(1) Associazione di Studio e Ricerca in Medicina Tradizionale Cinese MediCina, Milano, Italy;

(2) Istituto di Bioimmagini e Fisiologia Molecolare del Consiglio Nazionale delle Ricerche, Segrate, Milano, Italy.

Summary
Background: Wrist-ankle acupuncture (WAA) is a modern microsystem of acupuncture considered a simple and effective technique for the treatment of several painful conditions, but its real effectiveness has scarcely been quantified on the clinical ground.
Objective: Aim of the study is to evaluate the acute and short-term effects of the use of WAA technique in the treatment of shoulder chronic pain, without the supplementation of conventional acupuncture.
Patients and Design: Twenty-five consecutive patients (17 males, 8 females; mean age 61.8 yr. ± 1.5 SEM) with shoulder pain localised in taiyin, shaoyang e yangming regions, with onset >30 days earlier, have been investigated. The intervention was conducted by two different acupuncturists with the same protocol entailing a duration of 4 weeks (with 2 session per week in the first 2 weeks, and 1 session per week thereafter). At each session, a 1 cun acupuncture needle was subcutaneously inserted alternatively at Upper 4, 5 and 6 position (depending on pain localisation) and retained for 24 hours. Three weeks after the completion of the course, a follow-up session was performed. Before and during the intervention, and at the follow-up, pain intensity (PI) and quality (PQ) and active shoulder motility (ASM) have been evaluated with a visual analogic scale, McGill Pain Questionnaire and Constant’s motion scale, respectively.
Results: Before the intervention, average values of PI and ASM (expressed on a 10-grade scale) were 5.1 ± 0.4 SEM (range: 1.3-9.3) and 5.4 ± 0.6 SEM (range: 1.5-10.0), respectively, without significant effects due to gender, age and pain localisation (p>0.05, multifactor ANOVA), while PQ was mainly defined as shooting, aching and exhausting. During the first session, needle insertion acutely induced a 32.7% reduction in PI (p<0.001, paired data Student’s t-test) and a 39.2% increase in ASM (p<0.001). After the intervention the values of PI and ASM were on average 1.8 ± 0.3 SEM and 8.4 ± 0.3, respectively, which resulted significantly lower (p<0.001) than the values observed before the treatment. A significant negative correlation was found between ASM and PI before and in the course of treatment (ASM = 9.79 -0.88 * PI; R2 = 0.97; p < 0.001), which indicates a substantial influence of subjective pain on functional motor limitation. At follow-up, a further significant increase in ASM value (9.1 ± 0.2, p < 0.001) and a decrease (not statistically significant) in PI value (1.6 ± 0.3) were observed. According with presently applied tests, 3 patients (13.6%) attained a complete pain suppression, and in 6 (30%) a full functional recovery was assessed. Although quantitatively reduced, PQ resulted substantially unchanged across the intervention. All changes observed in the course of the study resulted independent from gender, age, pain localisation, clinical history and acupuncturist performing the treatment (ANOVA). Overall, 3 patients (12%) dropped-out during the intervention for needle retention intolerance, and in 2 patients (8%) local side-effects not requiring treatment suspension were observed.
Conclusions: WAA technique, without supplementation of traditional acupuncture, appears a simple, well tolerated and effective treatment of shoulder chronic pain, attaining significant pain and motor impairment reduction on both acute and short-term basis. Further longer term evaluation of results may better help defining the anti-inflammatory effects of this approach.