One of the most common questions we receive in our Boulder Physical Therapy practice involves how much pain should be felt with exercise. This is a complicated answer dependent on many factors including but not limited to the nature of the injury. In general, the field of sports medicine is moving away from a purely R.I.C.E. (rest, ice, compression, elevation) approach to injury recovery and has found a progressive, optimal loading approach may be better suited to less severe muscle injury. In fact, within acute muscle strains, exercise has been shown to accelerate a patient’s recovery compared to rest. General guidelines exist on the acceptance of a mild to moderate pain (1-4/10) which stops at the conclusion of exercise in these muscle strains, but a new research study examined the differences between this approach and a pain avoidance approach.
Hickey and colleagues in the Journal of Orthopedic and Sports Physical Therapy randomized 43 men with acute hamstring strains to one of two Physical Therapy groups (2019). Both groups underwent the same bi-weekly progressive rehabilitation program (bridging, hip extension, hamstring sliders, and nordic hamstring curls) but one group was instructed to remain pain free (0/10) while the other was allowed to complete these exercises with mild pain (<4/10). Authors completed a subjective and clinical examination at the start and conclusion of the study period (2 months) and also followed each athlete up to 6 months after their return to play. Authors reported no difference in time to return to play between the two groups, but the athletes allowed to exercise with mild pain demonstrated improved strength and hamstring muscle healing (measured by ultrasound) compared to the pain free group. Authors reported “the conventional practice of pain avoidance during hamstring strain rehabilitation may not be necessary” and instead advocated for an approach consistent with progressive, optimal loading.