Preuss Richard A, Grenier Sylvain G, McGill Stuart M
School of Physical and Occupational Therapy, McGill University, Montreal, Canada.
Arch Phys Med Rehabil. 2005 Dec;86(12):2309-15. doi: 10.1016/j.apmr.2005.07.302.
To evaluate the neuromuscular strategy adopted during sitting balance on an unstable surface in the frontal plane.
Electromyographic evaluation of trunk muscles.
University spine biomechanics laboratory.
Seventy asymptomatic men (mean age, 34.5 y).
Not applicable.
"Balancers" and "nonbalancers" were identified by principal component analysis of their lumbar spine side flexion angle during sitting balance. Average electromyographic levels were used as a measure of muscle activation. Pearson correlations were used to identify coactivation versus asymmetrical muscle activation of opposite muscle groups.
External oblique, internal oblique, and thoracic erector spinae (TES) were most active, and most likely to be used asymmetrically, with other muscles showing low levels of coactivation. Between groups, the average electromyographic levels in the balancers was lower than in the nonbalancers (P<.05), with further differences in the symmetry of external oblique, internal oblique, and TES activation between groups.
Sitting balance in the frontal plane appears to involve a combined feedforward-feedback strategy of muscle activation. Successful balance was characterized by low levels of muscle coactivity, along with higher levels of asymmetric activation in the global trunk muscles, specifically external oblique, internal oblique, and TES.
评估在额状面不稳定表面上坐位平衡时所采用的神经肌肉策略。
躯干肌肉的肌电图评估。
大学脊柱生物力学实验室。
70名无症状男性（平均年龄34.5岁）。
不适用。
通过坐位平衡期间腰椎侧屈角度的主成分分析确定“平衡者”和“非平衡者”。平均肌电图水平用作肌肉激活的指标。使用Pearson相关性来确定相反肌肉群的共同激活与不对称肌肉激活。
腹外斜肌、腹内斜肌和胸段竖脊肌最活跃，且最有可能不对称使用，其他肌肉的共同激活水平较低。在两组之间，平衡者的平均肌电图水平低于非平衡者（P<0.05），两组之间腹外斜肌、腹内斜肌和胸段竖脊肌激活的对称性存在进一步差异。
额状面的坐位平衡似乎涉及肌肉激活的前馈 - 反馈联合策略。成功的平衡表现为肌肉共同激活水平低，以及整体躯干肌肉，特别是腹外斜肌、腹内斜肌和胸段竖脊肌的不对称激活水平较高。
