Effects of motor imagery using virtual reality on pain sensitivity and affect in healthy individuals: A prospective randomized crossover study.

OBJECTIVE: Exercise induces a hypoalgesic response and improves affect. However, some individuals are unable to exercise for various reasons. Motor imagery, involving kinesthetic and visual imagery without physical movement, activates brain regions associated with these benefits and could be an alternative for those unable to exercise. Virtual reality also enhances motor imagery performance because of its illusion and embodiment. Therefore, we examined the effects of motor imagery combined with virtual reality on pain sensitivity and affect in healthy individuals. DESIGN: Randomized crossover study. SETTING: Laboratory. SUBJECTS: Thirty-six participants (women: 18) were included. METHODS: Each participant completed three 10-min experimental sessions, comprising actual exercise, motor imagery only, and motor imagery combined with virtual reality. Hypoalgesic responses and affective improvement were assessed using the pressure-pain threshold and the Positive and Negative Affect Schedule, respectively. RESULTS: All interventions significantly increased the pressure-pain threshold at the thigh (P<0.001). Motor imagery combined with virtual reality increased the pressure-pain threshold more than motor imagery alone, but the threshold was similar to that of actual exercise (both P≥0.05). All interventions significantly decreased the negative affect of the Positive and Negative Affect Schedule (all P<0.05). CONCLUSIONS: Motor imagery combined with virtual reality exerted hypoalgesic and affective-improvement effects similar to those of actual exercise.

Consensus statement on smoking cessation in patients with pain.

Smoking is closely associated with the development of various cancers and tobacco-related illnesses such as cardiovascular and respiratory disorders. However, data are scarce on the relationship between smoking and both acute and chronic pain. In addition to nicotine, tobacco smoke contains more than 4000 different compounds. Although nicotine is not the sole cause of smoking-induced diseases, it plays a critical role in pain-related pathophysiology. Despite the acute analgesic effects of nicotine, long-term exposure leads to tolerance and increased pain sensitivity due to nicotinic acetylcholine receptor desensitization and neuronal plastic changes. The purpose of smoking cessation interventions in smoking patients with pain is primarily not only to reduce their pain and associated limitations in activities of daily living, but also to improve the outcomes of underlying pain-causing conditions and reduce the risks of tobacco-related disorders. This statement aims to summarize the available evidence on the impact of smoking on pain and to inform medical professionals of the significance of smoking cessation in patients with pain.

Impact of a multi-professional expert team on EOL care of children with cancer.

BACKGROUND: The quality of end-of-life (Q-EOL) care is influenced by various factors such as resources for palliative care (PC). We introduced a multi-professional expert team (MET) in 2014, which provides home-based care for children and adolescents with incurable cancer. This study investigated the impacts of the outreach activities by the MET on Q-EOL care of pediatric oncology patients. METHODS: This observational study retrospectively examined 112 patients receiving end-of-life care between 1989 and 2018 at a pediatric cancer center in Japan. Some of the indicators of Q-EOL care before and after the introduction of the outreach activities by the MET were compared. The subjects were 92 in pre-MET and 20 in post-MET periods. RESULTS: The median number of days for which the patients stayed at home during the final seven or 30 days were significantly prolonged in the post-MET period (0.0 vs 1.5 days, P = 0.020, 3.0 vs 12.0 days, P = 0.042). The change was more significant in hematologic malignancies than solid and central nervous system tumors. Patients receiving longer PC before their deaths could stay at home longer during the last 7 days. The ratio of patients receiving PC for more than 2 months was significantly increased in post-MET period (60.9 vs 90.0%, P = 0.014). More patients also greeted their deaths at home in the post-MET period (3.3 vs 25.0%, P < 0.001). CONCLUSIONS: The activities of the MET transformed the end-of-life care of children and adolescents with incurable cancer. Earlier transitions to PC from curative treatment were associated with longer home-based care and more deaths at home.

Application of three hygrometers under different skin conditions in dogs: dry, moist and haired skin.

