MSK anatomy Flashcards
what is the glenohumeral joint?
the shoulder joiny - synovial ball and socket
between scapula and proximal humerus
what is the elbow joint and what does it allow for?
synovial hinge joint between distal humerus and ulna and radius.
allows for flexion and extension of forearm
what type of joints are the proximal and distal radioulnar joints?
what does it allow for?
synovial jointe between radius and ulna.
allows for pronation and supination of the forearm and hand
what type of joint is the radiocarpal joint?
what does it allow for?
wrist joint, synovial joint between distal radius and two carpal bones.
allows for flexion, extension, abduction, and adduction.
movement of the scapula?
Protraction (reach arm out anteriorly)n and Retraction (pull shoulder back) .
The scapula can be elevated (shrugging), depressed and rotated
movements of the shoulder joint?
alot!
flexion
extention
abduction
adduction
internal rotation
external roation
circumduction
movements of the shoulder almost always accompanied by movements of the scapula on the chest wall. when we raise our upper limb, the scapula rotates.
movements of the elbow joint?
flexion and extension
movements of the radioulnar joints?
pronation, supination
movements of the wrist joint?
flexion and extension
abduction and adduction
movements of the fingers and thumb?
flexion and extension
adduction and abduction
what is the most commonly fractured bone?
what does it articulate with?
the clavicle.
-articulates with manubrium of sternum
and
acromion of the scapula
(synovial)
posterior ridge of the scapula is called?
spine
the lateral end of the spine of the scapula expands to form?
the acromion (highest point of the shoulder)
Just inferior to the acromion on the anterior surface of the scapula, there is a projection of bone called the
coracoid process - site of attachement of several muscles.
“raven-like”
the clavicle, scapula and the attached muscles compromise the…?
pectoral girdls
what does the geloid fossa of the scapula artiuclate with?
humerus
“shallow socket” - poor fit for the humerus
increases range of movement but compromises the stability of the joint.
what are the names of the two small projections of bone inferior and superior the glenoid fossa?
supraglenoid tubercle and infraglenoid tubercle
the head of the humerus articulates with?
the glenoid fossa of the scapula
Laterally, the proximal humerus bears a projection of bone called the ? – an important site for muscle attachments. A smaller anterior projection – ? – is also a site for muscle attachment.
greater tubercle
lesser tubercle
which nerve runs close to the surgucal neck of the humerus?
axillary nerve.
the surgical neck if clinically important as it is sommonly fractures, espescially in elderly, axillary nerve can be damaged as a result of an injury to the surgical neck of dislocation of the humeral head.
The upper lateral aspect of the humeral shaft has a slight protuberance called the
deltoid tuberosity - site of attachment for the deltoid muscle.
what is the radial (/spiral) groove a landmark for on the humerus?
the path of the radial nerve over the posterior aspect of the humeral shaft.
movements of the scapula?
-
Protraction - this extends the upper limb, for example, when we stretch out the arm to push
open a door. - Retraction - ‘squaring’ the shoulders or pulling them backwards.
- Elevation - shrugging the shoulders.
- Depression – lowering the shoulders.
- Rotation - this tilts the glenoid fossa cranially to aid elevation of the upper limb. Rotation of the scapula is very important. When raising the arm above the head, for every 2˚ of abduction of the shoulder, the scapula rotates 1˚. If you observe someone from behind as they raise their arm, you will see the movement of the scapula.
muscles of the anterior pectoral girdle?
pectoralis major
pectoralis minor
serratus anterior
what are the two large superficial muscles of the posterior pectoral girdle?
trapezius and
latissimus dorsi (“broadest muscle of the back”)
what are the trhee smaller, deeper muscles of the posterior pectoral girldle?
- Levator scapulae
- Rhomboid major
- Rhomboid minor.
all the muscles of the posterior pectoral girdle attch to the vertebral column except?
latissimus dorsi - attaches to the humerus
The origin is the more ‘fixed’
or stable bone, and the insertion point is located on the bone that moves when the muscle
contracts.
most muscles of the posterior pectoral girdle are innervated by branches from which structure?
brachial plexus
(trapezius = XI)
what is the latissimus dorsi innervated by?
branch of the brachial plaxus called the thoracodorsal nerve
why is the shoulder joint the most commonly dislocated joint in the body?
the fit between the joint surfaces – the glenoid fossa of the scapula and the head of the humerus – is poor. This is key for extensive mobility at the joint. The downside of the shallow socket and poor fit is that the joint is less stable
Six muscles attach the scapula to the humerus. They move and stabilise the shoulder joint. The six muscles are:
- Deltoid
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
- Teres major
Except for deltoid, all of these muscles lie deep to the posterior pectoral girdle muscles.
which of the six muscles that attch the scapula to the humerus are reffered to as the “rotator cuff”?
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres minor
action of the Deltoid?
shoulder joint:
abduction over 15°
flexion (anterior fibres) and extension (posterior fibres)
innervation of the deltoid?
It is innervated by a major branch of the brachial plexus called the axillary nerve. Injury to the axillary nerve can lead to atrophy and weakness (or even paralysis) of deltoid, which greatly impacts a patient’s activities of daily living.
Teres major is an interesting muscle as although it arises from the [?] aspect of the scapula, its tendon slots [?] and inserts onto the [?] aspect of the humerus. This arrangement explains its action as an [?] of the shoulder joint.
