REDISTRIBUTION OF VERTICAL GROUND REACTION FORCE IN DOGS WITH EXPERIMENTALLY-INDUCED CHRONIC HINDLIMB LAMENESS

When lameness occurs in a load-bearing limb, compensatory load adjustm ents are made in the other supporting limbs. The vertical component of the ground reaction force, as measured by force platform analysis, re flects these adjustments. This study describes the pattern of vertical ground reaction force redistribution during experimental, chronic hin dlimb lameness in dogs. The peak and impulse of the vertical ground re action force were measured and described in 13 dogs before, and at 2, 6, and 12 weeks after transection of the cranial cruciate ligament. Th ese variables were compared among limbs. The vertical ground reaction force in the forelimbs did not change significantly during the course of the study. At 2, 6, and 12 weeks after surgery, means of peak verti cal force in the limb that underwent surgery were 18.9%, 44.0%, and 61 .3% respectively, of presurgical values. In the contralateral limb, co rresponding values were 131.7%, 112.8% and 112.9% respectively. If one accepts the relationship of mechanical loading to musculoskeletal arc hitecture and the now certain relationship between lameness and compen satory loading of other limbs, then the use of another limb of the sam e animal as a control is a potential study design flaw. (C) 1995 by Th e American College of Veterinary Surgeons