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 (05 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.
THE WRIST IS A COMMON site of pain and disability resulting from sports-related and occupational injuries. The complexity of wrist injuries and associated patient distress has resulted in wrist pain being termed the back of the upper extremity.1 In the 1988 National Health Interview Survey, 1.87 million respondents reported having carpal tunnel syndrome (CTS), 588,000 reported having tendonitis or related syndromes of the hand, and an estimated 2 million had hand-wrist arthritis with 20% reporting a resultant major change in work activities, jobs, or missed work days.2
Wrist pain can occur after a single traumatic incident, repetitive activity, or secondary to arthritis. Repetitive activity is a mechanism of injury for work-related musculoskeletal disorders (WRMSD). Also referred to as cumulative trauma disorder, WRMSDs are associated with significant disability among working-age individuals.3 The burden on society has continued to grow as jobs have changed from being task oriented to time dependent. Increased requirements for speed and efficiency have led to increased muscular tension within the upper extremities, accelerating muscular overload and biomechanic stress on tendons, synovial membranes, joints, and nerves.4 The economic impact of these disorders, estimated at more than $500 million in 1989, has led to requests for sweeping changes in the work environment.5 Of these, CTS is among the most frequently claimed WRMSD and one of the most costly injuries of the upper extremity.6
Various intervention strategies are used to treat wrist pain when the etiology is not because of fracture or carpal instability. These interventions include the use of pharmacologic agents such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), local steroid injections, immobilization with splints, and in some cases surgical intervention. Despite these interventions, more than 50% of people suffering from upper-extremity WRMSDs continue to have symptoms interfering with work and recreational activities more than 1 year after presentation.7, 8
A novel new treatment modality delivering continuous low-level topical heat for at least 8 hours via a wearable wrap has been developed to treat painful conditions of the musculoskeletal system. This heat wrap therapy has been reported to be effective and safe in the treatment of nonspecific low back pain and primary dysmenorrhea.9, 10, 11, 12 Our study was undertaken to evaluate the therapeutic benefit of continuous low-level heat wrap therapy in the treatment of common painful musculoskeletal disorders of the wrist. The objective of our study was to determine the clinical efficacy of continuous low-level heat wrap therapy as compared with oral placebo treatment in subjects with wrist pain because of strains or sprains (SS), tendinosis