In Situ Low Load Mechanical Behavior of Skeletal Muscle: An Improved Understanding of Injury and Healing

0201783 BestUnder this Investigator Initiated Award，将进行研究，以提高对骨骼肌基本生物力学及其对拉伸损伤和愈合的机械反应的理解。 特别是，拉伸率和刺激对正常肌肉行为的影响，以及肌肉从偏心拉伸损伤中恢复的影响将得到解决。 骨骼肌是一种具有非线性粘弹性的复杂材料。 对单轴拉伸的机械响应开始于非线性应变硬化或前束行为，随后是线性响应，并且最终在失效之前材料软化。 将在兔胫骨前肌中体内检查健康和拉伸损伤骨骼肌对拉伸速率和刺激状态变化的敏感性。 PI新的现象学肌肉模型由非线性麦克斯韦流体元件与收缩元件和刺激诱导线性弹簧并联组成，已证明可解释上述机械响应，结合精心计划的统计设计，将用于解释实验载荷-位移数据。 研究结果有可能影响骨骼肌损伤的治疗计划。

0201783BestUnder this Investigator Initiated Award, studies will be performed that will improve understanding of the fundamental biomechanics of skeletal muscle and its mechanical response to stretch injury and healing. In particular, the stretch rate and stimulation effects on normal muscle behavior, and that of muscle recovering from eccentric stretch injury will be addressed. Skeletal muscle is a complex material that exhibits nonlinear viscoelastic behavior. Mechanical response to uniaxial stretch begins with nonlinear strain-stiffening, or toe-in behavior, followed by a linear response, and ultimately material softening prior to failure. Sensitivity to stretch rate and stimulation state variations, in both healthy and stretch-injured skeletal muscles, will be examined in vivo in rabbit Tibialis Anterior muscles. The PIs new phenomenological muscle model consisting of a nonlinear Maxwell fluid element combined in parallel with a contractile element and a stimulation induced linear spring, already demonstrated to explain the mechanical response outlined above, in conjunction with a carefully planned statistical design, will be used to interpret the experimental load-displacement data. Results of the studies have the potential of influencing treatment plans for skeletal muscle injuries.