where there is misalignment of the tibia and femur.
Leads to internal bleeding and compartment syndrome, eventual ischaemic necrosis of the more distal structures.
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Gastrocnemius
O: Medial and lateral femoral condyles.
I: Achilles Tendon--> calcaneus
F: Plantarflexion at the ankle and flexion of the knee. Lifts heel against gravity to take steps. Consists mainly of type IIb fast glycolytic fibres, so is useful for short, strong contractions.
N: Tibial
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Soleus
O: Superior third of the tibia, fibula and associated interosseous membrane.
I: Achilles tendon
F: Plantarflexion of ankle by tonal contraction to maintain posture and for walking--> type I slow oxidative
N: Tibial
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Plantaris
O: Superior to the lateral head of the gastrocnemius on the femur.
I: Medial face of the calcaneus.
F: Vestigial ankle plantarflexor. Harvested for tendon reconstruction.
N: Tibial.
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Tibialis posterior
O: Tibia, fibula and associated interosseous membrane. Deepest of the posterior compartment of the leg.
I: Primarily the navicular tuberosity but forms slips to all cuneiforms. INSERTS ON THE PLANTAR SIDE.
F: Plantarflexion and inversion of foot. Maintains the shape of the medial arch.
N: Tibial
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Flexor digitorum longus
O: Middle of the posterior face of the tibia.
I: Distal phalanges of the toes.
F: Flexion of the toes and plantarflexion of the ankle.
N: Tibial
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Flexor hallucis longus
O: Inferior third of fibula and the associated interosseous membrane.
I: Distal phalanx of the hallux.
F: Flexion of toe and plantarflexion of ankle.
N: Tibial
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Popliteus
O: Lateral meniscus and the lateral femoral condyle.
I: Posterior face of the tibial, superior to the soleal line.
F: Medial rotation of the tibia to unlock the knee from a fully extended position. Prevents excessive lateral rotation.
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Sural nerve origin, branching and innervation
The medial sural nerve originates from the tibial nerve just before it leaves the popliteal fossa.
The lateral sural nerve leaves from the common peroneal nerve and innervates the posterolateral cutaneous region of the leg. Joins onto the medial sural nerve via the sural communicating nerve to form the proper sural nerve.
Terminates by innervating the lateral aspect of the foot.
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Vasculature of the posterior compartment of the leg and plantar
The popliteal artery splits into the anterior and posterior tibial arteries.
Posterior tibial artery splits further to form the more lateral peroneal artery, which sends perforating branches into the lateral compartment.
The latter two arteries reside between the deep and superificial compartments of the posterior compartment.
Vein distribution is similar to that of the arteries. Lesser saphenous vein forms from the popliteal vein and travels down the superficial surface of the posterior compartment of the leg.
Tibial nerve splits into the medial and lateral plantars, which provide cutaneous innervation to the medial 2/3 and the lateral 1/3 of the plantar, and the medial 3.5 digits and the lateral 1.5 digits.
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Tarsal tunnel
Area between the medial malleolus to the calcaneus. Structures from anterior to posterior:
Tibialis posterior, Flexor digitorum longus, Posterior tibial artery/vein, tibial nerve, flexor hallucis longus.
Covered superficially by the flexor retinaculum to prevent bowstringing.
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Achilles Tendon Pathology
Ruptures about 1cm above the calcaneus during sudden contraction of the superficial compartment muscles as that region is the most poorly vascularised- accompanied with a loud 'pop'.
Walking is still possible as the weak deep plantarflexors are still intact but forceful contraction is no longer possible.
Treated either surgically with sutures or using a cast to put the foot in plantarflexion.
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Places to take a pulse in the lower extremity
Femoral: Mid point between ASIS and pubic tubercle, along the inguinal ligament, lateral to the adductor muscle mass.
Popliteal pulse: Popliteal fossa when knee is relaxed and flexed.
Posterior tibial pulse: Palpable between the malleolus and the calcaneus, against the tendon of the FDL.
Dorsalis pedis: Along the axis of the second toe.
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Ankle joint
Hinge joint allowing only flexion and dorsiflexion up to a range of 30 degrees.
Formed from the talus and the lateral and medial malleoli. Talus forms two articular surfaces superiorly to fit the malleoli.
The talus is wider anteriorly than posteriorly, hence the joint is most stable during dorsiflexion of the ankle. Distal ends of the fibula and tibia connected by syndesmoses to prevent them from moving apart when a force is applied superiorly from the talus.
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Subtalar joint
Joint between the talus, calcaneus, and the calcaneonavicular ligament. Talus articulates anteriorly within the sockets created at the talocalcaneonavicular joint, and posteriorly between the large calcaneal articular facet and the posterior talar facet.
Confers inversion and eversion of the foot between the talus and the calcaneus.
Allows supination and pronation to occur at the talocalcaneonavicular joint.
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Lateral ligaments of the foot
Anterior and posterior fibulotalar, fibulocalcaneal.
Resists varus alignment and excess inversion of the foot.
Anterior FT ligament weakest and most prone to rupture.
Damage diagnosable by pain and swelling.
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Medial ligaments of the foot
Stronger 'deltoid' ligament originating from the tibial malleolus and connecting to the talus, navicular and calcaneus.
Provides stability to the medial side and prevents excess eversion/ varus alignment. Maintains positions of the bones in the joint.
