While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aimed to determine the effects of depth of needle penetration on muscle pain. Twenty-two healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups: control group, skin group (depth of 3mm: extensor digital muscle), muscle group (depth of 10mm: extensor digital muscle) and non-segmental group (depth of 10mm: anterior tibial muscle). Pressure pain threshold (PPT) and electrical pain threshold (EPT) of the skin, fascia and muscle were measured at a point 20mm distal to the maximum tender point on the second day after the exercise. PPT of the skin group and muscle group were significantly higher than the control group, whereas EPT at fascia of the muscle group was significantly higher than the control group; however, there were no significant differences between the control and other groups. The authors concluded that acupuncture stimulation of muscle increases PPT and EPT of fascia and that the depth of needle penetration is important for the relief of muscle pain. Chin Med. 2011 Jun 22;6(1):24. PMID: 21696603.