Teres major is an interesting muscle as although it arises from the posterior aspect of the scapula, its tendon slots underneath the humerus and inserts onto the anterior aspect of the humerus. This arrangement explains its action as an internal rotator and adductor of the shoulder joint.
Supraspinatus, infraspinatus, and teres minor originate from the [a] of the
scapula and insert onto the greater tubercle. Their tendons fuse with the [b] that
surrounds the shoulder joint. Supraspinatus is particularly clinically important because as it
travels from the supraspinous fossa to the greater tubercle it travels [c]. The tendon can become [d] between the acromion and humerus during movements of the shoulder. This is called impingement and is a common cause of shoulder pain, particularly during large movements of the shoulder joint, such as serving in tennis.
Supraspinatus, infraspinatus, and teres minor originate from the posterior surface of the
scapula and insert onto the greater tubercle. Their tendons fuse with the fibrous capsule that
surrounds the shoulder joint. Supraspinatus is particularly clinically important because as it
travels from the supraspinous fossa to the greater tubercle it travels under the acromion. The
tendon can become inflamed and pinched between the acromion and humerus during
movements of the shoulder. This is called impingement and is a common cause of shoulder
pain, particularly during large movements of the shoulder joint, such as serving in tennis.
The quadrilateral space is a square-shaped space bounded by:
what travels through this space?
teres minor above, teres major below, the long head of triceps medially and the surgical neck of the humerus laterally.
axillary nerve travels though this space to enter the posterior scapula region and innervate the deltoid and teres minor.
what group of muscles provide stability to the shoulder joint?
how do they do this?
the rotator cuff muscles.
Contraction of the rotator cuff muscles holds the head of the humerus in the glenoid fossa and the rotator cuff tendons fuse with the capsule of the shoulder joint. The rotator cuff muscles and / or tendons can be injured,
become inflamed or degenerate. When this happens, patients usually experience pain and impaired movement, and the stability of the joint is compromised.
aside from the rotator cuff muscles, what other structure contribute to stability of the shoulder?
- A rim of fibrocartilage around the margin of the glenoid fossa – the glenoid labrum – which deepens the shallow fossa and aids stability. Labrum is derived from Latin meaning ‘lip’.
- The capsule is reinforced by ligaments.
- The tendon of biceps brachii, which lies in the anterior arm, also reinforces the joint.
six boundaries of the axilla?
- Anterior wall – pectoralis major and minor
- Posterior wall – subscapularis, teres major and latissimus dorsi
- Lateral wall – proximal humerus
- Medial wall – serratus anterior and the thoracic wall
- Apex – first rib, clavicle, and scapula. It is the passage between the neck and the axilla.
- Base – skin and fascia between the thoracic wall and arm (the skin of armpit).
name some structures found in the axilla
- Lymph nodes – which drain the upper limb, thorax, breast, and the abdominal wall as far as the umbilicus.
- Axillary artery – the major artery of the upper limb.
- Axillary vein – the major vein draining the upper limb.
- Brachial plexus (sp
how many groups of lymph nodes found in the axilla?
5
They drain the upper limb, breast, chest wall,
scapular region and the abdominal wall as far as the umbilicus. The lymph nodes located in the
apex of the axilla – the apical nodes – receive lymph from all other lymph nodes in the axilla.
when does the subclavian artery become the axillary artery?
when does the axillary artery become the brachial artery?
The axillary artery is the continuation of the subclavian artery as it progresses laterally. The subclavian artery travels over the first rib and under the clavicle and into the axilla. It becomes
the axillary artery after it passes over the lateral border of the first rib. The axillary artery gives rise to several branches. It continues into the arm as the brachial artery (it becomes the brachial artery as it crosses the inferior border of teres major).
the axillary vein is formed from a union of?
the brachial veil and the basilic vein.
the cephalic vein also joins the axillary vein in the axilla.
at the lateral border of the first rib, the axillary vein become the subclavian vein.
Tears of the roatator cuff are usually painful [?]
at rest and on movement and cause weakness
if the supraspinatus tendon become injured, what would you expect the presentation to be?
it may become impinged between the acromion and the humeral head, as the space here is small. The first part
of abduction is not painful, but between 60˚– 120˚ of abduction, the inflamed tendon is compressed against the acromion, and this is when patients experience pain. An inflamed tendon may ultimately rupture.
removing axillary lymph nodes risk which two nerves?
The long thoracic nerve innervates serratus anterior and lies superficially on the surface of the muscles in the medial wall of the axilla. Injury to this nerve causes
weakness or paralysis of serratus anterior. One of the functions of this muscle is to hold the anterior border of the scapula flat against the posterior thoracic wall. If the muscle is
paralysed, the anterior border lifts off the thoracic wall and the scapula appears to ‘stick out’. This is called a ‘winged scapula’
* The thoracodorsal nerve to latissimus dorsi is also vulnerable to injury as it runs along the subscapularis muscle, which forms part of the posterior wall of the axilla.
The anterior compartment of the arm contains three muscles: ?
All three act as flexors and all three are innervated by the ? nerve.
biceps brachii, brachialis and coracobrachialis.
musculocutaneous nerve
Biceps brachii (the name of which name derives from Latin meaning ‘two-headed muscle of the
arm’) lies most [a] in the anterior arm. It has two heads – the [b] head and the [c] head. Proximally, both heads are attached to the [d] ; the long head to the [e] and the short head to the [f] . The tendon of the long head of biceps pierces the [g] and helps to stabilise the joint. The two muscle bellies
converge to their insertion via a common tendon onto the [h] of the radius.
