Oksa J, Rintamäki H, Mäkinen T, Hassi J, Rusko H
Oulu Regional Institute of Occupational Health, Finland.
Aviat Space Environ Med. 1995 Jan;66(1):26-31.
The effect of whole body cooling on the muscular performance and electromyographic (EMG) activity of agonist and antagonist muscles during dynamic exercise was studied. Eleven slightly clothed male subjects were exposed to ambient temperatures of 27 degrees C and 10 degrees C for 60 min. After the exposures the subjects performed an overhead ball throwing test. Five balls, weighing from 0.3 kg to 3.0 kg were thrown and the velocity of the balls was measured. The EMG activity of two agonist-antagonist muscle pairs (m. triceps brachii--m. deltoideus and m. rectus abdominis--m. erector spinae) were measured during throwing. Cooling decreased mean skin temperature by 6.3 +/- 0.5 degree C (mean +/- SE). The temperature of m. triceps brachii decreased by 4.0 +/- 1.6 degrees C and 1.8 +/- 0.6 degrees C from the depth of 20 and 30 mm underneath the skin surface, respectively. The corresponding values of m. deltoideus were 5.1 +/- 0.4 degrees C and 3.2 +/- 0.8 degrees C. The cooling-induced decrement in ball velocity varied from 9.4 +/- 3.3% (0.3-kg ball) to 5.6 +/- 2.8% (3.0-kg ball) (p < 0.001-0.01). After cooling, the time to reach the maximal level of integrated electromyographic (IEMG) activity in m. triceps brachii (agonist) was increased (30-42%, p < 0.05-0.001). Moreover, cooling decreased the mean IEMG activity m. triceps brachii, while the activity of m. deltoideus (antagonist) was increased. The alteration was significant (p < 0.05-0.001) with the three lightest balls.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了全身冷却对动态运动过程中主动肌和拮抗肌的肌肉性能及肌电图（EMG）活动的影响。11名穿着轻便的男性受试者分别在27摄氏度和10摄氏度的环境温度下暴露60分钟。暴露后，受试者进行头顶投球测试。投掷5个重量从0.3千克到3.0千克的球，并测量球的速度。在投球过程中测量两组主动肌-拮抗肌对（肱三头肌-三角肌和腹直肌-竖脊肌）的EMG活动。冷却使平均皮肤温度降低了6.3±0.5摄氏度（平均值±标准误）。肱三头肌温度分别从皮肤表面下20毫米和30毫米深处降低了4.0±1.6摄氏度和1.8±0.6摄氏度。三角肌的相应值分别为5.1±0.4摄氏度和3.2±0.8摄氏度。冷却引起的球速下降幅度从9.4±3.3%（0.3千克的球）到5.6±2.8%（3.0千克的球）不等（p<0.001-0.01）。冷却后，肱三头肌（主动肌）达到肌电图积分（IEMG）活动最大水平的时间增加（30-42%，p<0.05-0.001）。此外，冷却降低了肱三头肌的平均IEMG活动，而三角肌（拮抗肌）的活动增加。对于三个最轻的球，这种变化具有显著性（p<0.05-0.001）。（摘要截短于250字）
