Objective: To evaluate the efficacy of continuous low-level heat wrap therapy for the treatment of various sources of wrist pain including strain and sprain (SS), tendinosis (T), osteoarthritis (OA), and carpal tunnel syndrome (CTS).
Design: Prospective, randomized, parallel, single-blind (investigator), placebo-controlled, multicenter clinical trial.
Setting: Two community-based research facilities.
Participants: Ninety-three patients (age range, 18-65 y) with wrist pain.
Intervention: Subjects with moderate or greater wrist pain were randomized and stratified to 1 of the following treatments: efficacy evaluation (heat wrap, n=39; oral placebo, n=42) or blinding (oral acetaminophen, n=6; unheated wrap, n=6). Data were recorded over 3 days of treatment and 2 days of follow-up.
Main outcome measures: The primary comparison was between the heat wrap and the oral placebo group among SS/T/OA subjects for pain relief. Outcome measures included pain relief (0-5 scale), joint stiffness (101-point numeric rating scale), grip strength measured by dynamometry, and perceived pain and disability (Patient Rated Wrist Evaluation [PRWE]); subjects with CTS also completed the Symptom Severity Scale and Functional Status Scale.
Results: Heat wrap therapy showed significant benefits in day 1 to 3 mean pain relief (P=.045) and increased day 3 grip strength (P=.02) versus oral placebo for the SS/T/OA group. However, joint stiffness and PRWE results were comparable between the 2 treatments. For the CTS group, heat wraps provided greater day 1 to 3/hour 0 to 8 mean pain relief (P=.001), day 1 to 3 mean joint stiffness reduction (P=.004), increased day 3 grip strength (P=.003), reduced PRWE scores (P=.0015), reduced symptom severity (P=.001), and improved functional status (P=.04). In addition, the heat wrap showed significant extended benefits through follow-up (day 5) in the CTS group.
Conclusions: Continuous low-level heat wrap therapy was efficacious for the treatment of common conditions causing wrist pain and impairment.