著者
脇田 裕久 水谷 四郎 矢部 京之助
出版者
一般社団法人 日本体育・スポーツ・健康学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
vol.32, no.1, pp.49-56, 1987-06-01 (Released:2017-09-27)

It has been observed that the premotion silent period appears just before a rapid voluntary movement. This phenomenon is believed to be caused by one of the inhibitory discharge from the central nervous system. On the other hand, the silent period is also observed when muscles are relaxed by counter movement. The present study was designed to compare some physical performances of both silent periods. Twenty healthy males aged 18-24 years were subjected to a series of experiment. They were asked to maintain the posture of standing with flexed knee joint at about 50 degrees on the force plate. In the first condition, they were requested to extend their knee joint responding to a flashing lamp as quickly as possible (Non-counter movement). In the second condition, they were asked to extend knee joint as quickly as possible with counter movement to a flashing lamp. The EMG activities of M. rectus femoris, M. vastus lateralis, M. vastus medialis and M. biceps femoris were recorded using bipolar surface electrodes. Force curve from a force plate and electrogoniogram were recorded simultaneously. The following results were obtained from this experiment. 1) The rate of appearance in complete silent period was higher on the counter movement (M. rectus femoris: 37.8%, M. vastus lateralis: 81.6%, M. vastus medialis: 59.7%) than on the non-counter movement (28.2%, 57.6%,46.5%, respectively). 2) The latency of silent period was significantly later on the counter movement (M. vastus lateralis:132.8 msec, M. vastus medialis: 135.5 msec) than on the non-counter movement (119.4 msec, 116.4 msec,respectively). 3) The duration of silent period was significantly longer on the counter movement (M. vastus lateralis: 100.0 msec, M. vastus medialis: 96.6 msec) than on the non-counter movement (40.9 msec, 41.9 msec, respectively). 4) No significant difference in the rate of tension rise was found between the counter movement (3.7kg/msec) and the non-counter movement (2.7 kg/msec). 5) The peak value of the force curve was significantly greater on the counter movement (173.0 kg)than on the non-counter movement (141.2 kg). It is suggested from these results that the silent period of the counter movement delayed the reaction time (latency and duration) and increased the muscular strength in comparison with the premotion silent period.
著者
脇田 裕久 八木 規夫 水谷 四郎 小林 寛道
出版者
三重大学
雑誌
三重大学教育学部研究紀要. 自然科学 (ISSN:03899225)
巻号頁・発行日
vol.36, pp.141-148, 1985

The stretching effect on the repeated exertion of maximum hand grip strength were investigated when the wrist joint stretching was added in different muscle groups and/or different frequencies. The subjects were six healthy males aged 18-22 years. They were asked to exert their maximum hand grip strength for 6 seconds, 20 times with 1 minute intervals between each bout. Subjects performed 6 series of experiments in different interval conditions such as, Condition-A : hold resting during each enterval, B : add stretching of dorsi-flexion (7 sec×4 times), C : add stretching of palmar flexion (7 sec×4 times), D : add stretching both palmar and dorsi-flexions, alternately (7 sec×2 times each), E : hold resting until 10th trial, and then add stretching to 20th trial in the same way as in Condition-D during each interval, F : add stretching once every 5 intervals in the same way as in Condition-D. Following results were obtained. 1) No significant differences in average impulses (kg・sec) of 20 times in maximum hand grip strength were found among different conditions. 2) The greater impulses in 11-20th trials were observed in Condition-C and -D in comparison with Condition-A (p<0.05). 3) The impulses in Condition-D were greater than Condition-B in 16-20th trials (p>0.05). 4) The greater impulses were observed in 11-20th trials for Condition-D and -F in comparison with Condition-A (p<0.05). 5) The impulses in 11-15th trials were greater in Condition-F than Condition-E (p<0.05). Therefore, stretching of palmar flexion or, both palmar and dorsi-flexions are effective to prevent the decrease of hand grip strength. Stretching of every 5 trials of 20 maximum bouts is equally effective with that of every one trial.健康な男子大学生6名(18-22歳)を被検者とし、1分間の休息期をはさみながら最大努力で6秒間の握力発揮を20試行繰り返させ、手関節へのストレッチングが握力発揮にどう影響するかを、方法、時期、頻度を違えて実施した。各試行間の休息期には、毎回安静休息を保つ条件(A)、と静的ストレッチングを加える条件(B~F)があり、後者には毎回手関節の背屈方向のみ(B)、掌屈方向のみ(C)、背屈・掌屈双方(D)、第10試行まで安静休息、その後毎回背屈・掌屈双方(E)、第5、10、15試行後にのみ背屈・掌屈双方(F)の5条件とし、合計6条件を指示した。本実験結果は、次のようである。 1)各条件下における全試行の平均力積は、いずれの条件間にも有意な差が認められなかった。 2)第11-20試行では、条件C、Dが条件Aより有意に大きな力積を示した(P<0.05)。第16-20試行では、条件Dが条件Bに比較して有意に大きな力積を示した(P<0.05)。 3)第11-20試行では、条件D、Fが条件Aより有意に大きな力積を示した(P<0.05)。第11-15試行では、条件Fが条件Eに比較して有意に大きな力積を示した(P<0.05)。 以上の結果から、休息期に毎回掌屈または背屈・掌屈双方の静的ストレッチを加えることは、安静休息を保つ場合に比較して、握力低下の抑制に効果的であり、また、その効果については、5試行ごとに加えられた静的ストレッチングと毎回のそれとの間に差のないことが明らかとされた。