Biceps brachii (the name of which name derives from Latin meaning ‘two-headed muscle of the
arm’) lies most superficially in the anterior arm. It has two heads – the long head and the short head. Proximally, both heads are attached to the scapula; the long head to the supraglenoid tubercle and the short head to the coracoid process. The tendon of the long head of biceps pierces the capsule of the shoulder joint and helps to stabilise the joint. The two muscle bellies converge to their insertion via a common tendon onto the radial tuberosity of the radius.
action of biceps brachii?
- flexor of elbow joint.
- also crosses over shoulder joint to contributes to flexion of shoulder joint
- also a powerful supinator of the forearm when the elbow is flexed
When a right-handed person tightens a screw (turning to the right) they
supinate the forearm – however, the power to turn the screw very tightly depends upon the
elbow being flexed at the same time; supination is much weaker if the elbow is extended.
Brachialis lies [a] to biceps. Proximally, it is attached to the [b], and it crosses the elbow joint to insert distally upon the [c] . It is a powerful [d] of the elbow joint, but it does not cross the shoulder joint, so cannot act upon it.
Brachialis lies deep to biceps. Proximally, it is attached to the anterior aspect of the distal half of
the shaft of the humerus, and it crosses the elbow joint to insert distally upon the** ulna tuberosity**. It is a powerful flexor of the elbow joint, but it does not cross the shoulder joint, so
cannot act upon it.
Coracobrachialis is a deep and much smaller muscle that attaches proximally to the [a] and distally to the [b]. It crosses the shoulder joint and acts upon it as a [c].
Coracobrachialis is a deep and much smaller muscle that attaches proximally to the coracoid process of the scapula and distally to the medial aspect of the middle part of the humerus. It crosses the shoulder joint and acts upon it as a weak flexor.
A single large muscle – [a] – is located in the posterior compartment of the arm. It has three muscle bellies, or heads, which all converge via a common tendon onto a single
insertion point – [b]. The muscle crosses the posterior aspect of the elbow joint, therefore, when it contracts, it [c] the elbow.
A single large muscle – triceps brachii– is located in the posterior compartment of the arm. It
has three muscle bellies, or heads, which all converge via a common tendon onto a single
insertion point – the olecranon of the ulna. The muscle crosses the posterior aspect of the
elbow joint, therefore, when it contracts, it extends the elbow.
The three heads of triceps are individually named and originate from different regions:
* Long head: orginates?
* Lateral head: orginiates?
* Medial head: originates?
Because of its attachment to the scapula, the long head is able to contribute to [?] of them shoulder joint in addition to [?] of the elbow joint.
The three heads of triceps are individually named and originate from different regions:
* Long head: infraglenoid tubercle of the scapula. It is the most medial part of triceps.
* Lateral head: posterior humerus, proximal to the radial groove.
* Medial head: posterior humerus, distal to the radial groove.
Because of its attachment to the scapula, the long head is able to contribute to extension of the
shoulder joint in addition to extension of the elbow joint.
the triceps are innervated by?
the radial nerve
a major terminal branch of the brachial plexus.
a fracture in the shaft of the humerus can injur which nerve?
radial nerve
It winds around the posterior aspect of the humerus in the radial (spiral) groove between the medial and lateral heads of triceps. The nerve runs along the surface of the bone in this region, so a fracture of the shaft of the humerus may also cause injury to the radial nerve.
the brachial plexus is formed by which spinal nerves?
C5 C6 C7 C8 T1
motor and sensory
draw out the brachial plexus
Read, That, Damn, Cadaver, Textbook
Some Muscles I Like Particularly Meaty
Missing Anatomy Makes Revision Unpleasant
Axillary nerve innervates?
branches from?
Vulnerable to?
- It innervates deltoid and teres minor and a small region of skin over the upper lateral arm.
- It is a branch of the posterior cord and contains fibres from spinal nerves C5 and C6.
- It runs close to the surgical neck of the humerus and is vulnerable to injury in fractures of the surgical neck of the humerus or dislocations of the humeral head.
Radial nerve innervates?
Branches from?
Vulnerable to?
- The radial nerve innervates triceps in the posterior arm. The radial nerve also innervates all the muscles in the posterior compartment of the forearm which are extensors of the wrist and digits. The radial nerve also innervates regions of skin over the arm, forearm, and hand.
- It is the continuation of the posterior cord and contains fibres from C5 - T1.
- It runs along the radial (spiral) groove on the posterior surface of the humerus and is vulnerable in mid-shaft fractures of the humerus.
Musculocutaneous Nerve innervates?
Branches from?
Vulnerable to?
- The musculocutaneous nerve innervates the three muscles in the anterior compartment of the
arm: biceps brachii, brachialis and coracobrachialis. - It arises from the lateral cord and contains fibres from spinal nerves C5 - C7.
- After supplying motor fibres to three muscles named above, it continues as a sensory
nerve that innervates a region of skin over the lateral forearm. - Because of its location, the musculocutaneous nerve is rarely injured in isolation.
Median Nerve innervation of arm?
Branches from?
