Article

Force-sensing split-belt treadmills (TMs) provide an alternative to
the conventional overground (OG) setting and allow new avenues for analyzing the
biomechanics and motor control of walking. However, walking control may differ on
a TM compared with walking OG. OBJECTIVE: To compare spatiotemporal, kinematic,
and EMG-based measures of motor control between TM and OG walking at
self-selected and fastest comfortable speeds in persons with poststroke
hemiparesis. METHODS: Individuals with chronic hemiparesis (56) and similarly
aged healthy individuals (17) walked over an instrumented walkway and on an
instrumented split-belt TM; 16 channels of EMG recorded bilateral muscle
activity, and a 12-camera motion capture system collected bilateral 3D
kinematics. The authors applied a nonnegative matrix factorization (NNMF)
algorithm to examine the underlying patterns of motor control. RESULTS:
Self-selected walking patterns differed on the TM versus OG in controls: speed
decreased, stride length decreased, stance percentage increased, and
double-support percentage increased. Poststroke, responses were similar, but
cadence also decreased, and step length asymmetry increased. Kinematic patterns
were similar except those associated with slower walking speeds. NNMF
demonstrated similar EMG variance in the 2 environments. CONCLUSION: Persons,
both healthy and poststroke, walk with different gait parameters on the TM.
Although measures of motor control were mostly similar between the 2
environments, the TM induced step length asymmetry in 30% of participants (60% of
whom took longer paretic steps). TM walking, therefore, is a valid method for
detecting motor control deficits.

Langue : ANGLAIS