Kinesiology Laboratory, Institute of Orthopedics and Traumatology, LEM, IOT, University of São Paulo School of Medicine (FMUSP), São Paulo, Brazil.
Osteoporos Int. 2013 Jul;24(7):2007-13. doi: 10.1007/s00198-013-2285-x. Epub 2013 Feb 2.
The task of standing up from a chair forms a part of daily life for all independent individuals. However, this task becomes more difficult with advancing age. Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.
This study aims to evaluate postural balance during the transition from sitting to standing and its relationship with knee extensor and flexor strength among women with and without postmenopausal osteoporosis.
Assessments were made on 126 women (aged 55-65 years), divided into osteoporosis and control groups according to lumbar bone density. Their balance during the task of standing up from a chair was evaluated using the Balance Master® device. Knee muscle strength was evaluated using an isokinetic dynamometer (Biodex®), in concentric/concentric mode, at a velocity of 60°/s. Spearman's correlation between the variables of muscle strength and postural balance was evaluated. Subsequently, to evaluate the association of each balance variable with the group and with muscle strength, multiple linear regression models were fitted. The significance level was set at 0.05.
There was a difference in knee muscle strength between the groups (P < 0.05). However, independent of the muscle strength values, there were no differences in relation to weight transfer times (P = 0.556) or center of gravity sway velocity (P = 0.952). Transfer time diminished with increasing extensor strength (P = 0.025). The center of gravity sway velocity tended to increase with increasing extensor strength (P = 0.013) and was the same in the two groups (P = 0.264).
Women with postmenopausal osteoporosis presented diminished knee extensor and flexor muscle strength. There was a weak correlation between knee muscle strength (greater with extensor strength) and postural balance during the act of standing up.
本研究旨在评估绝经后骨质疏松症女性与非骨质疏松症女性在从坐姿站起过程中的平衡能力，并分析其与膝关节伸肌和屈肌力量的关系。
对 126 名 55-65 岁女性进行评估，根据腰椎骨密度将其分为骨质疏松症组和对照组。使用平衡大师®设备评估其从椅子上站起来时的平衡能力。使用等速测力仪（Biodex®）以 60°/s 的速度进行同心/同心模式下的膝关节肌肉力量评估。采用 Spearman 相关分析评估肌肉力量和姿势平衡之间的相关性。随后，为了评估每个平衡变量与组和肌肉力量的相关性，拟合了多元线性回归模型。显著性水平设定为 0.05。
两组间膝关节肌肉力量存在差异（P < 0.05）。然而，无论肌肉力量值如何，在体重转移时间（P = 0.556）或重心摆动速度（P = 0.952）方面均无差异。随着伸肌力量的增加，转移时间减少（P = 0.025）。随着伸肌力量的增加，重心摆动速度趋于增加（P = 0.013），且两组间相同（P = 0.264）。
绝经后骨质疏松症女性膝关节伸肌和屈肌力量减弱。在从坐姿站起过程中，膝关节肌肉力量（伸肌力量越大）与平衡能力呈弱相关。
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