Upper Limb Strength and Muscle Volume in Healthy Middle-Aged Adults
Katherine R Saul1, Meghan E Vidt, Garry E Gold
1Mechanical and Aerospace Engineering Department, North Carolina State University, Raleigh, NC.
Abstract:
Our purpose was to characterize shoulder muscle volume and isometric moment, as well as their relationship, for healthy middle- aged adults. Muscle volume and maximum isometric joint moment were assessed for 6 functional muscle groups of the shoulder, elbow, and wrist in 10 middle-aged adults (46–60 y, 5M, 5F). Compared with young adults, shoulder abductors composed a smaller percentage of total muscle volume (P = .0009) and there was a reduction in shoulder adductor strength relative to elbow flexors (P = .012). We observed a consistent ordering of moment-generating capacity among functional groups across subjects. Although total muscle volume spanned a 2.3-fold range, muscle volume was distributed among functional groups in a consistent manner across subjects. On average, 72% of the variation in joint moment could be explained by the corresponding functional group muscle volume. These data are useful for improved modeling of upper limb musculoskeletal performance in middle-aged subjects, and may improve computational predictions of function for this group.
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