Locomotor Flashcards
(105 cards)
1
Q
Describe the anatomy of the femur? (5)
A
Diaphysis - shaft. Epiphysis - around the growth plate. Head Metaphysis - growth plate. Trochanter.
2
Q
What is abduction? (1)
A
Movement away from the midline.
3
Q
What is adduction? (1)
A
Movement towards the midline.
4
Q
Define cranial translation of the proximal tibia. (1)
A
Sliding movement in a cranial direction.
5
Q
Define valgus deviation of the carpus. (1)
A
Lateral deviation, refers to distal limb only.
6
Q
Define varus deviation of the stifle/knee. (1)
A
Medial deviation of the distal limb.
7
Q
Define dorsal (sub)luxation of the femoral head. (1)
A
Separation of joint surfaces, i.e. dislocation.
8
Q
How do levers change the force required to move a set mass? (2)
A
Altering the length of the lever arms to reduce load or increase speed.
9
Q
Outline the terminology for levers. (4)
A
Lever - rigid bar (bone).
Fulcrum - pivot point (joint).
Load - the mass that requires moving (limb/bodyweight).
Effort/force - force input to generate movement (muscle).
10
Q
What is a type 1 lever? Give an example. (2)
A
See-saw, effort and load in opposite directions, fulcrum in the centre. E.g. elbow.
11
Q
What is a type II lever? Give an example. (2)
A
Wheelbarrow, effort and load run in the same direction, fulcrum at one end. E.g. dog standing up, pivots on toes. load close to the fulcrum.
12
Q
What is a type III lever? Give an example. (2)
A
Most levers are of this type. Baseball swing, effort and load in the same direction, effort close to the fulcrum.
13
Q
Describe the hierarchical structure of skeletal muscle. (4)
A
Myofibrils
14
Q
What is the function of a tendon? (1)
A
Join muscle bellies to bones or other tendons.
15
Q
What is the function of a ligament? (1)
A
Join bone to bone.
16
Q
What is the origin of a muscle? (1)
A
Less movable attachment, typically proximal.
17
Q
What is the insertion of a muscle? (1)
A
Mobile segment of the body with attachment - typically distal.
18
Q
What is Wolff’s law? (1)
A
Every change in the function of a bone is followed by a certain definite change in it’s internal architecture and it’s external conformation.
The bone’s shape is a result of the functional forces experienced through life optimising the architecture to resist failure/fracture.
19
Q
What is the name of the type of joint between the quadruped forelimb and the thorax. (3)
A
Synsarcosis. There is no bony attachment to the trunk, as a result there is a greater possible range of motion with the attachments made from purely muscular and connective tissue.
20
Q
What is the function of the olecranon? (1)
A
Attaches the insertion of the triceps brachii, allows extension of the elbow.
21
Q
What are the functions of the collateral ligaments? (3)
A
Connects the lateral epicondyle to the lateral radial head and lateral ulna.
Connects the medial epicondyle to the medial radial head.
Prevents lateral or medial translation.
22
Q
What is the annular ligament? (1)
A
Encircles the head of the radius and attaches it to the ulna notch either side.
23
Q
What is the function of the radius? (1)
A
Bears most of the weight.
24
Q
What is the function of the ulna? (1)
A
Provides rotational and joint stability.
25
Describe the anatomy of the radius and ulna. What is the clinical relevance of this? (4)
There is a strong fibrous attachment between radius and ulna that allows rotation.
The radius has a proximal and distal growth plate for longitudinal lengthening.
The ulna only has a growth plate at the distal end of the bone.
This can make for discrepancies in the length between radius and ulna, known as joint incongruity.
26
Why is the medial coronoid process prone to problems in dogs? (1)
Most common cause of lameness, due to un-equal load sharing between radius and ulna due to joint incongruity.
27
Describe the anatomy of the carpus? (4)
Collateral ligaments prevent lateral and medial translation.
Short dorsal carpal ligaments hold together the carpal bones.
Distal accessory carpal ligament connects accessory carpal bone to the metacarpals.
Palmar carpal ligament connects the accessory carpal bone to the ulnaris lateralis and FCU tendon.
28
What are extrinsic muscles of the forelimb? (1)
Muscles which attach from the limb to the body.
29
What are the intrinsic muscles of the forelimb? (1)
Muscles that have both origin and insertion within the limb.
30
What is the function of the trapezius muscle? (1)
Attaches the dorsal scapula to the trunk. Allows elevation of the limb and some protraction (cervical) and retraction (thoracic).
