Muscle viscosity as a protective mechanism for absorbing mechanical shock

描述（申请人提供）：肌肉在时间和空间上重新分配机械冲击能量并卸载骨骼关节的能力在身体活动中至关重要，例如跑步和跳跃，踢足球，摔跤，在这些活动期间发生的冲击可能超过关节之间的软骨垫可耐受的水平，所述软骨垫缓冲伴随日常活动的中等冲击，走路我们假设，耗散机械能的外部冲击，以吸收机械冲击是骨骼肌的基本功能和骨骼肌的粘度是一个可变的参数，可以通过改变收缩肌肉的张力自愿控制。我们进一步假设，肌肉吸收冲击的能力是在生物进化过程中发展起来的，允许生命从海洋移动到陆地，从水动力环境移动到空气动力环境，肌肉骨骼系统的负载条件截然不同。到目前为止，还没有可用的实用工具来评估肌肉动态粘度。我们建议开发一种紧凑和易于使用的仪器，用于评估在体骨骼肌的粘弹性，可用于探索的机制和能力的肌肉在减少外部冲击对骨和关节的有害影响。该装置将基于使用声辐射力脉冲来在组织中产生局部位移，并且将在松弛期间使用基于互相关的方法来跟踪所产生的位移。该项目的目标包括在肌肉幻影上对所开发的设备进行台架测试，并对有限的运动员进行初步试点研究，以证明所提出的技术的可行性。将在体内获得的实验数据与肌肉粘度的分子机制的数学模型的理论预测进行比较。肌肉粘度的定量评价可以为医学生物力学和运动医学的许多问题提供参考。可以通过用于定量评估肌肉粘弹性的装置评估的肌肉病症的列表包括肌肉营养不良、运动神经元疾病、炎性和代谢性肌病等等。监测肌肉粘度可以帮助预测关节疾病，如肌腱炎，滑囊炎和骨关节炎，并降低骨质疏松性骨折的概率。这种装置的潜在应用领域包括一般临床应用;康复和职业医学;运动医学：评估运动员的肌肉状况和表现;老年医学：评估衰老中的肌肉变化，特别是在骨质疏松症和骨关节炎期间肌肉骨骼系统完全减弱之后，以及评估康复功效。

DESCRIPTION (provided by applicant): The ability of muscle to redistribute the energy of mechanical shock in time and space and unload skeletal joints is of key importance in physical activities, such as running and jumping, playing soccer, wrestling, etc. The impacts that occur during such activities may exceed the level that can be tolerated by cartilage pads between joints which cushion the moderate impacts accompanying mundane activities such as walking. We hypothesize that dissipation of mechanical energy of external impacts to absorb mechanical shock is a fundamental function of skeletal muscle and the viscosity of the skeletal muscle is a variable parameter which can be voluntarily controlled by changing the tension of the contracting muscle. We further hypothesize that an ability of muscle to absorb shock had been developed in the course of biological evolution, allowing the life to move from the ocean to land, from hydrodynamic to aerodynamic environment with dramatically different loading conditions for musculoskeletal system. To date there are no available practical tools for assessment of muscle dynamic viscosity. We propose to develop a compact and easy-to-use instrument for assessment of viscoelastic properties of skeletal muscle in vivo that can be used in exploring the mechanism and the ability of muscle in reducing the harmful effect of external impacts on bones and joints. The device will be based on the use of an acoustic radiation force impulse to generate localized displacements in tissue and the resulting displacements will be tracked during relaxation using cross-correlation based methods. The goals of this project include bench-testing of the developed device on muscle phantoms and conducting preliminary pilot study on a limited group of athletes demonstrating feasibility of the proposed technology. Experimental data obtained in vivo will be compared with theoretical predictions of the mathematical model for the molecular mechanism of the muscle viscosity. Quantitative assessment of muscle viscosity may shed light to many problems of medical biomechanics and sports medicine. The list of muscle disorders that can be assessed by a device for quantitative assessment of muscle viscoelasticity includes muscle dystrophy, motor neuron diseases, inflammatory and metabolic myopathies and many more. Monitoring muscle viscosity could help in anticipating joint diseases, such as tendonitis, bursitis and osteoarthritis and decreasing the probability of osteoporotic bone fracture. The fields of potential applications of such device include general clinical applications; rehabilitation and occupational medicine; sports medicine: assessment of muscle condition and performance in athletes; gerontology: assessment of muscle changes in aging, particularly following total weakening of musculoskeletal system during osteoporosis and osteoarthritis, and estimation of the prophylactics efficacy.