Man Ther. 2009 Aug 19. [Epub ahead of print]
The association between degenerative hip joint pathology and size of the gluteus medius, gluteus minimus and piriformis muscles.
Grimaldi A, Richardson C, Stanton W, Durbridge G, Donnelly W, Hides J.
Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane 4072, Australia.
study aimed to investigate changes in the deep abductor muscles,
gluteus medius (GMED), piriformis (PIRI), and gluteus minimus (GMIN),
occurring in association with differing stages of unilateral
degenerative hip joint pathology (mild: n=6, and advanced: n=6). Muscle
volume assessed via magnetic resonance imaging was compared for each
muscle between sides, and between groups (mild, advanced, control
(n=12)). GMED and PIRI muscle volume was smaller around the affected
hip in subjects with advanced pathology (p<0.01, p<0.05) while no
significant asymmetry was present in the mild and control groups. GMIN
showed a trend towards asymmetry in the advanced group (p=0.1) and the
control group (p=0.076) which appears to have been associated with leg
dominance. Between group differences revealed a significant difference
for the GMED muscle reflecting larger muscle volumes on the affected
side in subjects with mild pathology, compared to matched control hips.
This information suggests that while GMED appears to atrophy in
subjects with advanced hip joint pathology, it may be predisposed to
hypertrophy in early stages of pathology. Assessment and exercise
prescription methods should consider that the response of muscles of
the abductor synergy to joint pathology is not homogenous between
muscles or across stages of pathology.