Lower limb force production and bilateral force asymmetries are based on sense of effort.
Lower limb force production and bilateral force asymmetries are based on sense of effort.
复制标题
下肢力量的产生和双侧力量的不对称是基于努力感。
DOI：
10.1007/s00221-008-1288-x
复制
发表时间：
2008
影响因子：
2
通讯作者：
Ferris,DanielP
中科院分区：
文献类型：
--
作者：
Simon,AnnM;Ferris,DanielP
先前的研究表明，人们使用努力感而不是本体感觉反馈来衡量上肢的力量产生。我们采用等距力匹配任务来确定双侧力产生过程中下肢之间的力不对称是否是由与努力感相关的神经机制引起的。我们假设尝试产生相等下肢力的受试者将产生相等百分比的双侧最大自愿力量，而不是相等的绝对肢体力。十名受试者在健身机上进行等长下肢伸展。受试者尝试将下肢的力量匹配到三个不同的次最大水平（双侧最大自主收缩期间较弱肢体峰值力量的 20%、40% 和 60%）。受试者仅收到目标和更强的肢体力量的视觉反馈。结果表明，当标准化至单侧最大自主收缩力时，受试者在所有力匹配水平下其较弱肢体始终产生较小的力（方差分析 20%P= 0.0473、40%P= 0.0012、60%P= 0.0007）。正如我们的假设所预测的那样，通过双侧最大自主收缩力对力大小进行标准化显示，在所有力水平下，肢体之间没有显着差异（方差分析= 0.8490）。无论人类产生最大还是次最大力，肢体力不对称似乎与神经因素有关，而不是与肢体之间机械能力的差异有关。我们的研究结果对健康和神经受损人群运动过程中的双边不对称具有影响。
Previous research suggests that individuals use a sense of effort, more than proprioceptive feedback, to gauge force production in their upper limbs. We have adopted an isometric force matching task to determine if force asymmetry between lower limbs during bilateral force production results from a neural mechanism related to sense of effort. We hypothesized that subjects attempting to produce equal lower limb forces would generate equal percentages of their bilateral maximum voluntary strength rather than equal absolute limb forces. Ten subjects performed isometric lower limb extensions on an exercise machine. Subjects attempted to match forces in their lower limbs at three different submaximal levels (20, 40, and 60% of their weaker limb peak force during bilateral maximum voluntary contraction). Subjects received visual feedback of only the target and stronger limb force. Results showed that subjects consistently produced less force in their weaker limb during all force matching levels when normalized to their unilateral maximum voluntary contraction force (ANOVAs 20%P= 0.0473, 40%P= 0.0012, 60%P= 0.0007). As predicted by our hypothesis, normalizing force magnitudes by bilateral maximum voluntary contraction forces revealed no significant differences between limbs at all force levels (ANOVAP= 0.8490). Regardless of whether humans produce maximal or submaximal forces, limb force asymmetry appears to be related to neural factors rather than differences in mechanical capabilities between the limbs. Our findings have implications for bilateral asymmetries during movement in healthy and neurologically impaired populations.