Pain Outcomes with an Elliptical Regimen (POWER) Study: Identifying the Proper Dosage of Exercise for Therapeutic Effect in Persons with Chronic Back Pain.

Background context: Exercise therapy for low back pain has long been prescribed as one of the initial remedies for back pain. Traditional therapy is completed under a therapist's supervision and consists of lumbar stabilization, aerobic exercise and stretching exercises. Recent studies have explored treating back pain with aerobic exercise such as walking which can be done anywhere and without supervision which is lower cost and easily administered.

Purpose: To assess a therapeutic dosage of aerobic exercise that is associated with pain reduction in persons experiencing low back pain.

Study design: Case series.

Participant description: Sixteen patients entered the study and twelve patients completed the study (mean ± SD: age 51 ± 11 years; weight 89.2 ± 16 kg). Subjects were included if they were ages 18-65, had chronic back pain lasting for more than 3 months and a score of greater than 30% on the Oswestry Low Back Disability Questionnaire.

Methods: Subjects underwent a six-week exercise program using the elliptical trainer three times each week. Exercise duration was steadily increased each week for the length of the study. The total cumulative amount of work that coincided with significant reductions in chronic low back pain was then identified.

Results: At 4 weeks, pain scores were significantly reduced from baseline (3.2 vs 4.7, p<0.0001). This significant pain reduction corresponded to an average of 30.8 Kcal/kg of body mass in cumulative work performed. Pain was significantly reduced by 21% and 32% on the Oswestry Questionnaire and the PROMIS 29 respectively.

Conclusions: These pilot findings suggest that approximately 30.8 kcal/Kg of accumulated physiological work is a therapeutic "dosage" of exercise needed for significant reduction in chronic back pain. Clinicians can begin to use this benchmark for their oversight of rehabilitation programs to determine if an exercise program has been sufficiently intense and long enough in duration for managing their patients with chronic low back pain.