The Effects Of Transcutaneous Electrical Nerve Stimulation On Proprioception Following Exercise-Induced Muscle Damage

Injuries cause pain that leads to sequelae that reduce quality of life. These contribute to changes in the nervous system which cause sensorimotor deficits potentially increasing injury risk. Eccentric muscle damage protocols cause pain and reductions to proprioception similar to injuries. Joint position sense (JPS), linked to proprioception, is decreased after eccentric exercise and in injury models, possibly arising from muscle spindle alteration in the brain from pain. Transcutaneous electrical nerve stimulation (TENS) is used to modulate pain. TENS reducing pain after eccentric exercise warrants its exploration to improve proprioception. We hypothesized TENS to modulate pain following eccentric damage improves proprioception during a JPS assessment. Subjects underwent eccentric exercise followed by TENS; outcome measures included pain during sit to stand (PDSS) and JPS. Pain increased significantly after the protocol, but no reductions to PDSS occurred after TENS. JPS significantly decreased indicating eccentric exercise caused subjects to underestimate JPS angles but was not recovered after the use of TENS. The results indicate muscle spindle sensitivity is changed from pain after EIMD. Proprioceptive reductions after eccentric exercise need to be highlighted by clinicians as injury risk may be greater. Further studies need to assess TENS on proprioception after eccentric exercise.