Forelimb Flashcards
What is ground reaction force?
-ground reaction force = the force that acts on the body as a result of the body contacting the ground
Why there is an uneven split of ground reaction force between the hindlimbs and forelimbs of a quadruped?
- the centre of mass of the animal is more cranial so there is greater GRF on the forelimbs
Ground reaction force us a vector that can be resolved into two components, what are these components?
- horizontal ground reaction force, relevant during acceleration and deceleration
- mediolateral ground reaction force, relevant during manoeuvre, balance and changing direction
From proximal - distal name the key bones in the thoracic limb
- scapula
- humerus
- radius
- ulna
- carpal bones
- metacarpal bones
- phalanges
From proximal-distal name the joints in the thoracic limb
- scapulohumeral
- elbow (humeroradial, humeroulnar, radioulnar)
- carpus
- metacarpo-phalangeal
- proximal interphalangeal
- distal interphalangeal
What is the thoracic girdle?
- unites limb to trunk
- greatly reduced in cursorial animals
- equivalent to clavicle in humans - some animals have have a loss or reduction in clavicle
- some animals will have a coracoid bone connecting the cranial edge of the sternum to the shoulder joint (lost in many mammals now)
How is the scapula attached to the thoracic girdle?
- scapula attached to the thoracic girdle via extrinsic muscles (this enables sliding over the thorax to increase stride length)
Where is the acromion found on the scapula?
- at the base of the scapula spine (not present in horses)
what are the key features of the humerus bone?
- has a greater tubercle and a lesser tubercle
- has a humeral condyles at the base of the bone
where is the olecranon found?
- found at the top of the ulna
what is the different about the radius and the ulna in horses?
- radius and ulna fuse together in horses in order to reduce limb mass
What is found at the base of the ulna?
- styloid processes found at the base of the ulna
what is the difference between the carpal regions in a dog and in a horse?
- Horses have fever carpal bones than dogs
- 5 carpal bones in a dog but only 4 tend to be visible
What is the brachial plexus
- the combination and reorganisation of spinal nerves in the thoracic limb
What are extrinsic muscles?
- originate outside of the limb skeleton
- insert on the limb skeleton
