Table 2.
Associations of Postural Sway With Muscle Size and Density in Men and Women
| Men | Women | |
|---|---|---|
| RMS of AP motion | ||
| All muscles | ||
| CSA | 0.78 (0.16, 1.39) | 0.24 (−0.03, 0.52) |
| Density | −0.70(−1.19, −0.22) | −0.11 (−0.40, 0.19) |
| Paraspinal | ||
| CSA | 0.67 (0.10, 1.23) | 0.03 (−0.24, 0.30) |
| Density | −0.79 (−1.26, −0.31) | −0.23 (−0.51, 0.04) |
| Posterior abdominal | ||
| CSA | 0.49 (0.06, 0.91) | 0.06 (−0.19, 0.32) |
| Density | −0.91 (−1.36, −0.45) | −0.14 (−0.42, 0.14) |
| Anterior abdominal | ||
| CSA | 0.56 (−0.04, 1.16) | 0.39 (0.14, 0.64) |
| Density | −0.39 (−0.91, 0.12) | 0.05 (−0.22, 0.32) |
| RMS of AP velocity | ||
| All muscles | ||
| CSA | −1.63 (−5.76, 2.51) | 2.84 (1.10, 4.58) |
| Density | −4.62 (−7.89, −1.35) | −2.49 (−4.21, −0.63) |
| Paraspinal | ||
| CSA | −1.36 (−5.27, 2.55) | 1.52 (−0.24, 3.27) |
| Density | −4.23 (−7.49, −0.97) | −2.20 (−3.99, −0.41) |
| Posterior abdominal | ||
| CSA | 0.52 (−2.23, 3.27) | 2.24 (0.59, 3.89) |
| Density | −6.76 (−9.72, −3.81) | −2.22 (−4.04, −0.40) |
| Anterior abdominal | ||
| CSA | −0.26 (−4.41, 3.88) | 2.69 (1.01, 4.36) |
| Density | −2.89 (−6.41, 0.64) | −1.57 (−3.33, 0.19) |
| RMS of ML motion | ||
| All muscles | ||
| CSA | 0.25 (−0.41, 0.90) | 0.04 (−0.23, 0.30) |
| Density | −0.38 (−0.90, 0.14) | −0.19 (−0.47, 0.09) |
| Paraspinal | ||
| CSA | 0.15 (−0.44, 0.75) | −0.13 (−0.39, 0.12) |
| Density | −0.42 (−0.92, 0.02) | −0.36 (−0.63, −0.10) |
| Posterior abdominal | ||
| CSA | 0.35 (−0.11, 0.80) | 0.06 (−0.18, 0.31) |
| Density | −0.47 (−0.96, 0.02) | −0.30 (−0.57, −0.02) |
| Anterior abdominal | ||
| CSA | 0.15 (−0.47, 0.77) | 0.21 (−0.04, 0.46) |
| Density | −0.16 (−0.68, 0.37) | −0.01 (−0.27, 0.26) |
| RMS of ML velocity | ||
| All muscles | ||
| CSA | 0.26 (−1.33, 1.85) | 0.67 (0.12, 1.21) |
| Density | −2.14 (−3.40, −0.50) | −0.56 (−1.15, 0.02) |
| Paraspinal | ||
| CSA | −0.17 (−1.65, 1.30) | 0.09 (−0.45, 0.63) |
| Density | −2.00 (−3.23, −0.77) | −0.80 (−1.35, −0.25) |
| Posterior abdominal | ||
| CSA | 0.61 (−0.47, 1.68) | 0.48 (−0.03, 1.00) |
| Density | −2.60 (−3.76, −1.44) | −0.68 (−1.24, −0.11) |
| Anterior abdominal | ||
| CSA | 0.73 (−0.88, 2.33) | 0.92 (0.41, 1.43) |
| Density | −1.35 (−2.71, 0.01) | −0.15 (−0.69, 0.39) |
| SPPB | ||
| All muscles | ||
| CSA | 0.47 (−0.54, 1.48) | 0.14 (−0.33, 0.62) |
| Density | 0.34 (−0.45, 1.14) | 0.75 (0.24, 1.26) |
| Paraspinal | ||
| CSA | 0.31 (−0.60, 1.22) | 0.22 (−0.25, 0.68) |
| Density | 0.48 (−0.27, 1.22) | 0.50 (0.01, 0.98) |
| Posterior abdominal | ||
| CSA | 0.08 (−0.64, 0.80) | −0.22 (−0.65, 0.21) |
| Density | 0.67 (−0.09, 1.44) | 1.03 (0.56, 1.50) |
| Anterior abdominal | ||
| CSA | 0.10 (−0.86, 1.07) | −0.08 (−0.53, 0.37) |
| Density | 0.15 (−0.66, 0.97) | 0.72 (0.24, 1.19) |
Notes: Beta coefficients per SD increase in muscle measure (95% confidence interval) for fully adjusted models. Fully adjusted models include age, weight, Physical Activity Scale for the Elderly, and baseline falls history as covariates. Associations in bold are significant (p < .05). AP = anteroposterior; CSA = cross-sectional area; ML = mediolateral; RMS = root mean square; SPPB = Short Physical Performance Battery.