Shinohara M, Kouzaki M, Yoshihisa T, Fukunaga T
Department of Life Sciences, The University of Tokyo, Meguro, Japan.
Eur J Appl Physiol Occup Physiol. 1997;76(4):314-9. doi: 10.1007/s004210050254.
The mechanical activity of the human quadriceps muscle during maximal incremental cycle ergometry was investigated by mechanomyography (MMG). MMG and surface electromyography (EMG) recordings of vastus lateralis muscle activity were obtained from nine males. Cycle ergometry was performed at 60 rev/ min and work load was incremented step wise by 20 W (3.2 Nm) every minute until volitional fatigue. The mean amplitudes of MMG (mMMG) and EMG (mEMG) during the contraction phase were calculated from the last six contractions in each load. The duration, load and work rate of exercise at exhaustion were 13.3 (1.6) min, 44.1 (5.5) Nm, 276.7 (34.7) W, respectively. A linear relationship between mMMG and load was evident in each subject (r = 0.868-0.995), while mEMG seemed to dissociate as the load became greater. In the grouped mean data, mMMG was linearly related to load whether aligned to the absolute (r = 0.995) or maximal (r = 0.995) load. Involvement of the noise component was further investigated by studying passive cycling by four subjects. Pedals were rotated passively for the first half of each stage (PAS) and the subject then pushed the pedals for the second half (ACT). In the lighter load region, the mMMG of ACT was as small as that of PAS. However, the change in the mMMG of PAS was very small compared with that of ACT. In conclusion, this study demonstrates a linear relationship between the mMMG of the quadriceps muscle and work load during maximal incremental cycle ergometry. The effect of movement noise was thought to be small and stable.
通过肌动图（MMG）研究了人体股四头肌在最大递增式蹬车运动中的机械活动。从9名男性身上获取了股外侧肌活动的MMG和表面肌电图（EMG）记录。以60转/分钟的速度进行蹬车运动，工作负荷每分钟逐步增加20瓦（3.2牛米），直至自愿疲劳。根据每个负荷下最后6次收缩计算收缩期MMG（mMMG）和EMG（mEMG）的平均幅度。力竭时运动的持续时间、负荷和工作速率分别为13.3（1.6）分钟、44.1（5.5）牛米、276.7（34.7）瓦。每个受试者的mMMG与负荷之间均呈现明显的线性关系（r = 0.868 - 0.995），而随着负荷增加，mEMG似乎出现解离。在分组平均数据中，无论与绝对负荷（r = 0.995）还是最大负荷（r = 0.995）对齐，mMMG与负荷均呈线性相关。通过研究4名受试者的被动蹬车情况，进一步探讨了噪声成分的影响。在每个阶段的前半段进行被动蹬车（PAS），然后受试者在后半段推动踏板（ACT）。在较轻负荷区域，ACT的mMMG与PAS的一样小。然而，与ACT相比，PAS的mMMG变化非常小。总之，本研究表明在最大递增式蹬车运动中，股四头肌的mMMG与工作负荷之间存在线性关系。运动噪声的影响被认为较小且稳定。
