Ashe M C, Liu-Ambrose T Y L, Cooper D M L, Khan K M, McKay H A
Centre for Hip Health and Mobility, Vancouver, BC, Canada.
Osteoporos Int. 2008 Dec;19(12):1725-32. doi: 10.1007/s00198-008-0655-6. Epub 2008 Jul 16.
We enrolled 65 to 75 year-old community-dwelling women and measured muscle power, strength, physical activity using accelerometry and tibial bone strength using peripheral quantitative computed tomography (pQCT). Muscle power contributed 6.6% of the variance in the bone strength-strain index and 8.9% in the section modulus after accounting for age, height, weight, and physical activity; moderate to vigorous physical activity was related to muscle power in the lower extremity.
Muscle power is associated with DXA measurements of bone mass, but it is not known whether muscle power is associated with bone strength. There are no reports of investigations that have tested the effect of muscle power on bone compartments using advanced imaging.
We enrolled 74 community-dwelling women aged 65-75 years. We measured muscle power and strength of leg extension using Keiser air-pressure resistance equipment. All participants wore a waist-mounted Actigraph accelerometer to record physical activity. We used peripheral quantitative computed tomography (pQCT) to measure tibial mid-shaft (50% of the site) bone strength (strength-strain index, section modulus). We used Pearson correlations and multi-level linear regression to investigate the associations between muscle and bone.
Muscle power contributed 6.6% (p = 0.007) of the variance in the bone strength-strain index and 8.9% (p = 0.001) the variance in the section modulus in older women after accounting for age, height, weight, and physical activity. Moderate to vigorous physical activity was significantly related to muscle power in the lower extremity (r = 0.260; p = 0.041).
Muscle power significantly contributed to the variance in estimated bone strength. Whether power training will prove to be a more effective stimulus for bone strength than conventional strength training will require further studies.
我们招募了65至75岁的社区居住女性，使用加速度计测量肌肉力量、强度和身体活动，并使用外周定量计算机断层扫描（pQCT）测量胫骨骨强度。在考虑年龄、身高、体重和身体活动后，肌肉力量对骨强度应变指数的方差贡献率为6.6%，对截面模量的方差贡献率为8.9%；中度至剧烈身体活动与下肢肌肉力量相关。
肌肉力量与双能X线吸收法（DXA）测量的骨量相关，但尚不清楚肌肉力量是否与骨强度相关。尚无使用先进成像技术测试肌肉力量对骨腔室影响的研究报告。
我们招募了74名65 - 75岁的社区居住女性。我们使用凯泽气压阻力设备测量腿部伸展的肌肉力量和强度。所有参与者佩戴腰部安装的活动记录仪加速度计来记录身体活动。我们使用外周定量计算机断层扫描（pQCT）测量胫骨中轴（该部位的50%）骨强度（强度应变指数、截面模量）。我们使用Pearson相关性和多水平线性回归来研究肌肉与骨骼之间的关联。
在考虑年龄、身高、体重和身体活动后，肌肉力量对老年女性骨强度应变指数的方差贡献率为6.6%（p = 0.007），对截面模量的方差贡献率为8.9%（p = 0.001）。中度至剧烈身体活动与下肢肌肉力量显著相关（r = 0.260；p = 0.041）。
肌肉力量对估计的骨强度方差有显著贡献。力量训练是否会被证明比传统力量训练对骨强度更有效，这需要进一步研究。