31
What muscles are involved primarily in the thoracic girdle? (4)
Major muscles: Pectorals (deep and superficial), serratus ventralis and rhomboideus.
Minor: other extrinsic muscles. Trapezius, latissimus dorsi, omotransversarius, brachiocephalicus.
32
What is the function of the brachiocephalicus? (1)
Protracts the limb.
33
What are the purposes of the muscles of the thoracic girdle? (3)
Serratus ventralis - suspends the thorax.
Pectorals - adduction and support.
Rhomboideus - suppot, elevates the limb, abducts the limb by moving the proximal scapula medially.
34
What is the function of the latissimus dorsi? (1)
Retracts the limb.
35
Where does the trapezius attach? What is it's fibre direction? (2)
The trapezius has two bellies, it attaches from the scapular spine to the cervical midline cranially and the dorsal midline caudally. The fibres are caudo-ventral in the cervical portion, and cranio-ventral in the thoracic portion.
36
Where does the omotransversarius attach? (1)
From the distal scapular spine to the transverse process of C1-2.
37
Describe the anatomy of the brachiocephalicus. (1)
Two portions, the cleidobrachialis and the cleidocephalicus.
38
Describe the anatomy of the latissimus dorsi. (1)
Large fan shaped muscle from the teres major tuberosity on the caudal humerus to the thoracolumbar fascia and the last 2-3 ribs.
39
Describe the location of the superficial pectorals. (1)
First 2-3 sternebrae to the greater tubercle.
40
Describe the location of the deep pectorals. (1)
Whole sternum to the lesser tubercle and the brachial fascia.
41
Describe the intrinsic shoulder muscles. (4)
Supraspinatus - supraspinous fossa to the greater tubercle. Shoulder extensor. Innervated by the suprascapular nerve.
Infraspinatus - infraspinous fossa to the lateral greater tubercle, offers lateral support. Innervated by the suprascapular nerve.
42
Describe the shoulder flexor muscles. (4)
Deltoideus - lateral, acromion and scapula spine to the deltoid tuberosity. Innervated by the axillary nerve.
Teres Major - medial, caudal scapula margin to the medial humeral diaphysis. Innervated by the axillary nerve.
43
What is the medial shoulder muscle? (2)
Subscapularis - subscapular fossa to medial humeral neck. Medial joint support to prevent abduction. Innervated by the subscapular nerve.
44
Describe the elbow flexors. (2)
Brachialis - caudomedial humeral shaft, spirals laterally then inserts on cranial radius.
Biceps brachii - supraglenoid tubercle to radial tuberosity. Innervated by the musculocutaneous nerve.
45
Descibe the elbow extensors. (6)
```
Triceps brachii - four heads.
Long - caudal scapula.
Lateral - lateral humerus.
Accessory - neck of the humerus.
Medial - medial humerus.
All insert on the olecranon process. Innervated by the radial nerve.
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46
Why are extensors larger than elbow flexors? (1)
When the dog is standing, most of the joints are already flexed. Flexed positions are more natural, and require stronger extensors to prevent over-flexion or limb buckling.
47
What structures support the stability of the cranial aspect of the shoulder joint? (2)
Biceps tendon and the supraspinatus tendon.
48
Which muscle bridges the craniomedial aspect of the shoulder joint? (1)
Biceps brachii in the intertubercular groove.
49
What is the synovial structure surrounding the tendon? Is it separate from the shoulder joint? (2)
The biceps tendon sheath, continuous with scapulohumeral joint capsule in the dog.
50
What structures limit the movement of the elbow in one plane? (1)
Collateral ligaments, trochlear, trochlear notch, anconeal process.
51
Why are the forelimb nerves more prone to injury from avulsion than those in the hindlimb? (2)
There is less bony attachment in the forelimb, musculature and nerves are more easily stretched.
The forelimb is more mobile against the trunk, more tension can be placed on nerve roots than in the hindlimb.
52
Why are the forelimb nerves more prone to injury from avulsion than those in the hindlimb? (2)
There is less bony attachment in the forelimb, musculature and nerves are more easily stretched.
The forelimb is more mobile against the trunk, more tension can be placed on nerve roots than in the hind limb.
53
What is the largest muscle belly on the craniolateral aspect of the antebrachium? What action does it have? (2)
Extensor carpi radialis - carpal extensor. Largest because it has the largest load to move as it extends the carpus, not just a digit.
