The effect of electrical stimulation on impairment of the painful post-stroke shoulder

Background: Transcutaneous electrical nerve stimulation (TENS) and transcutaneous neuromuscular electrical stimulation (t-NMES) are commonly used therapies in the treatment of chronic hemiplegic shoulder pain. These treatments are often utilized during physical or occupational therapy sessions, yet research into the acute analgesic effects of TENS and t-NMES on hemiplegic shoulder pain and use during therapy is limited. Objective: To compare the acute effects of transcutaneous electrical nerve stimulation (TENS), transcutaneous neuromuscular electrical stimulation (t-NMES), and no stimulation on pain-free passive range of motion of the shoulder in subjects with hemiplegic shoulder pain. Methods: Prospective cohort study of 10 subjects randomly treated with t-NMES, TENS, and one non-stimulation experimental condition. Pain-free passive external rotation and abduction range of motion of the affected shoulder were measured during stimulation. Results: There was not a significant within-subject difference in pain-free range of motion for external rotation or abduction. Subject to subject differences explained the majority of the variability in pain-free range of motion. Conclusion: This pilot study is the first to measure pain-free passive range of motion during electrical stimulation. Our findings demonstrate the lack of an acute effect of TENS and t-NMES on pain reduction.