Vulnerable to?
- The median nerves do not innervate any muscles in the arm. It innervates most of the muscles of the anterior forearm, which are flexors of the wrist and digits. It also innervates the small muscles of the thumb. It provides sensory innervation to skin over the lateral aspect of the palm of the hand and over the lateral digits
- The median nerve is formed from contributions from both the lateral and medial cords.
- Normally, it contains fibres from C6-T1, but in some individuals, it may contain fibres
from C5-T1. - It is most vulnerable in the arm as it crosses the anterior aspect of the elbow, in a region
called the cubital fossa.
Ulnar nerve innervates?
Branches from?
Vulnerable to?
- It innervates most of the small muscles in the hand and therefore is vital for fine movements of the digits. It also innervates skin over the medial aspect of the hand and medial digits
- The ulnar nerve is formed by the continuation of the medial cord, after it has given a contribution to the median nerve. It contains fibres from spinal nerves C8 - T1.
- It is vulnerable to injury behind the medial epicondyle as it lies in a superficial position
here (it is easily palpable in this location).
How can Axillary nerve injuries occur and how do they present?
Because of its close proximity to the surgical neck of the humerus, the axillary nerve can be injured by fractures in this region (which are common in the elderly) or dislocation of the
shoulder joint.
The motor fibres of the axillary nerve innervate deltoid and teres minor. Its sensory fibres innervate a patch of skin over the upper lateral arm. Injury to the axillary nerve can therefore result in weakness or paralysis of deltoid – this presents functionally as difficulty abducting the shoulder - and altered sensation or numbness over the upper lateral arm.
Radial nerve injury.
how can they occur and how do they present?
As it travels along the radial groove of the posterior humerus, the radial nerve lies very close to the bone, thus fractures of the humeral shaft can injure the nerve.
This can lead to weakness or paralysis of the muscles that are innervated by the radial nerve ‘downstream’ of the point at which the nerve is injured. As most of the radial nerve fibres that supply the triceps have already branched and entered the triceps at the point of the mid-humerus, the triceps itself is not likely to be significantly affected by damage to the radial nerve at this level. However, it will likely affect movements at the wrist because the radial nerve innervates all the muscles of the
posterior forearm, which extend the wrist and digits.
Ulnar nerve injury.
how do they occur and how do they present?
The ulnar nerve is vulnerable in the lower arm as it travels behind the medial epicondyle – it issuperficial here. Fractures of the medial epicondyle may injure the nerve.
Injury to the nerve at this level leads to motor impairments of the hand (as it innervates most of the small muscles of
the hand) and causes sensory impairment in the hand (the medial side and the medial 1½ fingers). It is extremely common to knock the elbow in this region - referred to as the ‘funny
bone’. A blow to the nerve here causes pain and tingling in the same regions of the hand.
Upper brachial plexus injury (Erb’s Palsy)
how is it caused and what are its prentations
In this type of injury - which is uncommon - the upper parts of the brachial plexus are affected. It may involve C5 - C6, or C5-7.
The typical picture is one of paralysis of the lateral rotators of the shoulder and the extensors of the wrist. The affected limb typically appears medially rotated with the wrist flexed.
It is typically caused by trauma – specifically mechanisms that stretch the head away from the shoulder. This may be seen when someone is thrown from a motorbike or a horse. It may also be seen in new-borns if the baby’s shoulder becomes stuck during delivery and its neck is excessively stretched to one side.
Lower brachial plexus injury (Klumpke’s Palsy)
How is it caused and how does it present?
This type of injury is also uncommon. The lower parts of the brachial plexus are affected, classically C8 and T1. The typical picture is one of paralysis of the small muscles of the hand.
Again, it is most often caused by trauma – specifically mechanisms that forcefully and suddenly pull the arm upwards – this stretches the lower nerves of plexus. It may be sustained in babies during delivery if their arm is forcefully pulled superiorly to aid delivery.
How can a brachial plexus injury result it Horner’s syndrome?
Horner’s syndrome is the triad of drooping of the eyelid (ptosis), a constricted pupil (miosis) and lack of sweating (anhidrosis) on one side of the face. It results when the sympathetic nerve supply to the face is interrupted. The T1 spinal nerve carries sympathetic fibres which are destined to supply the face. Therefore, a brachial plexus injury affecting the T1 nerve root may result in Horner’s syndrome as well.
what connects the ulna and radius?
an interosseous membrane
how does the ulna articulate with the humerus?
the trochlea notch of the ulna articulates with the trochlea of the humerus
how does the radius articulate with the humerus?
the radial head articulates with the capitellum of the humerus
how do the radius and ulna artiuclate with eachother?what movement do these joints alloow for?
at the proximal and distal radioulnar joints.
allo for pronation and supination of forearm and hand.
the radius pivots around the ulna
the proximal ulna form a bulk process posteriorly called?
the olecranon
can be easily palpated
the olecranon fits in to the [?] to allow full extension
olecranon fossa
the ulna has a process that prtrudes anteriorly near its porximal end called the [?] it fits into the [?]
coronoid process
coronoid fossa
The radius has a roughened lump near it proximal end, but distal to the head and neck, known as
the [?] what inserrts here?
radial tuberosity
biceps brachii tendon inserts onto radius
styloid process implicated in fractures
what makes up the elbow joint?
