Additional kinematic variables to describe differences in the trot betweenclinically normal dogs and dogs with hip dysplasia

Objective--To describe the abnormal gait of dogs with hip dysplasia by use of kinematic gait analysis. Animals--19 large-breed dogs with moderate to severe clinical and radiograp hic evidence of hip dysplasia and 10 clinically normal dogs (controls). Procedure--Kinematic and force plate data were collected, and degree of cox ofemoral joint abduction-adduction, mediolateral foot movement, distance be tween hind feet, maximum hind foot elevation, mediolateral pelvic movement, and coxofemoral joint angular acceleration were calculated. Essential Four ier coefficients were determined and used to reconstruct mean angular accel eration curves. Fourier coefficients and foot and pelvic movement data were compared between groups. Results--Dogs with hip dysplasia had a greater degree of coxofemoral joint adduction and range of abduction-adduction and greater lateral pelvic movem ent, compared with controls. Foot movement variables did not differ signifi cantly between groups. Coxofemoral joint angular acceleration was greater i n the middle to end of the stance phase, whereas deceleration was greater i n the late stance to early swing phase and middle to end of the swing phase in dogs with hip dysplasia, compared with controls. Conclusions and Clinical Relevance-Differences in degree of coxofemoral joi nt abduction-adduction, amount of mediolateral pelvic movement, and coxofem oral joint angular acceleration between clinically normal dogs and dogs wit h hip dysplasia may indicate a compensation in gait of affected dogs as a r esult of discomfort or biomechanical effects attributable to hip dysplasia and degenerative joint disease. information gained from kinematic and kinet ic gait analyses may be useful in evaluating treatments for hip dysplasia i n dogs.