54
Why are the digital flexor muscle bellies larger than the digital extensor muscles? (2)
The force required to flex the carpus and digits for locomotion is greater than the required force for extension of the limb to reposition for the next stride.
55
What is the primary innervation to the carpal/digital extensor group? (1)
Radial nerve.
56
What is the common origin for all of the craniolateral muscles of the antebrachium? (1)
Lateral epicondyle of the humerus.
57
On the palmar aspect of the carpus, what is the structure containing the flexor tendons and neurovascular structures? (1)
Carpal flexor retinaculum.
58
What structures form the boundary of the carpal flexor retinaculum? (3)
Accessory carpal bone is lateral, palmar carpal fibrocartilage is dorsal and the flexor retinaculum palmar.
59
Describe the rotational muscles of the forelimb. (4)
Supinator, pronator teres, pronator quadratus, abductor pollicus longus.
60
Why is the medial coronoid process more susceptible to pain and overload than the lateral? (1)
More protuberant and experiences greater loads during weight bearing than the lateral coronoid process.
61
Which joint level of the carpus has the greatest range of motion? (1)
Antebrachiocarpal (ABC).
62
Do the ABC joint space and the middle carpal joint space communicate? Why is this important to know? (2)
No, this is important because the joint space being separate means you should take samples from both spaces if concerned about potential infection or inflammation.
63
What structures resist medial and lateral bending in the carpus? (1)
Lateral and medial collateral ligaments.
64
Are the caudal structures of the carpus individual ligaments, or one large mass of fibrous tissue? (2)
The ligaments theoretically run between each individual bone and their adjacent neighbour, but in a functional and visible sense this all merges to form one big bundle of fibrocartilage which provides the key support to resist the hyperextension in the carpal joint.
65
What is the canine stance known as? (1)
Digitigrade.
66
What is the name of the bones contained a pair of small bones distally? (1)
Palmar proximal sesamoids.
67
What is the name of the muscle that inserts on the palmar proximal sesamoids? (1)
Interosseous.
68
Describe the anatomy of the pads. (2)
Specialised epithelial tissues to resist impact and wear. A modified subcutis contains increased fat, collagen and elastic fibres to improve shock absorption from locomotion.
69
Describe the arterial supply to the forelimb. (4)
Axillary and brachial arteries, cranial and superficial antebrachial arteries, and median artery is the pulse point between the carpus and metacarpal pad.
70
Describe the venous supply to the forelimb. (
The cephalic veins drain to the external jugular vein. There is also the accessory cephalic and median at the distal limb, and the median cubital and collateral ulna on the proximal limb. The axillary vein lies on the scapular.
71
Describe the venous supply to the forelimb. (4)
The cephalic veins drain to the external jugular vein. There is also the accessory cephalic and median at the distal limb, and the median cubital and collateral ulna on the proximal limb. The axillary vein lies on the scapular.
72
Describe the anatomical differences in the scapulars of the horse, ox and dog. (3)
Dogs have prominent scapula cartilage.
Horse scapula has very rounded edges.
Ox have a very triangular scapula.
73
What makes the cat humerus different? (1)
Supracondylar foramen, the brachial artery and median nerve pass through here.
74
What is the main difference that you can see between the equine forelimb and the canine forelimb? (excluding size). (1)
Fewer digits, one weight bearing digit. The limb is unguligrade not digitigrade.
75
What landmark of the forelimb is present in dogs and not horses? Why? (2)
Acromion. There is no acromial head of the deltoideus, and the horse has a limited need to abduct the shoulder.
76
What limits the ability of the antebrachium to pronate and supinate in horses? (1)
Fusion of the radius and ulna, they cannot move independently.
77
Which structure of the pectoral girdle shows the most significant difference in structure between dogs and horses? (2)
Serratus ventralis - tendinous portions in each segment, running the length of the muscle. This helps to support bodyweight, reducing the muscular effort required.
78
Which extrinsic muscle is present in horses but not dogs? (1)
Subscapularis - functionally similar to pectorals.
79
Which muscles contribute to shoulder and elbow movement? (1)
Triceps brachii.
80
What special features does the biceps brachii muscle have to limit shoulder movement when standing and resting. (1)
Cranial tendon runs the length of the muscle.
81
Name the feature of the equine biceps brachii which separate it from the canine version. (1)
Internal tendon and lacertus fibrosus which branches off the internal tendon and inserts on the ECR epimysium to limit flexion of the carpus whilst there is tension in the biceps.
