The Impact of Exercise in Rodent Models of Chronic Pain

Abstract

Purpose of ReviewPhysical activity is increasingly recommended for chronic pain. In this review, we briefly survey recent, high-quality meta-analyses on the effects of exercise in human chronic pain populations, followed by a critical discussion of the rodent literature.Recent FindingsMost meta-analytical studies on the effects of exercise in human chronic pain populations describe moderate improvements in various types of chronic pain, despite substantial variability in the outcomes reported in the primary literature. The most consistent findings suggest that while greater adherence to exercise programs produces better outcomes, there is minimal support for the superiority of one type of exercise over another. The rodent literature similarly suggests that while regular exercise reduces hypersensitivity in rodent models of chronic pain, exercise benefits do not appear to relate to either the type of injury or any particular facet of the exercise paradigm. Potential factors underlying these results are discussed, including the putative involvement of stress-induced analgesic effects associated with certain types of exercise paradigms.SummaryExercise research using rodent models of chronic pain would benefit from increased attention to the role of stress in exercise-induced analgesia, as well as the incorporation of more clinically relevant exercise paradigms.

Voluntary exercise improves voiding function and bladder hyperalgesia in an animal model of stress‐induced visceral hypersensitivity: A multidisciplinary approach to the study of urologic chronic pelvic pain syndrome research network study

“…After initiation of the voluntary exercise protocol, the exercise group had a progressive decline in voiding frequency back to the baseline that correlated with an increase in volume per void. Significant differences among groups were seen after 2 weeks of exercise, consistent with prior studies which demonstrated a delay in improved pain outcomes, as measured by tactile allodynia, after 5 days to 6 weeks of exercise . While voiding frequency is clearly not the same as tactile allodynia, these findings support the idea that modulation of either pain or voiding dysfunction is not an immediate response and requires a period of time from the initiation of exercise possibly due to nerve modulation .…”

“…While human literature is scant, numerous studies have demonstrated that exercise can either prevent or improve pain and stress metrics, such as autonomic dysfunction and corticosterone levels, in a variety of animal models of chronic pain . Exercise was additionally able to improve bladder function and bladder hypersensitivity in an animal model of chronic stress, however, this study did not evaluate the relationship between the amount of exercise and degree of symptom improvement …”

“…To date, the only published study of the effect of exercise on IC/BPS in humans is an internet survey of 1982 IC/BPS patients which found that exercise improved symptoms in 65% of patients. 14 There are a number of limitations with this study, including lack of physician confirmation of diagnosis, no description on which symptoms are improved, and no standardization of the amount or method of exercise. Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is similar to IC/BPS in terms of lifetime and current stress.…”

“…11 In addition, exercise is currently recommended by the Center for Disease Control as one of the initial nonpharmacologic steps in management of chronic pain disorders, such as IC/BPS. 12 While there is growing evidence to support the use of exercise as first-line nonpharmacologic management of chronic pain disorders 13 and patients with IC/ BPS report beneficial effects of exercise, 6,14 there is still limited evidence regarding the effectiveness of exercise as a therapeutic intervention specifically for IC/BPS patients.…”

Music-Enhanced Analgesia and Antiseizure Activities in Animal Models of Pain and Epilepsy: Toward Preclinical Studies Supporting Development of Digital Therapeutics and Their Combinations With Pharmaceutical Drugs

“…For example, the American College of Physicians updated clinical guidelines recommending physical exercise and yoga as the first line therapy for lower back pain (75). While there are many animal studies on exerciseinduced analgesia (76,77), analgesic properties of music have been sparsely investigated in animal models (43) in contrast to growing clinical evidence (22,(24)(25)(26)(78)(79)(80)(81)(82). show that hyperalgesia was observed in animals exposed to control conditions and music-exposed mice show a reduced latency difference.…”