Comparison of elliptical training, stationary cycling, treadmill walking and overground walking.

The extent to which therapeutic, exercise or robotic devices can maximize gait function is a major unresolved issue in neurorehabilitation. Several factors may influence gait outcomes such as similarity of the task to overground walking, degree of coordination within and across limbs, and cycle-to-cycle variability in each device. Our objective was to compare lower extremity kinematics, coordination and variability during four locomotor tasks: overground walking, treadmill walking, elliptical training and stationary cycling in 10 non-disabled adults (6 male; mean age 22.7±2.9 yrs, range 20-29). All first performed four overground walking trials at self-selected speed with mean temporal-spatial data used to pace the other conditions. Joint positions, excursions, and the Gait Deviation Index (GDI) were compared across conditions to evaluate kinematic similarity. Time-series data were correlated within and across limbs to evaluate intralimb and interlimb coordination, respectively. Variability in cadence was quantified to assess how constrained the locomotor rhythm was compared to overground walking. Treadmill walking most closely resembled overground with GDI values nearly overlapping, reinforcing its appropriateness for gait training. Cycling showed the largest GDI difference from overground, with elliptical closer but still a significant distance from all three. Cycling showed greater hip reciprocation Cycling and elliptical showed stronger intralimb synergism at the hip and knee than the other two. Based on kinematics, results suggest that elliptical training may have greater transfer to overground walking than cycling and cycling may be more useful for enhancing reciprocal coordination. Further evaluation of these devices in neurological gait disorders is needed.