Effectiveness of Shortwave Diathermy for Subacromial Impingement Syndrome and Value of Night Pain for Patient Selection: A Double-Blinded, Randomized, Placebo-Controlled Trial

OBJECTIVEThe aim of this study was to investigate the effectiveness of short wave diathermy (SWD) in patients with subacromial impingement syndrome. DESIGNIn this double-blinded, randomized, placebo-controlled trial, 57 patients (aged 35–65 yrs) were classified into night pain positive (NP[+]) (n = 28) and night pain negative (NP[−]) (n = 29) groups. Both groups were randomly assigned to SWD (NP[+], n = 14; NP[−], n = 14) and sham (NP[+], n = 15; NP[−], n = 14) subgroups. Visual analog scale, Constant-Murley Scale (CS), and Shoulder Disability Questionnaire (SDQ) scores were used for evaluation. RESULTSThere was only a significant difference in pain with activity at 1-mo (mean difference [MD], −1.65; 95% confidence interval, −3.01 to −0.28]) and 2-mo evaluations (MD, −2.1; 95% confidence interval, −3.51 to −0.69) between SWD versus sham groups. In the NP(+) SWD group, the CS pain score was significantly higher than in the NP(+) sham group at all evaluations after treatment. At 1 mo, the NP(−) SWD group showed significantly better pain, strength, total CS, and SDQ scores than the NP(−) sham group. At 2 mos, the pain, range of motion, strength, and total CS and SDQ scores were better in the NP(−) SWD group than in the NP(−) sham group (P < 0.05). CONCLUSIONSShort wave diathermy is more effective in subacromial impingement syndrome without NP.