According to a new Cochrane review of randomized controlled and controlled clinical trials, low-level laser therapy (LLLT) is a useful electrotherapy modality for the treatment of adhesive capsulitis. However, the effects of this treatment are marginal and evidence is not conclusive, as indicated on a news release from the American Physical Therapy Association (APTA). The research is aimed to evaluate the effectiveness of a range of electrotherapy interventions in addition to LLLT, including pulsed electromagnetic field therapy, therapeutic ultrasound, and interferential current, in relation to placebos and other interventions.
The researchers discovered that evidence was lacking in nearly all parameters, and nothing conclusive could be drawn from the 19-trial, 1,249-participant review that was studied, but with one exception. According to the APTA news release, although authors provided plenty of qualifications to their findings, the research team did acknowledge low- to moderate-quality support for the use of LLLT in several ways, including that it may be slightly better than placebo “in terms of global treatment” at 6 days. LLLT may also be an “effective adjunct” to exercise in reduction of pain up to 4 weeks and increase in function up to 4 months.
The APTA news release notes that authors were not able to render any conclusions beyond those related to LLLT, largely due to design flaws in trials, all but one that was downgraded to “low” or “very low” primarily because of unclear allocation concealment, small sample sizes, and lack of blinding. The authors write that even findings that pointed to possible benefits may change if and when better-quality research is conducted, according to APTA. The authors write, “Further high-quality trials may show even smaller effect estimates than those summarized in this review.”
The APTA news release notes that the authors call for additional high-quality research that compares different electrotherapy modalities, evaluates effectiveness versus placebo, and analyzes their use in combination with manual therapy and exercise. The authors of the study also say there is a need for studies that examine long-term effects of the modalities, saying that most of the trials studies “have only assessed outcomes during treatment or in the weeks following cessation.”