BACKGROUND: Hydration is one parameter of skin barrier function. The Skicon-200EX® and Corneometer CM825® are hygrometers used to measure skin hydration in humans based on different measurement methods. The ASA-MX3® is a hygrometer used to obtain measurements at haired skin sites in humans. HYPOTHESIS/OBJECTIVES: To validate three hygrometers to measure skin dryness in dogs. ANIMALS: Six clinically normal research dogs. METHODS: In vivo evaluation of three hygrometers for three different skin types was performed. Measurement of hydration was performed at five different regional sites. Dry and moist skin were induced by treatment with a sorbent and petrolatum, respectively, and measurements were collected for 120 min. Skin sites with three different hair lengths were evaluated to determine whether hair would interfere with hydration measurements. RESULTS: All three hygrometers obtained measurements at the nonhaired skin sites, except the ASA-MX3® hygrometer at the ear site. At the dry skin sites the Skicon-200EX® hygrometer detected a significant decrease of water content for longer than the other devices. At the moist skin sites the Corneometer CM825® and ASA-MX3® hygrometers showed a significant increase in water content. The ASA-MX3® hygrometer was the only device that could obtain measurements at sites with hair. CONCLUSIONS AND CLINICAL IMPORTANCE: The Skicon-200EX® hygrometer was the most sensitive for detecting skin dryness, whereas the Corneometer CM825® and ASA-MX3® hygrometers detected an emollient effect. Only the ASA-MX3® could provide measurements at the haired sites. This study may assist in the selection of a hygrometer based on the purpose of use.

The effect of a herbal paste and oil extract on the lipid content of canine hair fibres.

BACKGROUND: Application of herbal paste and oil to a dog's coat and body before rinsing (often combining with shampooing) is a cosmetic therapy available in Japan. It is highly appreciated by users, who claim that the treatment makes the coat shinier, improves volume and eliminates tangles. However, there has been no scientific evaluation of such treatments. HYPOTHESIS/OBJECTIVES: Improvement of hair condition is derived from oils such as sebum and conditioning oils because chemicals are not used. Therefore, we examined nonpolar lipids (the primary lipids in dog hair) and the botanical oils used in this therapy. ANIMALS: Hair samples were obtained from six beagle dogs. METHODS: Groups were based on different combinations of the following processes: rinsing, shampooing, herbal therapy and herbal therapy with oil extract. Analysis of lipids was performed by high performance thin layer chromatography. RESULTS: The processes of shampooing and herbal therapy were associated with an equivalent reduction in cholesterol ester and triglyceride (TG). However, hair treated by herbal therapy combined with oil extract had an almost three-fold higher TG content, even after shampooing. CONCLUSIONS AND CLINICAL IMPORTANCE: This study demonstrated that the herbal therapy was able to coat hair samples with TG that was not removed with rinsing. Further investigation is required to evaluate the possible benefits of the application of botanical products containing lipids, such as TG, on hair coat quality in dogs.

Measurement of transepidermal water loss (TEWL) in cats with experimental skin barrier dysfunction using a closed chamber system.

BACKGROUND: A closed chamber evaporimeter is suitable for measuring transepidermal water loss (TEWL) in cats because of the compact device size, tolerance to sudden movement and short measuring time. TEWL is a representative parameter for skin barrier dysfunction, which is one of the clinical signs of atopic dermatitis in humans and dogs. Measurement of feline TEWL has been reported, but applicability of this parameter has not been validated. HYPOTHESIS/OBJECTIVES: The aims of this study were to determine if tape stripping is a valid experimental model in cats for studying TEWL and to determine if a closed chambered system is a suitable measurement tool for cats. ANIMALS: Ten clinically normal cats. METHODS: In order to evaluate variation of the measured values, TEWL was measured at the right and left side of the three clipped regions (axillae, lateral thigh and groin). Subsequently, TEWL was measured using sequential tape stripping of the stratum corneum as a model of acute barrier disruption. RESULTS: The variations between both sides of the three regions showed no significant difference. Sequential tape stripping was associated with increasing values for TEWL. CONCLUSIONS AND CLINICAL IMPORTANCE: Feline TEWL was shown to reflect changes in the skin barrier in an experimental model using a closed chamber system and has the potential for evaluating skin barrier function in cats with skin diseases.

[Concept of the Pain Rehabilitation].

Pain causes physical disability and psychosocial issues and consequently reduces quality of life. Pain rehabilitation with exercise, cognitive-behavioral therapy, interdisciplinary rehabilitation and patient education improves not only subjective pain perception but also pain-associated dysfunction. The pain rehabilitation is characterized by enabling self-management based on patient-centered perspective and decision-making by the patient.

