Martin A, Morlon B, Pousson M, Van Hoecke J
Groupe Analyse du Mouvement, Université de Bourgogne, Dijon, France.
Eur J Appl Physiol Occup Physiol. 1996;73(1-2):157-62. doi: 10.1007/BF00262825.
The aim of the present study was to estimate the damping coefficient (B factor) of the elbow flexor muscles during both eccentric and concentric muscle actions. We used a muscle model consisting of a viscous damper associated in parallel with a contractile component, both in series with an elastic component. The viscous damper allowed the concentric loss and the eccentric gain of force to be modelled. Eight volunteer subjects performed maximal eccentric and concentric elbow movements on an isokinetic dynamometer at angular velocities of 0.52, 1.04 and 2.09 rad*s(-1). Torques at an elbow joint angle of 90 degrees were recorded. Electromyogram (EMG) signals from the belly of the right elbow flexor and from the long head of the triceps brachia muscles were recorded using two pairs of bipolar surface electrodes. The root mean square (rms) of the EMG was determined. Eccentric and concentric rms were not significantly different (P >0.05). The B factor was higher in the concentric than in the eccentric conditions (P <0.05), and, whatever the muscle action type it decreased as the velocity increased. These results indicated that the concentric loss and the eccentric gain of force were attributable to the behaviour of the contractile machinery. Furthermore, whatever the exact cause of loss and gain of tension, our study showed that the total effect can be modelled by the viscous damper of a three-component muscle model.
本研究的目的是评估在离心和向心肌肉动作过程中肘屈肌的阻尼系数（B因子）。我们使用了一个肌肉模型，该模型由一个与收缩成分并联的粘性阻尼器组成，二者均与一个弹性成分串联。粘性阻尼器可以对向心力量损失和离心力量增加进行建模。八名志愿者在等速测力计上以0.52、1.04和2.09弧度·秒⁻¹的角速度进行最大离心和向心肘部运动。记录肘关节角度为90度时的扭矩。使用两对双极表面电极记录右肘屈肌肌腹和肱三头肌长头的肌电图（EMG）信号。测定EMG的均方根（rms）。离心和向心rms无显著差异（P>0.05）。向心条件下的B因子高于离心条件（P<0.05），并且无论肌肉动作类型如何，B因子均随速度增加而降低。这些结果表明，向心力量损失和离心力量增加归因于收缩机制的行为。此外，无论张力损失和增加的确切原因是什么，我们的研究表明，总效应可以用三分量肌肉模型的粘性阻尼器来建模。
