Influence of choice of electrical stimulation site on peripheral neurophysiological and hypoalgesic effects.
OBJECTIVE
To investigate whether the choice of electrode placement site in transcutaneous electrical nerve stimulation (TENS) over acupuncture points vs peripheral nerve points influences the peripheral neurophysiological effects as reflected in negative peak latency in the superficial radial nerve, and on sensory changes in terms of peripheral mechanical pain threshold and mechanical pain tolerance in humans.


METHODS
Randomized controlled trial.


METHODS
Forty-five healthy subjects by convenience sampling.


METHODS
Subjects were randomly assigned to receive: (i) TENS with electrode placement on acupuncture points; (ii) TENS on non-acupuncture points along the same peripheral nerve; or (iii) no stimulation as the control. In the TENS groups, electrical stimulation was delivered at a frequency of 4 Hz and pulse duration of 200 mus for 30 min.


RESULTS
Significant increases in negative peak latency and mechanical pain threshold over time (p = 0.015, 0.002) were found within the 2 active TENS groups. However, there was no significant difference between the 3 groups in all outcome measures at any of the measurement points (all p = 0.05).


CONCLUSIONS
TENS over acupuncture points offers no additional hypoalgesic effects vs TENS over peripheral nerve points in a specific anatomical region.
Cheing
Gladys L Y
GL
Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. gladys.cheing@inet.polyu.edu.hk
Chan
Winnie W Y
WW
D015669:Acupuncture Points; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D017063:Outcome Assessment, Health Care; D010146:Pain / Q000503:physiopathology; D059408:Pain Management; D017288:Pain Threshold / Q000502:physiology; D010525:Peripheral Nerves / Q000502:physiology; D011826:Radial Nerve / Q000502:physiology; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*; D055815:Young Adult