Article

The aim of this study was to examine the associations of computed
tomography-based x-ray attenuation and paraspinal electrical impedance myography
measures of trunk muscles with absolute and relative (normalized by body weight)
trunk extension strength, independent of muscle cross-sectional area. DESIGN:
This is a cross-sectional study of mobility-limited community-dwelling older
adults (34 women, 15 men; mean [SD] age, 78.2 [7.2] yrs) recruited from within an
existing prospective research cohort. Trunk extension strength, computed
tomography-based trunk muscle cross-sectional area and attenuation at L4 level,
and paraspinal electrical impedance myography measures were collected. RESULTS:
Attenuation was positively correlated with absolute and relative strength for
multiple muscle groups (r = 0.32-0.61, P < 0.05). Paraspinal electrical impedance
myography phase was positively correlated with paraspinal attenuation (r = 0.30,
P = 0.039) and with relative strength (r = 0.30, P = 0.042). In multivariable
linear regressions adjusting for sex and cross-sectional area, attenuations of
the anterior abdominal muscles (semipartial r = 0.11, P = 0.013) and combined
muscles (semipartial r = 0.07, P = 0.046) were associated with relative strength.
CONCLUSIONS: Although attenuation was associated with relative strength, small
effect sizes indicate limited usefulness as clinical measures of muscle strength
independent of muscle size. However, there remains a need for additional studies
in larger and more diverse groups of subjects.

Langue : ANGLAIS