Physical exercise as non-pharmacological treatment of chronic pain: Why and when

Abstract

Chronic pain broadly encompasses both objectively defined conditions and idiopathic conditions that lack physical findings. Despite variance in origin or pathogenesis, these conditions are similarly characterized by chronic pain, poor physical function, mobility limitations, depression, anxiety and sleep disturbance and are treated alone or in combination by pharmacologic and nonpharmacologic approaches, such as physical activity (aerobic conditioning, muscle strengthening, flexibility training and movement therapies). Physical activity improves general health, disease risk and progression of chronic illnesses such as cardiovascular disease, type-2 diabetes and obesity. When applied to chronic pain conditions within appropriate parameters (frequency, duration, intensity), physical activity significantly improves pain and related symptoms. For chronic pain, strict guidelines for physical activity are lacking, but frequent movement is preferable to sedentary behavior. This gives considerable freedom in prescribing physical activity treatments, which are most successful when tailored individually, progressed slowly and account for physical limitations, psychosocial needs and available resources.

Chronic Pain and Exercise: Studies on pain intensity, biochemistry, adherence and attitudes

“…The PA&E in this trial were based and modified from previous studies [193,216] which reported improvements in pain intensity and strength for women with pain in the neck-and shoulder muscles. PA&E in various combinations are often used for the treatment of chronic pain [3,[33][34][35][36][37][38][39]. However, despite the large amount of research on PA&E as treatment for chronic pain, there is still a lack of knowledge on physiological effects mechanisms behind the positive effects.…”

“…However, in accordance with the suggestion that chronification of pain might be related to an imbalance between facilitating and inhibitory neurobiological systems [47,236], it is important to highlight the potential of PA&E to impact both ascending pain inducing activities as well as pain modulatory and descending activities in the nervous system. In future studies, the clinical effect on pain intensity and function as a result of different types of PA&E might not be of main interest to evaluate further, as several reviews [3,33,34,[36][37][38][39] and a metaanalyse [35] consistently shows that PA&E of different types are beneficial for chronic pain. To advance the research field, it might instead be interesting to add a focus on the physiological and neurobiological effect mechanisms associated to acute and long-term effects of PA&E in chronic pain.…”

“…Adherence to prescribed PA&E are often troublesome [7,172], which also were shown in paper 1 and paper 4. Because PA&E are beneficial for chronic pain [3,[33][34][35][36][37][38][39], and that the physiological responses of the PA&E normally are depending on the dose and frequency [137], it should reasonably be important to strive after higher adherence to prescribed PA&E in order to optimize the effect of the PA&E. Adherence is targeted in models of health behaviour change, but such models are seldom included in research on PA&E interventions for chronic pain. In future studies and clinical application of PA&E as treatment, it is therefore interesting to further emphasize behavioural strategies for increased adherence to the prescribed PA&E, separate from and parallel to behavioural approaches focusing on the chronic pain.…”

“…The effects of aerobic PA&E are increased stroke volume of the heart, increased uptake of oxygen in the red blood cells, and increased blood volume in combination with extended capillary net and increased numbers of mitochondria, in order to receive and consume the oxygen for energy expenditure [139,140]. Intensity of aerobic PA&E is described as percentages of maximal oxygen-uptake (VO2max) [34], where light intensity refers to less than 60 % of VO2max , medium intensity to 60 -75 % of VO2max and high intensity to more than 75 % of VO2max. [141,142].…”

“…Management of chronic pain is instead aiming at increase bodily and vocational functioning, increase psychological well-being, and limit pain intensity [15]. The effects of the best available chronic pain treatment, such as pharmacological treatment [20,30], multimodal rehabilitation [31,32], PA&E [3,[33][34][35][36][37][38][39] and psychological treatment [40][41][42] have in general been weak to moderate. Thus, it is important to improve the treatment for chronic pain.…”