Pilot Study: Physical Examination Evidence of Acupuncture Principal Meridian Coupling

Objective: This pilot study of acupuncture primary channel coupling examined the effect of anterior tibialis (AT) muscle activation (Stomach = ST channel distribution muscle) on ipsilateral anterior deltoid shoulder elevation strength (Large Intestine = LI channel distribution muscle). Design: Pilot study: prospective before and after trial, nonblinded. Materials and Methods: Twenty healthy adults ages 20-60 years without shoulder pathology were recruited from our institution. All subjects consented with the IRB-approved minimal risk protocol for this study. Average shoulder elevation break strength (kg) with arm elevated 90° from side was measured by dynamometer over 3 trials for each of 4 conditions: standing (baseline), standing with ipsilateral AT activation, seated with legs dangling ipsilateral AT activation, and seated with legs dangling ipsilateral gastrocsoleus (GS) activation. The main outcome measures were percentage decrement in shoulder elevation strength in AT and GS conditions compared with baseline. Paired t-test with a statistical significance alpha level of 0.05 was used for all statistical analyses. Results: A statistically and clinically significant 9.5%-12.5% (P < 0.001) decrease in shoulder elevation strength was found with ipsilateral AT activation whether in the standing or seated position. Reciprocal inhibition of the AT muscle through GS activation in the seated position produced markedly smaller 3%-4% decreases in shoulder elevation strength from baseline. Conclusions: This study provides quantitative physical examination evidence of LI-ST channel coupling, demonstrating a statistically (P < 0.001) and clinically significant decrement in shoulder elevation strength (9.5%-12.5%) with ipsilateral AT activation. These findings support the acupuncture concept of primary channel coupling, with results suggesting a neural basis for these results rather than from a fascial signaling mechanism.