Article

This study investigated if asymmetry exists in the responses of trunk muscles to
a perturbation of the trunk induced by loading of an outstretched arm. Nineteen
healthy right-handed subjects were recruited into the study. Electromyographic
recordings were made from trunk muscles (erector spinae and rectus abdominus) and
upper limb muscles (deltoid).
A weight was dropped into a receptacle held out
laterally by the subjects. The perturbation induced a rise in EMG activity in the
deltoid at a latency which was not different between the dominant and
non-dominant arms. It also induced a rise in EMG activity in the contralateral
trunk muscles. Although not significantly different, there was a trend for the
responses from the right trunk to be longer than those from the left trunk.
Furthermore, there were higher levels of EMG activity in the trunk muscles
opposite the dominant arm than those in the trunk muscles opposite the
non-dominant arm. This study reveals a pattern of trunk muscle activation
following movement in the arm induced by loading of an outstretched hand that is
different on the side of the back opposite the dominant arm than on the side of
the back opposite the non-dominant arm. These results may have implications in
terms of mechanisms contributing to low back pain and further work is warranted
to examine these responses in left-handed individuals.

Langue : ANGLAIS