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Diagram showing the location of the hock.
The hock, or gambrel, is the tarsal joint of a digitigrade quadruped, such as a horse, cat, or dog. It is the anatomical homologue of the heel of the human foot.
[edit] The Equine Hock
Although the tarsus refers specifically to the bones and joints of the hock, most horsemen refer to the hock in such a way to include the bones, joints, and soft tissue of the area. The hock is especially important in equine anatomy, due to the great strain it receives when the horse is worked. Jumping, and movements that require collection, are some of the more stressful activites.
[edit] Primary joints and bones of the hock
In the horse, the hock consists of multiple joints, namely:
- Tibiotarsal or Tarsocrural joint
- Proximal Intertarsal joint or Talocalcanealcentroquartal joint
- Distal Intertarsal joint or Centrodistal joint
- Tarsometatarsal joint
- Talocalcaneal joint
In the horse, the hock consists of the following bones
- Talus
- Calcaneus
- Central tarsal bone
- 3rd tarsal bone
- 3rd metatarsal bone
- 4th tarsal bone
- Fused 1st and 2nd tarsal bone
[edit] Equine disease states
- Horses may suffer from "capped hock", which is caused by swelling of the calcanean bursa, a synovial sac beneath the skin which protects the bone. Capped hock is usually caused by trauma such as kicking or slipping when attempting to stand. In the absence of a wound, it does not require immediate veterinary attention and is usually only of cosmetic significance. On the other hand, a wound into the calcanean bursa is a serious problem. A capped hock is extremely unlikely to be a cause of lameness, even if severe.
- An increase in the synovial fluid of the tibiotarsal joint is called bog spavin.
- Degenerative joint disease of the tarsometatarsal or distal intertarsal joint is referred to as bone spavin.
- Curb, or tarsal plantar desmitis, is a sprain of the plantar ligament, which runs down the back of the hock
- Stringhalt is a condition similar to intermittent fixation of the patella, resulting in the horse exaggerating the flexion of the hock.
[edit] Conformational defects
Also see equine conformation
Because the hock takes a great deal of strain in all performance disciplines, correct conformation is essential if the horse is to have a sound and productive working life. Common conformational defects include sickle hocks, post leg conformation/straight hocks, cow hocks, and bowed hocks. Depending on the use of the horse, some defects may be more acceptable than others
