The acute effect of stretching on the passive stiffness of the human gastrocnemius muscle tendon unit
The acute effect of stretching on the passive stiffness of the human gastrocnemius muscle tendon unit
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DOI：
10.1113/jphysiol.2007.140434
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发表时间：
2008-01-01
影响因子：
5.5
通讯作者：
Jones, D. A.
中科院分区：
文献类型：
--
作者：
Morse, C. I.;Degens, H.;Jones, D. A.
被动拉伸通常用于在运动表现之前增加肢体的运动范围，但尚不清楚肌肉肌腱单位 (MTU) 的哪个组成部分会受到此过程的影响。在标准拉伸过程中，通过超声检查测量了 8 名男性参与者（20.5 +/- 0.9 岁）腓肠肌内侧肌肌腱连接处 (MTJ) 的运动，其中踝关节被动背屈 1 度 s(-1)，从 0 度（脚与胫骨成直角）到参与者的意志运动末端范围 (ROM)。还测量了被动扭矩、肌束长度和羽状角。标准拉伸测量是在五次被动调节拉伸之前（前）和之后（后）进行的。在每次调节拉伸期间，MTU 被带到最终 ROM 并保持 1 分钟。在拉伸过程中预调节 MTU 的伸展几乎被肌肉和肌腱同等地占用。经过调节后，ROM 增加了 4.6 +/- 1.5 deg (17%)，MTU 的被动刚度从 16.0 +/- 3.6 减少到 10.2 +/- 2.0 Nm deg(-1)，减少了 47%（20 到 25 deg 之间）。远端 MTJ 位移（0 到 25 度之间）从 0.92 +/- 0.06 增加到 1.16 +/- 0.05 cm，解释了所有额外的 MTU 伸长，表明肌腱特性没有变化。肌肉伸展预调节可以通过束的长度和旋转角度的变化来解释，但后调节情况并非如此，这表明调节拉伸时肌肉的至少部分变化是由于结缔组织特性的改变所致。
Passive stretching is commonly used to increase limb range of movement prior to athletic performance but it is unclear which component of the muscle-tendon unit (MTU) is affected by this procedure. Movement of the myotendinous junction (MTJ) of the gastrocnemius medialis muscle was measured by ultrasonography in eight male participants (20.5 +/- 0.9 years) during a standard stretch in which the ankle was passively dorsiflexed at 1 deg s(-1) from 0 deg (the foot at right angles to the tibia) to the participants' volitional end range of motion (ROM). Passive torque, muscle fascicle length and pennation angle were also measured. Standard stretch measurements were made before (pre-) and after (post-) five passive conditioning stretches. During each conditioning stretch the MTU was taken to the end ROM and held for 1 min. Pre-conditioning the extension of the MTU during stretch was taken up almost equally by muscle and tendon. Following conditioning, ROM increased by 4.6 +/- 1.5 deg (17%) and the passive stiffness of the MTU was reduced (between 20 and 25 deg) by 47% from 16.0 +/- 3.6 to 10.2 +/- 2.0 Nm deg(-1). Distal MTJ displacement (between 0 and 25 deg) increased from 0.92 +/- 0.06 to 1.16 +/- 0.05 cm, accounting for all the additional MTU elongation and indicating that there was no change in tendon properties. Muscle extension pre-conditioning was explicable by change in length and pernnation angle of the fascicles but post-conditioning this was not the case suggesting that at least part of the change in muscle with conditioning stretches was due to altered properties of connective tissue.