Article

This study's main objective was to determine if upper-limb (UL) muscular demand
was reduced when individuals with a spinal cord injury (SCI) performed a sitting
pivot transfer (SPT) in the preferred direction compared with that in a
nonpreferred direction. Fourteen individuals (mean +/- standard deviation age
47.0 +/- 8.3 yr, height 1.80 +/- 0.08 m, and weight 75.3 +/- 11.3 kg) with SCI
levels ranging from the sixth cervical to first sacral vertebra levels
volunteered to participate in this study during the 2008 National Disabled
Veterans Winter Sports Clinic. Surface electromyography (EMG) was used to record
activity of the biceps, triceps, deltoid, pectoralis major, trapezius, and
latissimus dorsi bilaterally during SPTs. These transfers were performed in each
of the preferred and nonpreferred directions from the individuals' wheelchairs to
a padded tub bench of even height. To quantify electromyographic muscular
utilization ratio (MUR(EMG)), we normalized EMG data recorded during the transfer
tasks to values obtained during static maximum voluntary contraction and then
multiplied this ratio by 100 to obtain a percentage MUR(EMG) (%MUR(EMG)). The
overall peak %MUR(EMG) and the area under the %MUR(EMG) curve were selected as
primary outcome measures. Similar peak %MUR(EMGs) were found between the
preferred and nonpreferred transfer directions for all muscles from which data
were recorded (p = 0.053 to 0.961). The peak %MUR(EMGs) were also found to be
similar between the leading and trailing ULs during the transfers in all muscles
from which data were recorded (p = 0.125 to 0.838), except for the anterior
deltoid, which was found to be solicited the most in the trailing UL (p = 0.008).
Comparable areas under the %MUR(EMG) curves were calculated between the preferred
and nonpreferred transfer directions for all muscles (p = 0.289 to 0.678) and
between the leading and trailing ULs (p = 0.104 to 0.946). These results indicate
that direction preference expressed by individuals with SCI when transferring
between seats of even height is not explained by relative muscular demand
differences.

Langue : ANGLAIS