The purpose of this study was to examine the ability of subjects with unilateral cerebrovascular accidents (CVAs) to utilize kinetic feedback to modify pedaling techniques. Individual joint contribution changes were assessed by calculating generalized muscle moments, muscle power and work.

Eight male subjects with unilateral CVAs were randomly assigned to two groups. Pedal forces from four normal subjects also were collected. The bicycle apparatus was a recumbent bicycle with pedals capable of measuring normal (F_N) and tangential (F_T) components of the applied force. Pre/post comparisons were done for strength, measured using an isokinetic dynamometer, walking speed, evaluated using fifty foot walk times and bicycle kinematics obtained using a high speed cine camera (50 fps) and pedal forces (200 Hz). Pedal force data was collected one month post training. No feedback was given during any testing session. Training consisted of twelve one-minute trials with one minute rest between trials, three times a week for four weeks. Feedback consisted of visual and verbal feedback regarding patterns approximating the effective force (Fe) bilaterally after each trial during the rest periods. The no-feedback (NF) group received no feedback.

Results indicate that the feedback (FB) group did not decrease the amount of asymmetry associated with cycling. The NF group showed improvements in all parameters associated with the involved leg. Asymmetry did not always decrease in the NF group as measured by the I/N ratio.. Peak Fn increased in the involved leg while it decreased in the noninvolved leg. The mean I/N ratio prior to training was as much below unity (1.0) as it was above unity after training where 1.0 represented perfect symmetry between values of each leg. Effective pedaling was determined by the amount of positive W_CR I/N ratio. The NF group showed improvement, but the FB group did not. Possible explanations for the lack of improvement in the FB group are:​ 1) the cyclical nature of cycling allowed for natural patterns to develop without feedback, 2) with feedback, frequent trial-to-trial changes interfered with the development of natural patterns, 3) the feedback may have been too complicated for this population, and 4) learning and integrating abilities of these subjects were compromised.