The effect of high frequency transcutaneous electrical nerve stimulation on knee joint proprioception

BACKGROUND: Proprioceptive information arises from mechanoreceptors situated in the muscles, joints, ligamentand cutaneous tissues. Together with the visual and vestibular system they all contribute to the ability of defining the position of the body and the position of the joints in relation to each other. There is a known deterioration in proprioception sense with greater age and various diseases and injuries, such as osteoarthritis (OA). High frequency TENS is a common treatment for pain relief in this patients. Previous investigations have evaluated the effect on proprioception sense by applying an electrical noise or high frequency TENS to the subject ́s knee or lower limb. To our knowledge there are no studies on the possible effect of high frequency TENS on proprioception sense after the actual TENS treatment. OBJECTIVE: The aim of this study was to evaluate the effect of 30 min high frequency TENS on the knee joint proprioception in healthy subjects. RESEARCH QUESTION: How is the ability to reproduce an angle of 700 in the dominant knee joint, in relation to the collateral (control) knee joint before TENS, during TENS stimulation, immediately after and five minutes after a 30-minute HighTENS intervention? METHODS: Ten subjects (five women), mean age 26 years (range 20-45) were included in the study. Inclusion criteria were that they consider themselves as healthy and that they had not undergone any surgery in the knee or hip in the past six months. High frequency TENS was applied bilaterally over the subject ́s knee joint. To evaluate any effect on proprioception sense we used joint position sense (JPS). Multiple T-tests and Bonferroni correction was used to determine differences between the measurements. RESULTS: There was no difference in JPS between control measures and during (p=013), immediately after (p=0.093) and 5 minutes after (p=0.333) the TENS intervention. CONCLUSIONS: High frequency TENS seems to have no impact on proprioception sense in the knee joint as measured by JPS in healthy adults.