Effects of dual task constraints on intra-limb coordination during treadmill walking in people with chronic stroke

This study examined effects of dual task constraints on intra-limb coordination patterns in samples of stroke survivors and able-bodied individuals during treadmill walking. Twenty participants (N_patients=10 and N_able-bodied=10) participated voluntarily in this study and lower limb coordination data were collected using a 3D motion analysis system whilst walking on a treadmill. The dual task constraints involved using cognitive activity (subtracting random numbers) during treadmill walking. Continuous relative phase was used to assess coordination between the foot-shank and shank-thigh complexes during the gait cycle. Statistical analysis revealed a significant reduction of variability in lower limb coordination patterns (foot-shank and shank-thigh couplings) among stroke patients, compared to able-bodied counterparts, regardless of whether they were dual-tasking. Findings revealed that gait retraining in stroke survivors should emphasize increasing variability in inter-joint coordination, regardless of the nature of task.