EA 3300, Laboratoire Adaptations Réadaptations, Université de Picardie Jules Verne, Amiens, France.
J Electromyogr Kinesiol. 2011 Feb;21(1):87-94. doi: 10.1016/j.jelekin.2010.10.011. Epub 2010 Nov 16.
Clinical studies frequently report an increase in stiffness and a loss of range of motion at joints placed in disuse or immobilization. This is notably the case for subjects maintained in bed for a long period, whilst their joints are not affected. Recently we documented on healthy subjects the benefit in terms of force and activation capacities of the triceps surae offered by vibrations applied to the Achilles tendon. Knowing that stiffness changes may contribute to force changes, the aim of the present study was to investigate the effects of tendon vibration on the triceps surae stiffness of healthy subjects. The vibration program consisted in 14 days of 1h daily Achilles tendon vibration applied at rest. Nineteen healthy students were involved in this study. Before and at the end of the vibration program, musculo-tendinous stiffness in active conditions was determined by use of a quick-release test. Passive stiffness was also analyzed by a flexibility test: passive torque-angle relationships were established from maximal plantar-flexion to maximal dorsiflexion. Passive stiffness indexes at 10°, 15° and 20° dorsiflexion were defined as the slope of the relationships at the corresponding angle. Tendinous reflex, influenced by stiffness values, was also investigated as well as the H reflex to obtain an index of the central reflex excitability. After the program, musculo-tendinous stiffness was significantly decreased (p=.01). At the same time, maximal passive dorsiflexion was increased (p=.005) and passive stiffness indexes at 10°, 15° and 20° dorsiflexion decreased (p<.001; p<.001 and p=.011, respectively). Tendinous reflex also significantly decreased. As the triceps surae parameters are diminished after the vibration program, it could be beneficial to immobilized persons as hypo-activity is known to increase muscular stiffness.
临床研究经常报告在关节处于闲置或固定状态时，关节的僵硬和活动范围的丧失会增加。对于长时间卧床的受试者来说，这种情况尤为明显，尽管他们的关节没有受到影响。最近，我们在健康受试者身上记录了在跟腱施加振动对三头肌的力和激活能力的益处。由于僵硬的变化可能会导致力的变化，因此本研究的目的是研究跟腱振动对健康受试者的三头肌僵硬的影响。振动方案包括每天 1 小时，共 14 天的跟腱休息时振动。19 名健康学生参与了这项研究。在振动方案之前和结束时，通过快速释放测试在主动状态下确定肌腱的僵硬程度。通过柔韧性测试也分析了被动僵硬：从最大跖屈到最大背屈建立被动扭矩-角度关系。在 10°、15°和 20°背屈处定义了被动刚度指数，定义为相应角度处关系的斜率。还研究了受刚度值影响的肌腱反射以及 H 反射，以获得中枢反射兴奋性的指标。方案结束后，肌腱的僵硬度显著降低（p=.01）。与此同时，最大被动背屈增加（p=.005），10°、15°和 20°背屈处的被动刚度指数降低（p<.001;p<.001 和 p=.011，分别）。肌腱反射也显著降低。由于振动方案后三头肌的参数减少，这可能对处于固定状态的人有益，因为已知活动不足会增加肌肉僵硬。