The Elbow Joint
This synovial hinge joint is formed by articulations between the trochlea of the humerus and
the trochlear notch of the ulna, and the capitellum of the humerus and the radial head.
The coronoid process (distally) and the olecranon (proximally)
of the ulna ‘pinch’ the trochlea of the humerus to help maintain stability. The joint capsule is reinforced by[?]
medial (ulnar) and lateral (radial) collateral ligaments.
the carpus is comprised of how many small bones?
8
what is the largest carpal bone?
capiate (centrally)
name the 8 carpal bones
Scaphoid
Lunate
Triquetrum
Pisiform
Hamate
CApitate
Trapezoid
Trapezium
sltphc20
silly lilly tried peeing having copulated twenty times
what is the radiocarpal joint formed from?
articulation of radius with scaphoid and lunate (silly lilly)
synovial joints, which are also reinforced by
ligaments, but they do not allow much movement.
what are the borders of the ACF?
- the lateral border is formed by brachioradialis, a posterior forearm muscle.
- the medial border is formed by** pronator teres**, an anterior forearm muscle.
- the superior border (or base) is formed by an imaginary line drawn between the medial and lateral epicondyles of the humerus.
- The apex is most distal, ‘pointing’ towards the forearm and hand.
three superficial veins in the subcutaneous tissue over the ACF?
cephalic
basilic
medial cubital veins
must watch out for median nerve and brachial artery
when the radial head moves distally out of the ligament, this is called?
Radial head subluxation / pulled elbow.
often in children pulled up by arms
what can occur from a scaphoid fracture?
The scaphoid forms from two bones, each with its own blood supply, that fuse together. With fusion, the artery to the proximal end degenerates, and the bone is supplied from its distal end. When the scaphoid fractures, the proximal part of the bone may be disconnected from the blood supply and death of the proximal segment results – this is called avascular necrosis.
Avascular necrosis is a serious problem because the proximal scaphoid articulates with the distal radius at the wrist joint. For this reason, fractures must not be missed. However, scaphoid
fractures are not always evident on X-rays taken soon after the fracture has occurred. If a fracture is suspected but not seen on X-ray, patients are still followed-up.
what does this xray show?
left distal radius fracture.
usually caused by FOOSH fall onto outstretched hand.
how many muscles in the anterior compartment of the forearm
There are eight muscles in the anterior compartment.
* They are arranged in three layers: superficial, middle, and deep.
* Most of them act as flexors of the wrist, fingers, or thumb.
* Most of them are innervated by the median nerve.
what are the four superficial muscles of the anterior compartment?
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor carpi ulnaris
from lateral to medial
attached to medial apicondyle of humerus, commonly reffered as “common flexor origin’
action of pronator teres?
as its name suggests – is a pronator (of the proximal radioulnar joint),
rather than a flexor.
action of flexor carpi radialis {FCR}
flexes and abducts the wrist. It inserts onto the radial side of
the carpus and hand, hence its name.
action of palmaris longus?
has a small muscle belly but a long, thin, easily recognisable tendon
when present (approximately 15% of us do not have one). Its tendon inserts into the
fascia of the palm of the hand.
action of flexor carpi ulnaris? (FCU)
flexes and adducts the wrist. It inserts onto the ulnar side of
the carpus and hand. This muscle is another exception to the general rule, as it is
innervated by the ulnar nerve, not the median.
There is one muscle in the middle layer of the anterior compartment of the forearm : [a] . It gives rise to [b]
tendons. Its name tells us that it is a flexor of the digits – so we can deduce that its tendons must travel beyond the wrist, into the hand and to the fingers (digits 2-5). We will look at the insertion points of the tendons in more detail in the next session. It is innervated by the [c] nerve, which travels between [d] and one of the deep muscles, [e]
There is one muscle in the middle layer: flexor digitorum superficialis (FDS). It gives rise to four
tendons. Its name tells us that it is a flexor of the digits – so we can deduce that its tendons must
travel beyond the wrist, into the hand and to the fingers (digits 2-5). We will look at the insertion
points of the tendons in more detail in the next session. It is innervated by the median nerve,
which travels between** flexor digitorum superficialis** and one of the deep muscles, flexor
digitorum profundus.
name the three muscles of the deep layer of anterior compartment of forearm
- Flexor digitorum profundus
- Flexor pollicis longus
- Pronator quadratus
action of FDP?
Flexor digitorum profundus (FDP) is a flexor of the digits and is located deep to flexor digitorum superficialis.
The word ‘profundus’ is derived from the Latin word for ‘deep’. It too gives rise to four tendons, which travel into the hand and to the fingers (digits 2-5).
innervation of the FDP?
dual innervation
* The lateral half of the muscle, which gives rise to the tendons that travel to the index and
middle fingers, is innervated by the median nerve.
* The medial half of the muscle, which gives rise to the tendons that travel to the ring and
little fingers, is innervated by the ulnar nerve.
* This is clinically important as injuries to either the ulnar or median nerve only affect one
half of the muscle.
action of the FPL?
Flexor pollicis longus (FPL) flexes the thumb (pollex is the Latin word for thumb). ‘Longus’ distinguishes it from another muscle, flexor pollicis brevis, which is much smaller and located
within the hand.
action of pronator quadratus?
is the deepest forearm muscle (it is considered a fourth layer by some). It is square-shaped (‘quadratus’) and is located over the distal ends of the radius and ulnar. It pronates the distal radioulnar joint.
the anterior forearm muscles are all flexors except for?
pronator teres and pronator quadratus.
the anterior forearm muscles are all innervated by the median nerve except for?
