Laser therapy:: A randomized, controlled trial of the effects of low intensity Nd:YAG laser irradiation on lateral epicondylitis

Objective: To assess the effectiveness of low intensity laser therapy in the treatment of lateral epicondylitis. Design: A double-masked, placebo-controlled, randomized clinical trial. Setting: A physical medicine and rehabilitation clinic. Participants: Fifty-two ambulatory men and women (age range, 18-70yr) with symptomatic lateral epicondylitis of more than 30 days in duration and a normal neurologic examination. Intervention: Subjects were bloc randomized into 2 groups with a computer-generated schedule. All underwent irradiation for 60 seconds at 7 points along the symptomatic forearm 3 times weekly for 4 weeks by a masked therapist. The sole difference between the groups was that the probe of a 1.06-mum continuous wave laser emitted 204mW/cm(2) (12.24J/cm(2)) for the treated subjects and was inactive for the control subjects. Subjects were assessed at the beginning, midpoint (session 6), and end (session 12) of treatment, as well as at follow-up 28 to 35 days after their last treatment. Main Outcome Measures: Pain in last 24 hours, tenderness to palpation, and patient's perception of change (benefit). Results: The treated and untreated groups were well matched demographically. Masking was maintained for subjects and therapists; however, the groups did not vary to a statistically significant extent in terms of the main outcome measures either during treatment or at follow-up. Secondary outcome variables, such as grasp and pinch strength, medication use, and pain with grasp and pinch, also failed to statistically differ significantly between the groups. No significant treatment side effects were noted. Conclusion: Treatment with low intensity 1.06-mum laser irradiation within the parameters of this study was a safe but ineffective treatment of lateral epicondylitis. Further research seems warranted in this controversial area.