Distribution of power across the hind limb joints in Labrador Retrievers and Greyhounds.
OBJECTIVE
To quantify angular excursions; net joint moments; and powers across the stifle, tarsal, and metatarsophalangeal (MTP) joints in Labrador Retrievers and Greyhounds and investigate differences in joint mechanics between these 2 breeds of dogs.


METHODS
12 clinically normal dogs (6 Greyhounds and 6 Labrador Retrievers) with no history of hind limb lameness.


METHODS
Small retroreflective markers were applied to the skin over the pelvic limb joints, and a 4-camera kinematic system captured data at 200 Hz in tandem with force platform data while the dogs trotted on a runway. Breed-specific morphometric data were combined with kinematic and force data in an inverse-dynamics solution for stance-phase net joint moments and powers at the stifle, tarsal, and MTP joints.


RESULTS
There were gross differences in kinematic patterns between Greyhounds and Labradors. At the stifle and tarsal joints, moment and power patterns were similar in shape, but amplitudes were larger for the Greyhounds. The MTP joint was a net absorber of energy, and this was greater in the Greyhounds. Greyhounds had a positive phase across the stifle, tarsal, and MTP joints at the end of stance for an active push-off, whereas for the Labrador Retrievers, the only positive phase was across the tarsus, and this was small, compared with values for the Greyhounds.


CONCLUSIONS
Gross differences in pelvic limb mechanics are evident between Greyhounds and Labrador Retrievers. Joint kinetics in specific dogs should be compared against breed-specific patterns.
Colborne
G Robert
GR
Department of Anatomy, Faculty of Medical and Veterinary Sciences, University of Bristol, Langford, North Somerset, UK BS40 5DU.
Innes
John F
JF
Comerford
Eithne J
EJ
Owen
Martin R
MR
Fuller
Cathy J
CJ
D000818:Animals; D001696:Biomechanical Phenomena; D001837:Body Weights and Measures; D004285:Dogs / Q000033:anatomy & histology / Q000502:physiology*; D005684:Gait / Q000502:physiology*; D006614:Hindlimb / Q000502:physiology*; D007596:Joints / Q000502:physiology*