Is Exercise Enough? Evidence from Controlled Clinical Trials on Rehabilitation with and Without Adjunct Modalities for Musculoskeletal Disorders

Background: Musculoskeletal disorders (MSDs) are a major contributor to global disability. Exercise-based rehabilitation is widely recommended as first-line management; however, in clinical practice, it is frequently combined with adjunct therapeutic modalities, and the incremental effectiveness of these approaches remains unclear. The present review addressed the research question: Do adjunct modalities provide additional benefits beyond exercise-based rehabilitation alone in individuals with musculoskeletal disorders? Methods: This systematic review was conducted according to PRISMA 2020 guidelines and prospectively registered in the PROSPERO database (registration number CRD420261309183). Electronic searches were performed in PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials to identify controlled clinical trials evaluating exercise-based rehabilitation delivered alone or combined with adjunct modalities. Outcomes included pain, functional disability, physical performance, strength, structural or imaging-based measures, biomechanical variables, injury risk, and work-related outcomes. Due to methodological heterogeneity across studies, a structured narrative and tabular synthesis were performed. Results: Twenty-one controlled clinical trials were included, encompassing tendinopathies (n = 7), knee osteoarthritis (n = 5), post-ACL reconstruction (n = 2), chronic spinal pain (n = 3), sarcopenia (n = 2), low bone mass (n = 2), and occupational musculoskeletal conditions (n = 1), with sample sizes ranging from 22 to 823 participants. Pain outcomes were reported in 18 studies (86%) and functional outcomes in 16 studies (76%). Exercise-based rehabilitation consistently produced clinically meaningful improvements across studies, whereas adjunct modalities demonstrated short-term advantages in a limited number of trials but rarely showed sustained long-term superiority. Conclusions: Evidence from controlled clinical trials indicates that exercise-based rehabilitation is an effective primary intervention for improving pain, functional capacity, and physical performance across diverse musculoskeletal conditions. Adjunct modalities may provide condition-specific or short-term benefits but do not consistently enhance long-term outcomes beyond structured exercise programs.