Author: Lam, Kit-yin
Title: The effectiveness of low level laser therapy in the management of lateral epicondylitis
Degree: M.Sc.
Year: 2006
Subject: Hong Kong Polytechnic University -- Dissertations
Tennis elbow -- Treatment
Elbow -- Wounds and injuries -- Treatment
Lasers in medicine
Department: Department of Rehabilitation Sciences
Pages: xv, 108 leaves : ill. (some col.) ; 30 cm.
Language: English
Abstract: Lateral epicondylitis is a common musculoskeletal pain condition characterized by inflammatory response induced by overuse of the tendon with an association of fibroblastic and vascular degeneration. The clinical features are pain and tenderness over the lateral elbow, which may also result in reduction in grip strength and impairment in physical function. Low level laser therapy (LLLT) has been shown effective in its therapeutic effects in tissue healing and pain control. Recent clinical trials also showed its efficacy in the management of this condition in reducing pain and improving grip strength and subjective rating of physical function. Various studies have been done but controversial findings were reported. In particular, there is a lack of common consensus on the choice of optimal treatment parameters. The objective of the study was to examine the effectiveness of LLLT in the management of lateral epicondylitis. A randomized, single-blind, placebo-controlled clinical trial was carried out. Thirty-nine subjects suffering from lateral epicondylitis were recruited in the study. They were randomly assigned either to receive active laser with pulse repetition frequency of 5000 Hz and an energy density of 2.4 J/cm² at each tender point with 904nm Ga-As infrared laser (laser group); or sham irradiation (placebo group) for a total of 9 sessions. All subjects received a standardized home exercise program. The outcome measures including mechanical pain threshold, maximum grip strength, pain at maximum grip strength using Visual Analogue Scale (VAS) and the subjective rating of physical function using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire were assessed at Session 1 (baseline), Session 5, Session 9 (last treatment session) and 3 weeks after the treatment completed.
After repeated applications of LLLT, the laser group demonstrated a significantly greater analgesic effect than did the placebo group. A greater cumulative improvement in the mechanical pain threshold and the VAS score at maximum grip strength was found in the laser group than did the placebo group in all subsequent sessions. Significant between-group differences were found in the mechanical pain threshold at Session 5 (p=0.009), Session 9 (p=0.001) and the 3-week follow-up (3-wk FU) session (p=0.000). Significant between-group differences were also found in the VAS score at maximum grip strength at Session 9 (p=0.001) and the 3-wk FU session (p=0.000). Improvement was also shown in the maximum grip strength and the score of DASH. The laser group showed a greater cumulative increase in maximum grip strength than did the placebo group in all subsequent sessions. Significant between-group difference was found at the 3-wk FU session (p=0.011). A greater cumulative reduction in the score of DASH was demonstrated in the laser group than the placebo group. Significant between-group difference was found in the score of DASH (Main Section) at the 3-wk FU session (p=0.002). However, no significant between-group difference was found in the other two sub-sections of DASH. In conclusion, nine sessions of LLLT in addition of exercise is effective in the management of lateral epicondylitis in terms of pain relief and improving grip strength and subjective rating of physical function in short term and 3-week follow-up period.
Rights: All rights reserved
Access: restricted access

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