Article

Gluteus minimus is believed to consist of two structurally and functionally
unique segments (anterior and posterior); however there is a lack of
electromyography (EMG) research that attempts to verify current theoretical
knowledge of this muscle. The purpose of this study was therefore to evaluate the
function of gluteus minimus during gait, and to determine whether anterior and
posterior segments are functionally independent. Bipolar fine wire intramuscular
EMG electrodes were inserted into anterior and posterior gluteus minimus segments
of fifteen healthy volunteers (9 males) according to previously verified
guidelines. Participants completed a series of four walking trials, followed by
maximum voluntary isometric contractions in five different positions. Temporal
and amplitude variables for each segment were compared across the gait cycle with
independent t-tests. The relative contribution of each segment to the maximum
resisted trials was compared with Mann-Whitney U tests (alpha = 0.05). Anterior
and posterior segments were contracting at different relative intensities for
three of the five maximum resisted trials (effect size = 0.39 to 0.62, P <
0.037). The posterior segment was larger in EMG amplitude (peak and average)
during the first 20% of the gait cycle (effect size = 0.96 to 1.03, P < 0.02),
while the anterior segment peaked later in the stance phase (effect size = 0.83,
P = 0.034). Gluteus minimus is therefore composed of functionally independent
segments. These results build on contemporary theoretical knowledge and may
signify hip stabilising roles for each segment across different phases of the
gait cycle.
CI - Crown Copyright (c) 2013. Published by Elsevier B.V. All rights reserved.

Langue : ANGLAIS