Investigación clínica sobre pie y tobillo

Abstracto

Isokinetic Cycling and Elliptical Stepping: A Kinematic and Muscle Activation Analysis

Nur Azah Hamzaid, Richard M Smith, and Glen M Davis

Background: Semi-recumbent cycling exercise has been used as a strategy to complement gait retraining in individuals with disordered walking ability. However, seated elliptical stepping might be a more potent exercise modality for this purpose. Yet, there has not been a kinematic analysis of elliptical stepping exercise, whereby the movement path is produced by a slider-crank mechanism. This study compared the kinematic and leg muscle activation patterns of two isokinetic exercise modalities–cycling and elliptical stepping.

Methods: Electromyographic and kinematic signals were collected from twelve healthy able-bodied subjects who performed steady-state seated cycling and stepping exercise. Leg joint excursions of both exercise modes were analysed using 3-D motion analysis. Electromyographic analyses of 10 leg muscles were performed to analyse activation duration and volume (EMG amplitude by time).

Results: Kinematic analyses indicated that the elliptical stepping movement created significantly greater hip and knee extension compared to cycling. The ankle joint angles were significantly closer to neutral, with larger ranges of motion during elliptical stepping. EMG descriptors revealed that elliptical stepping elicited greater muscle activation than cycling (9% more volume, 54% longer duration), particularly for the vastii (94% more volume, 150% longer duration) and ankle dorsiflexor muscles (141% longer time) without affecting other muscles’ activation periods.

Conclusion: These findings support the efficacy of seated elliptical stepping exercise over cycling for lower-limb training. More potent gait rehabilitation for the neurologically-compromised population might be achieved via seated isokinetic elliptical stepping, since leg movements closer to walking can be executed in a safe environment.