Exercise is an integral part of the rehabilitation of patients suffering a variety of chronic musculoskeletal conditions, such as fibromyalgia, chronic low back pain and myofascial pain. Regular physical activity is recommended for treatment of chronic pain and its effectiveness has been established in clinical trials for people with a variety of pain conditions. However, exercise can also increase pain making participation in rehabilitation challenging for the person with pain. Animal models of exercise‐induced pain have been developed and point to central mechanisms underlying this phenomena, such as increased activation of NMDA receptors in pain‐modulating areas. Meanwhile, a variety of basic science studies testing different exercise protocols, show exercise‐induced analgesia involves activation of central inhibitory pathways. Opioid, serotonin and NMDA mechanisms acting in rostral ventromedial medulla promote analgesia associated with exercise. This review explores and discusses current evidence on central mechanisms underlying exercised‐induced pain and analgesia.

Does exercise increase or decrease pain? Central mechanisms underlying these two phenomena

The imitation of pain sensation in Virtual Reality is considered valuable for safety education and training but has been seldom studied. This paper presents Douleur, a wearable haptic device that renders intensity-adjustable pain sensations with chemical stimulants. Different from mechanical, thermal, or electric stimulation, chemical-induced pain is more close to burning sensations and long-lasting. Douleur consists of a microfluidic platform that precisely emits capsaicin onto the skin and a microneedling component to help the stimulant penetrate the epidermis layer to activate the trigeminal nerve efficiently. Moreover, it embeds a Peltier module to apply the heating or cooling stimulus to the affected area to adjust the level of pain on the skin. To better understand how people would react to the chemical stimulant, we conducted a first study to quantify the enhancement of the sensation by changing the capsaicin concentration, skin temperature, and time and to determine suitable capsaicin concentration levels. In the second study, we demonstrated that Douleur could render a variety of pain sensations in corresponding virtual reality applications. In sum, Douleur is the first wearable prototype that leverages a combination of capsaicin and Peltier to induce rich pain sensations and opens up a wide range of applications for safety education and more.

Douleur: Creating Pain Sensation with Chemical Stimulant to Enhance User Experience in Virtual Reality

Chronic pain is defined as pain that persists past the normal healing time. Physical activity and exercise programs are increasingly being promoted and used for a variety of chronic pain conditions. Evidence suggests that physical exercise is an intervention with few adverse events that may improve pain severity and physical function, thus improving the quality of life. High-intensity interval training (HIIT) has been shown to improve physical outcome measures and to decrease disorder-related disability in people with chronic disorders. Since an overview of the benefits of HIIT on chronic pain conditions has not been published yet, this review aims to report the effects of HIIT alone or in combination with other forms of training on different kind of chronic pain conditions. A search in the main scientific electronic databases was performed. The results of the studies included in this review showed that HIIT is beneficial for several chronic pain conditions, improving pain and physical function. Since HIIT could represent a valid help to conventional drug therapies, it could improve the quality of life of these subjects. The actual quality of evidence remains very low, and further high evidence studies are needed to confirm the promising outcomes reported in this review.

High-intensity interval training for chronic pain conditions: a narrative review

Tusks, the extra-oral teeth.

This study aimed to examine the association between active commuting and sedentary time (ST) and physical activity (PA) in women with fibromyalgia.This cross-sectional study included 420 women with...

Is active commuting associated with sedentary behaviour and physical activity in women with fibromyalgia? The al-Ándalus project

Dental pain triggered by temperature differential is a misrecognized condition and a form of dental allodynia. Dental allodynia is characterized by recurrent episodes of diffuse, dull and throbbing tooth pain that develops when returning to an indoor room temperature after being exposed for a long period to cold weather. The pain episode may last up to few hours before subsiding. Effective treatment is to properly shield the pulpal tissue of the offending tooth by increasing the protective layer of the dentin/enamel complex. This review underscores the difference in dentin hypersensitivity and offers a mechanistic hypothesis based on the following processes. Repeated exposure to significant positive temperature gradients (from cold to warm) generates phenotypic changes of dental primary afferents on selected teeth with subsequent development of a "low-grade" neurogenic inflammation. As a result, nociceptive C-fibers become sensitized and responsive to innocuous temperature gradients because the activation threshold of specific TRP ion channels is lowered and central sensitization takes place. Comprehensive overviews that cover dental innervation and sensory modalities, thermodynamics of tooth structure, mechanisms of dental nociception and the thermal pain are also provided.

/pdf/dental-pain-induced-by-an-ambient-thermal-differential-2x0budg0bg.pdf

Dental pain induced by an ambient thermal differential: pathophysiological hypothesis.

We studied the effects of a specific cardio training program lasting 5 years on pain and quality of life in fibromyalgia patients.Method:An observational longitudinal pilot study was conducted in 1...

https://journals.sagepub.com/doi/pdf/10.1177/2050312120943072

A training program for fibromyalgia management: A 5-year pilot study

Passive music listening has shown its capacity to soothe pain in several clinical and experimental studies. This phenomenon—known as music-induced analgesia—could partly be explained by the modulation of pain signals in response to the stimulation of brain and brainstem centers. We hypothesized that music-induced analgesia may involve inhibitory descending pain systems. We assessed pain-related responses to endogenous pain control mechanisms known to depend on descending pain modulation: peak of first pain (PP), temporal summation (TS), and diffuse noxious inhibitory control (DNIC). Twenty-seven healthy participants (14 men, 13 women) were exposed to a conditioned pain modulation paradigm during a 20-minute relaxing music session and a silence condition. Pain was continually measured with a visual analogue scale. Pain ratings were significantly lower with music listening (p < .02). Repeated measures ANOVA indicated significant differences between conditions within PP and TS (p < .05) but not in DNIC. Those findings suggested that music listening could strengthen components of the inhibitory descending pain pathways operating at the dorsal spinal cord level.

/pdf/impact-of-music-on-first-pain-and-temporal-summation-of-hiqim5bcsj.pdf

Anais Le Fur-Bonnabesse

Papers

Dental pain induced by an ambient thermal differential: pathophysiological hypothesis.

A training program for fibromyalgia management: A 5-year pilot study

Impact of Music on First Pain and Temporal Summation of Second PainA Psychophysical Pilot Study