FCU and medial half od FDP
there are how many muscles of the posterior forearm?
* they are arranged in [a] layers: [b]
* most of them are [c] of the wrist, digits, or thumb.
* they are all innervated by the[d].
there are 11 muscles of the posterior forearm(6,5)
* they are arranged in two layers: superficial and deep.
* most of them are extensors of the wrist, digits, or thumb.
* they are all innervated by the radial nerve.
what are the seven superficial muscles of the posterior forearm?
- Brachioradialis
- Extensor carpi radialis longus
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digiti minimi
- Extensor carpi ulnaris
- Anconeus
As a general rule, the muscles of the posterior forearm are attached proximally to the [a] of the
humerus and, as most of them are [b], their origin is known as the ‘[c]’.
the exception to this rule is?
As a general rule, these muscles are attached proximally to the lateral epicondyle of the
humerus and, as most of them are extensors, their origin is known as the ‘common extensor
origin’.
brachioradialis is an exception to some of the rules It
is located on the boundary between the posterior and anterior compartments. It originates from the humerus, proximal to the lateral epicondyle, and inserts on the distal radius. It acts as a weak flexor of the elbow joint and hence functions as an anterior compartment muscle of the arm. However, it is innervated by the radial nerve.
Extensor carpi radialis longus (ECRL) and brevis (ECRB) are located on the [a] side of the posterior compartment. ECRL inserts onto the [b] metacarpal and ECRB inserts onto the [c] metacarpal, hence they [d] and [e] the wrist. Brevis is the Latin word for ‘short’.
Extensor carpi radialis longus (ECRL) and brevis (ECRB) are located on the radial side of
the posterior compartment. ECRL inserts onto the 2nd metacarpal and ECRB inserts onto
the 3rd metacarpal, hence they extend and abduct the wrist. Brevis is the Latin word for
‘short’.
action of extensor digitorum?
extends the digits via four long tendons that insert onto the
dorsal aspects of the fingers (digits 2-5). The tendons of ED are connected by fibrous
bands – this makes it difficult to fully extend the middle or ring fingers independently.
action of the extensor digit minimi
extends the little finger via its insertion onto the dorsum of
the little finger.
action of extensor carpi ulnaris?
is the most medial of the superficial muscles. It extends and
adducts the wrist via its insertion onto the 5th metacarpal.
At the wrist, the tendons of these muscles travel under a band of tissue, the [a]. It prevents the tendons from bowing when the wrist is extended.
extensor retinaculum
origin and insertion of aconeus?
action?
lateral epicondyle of humerus
to
olecranon
=very weak extensor of elbow
what are the five deeo muscles of the posterior forearm?
- Supinator
- Abductor pollicis longus
- Extensor pollicis brevis
- Extensor pollicis longus
- Extensor indicis.
Except for [a], all deep posterior forearm muscles attach proximally to the forearm bones and the interosseous membrane.
supinatot
action of supinator?
supinate forearm
action of abductor pollicis longus?
abducts the thumb - inserts on the 1st metacarpal.
insertion of EPB?
insertion of EPL?
insertion of EPB - proximal phalanx, extends metacarpophalangeal joint of thumb
insertion of EPL - distal phalanx, extends interphalangeal joint of thumb
insertion of extensor indicis?
action?
inserts on the dorsum of the index finger, allowing independent extension of this digit.
To summarise, all the posterior forearm muscles are:
* [a], except for[b]
* innervated by the [c] nerve.
The muscles that cross the wrist also contribute to wrist extension.
To summarise, all the posterior forearm muscles are:
* extensors, except for brachioradialis, supinator and abductor pollicis longus.
* innervated by the radial nerve.
The muscles that cross the wrist also contribute to wrist extension.
The brachial artery bifurcates in the cubital fossa into two terminal branches – [a/b]
* The radial artery travels along the [a] aspect of the forearm and it can usually be easily palpated at the wrist by locating the tendon of [d] at the level of the distal radius and palpating just laterally to this.
* The ulnar artery travels along the [e] aspect of the forearm. It can also be palpated, but not easily as it is located deep to the [f] tendon.
The brachial artery bifurcates in the cubital fossa into two terminal branches –** the radial artery
and the ulnar artery.**
* The radial artery travels along the lateral aspect of the forearm and it can usually be easily palpated at the wrist by locating the tendon of flexor carpi radialis at the level of the distal radius and palpating just laterally to this.
* The ulnar artery travels along the medial aspect of the forearm. It can also be palpated, but
not easily as it is located deep to the flexor carpi ulnaris tendon.
the radial and ulnar artey [a] in the palm of the hand
anastomose
keep perfusion adequate
ultimately all venous blood in the forearm drains into the [a]
axillary vein
cephalic vein =
basilic vein =
connected by =
cephalic vein = lateral
basilic vein = medial
connected by = median cubital
the floors and sides of crapal tunnel are formed by the [ ]
tunnnel completed by
carpal bones
completed by flexor retinaculum = roof
the flexor retinaculum is attched to:
scaphoid and trapezium laterally
and to the hook of the hamate and pisiform medially.
which tendons travel through the carpal tunnel?
