title: Changes in human muscle architecture in disuse-atrophy evaluated by ultrasound imaging.
abstract: The aim of this study was to investigate if changes in muscle architecture occurred as a result of disuse-atrophy. Anatomical cross-sectional area (ACSA), muscle volume (V), fibre length (Lf) and pennation angle (theta) of the gastrocnemius medialis (GM) were evaluated by MRI and real-time ultrasound in 8 male patients with unilateral lower limb atrophy. The architectural data of the injured (I) and uninjured (UN) legs were compared. Values are means +/- S.E.M. The GM ACSA was 23.1 +/- 2.8% smaller in the I leg (P<0.001). Both theta and Lf of the I leg GM were respectively smaller by 16.42 +/- 2.9% (P<0.001) and 12.7 +/- 1.9% (P<0.001) than of the UN leg GM. The decrease of GM ACSA was highly correlated (P<0.001, R2=0.925) with the decrease in theta. It is concluded that disuse muscle atrophy leads to significant changes in muscle architecture.
authors.affiliation: Institute of Advanced Biomedical Technologies, National Research Council, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Narici
authors.forename: P
authors.initials: P
authors.lastname: Cerretelli
mesh_terms: D000328:Adult; D006801:Humans; D007869:Leg Injuries / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000473:pathology / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology* / Q000502:physiology; D009133:Muscular Atrophy / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology*; D014463:Ultrasonography