Article

OBJECTIVE: To examine the effects of walking at different inclines and speeds on
Peroneus Longus (PL) muscle activation and medial gastrocnemius (MG) coactivation
with PL in healthy controls and subjects with stroke.
DESIGN: Nineteen persons
post-stroke (13M/6F) and fifteen healthy controls (10M/5F) walked on a treadmill
at different inclines (0 degrees , 3 degrees , and 6 degrees )
and speeds
(self-selected, self-selected+20%, self-selected+40%).
The electromyographic
activity of the PL and MG muscles in the stance phase of gait cycle was measured.
RESULTS: The paretic PL muscle activity did not change with incline, but
increased at +40% speed only
(p<0.05). The nonparetic PL increased at 6 degrees
incline and at faster speeds (p<0.05). In the healthy group, PL muscle activity
increased only on the right side at 6 degrees incline, but increased bilaterally
at +40% faster speed (p<0.05). The timing of PL muscle activity did not change
with incline (p>0.05), but was significantly delayed at +40% faster speed on the
paretic side only (p<0.05). In healthy controls, PL muscle activation timing was
unchanged with incline (p>0.05), but was significantly delayed at +40% speed only
on the left side (p<0.05).
The MG/PL amplitude and timing ratios were not
significantly different between various walking conditions (p>0.05). CONCLUSION:
An increase in PL activity occurs to provide ankle stability at walking speeds up
to 40% faster than the self-selected speed. Important interlimb differences which
may be related to leg dominance and motor control were observed in both stroke
and healthy control groups in both PL muscle timing and their clinical impact
should be investigated in future studies.
CI - Copyright (c) 2017 Elsevier B.V. All rights reserved.

Langue : ANGLAIS