Nakajima Takayuki, Izumizaki Masahiko, Sekihara Chikara, Atsumi Takashi, Homma Ikuo
Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo, 142-8555, Japan.
Exp Brain Res. 2009 Jan;192(2):211-9. doi: 10.1007/s00221-008-1571-x. Epub 2008 Sep 26.
As a result of intrafusal thixotropy, muscle contraction at a short length followed by passive lengthening enhances the subsequent tonic vibration reflex (TVR). We studied the effects of muscle vibration, contraction, and their combination on the subsequent TVR in the left biceps in 20 healthy men. The preceding vibration (20 or 80 Hz) conditioning at a short or long length was applied to the muscle belly with and without a contraction. After conditioning, distal tendon vibration (80 Hz) was used to elicit the TVR at the test length. The strength of the TVR was measured by surface electromyography. Conditioning with 80-Hz vibration at a short length followed by passive lengthening enhanced the subsequent TVR, which was greater in the presence than in the absence of a conditioning contraction. These results suggest that vibration and contraction work synergistically to develop intrafusal thixotropy.
由于肌梭内的触变性，短长度下的肌肉收缩继以被动拉长会增强随后的强直性振动反射（TVR）。我们研究了肌肉振动、收缩及其组合对20名健康男性左侧肱二头肌随后TVR的影响。在有或无收缩的情况下，对肌腹施加短或长长度的先前振动（20或80赫兹）预处理。预处理后，使用远端肌腱振动（80赫兹）在测试长度下诱发TVR。通过表面肌电图测量TVR的强度。短长度下80赫兹振动预处理继以被动拉长可增强随后的TVR，且有预处理收缩时比无预处理收缩时更大。这些结果表明，振动和收缩协同作用以产生肌梭内触变性。
