The aims of this study were to determine whether the application of vibration on a postural lower limb muscle altered the sensorimotor control of its joint as measured by isometric force production parameters and to compare present findings with previous work conducted on trunk muscle.Methods:
Twenty healthy adults were asked to reproduce submaximal isometric plantar flexion under 3 different conditions: no vibration and vibration frequencies of 30 and 80 Hz on the soleus muscle. Time to peak torque, variable error, as well as constant error and absolute error in peak torque were calculated and compared across conditions.Results:
Under vibration, participants were significantly less accurate in the force reproduction task, as they mainly undershot the target torque. Applying an 80-Hz vibration resulted in a significantly higher negative constant error than lower-frequency vibration (30 Hz) or no-vibration condition. Decreases in isometric force production accuracy under vibration influence were also observed in a previous study conducted on trunk muscle. However, no difference in constant error was found between 30- and 80-Hz vibration conditions.Conclusion:
The results suggest that acute soleus muscle vibration interferes with plantar flexion torque generation by distorting proprioceptive information, leading to decreases in accuracy of a force reproduction task. Similar results in an isometric trunk extension force reproduction task were found with vibration applied on erector spinae muscle. However, high-frequency vibration applied on soleus muscle elicited higher force reproduction errors than low-frequency stimulation.