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Arterial Branching of Dorsum of the Foot
Dorsalis pedis enters between the EDL and EHL. Forms the lateral and medial tarsal arteries to supply the tarsals and to anastomose with the lateral malleolar networks. Forms arcuate artery which moves laterally along base of the metatarsals and form dorsal metatarsals which split into dorsal digitals.
Dorsalis pedis itself passes between the first and second metatarsals to form the deep planatar artery that joins up with the deep plantar arch.
205
Arterial Branching of the Plantar of the Foot
Posterior tibial artery splits into the lateral and medial plantar arteries.
Medial plantar: travels along the medial side of foot to supply medial side of hallux and forms perforating arteries to anastomose with the dorsal metatarsals of the dorsum.
Lateral plantar: Moves across tarsals laterally and returns medially along the base of the metatarsals Forms plantar metatarsals for each toe except for the hallux which divide into two plantar digital arteries and an anterior perforating branch that anastomose with the dorsal metatarsal.
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Innervation of the dorsum of the foot
Superficial peroneal: Innervates the entirety of the dorsum except the lateral edge which is innervated by the sural nerve.
Deep peroneal: Innervates the web region between the first and second toes.
Saphenous: Innervates the medial facet of the dorsum, near the ankle.
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Arches of the Foot
Lateral: Calcaneus, cuboid, lateral two metatarsals.
Medial- More pronounced. Formed from the calcaneus, talus, navicular, cuneiforms, medial 3 metatarsals. Reinforced by tendons of tib. ant, tib. pos, and peroneus longus.
Transverse: Cuboid, cuneiforms, base of metatarsals. Reinforced by peroneus longus.
Arches maintained by the plantar calcaneonavicular ligament, the short and long (calcaneus-->cuboid) plantar ligaments and the plantar aponeurosis (calcaneus to the base of middle phalanx).
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Layering of the muscles in the foot
Four layers, with the transverse arch forming a cup (the fourth layer) that holds the superficial three. Neurovascular structures reside in the second layer.
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Pathology involving the arches
Arches are required as shock absorbers during walking and running. Disruption to the muscle tendons or the ligaments maintaining the arches will flatten the foot and cause pain when walking.
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Weber fractures
Weber A: Fracture site distal to the syndesmosis, meaning it is not disrupted. Only damage to the ligaments of the foot.
Weber B: Fracture at the level of the syndesmosis. Leads to widening of the ankle mortise ( the notch that the talus fits into),
Weber C: Fracture is more proximal compared to the syndesmosis--> the syndesmosis is always damaged.
Accompanied by a fibular malleolus fracture and swelling. Diagnosable by X-ray.
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Lisfranc injury
Axial load with an anterior componenr is applied through a plantarflexed ankle where the forefoot is still dorsiflexed. Leads to fracture or dislocation of the second metatarsal and fracture of the second cuneiform.
Symptoms: Pain when walking as arch is disrupted. Swelling.
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Origin of the anastomoses around the Knee Joint
Genicular arteries, originating as branches of the popliteal artery.
Superior lateral: Receives contributions from the descending branch of the lateral circumflex femoral artery.
Superior medial: Enters anterior of knee through the insertion of the adductor magnus.
Inferior lateral: Enters anterior of knee around the lateral tibial condyle.
Inferior medial: Enters anterior of knee around the medial tibial condyle. Receives contributions from the recurrent branch of the anterior tibial and the circumflex fibular artery.
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Innervation of the Knee Joint
Femoral (saphenous nerve and anterior cutaneous nerve of thigh passes the knee joint) , obturator (accompanies the popliteal artery into popliteal fossa), sciatic (tibial nerve innervates the hamstrings).
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Lipohemoarthritis of knee cause and diagnosis.
Occurs when a fracture of the tibia occurs during injury to the knee. Leads to rupture of vessels and effusion of blood and marrow fat into the suprapatellar bursa.
Fat is less dense than water so it will appear as a dark region suspended under the patella on X-ray. Blood will appear similar to the surrounding muscle.
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Which myotomes are tested by hip flexion?
L1- Psoas major
| L2- Iliopsoas and sartorius.
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Which myotomes are tested by hip extension?
L5- Gluteus maximus- only for a flexed hip.
| S1- Hamstrings
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Which myotomes are tested by knee flexion?
S1- Gastrocnemius and hamstrings
| S2- Gastrocnemius
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Which myotomes are tested by knee extension?
L3- Quadriceps.
| L4- Quadriceps
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Which myotomes are tested by thigh abduction?
L4/L5- Gluteus medius and minimus, tensor fascia lata.
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Which myotomes are tested by thigh adduction?
L2/L3- Medial compartment of the thigh
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Which myotomes are tested by foot plantarflexion?
L4- Tibialis posterior
| S1/S2: Posterior compartment of leg
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Which myotomes are tested by foot dorsiflexion?
L4: Tibialis anterior and peroneus tertius.
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Which myotomes are tested by foot eversion?
L5: Peroneus longus and brevis
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Which myotomes are tested by foot inversion?
L4: Tibialis anterior/posterior and peroneus tertius.
L5: Tibialis posterior
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Which myotomes are tested by toe extension and flexion?
Extension: L5/S1- EDL,EHL
Flexion: S2- FDL, FHL
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Which myotomes are tested by the patellar and Achilles' tendon reflexes?
Patellar tendon reflex: L3-L4- involves the quadriceps
| Achilles tendon reflex: S1-S2- involves the soleus and gastrocnemius.
