Effects of various modes of forward and backward cycling on neuro-biomechanical outcomes in individuals after stroke and healthy controls.

Abstract

Stationary cycling is recommended for post-stroke rehabilitation. This study assessed neuro-biomechanical outcomes of forward and backward cycling in three different modes: free-pedalling, constant speed (30 RPM) and constant resistance (5 or 10 Nm) in healthy controls and individuals after stroke. Ten individuals after stroke and 10 healthy controls performed 60s cycling trials in different directions and modes on a semi-recumbent bike prototype. Cycling performance (speed, torque, coefficient of variation) and the activity of the non-dominant limb muscles (rectus femoris, vastus lateralis, tensor fascia latae, and biceps femoris) were collected. Cycling performance was lower in backward than forward direction in both groups, but to a greater extent in individuals after stroke. Variability was reduced in backward compared to forward pedalling except for free-pedalling. At constant speed, both groups showed similar increase in rectus femoris activation during the propulsive phase of backward cycling while an increase was only observed in the stroke group for the tensor fascia latae. The constant resistance mode revealed more difference between groups: individuals after stroke showed changes of rectus femoris and vastus lateralis activation with pedalling direction in both phases while healthy controls had changes only in the vastus lateralis. Tensor fascia latae activation differed between groups but was not affected by direction. The biceps femoris activation was more variable. Various cycling directions and modes influenced neuro-biomechanical outcomes, even more in individuals after stroke. Future research should determine how they could enhance functional abilities after stroke when used during rehabilitation.