Cycling at faster pedaling rates leads to symptomatic improvement in patients with Parkinson’s disease (PD). However, these patients show inter-limb asymmetry in pedaling power when cycling at their slow self-selected cadence. The effects of faster pedaling cadence on symmetry of effort between limbs is unknown. We compared the effect of pedaling cadence on symmetry of crank power output in individuals with PD versus healthy controls. In this case series, two participants with PD and two healthy controls performed 3-minute bouts of stationary cycling at three cadences (50, 65, 80 rpm) at 60W and self-selected workload. Power output contribution of each limb towards total crank power output was computed over 60 crank cycles from the effective component of pedal force, which was perpendicular to the crank arm. Although no statistical analysis was performed for this case series, the data across the experimental conditions showed that individuals with PD demonstrated substantial interlimb asymmetry in power output (35-154%) compared to healthy controls (1-34%). There was no clear trend for the effect of pedaling cadence in participants with PD and healthy controls. Two patients with PD and one healthy control participant showed an increase in asymmetry with increase in pedaling cadence. In conclusion, participants with PD demonstrate large interlimb asymmetries in power output compared to healthy controls and this interlimb asymmetry is not systematically affected by pedaling cadence
