Motobe Mayuko, Murase Norio, Osada Takuya, Homma Toshiyuki, Ueda Chihoko, Nagasawa Takeshi, Kitahara Aya, Ichimura Shiro, Kurosawa Yuko, Katsumura Toshihito, Hoshika Akinori, Hamaoka Takafumi
Department of Preventive Medicine and Public Health, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, Japan 160-8402.
Dyn Med. 2004 Feb 6;3(1):2. doi: 10.1186/1476-5918-3-2.
In this research inactivity was simulated by immobilizing the forearm region in a plaster cast. Changes in skeletal muscle oxidative function were measured using near-infrared spectroscopy (NIRS), and the preventative effect of the training protocol on deterioration of skeletal muscle and the clinical utility of NIRS were examined. METHODS: Fourteen healthy adult men underwent immobilization of the forearm of the non-dominant arm by plaster cast for 21 days. Eight healthy adult subjects were designated as the immobilization group (IMM) and six were designated as the immobilization + training group (IMM+TRN). Grip strength, forearm circumference and dynamic handgrip exercise endurance were measured before and after the 21-day immobilization period. Using NIRS, changes in oxidative function of skeletal muscles were also evaluated. Muscle oxygen consumption recovery was recorded after the completion of 60 seconds of 40% maximum voluntary contraction (MVC) dynamic handgrip exercise 1 repetition per 4 seconds and the recovery time constant (TcVO2mus) was calculated. RESULTS: TcVO2mus for the IMM was 59.7 +/- 5.5 seconds (average +/- standard error) before immobilization and lengthened significantly to 70.4 +/- 5.4 seconds after immobilization (p < 0.05). For the IMM+TRN, TcVO2mus was 78.3 +/- 6.2 seconds before immobilization and training and shortened significantly to 63.1 +/- 5.6 seconds after immobilization and training (p < 0.05). CONCLUSIONS: The training program used in this experiment was effective in preventing declines in muscle oxidative function and endurance due to immobilization. The experimental results suggest that non-invasive monitoring of skeletal muscle function by NIRS would be possible in a clinical setting.
在本研究中，通过将前臂区域固定在石膏托中来模拟不活动状态。使用近红外光谱（NIRS）测量骨骼肌氧化功能的变化，并研究训练方案对骨骼肌退化的预防作用以及NIRS的临床效用。方法：14名健康成年男性非优势臂的前臂用石膏固定21天。8名健康成年受试者被指定为固定组（IMM），6名被指定为固定+训练组（IMM+TRN）。在21天固定期前后测量握力、前臂周长和动态握力运动耐力。使用NIRS还评估了骨骼肌氧化功能的变化。在以40%最大自主收缩（MVC）进行每秒1次重复的60秒动态握力运动完成后，记录肌肉氧消耗恢复情况，并计算恢复时间常数（TcVO2mus）。结果：IMM组在固定前TcVO2mus为59.7±5.5秒（平均值±标准误差），固定后显著延长至70.4±5.4秒（p<0.05）。对于IMM+TRN组，在固定和训练前TcVO2mus为78.3±6.2秒，在固定和训练后显著缩短至63.1±5.6秒（p<0.05）。结论：本实验中使用的训练方案可有效预防因固定导致的肌肉氧化功能和耐力下降。实验结果表明，在临床环境中通过NIRS对骨骼肌功能进行无创监测是可行的。
