Article

Aim of the present study was to identify the different modalities of activation
of rectus femoris (RF) during gait at self-selected speed, by a statistical
analysis of surface electromyographic signal from a large number (hundreds) of
strides per subject. The analysis of ten healthy adults showed that RF is
characterized by different activation modalities within different strides of the
same walk. RF most recurrent modality (observed in 53 +/- 6% of total strides)
consists of three activations, at the beginning of gait cycle, around foot-off
and in the terminal swing. Further two modalities of RF activation differ from
the most recurrent one because of the lack of activity around foot-off (26 +/-
6%) or the splitting into two (or three) small activations around stance-to-swing
transition (17 +/- 2%). Despite the large variability, our statistical analysis
allowed to identify two patterns of activation that characterize completely the
behavior of rectus femoris during gait. The first pattern, around stance-to-swing
transition, can be monophasic, biphasic or triphasic and is necessary to control
knee extension and hip flexion from pre-swing to initial swing. The second
pattern, from terminal swing to following mid-stance, is likely due to the
contribution of low-level RF activity and cross-talk from surrounding vastii.
CI - Copyright (c) 2012 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS