Objective—To quantify the effects of trotting velocity on joint angular excursions, net joint moments, and powers across the hind limb joints in Greyhounds.
Animals—5 healthy Greyhounds with no history of lameness of the hind limbs.
Procedures—Small reflective markers were applied to the skin over the joints of the hind limbs, and a 4-camera kinematic system was used to record positional data at 200 Hz in tandem with force platform data while the dogs trotted on a runway at slow, medium, and fast velocities. Breed-specific morphometric data were combined with kinematic and force data in an inverse-dynamics solution for net joint moments and powers at the hip, stifle, tarsal, and metatarsophalangeal joints.
Results—Angle, moment, and power patterns at the various joints were conserved among the 3 velocities. With increasing velocity, moments and powers at the tarsal, stifle, and hip joints during the stance phase were increased in amplitude, whereas amplitudes during the swing phase were not. The main contributors to increased velocity were the hip extensors and stifle flexors during the early part of the stance phase and the tarsal extensors during the late part of the stance phase.
Conclusions and Clinical Relevance—Increases in trotting velocity in Greyhounds do not alter the basic patterns of work and power for various joints of the hind limbs, but local burst amplitudes during the stance phase increase incrementally.
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
Animals—12 clinically normal dogs (6 Greyhounds
and 6 Labrador Retrievers) with no history of hind
Procedure—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
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
Conclusions and Clinical Relevance—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. (Am J Vet Res 2005;66:1563–1571)