82
Why are the supinator and pronator teres muscles not present in horses? (1)
They do not need to pronate or supinate as they are sprinters not hunters, and have a fused radius and ulna as a result.
83
If the nerve supplying the biceps brachii wasn't functioning due to a tumour, would the horse be able to prevent it's shoulder joint from collapsing? (1)
Horses can stand on the tendon alone - limits shoulder flexion whilst weight bearing.
84
Why can't you see distinct ligaments medially and laterally in the joint? (1)
Lateral and medial glenohumeral ligaments are less distinct thickenings in the shoulder of the horse. The stability relies more on the surrounding muscle.
85
What are the three synovial structures in the shoulder region? (3)
Scapulohumeral joint (largest), bicipital bursa, infraspinatus bursa.
86
What appearance does the tissue lining a synovial structure typically have? (1)
Smooth and shiny.
87
How is the elbow of the horse stabilised? (1)
Stabilised by stout collateral ligaments and powerful flexor and extensor muscles.
88
What part of the ulna does the triceps brachii insert on? (1)
Olecranon.
89
How many components are there to the elbow synovial pouch? (1)
One - a large capacious joint which extends cranial and caudal to the condyle.
90
Why is medial coronoid process disease not seen in horses? (2)
The coronoid process is less significant for weight-bearing in horses because the radius and the ulna are fused- they do not move independently from one another. The radius and the ulna fuse very early in development and grow in unison, so there are no size discrepancies.
91
The carpal flexors and extensors all cross the elbow joint. Using your knowledge of biomechanical principles, consider what effect, if any, the muscles will have on the elbow joint. Justify your reasoning for this. (3)
The carpal flexors and extensors have minimal (if any) effect on the elbow joint, as they are attached laterally to the joint and tension from this point will result in an abduction or adduction force. This is strictly limited by the collateral ligaments and the trochlea and anconeal process.
Whilst some may theoretically be able to slightly flex or extend the elbow, depending how cranial or caudal they are on the epicondyles, functionally this has effectively zero effect.
92
What muscles insert on the accessory carpal bone in the horse? (2)
Ulnaris lateralis and flexor carpi ulnaris.
93
What are the structures that support the distal tendons and reduce friction over the joints? (2)
Retinaculi guide the path of the distal tendon, and the tendon bursae and sheaths help reduce friction over joints and bony prominences.
94
How are the digital extensor tendons different in horses and dogs? (1)
The lateral digital extensor tendon inserts on the proximal aspect of P1 in horses, but combines with the common digital extensor tendon to insert on P3 in the dog.
95
What nerve controls the digital and carpal extensors in the horse? (1)
Radial nerve.
96
What are the functions of the check ligaments that run with the flexor tendons of the horse? What is the difference between deep and superficial check ligaments? (1)
Prevention of hyper-extension.
| Superficial have a higher origin than the deep, and they support different groups of joints.
97
What is the purpose of the extensor branches of the interosseous (suspensory) ligament? (1)
Functionally links the tension created on the suspensory ligament with the common/long digital extensor tendon and resists distal rotation of the pedal bone with tension on the DDFT.
98
What separates the deep digital flexor tendon from the navicular bone? (1)
Navicular bursa.
99
What is the difference in carpal bone arrangement in the proximal row of bones, compared to the dog? (1)
The horse has an additional bone, the intermediate carpal bone, which is fused with the radial carpal bone in the dog.
100
What is the primary structure that resists hyperextension of the carpal joint? (1)
Palmar fibrocartilage.
101
Describe the location of the carpal tunnel. What structures run through it? (2)
The palmar carpal tunnel is bordered by the palmar fibrocartilage, the accessory carpal bone and the flexor retinaculum. The Distal Digital Flexor, Superficial Digital Flexor Tendons, Flexor Carpi Radialis, Palmar veins, arteries and nerves all run through the carpal tunnel.
102
Why is the white line of the equine foot an important anatomical landmark for farriers? (2)
Signifies the separation of the hard tubular horn of the hoof wall from the solar elastic horn. It is also the indicator of the border between sensitive and insensitive tissue.
103
What part of the foot generates the hoof wall? (1)
The coronary epidermis.
104
What happens to P3 following weakening of the lamina after laminitis in horse? (2)
The bond between the hoof wall epidermal laminar and dermal lamina of P3 breaks down and the hoof wall separates from the P3, leading to rotation of the bone through tension on the DDFT from weight bearing.
105
What are the functions of the digital cushion for horses during walking? (2)
Absorbing concussion from walking or running and generating pressure for blood return to the heart.
