Evidence of compensatory joint kinetics during stair ascent and descent in Parkinson's disease.

•PD patients have altered patterns of lower limb joint kinetics during stair walking.•Despite weaker knee extensors, PD patients use their knees more during stair walking.•Fewer degrees of freedom afforded by the knee may improve one’s sense of stability.•Improving lower limb strength may assist clinicians with ameliorating falls risk.