Preliminary investigation into the effects of acupuncture on leg muscle strength: A randomized controlled trial in sports students

BACKGROUND: Acupuncture has been reported to enhance muscle strength in several studies using conventional needling techniques. Press tack needles offer a more practical modality; however, their efficacy with respect to leg muscle strength remains unknown. The purpose of this study was to investigate the effect of press tack needle acupuncture on leg muscle strength in sports students. METHODS: A double-blind randomized controlled trial was conducted among 30 male sports students who were randomized into an acupuncture group (n = 15) and a placebo group (n = 15). Press tack needles (0.20 mm × 1.2 mm) were applied bilaterally at ST36 and ST34 in the acupuncture group, while round plasters were applied at the same locations in the placebo group. Leg muscle strength was measured using a leg dynamometer before and 30 min after the intervention. RESULTS: No statistically significant difference between groups was observed in the primary outcome of leg muscle strength post-intervention (81 [67-107] kg vs 62 [50-100] kg; p = 0.066). However, both groups demonstrated significant within-group improvements (p < 0.001 and p = 0.001, respectively) and the mean change (±SD) in leg muscle strength was significantly greater in the acupuncture group than in the placebo group (10.2 ± 6.8 kg vs 5.6 ± 4.1 kg; p = 0.033). CONCLUSION: Press tack needle acupuncture at ST36 and ST34 did not demonstrate significant superiority over placebo on leg muscle strength, although the study appears in retrospect to have been underpowered for this primary outcome. The significant between-group difference for the changes in leg strength (pre- vs post-intervention) among individual participants is encouraging, and further investigation is warranted.