- flexor digitorum superficialis (4 tendons, to digits 2-5).
- flexor digitorum profundus (4 tendons, to digits 2-5).
- flexor pollicis longus (1 tendon to the thumb – the 1st digit).
three muscles of the thenar eminence and their actions?
- Flexor pollicis brevis (FPB) - flexes the thumb.
- Abductor pollicis brevis (APB) - abducts the thumb.
- Opponens pollicis - (OP) - opposes the thumb.
attachments of the adductor pollicis?
third metacarpal and proximal phalanx of thumb.
contraction pulls the thumb toward the palm
what are the three muscles of the hypothenar eminence?
- Flexor digiti minimi (FDM) - flexes the little finger.
- Abductor digiti minimi (ADM) - abducts the little finger.
- Opponens digiti minimi (ODM) - opposes the little finger.
what are the four lumbrical muscles origin, attachment and actions?
there is one lumbrical for each finger.
origin = tendonrs of flexor digitorum profundus
attachment - dorsal aspect for digit 2-5
action = flex MCP and extend IP
innervation of the lumbricles?
- the lateral two (digits 2 and 3) are innervated by the median nerve.
- the medial two (digits 4 and 5) are innervated by the ulnar nerve.
how many interossei muscles are there?
three palmer,
four dorsal
actions of the interossei muscles?
palmer interossei = adduct fingers
doral = abduct fingers
DAB PAD
muscles of the dorsum of the hand?
dorsal interossei
The dorsum of the hand is far less complex than the palm in terms of muscles – only the four
dorsal interossei are seen on the dorsal aspect. The extensor tendons are often visible under the
skin over the dorsum of the hand.
boundaries of the anatomical snuffbox?
medial = EPL tendon
laterally = EPV and APL tendons
Floor = scaphoid bone
C4 deramtone =
the superior aspect of the shoulder.
C5 dermatone:
the lateral shoulder over the deltoid, and anterior and posterior aspects of the arm.
C6 dermatone =
the lateral side of the anterior and posterior surfaces of the forearm, the lateral sides of
the anterior and posterior surfaces of the palm, and the anterior and posterior surfaces of the
thumb and index finger.
c7 dermatone =
the anterior and posterior surfaces of the middle finger and middle of the palm (over the
3rd metacarpal).
C8 dermatone =
C8: the medial side of the anterior and posterior surfaces of the forearm, the medial side of
the anterior and posterior surfaces of the palm, and the anterior and posterior surfaces of the
ring and little fingers.
T1 dermatone =
T1: the medial side of the anterior and posterior surfaces of the arm.
what is dupuytren’s contraction
In this condition, the fingers (usually the little and ring fingers) are pulled into flexion by progressive fibrosis of the palmar fascia and palmar aponeurosis. The palmar fascia is attached
to the flexor tendon sheaths of the fingers. The fascia shortens and pulls the fingers into flexion.
The fascia can be released surgically.
Each hip bone is formed from three separate bones – [a, b, c,] which fuse at the [d] – the socket of the hip joint. The hip bones articulate anteriorly with each other at the [d] and posteriorly with the sacrum at the [e].
Each hip bone is formed from three separate bones – the pubic bone, the ilium and ischium, which fuse at the acetabulum – the socket of the hip joint. The hip bones articulate anteriorly with each other at the pubic symphysis and posteriorly with the sacrum at the sacroiliac joints.
the obturator foram in surrounded by?
in life they are completed covered by obturator membrane and muscles attached to it. But there is a small gap in the membran and muscles called?
superior and inferior pubic rami.
obturator canal
the ischial spine attaches to?
the ischial tuberosity attaches to?
ischial spine = sacrospinous ligament
ischeal tuberosity = sacrotuberous ligament
Iliofemoral ligament
Pubifemoral ligament
Ischiofemoral ligament
the anterior cruciate ligament prevents…
the tibia moving anterior of the femur
the posterior cruciate ligament prevents?
the tibia moving posteriorly to the femur
what does this xray show?
right kneck of femur fracture
attatchments insertions, actions of gluteus medius and gluteus minimus
attchment: posterior ilium
insertion: greater trochanter
action: hip abduct and internal rotation
what are the deep gluteal muscles?
● Piriformis
● The superior and inferior gemelli
● Obturator internus
● Quadratus femoris
insertions of the deep glutreal muscles?
They all insert onto, or close to, the greater trochanter.
why is the piriformis a key landmark?
It attaches to the anterior surface of the sacrum, passes through the greater sciatic foramen, and inserts on the greater trochanter. The nerves of the sacral plexus are located on its surface in the pelvis. The sciatic nerve emerges below its inferior border in the gluteal region.
which four muscles make up the quadriceps femoris?
● Rectus femoris
● Vastus lateralis
● Vastus medialis
● Vastus intermedius.
what does the rectus femoris attatch to proximally?
