Thoracic limb/ Forelimb Flashcards
What is ground reaction force?
GRF = the force that acts on the body as a result of the body contacting the ground.
Why is there an uneven split of GRF 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.
GRF is 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 maneuver, balance and changing direction)
From proximal to distal, name the key bones in the thoracic limb.
- Scapula
- Humerus
- Radius
- Ulna
- Carpal bones
- Metacarpal bones
- Phalanges
From proximal to distal, name the key joints in the thoracic limb.
- Scapulohumeral
- Elbow (humeroradial, humeroulna, radioulnar)
- Carpus
- Metacarpo-phalangeal
- Proximal interphalangeal
- Distal interphalangeal
What is the the thoracic girdle?
- Thoracic girdle = equivalent to a clavicle in humans
- Some animals will have a coraccid bone connecting the cranial edge of the sternum to the shoulder joint
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 acromium found on the scapula..
Acromium found 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 humeral chongyles at the base of the bone.
Where is the olecranon found?
Found at the top of the ulna
What is different about the radius and the ulna in horses?
Radius and ulna fused 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 fewer carpal bones than dogs.
5 metacarpal bones in dogs
7 carpal bones in dogs
What is the brachial plexus?
Brachial plexus = the combination and reorganisation of spinal nerves in the thoracic limb.
