Neuromuscular Research Laboratory, Department of Exercise and Sports Science, University of North Carolina-Chapel Hill, 209 Fetzer Hall, CB# 8700, Chapel Hill, North Carolina, 27599, USA.
Muscle Nerve. 2013 Oct;48(4):571-7. doi: 10.1002/mus.23791. Epub 2013 Jul 30.
We examined the influence of maximum range of motion (MROM) and passive stiffness on the viscoelastic stretch response.
Four 30-s constant-angle passive stretches of the plantar flexors at a predetermined torque were performed to determine the rate and relative change in stress relaxation (decline in torque during each 30-s stretch) and creep (increase in ankle joint angle across all 4 stretches). Stress relaxation and creep responses were examined between participants after they were ranked into high and low groups based on MROM and passive stiffness values.
Stress relaxation responses were unaffected by MROM and passive stiffness; however, creep was influenced by differences in passive stiffness but not MROM.
Passive stiffness but not MROM influences the acute viscoelastic response to passive stretching. Participants with less stiff plantar flexors experience greater increases in range of motion when they are stretched at a constant torque.
我们研究了最大活动范围（MROM）和被动刚度对粘弹性拉伸反应的影响。
对足底屈肌进行 4 次预定扭矩的 30 秒恒角被动拉伸，以确定速率和相对的应变速率松弛（在每次 30 秒拉伸过程中扭矩的下降）和蠕变（所有 4 次拉伸过程中踝关节角度的增加）。根据 MROM 和被动刚度值，将参与者分为高组和低组后，研究了他们的应变速率松弛和蠕变反应。
应变速率松弛反应不受 MROM 和被动刚度的影响；然而，蠕变受到被动刚度的差异影响，但不受 MROM 的影响。
被动刚度而不是 MROM 影响被动拉伸的急性粘弹性反应。在恒定扭矩下拉伸时，被动伸展器较不僵硬的参与者的运动范围增加更大。