Anterior Inferior Iliac Spine
attachment of the vastus lateralis?
linea aspera on the posterior aspect of the femoral shaft
vastus medialis attachement?
also the linea aspera
sartorius
attachment
insertion
action
attachment - ASIS, twists accross thigh
insertion - medial aspect of proximal tibia
action - crosses both hip and knee joint so is able to flex and externally rotate the hip and knee joint (not primary mover)
the iliopsoas is formed from a converging of which two muscles into one tendon?
psoas majoy and iliacus
common tendon on the lesser trochanter of femur
these two muscles form the?
what are each innervated by?
iliosoas.
psoas majoy = L1-L3
liliacus = femoral nerve
attachment of pectineus muscle?
proximally at the superior pubic ramus and distally on the femur, just inferior to the lesser trochanter
- flexes and adducts the hip joint.
the adductor magnus has two parts: adductor part and hamstring part.
attachments, action, nerve supply?
adductor part
* attachment inferior pubic ramus and linea aspera
* action = adductor
* nerve = obturator
hamstring part
* attachment : isceal tuberosity and adductor tubercle
* extensor of the hip
* innervation: tibial part of sciatic nerve
what is the adductor hiatus and what travels through it?
The adductor hiatus is a gap formed between the distal attachments of the two parts of adductor magnus. The femoral artery and vein travel through the adductor hiatus to enter the posterior thigh.
gracilis:
attachment
action:
attaches to the pubic bone and the medial aspect of the tibia.
It is a weak adductor and flexor of the hip and a weak flexor of the knee.
obturator externus
attachment, insertion, action
attached to the external surface of the obturator membrane
inserts on the femur near the greater trochanter.
It stabilises and laterally rotates the hip joint.
The posterior compartment of the thigh contains four muscles. These are:
● Semimembranosus and semitendinosus
● Biceps femoris (a long and a short head)
● Hamstring part of adductor magnus.
which muscles of the posterior thigh are known as the hamstrings?
semimembranosus, semitendinosus, and the long head of biceps femoris
span both hip and knee
attachment of the ‘hamstrings’
action?
innervation?
attachment: ischial tuberosity
action: extend hip; flex knee
innervation: tibial part of sciatic nerve
semimembranous and semitendinosus insertion?
medial aspect of porximal tibia
long and short head of the biceps femoris inserts?
head of fibula
Boundaries of the femoral triangle
● lateral
● medial
● superior
● The apex
● The floor
● lateral - formed by the medial border of sartorius.
● medial - formed by the lateral border of adductor longus.
● superior - formed by the inguinal ligament.
● The apex is distal, where sartorius and adductor longus meet.
● The floor of the triangle is formed by iliopsoas laterally and pectineus medially.
the artery that supplies the deep muscles of the thigh?
produnda femoris / deep femoral
from femoral artery
Medially, the obturator artery is a branch of the [a]. It travels through the [b]l into the medial compartment of the thigh. It anastomoses with branches from
[c]
Medially, the obturator artery is a branch of the internal iliac artery. It travels through the obturator canal into the medial compartment of the thigh. It anastomoses with branches from
the femoral artery.
point to the tibeal tuberosity on your leg.
what inserts here?
patellar ligament
what are the tarsal bones?
talus
calcaneus (chalk)
navicular (boat)
medial cuneiform (wedge)
intermediate cuneiform
lateral cuneiform
cuboid
tiger cubs need MILC
movements of the anke joint?
dorsiflexion
plantarflexion (point toes)
no extension; inversion and eversion are subtalar joint!
what is the subtalar joint?
articulation of talus with the calcaneum and navicular
borders of the popliteal fossa?
insertion and action of tibialis anterior?
inserts onto medial cuneifrom
dorsiflexes and inverts foot
insertion and action of hallucis longus?
inserts distal phalanx of great toe.
extends great toe.
also dorsiflexes the foot
which muscle of the anterior compartment is not found on all patients, but is a weak dorsiflexor and evertor of the foot?
fibularis tertius
what are the two muscles of the lateral compartment of the leg?
innervation
action?
fibularis longus
fibularis brevis
innervation = superficial fibular
evert the foot at the subtalar joint
origin of gastrocnemius?
action?
origin via two heads to distal femur
flexes knee, plantar flexion
which muscle of the superficial posterior leg can be harvested an used to repair or replace damaged ligaments or tendons as a graft?
Plantaris - non-essential muscle, primary function can be carried out by other stronger muscles
of the four deep muscles of the posterior compartment of the leg, which does not travel pisterior to the medial malleolus and insert into the plantar surface of the bones of the foot?
popliteus - attached to tibia and femur.
small degree of knee rotation
As discussed in the last session, to help us to stand for long periods, the femur rotates a very small amount as the knee reaches full extension. This means the knee ‘locks’ in place and becomes very stable. Popliteus is responsible for ‘unlocking’ the knee by rotating the femur back again to permit flexion.
action of tibialis posterior
plantarflexion and inversion
The dorsum of the foot also contains a small muscle called?
innervation
extensor digitorum brevis
innervation = deep fibular nerve
the popliteal artery bifurcates in the popliteal fossa into?
anterior and posterior tibial arteries
fibular artery
what does the anterior tibial artery supply?
anterior compartment of leg
dorsum of foot (as the dorsalis pedis artery)
what does the posterior tibial artery supply?
posterior compartment of the leg and sole of foot.
It goves rise to the fibular artery which supplies the lateral compartment
what arteries supply the sole?
posterior tibial bifurcates into medial and lateral plantar arteries which supply the sole
the popliteal vein is formed fromt the union of?
The posterior tibial, anterior tibial and fibular arteries plus deep veins.
the dorsal venous network of the foot drains medially into the?
great saphenous vein –> femoral vein
small saphenous vein –> popliteal