The effects of exercise therapy for the improvement of jaw movement and psychological intervention to reduce parafunctional activities on chronic pain in the craniocervical region.

PURPOSE: Apparent organic abnormalities are sometimes not identified among patients suffering from chronic pain in the craniocervical region. In some cases, parafunctional activities (PAs) are recognized. PAs are nonfunctional oromandibular activities that include jaw clenching and bruxism, but are considered as factors that contribute to craniomandibular disorders (CMDs). It is now recognized that PAs and CMDs influence musculoskeletal conditions of the upper quarter. Exercise therapy (ET) to improve jaw movement and psychological intervention (PI) to reduce PAs are useful for PAs and CMDs. We hypothesized that ET and PI would be effective for craniocervical pain without organic abnormalities. METHODS: Thirty-nine subjects suffering from craniocervical chronic pain were allocated into 3 groups: The control group received only pharmacological treatment; the ET group received jaw movement exercise (JME); and the ET-PI group received JME and PI. Pain and jaw movement were evaluated using a numerical rating scale (NRS). RESULTS: After interventions, the NRS scores were significantly lower in the ET-PI group, compared with those in the other groups. Jaw movement improved 100% in the ET group, 92% in the ET-PI group, and 0% in the control group. CONCLUSION: A combination of jaw exercise and psychological intervention to reduce parafunctional activities is more effective than jaw exercise alone for the improvement of craniocervical pain without apparent organic abnormalities.

Pathology of knee osteoarthritis pain: contribution of joint structural changes and pain sensitization to movement-evoked pain in knee osteoarthritis.

Introduction: Movement-evoked pain (MEP) is the primary symptom in patients with knee osteoarthritis (KOA). Objectives: This study aimed to investigate the contribution of joint structural changes and pain sensitization to the mechanisms of MEP in patients with KOA. Methods: A total of 86 patients were assessed for demographic characteristics, osteoarthritis severity, Whole-Organ Magnetic Resonance Imaging Score-Hoffa synovitis and bone marrow lesions, pressure pain threshold and temporal summation of pain at the knee and forearm, Central Sensitization Inventory-9, and MEP. In measure of MEP, knee pain was scored using a numerical rating scale (NRS, 0-10) before and every minute during a 6-minute walking test (6MWT), and the MEP index was defined as the change in NRS pain score from baseline to the sixth minute of walking. Result: On average, pain during 6MWT increased by 1.4 ± 1.5 points on the NRS relative to baseline, with 30.2% of patients showing an increase of 2 points or more. The hierarchical linear regression analysis revealed that Hoffa synovitis, pressure pain threshold at the forearm, and temporal summation of pain at the knee were associated with the MEP index. Conclusion: The findings of this study suggest that both synovitis and neural mechanisms, such as pain sensitization, play a role in the development of MEP in KOA.

Characteristic Behaviors of Pain During Movement in the Older Individuals with Dementia.

Purpose: This study assessed the pain associated with movement and exercise in older individuals with cognitive decline, using the Abbey Pain Scale (APS) to identify the sub-items that effectively reflect pain during such activities. Patients and Methods: A cross-sectional study was conducted in 225 older patients with musculoskeletal disorders and cognitive decline at the Ikeda Rehabilitation Hospital in Toyama, Japan. Pain during walking or transferring was assessed using the verbal rating scale (VRS) and the APS. Item response theory (IRT) was used to identify the APS sub-items that most accurately reflected the presence and degree of pain. Results: Pain associated with movement scored 1.3 ± 1.1 on the VRS and 2.5 ± 2.6 on the APS. The IRT analysis extracted "vocalization", "facial expression", and "change in body language" as the most reliable indicators of pain. These extracted items showed good internal consistency (Cronbach's α = 0.72), were significantly positively related to changes in the VRS (rs = 0.370, p < 0.001), and showed significant differences between patients with and without subjective pain. Conclusion: Our study suggests that the APS sub-items "vocalization", "facial expression", and "change in body language" may be the most effective indicators of pain during movement and exercise in older individuals with cognitive decline. This approach may enhance the reliability of pain assessments and management during exercise therapy.

A decision tree algorithm to identify predictors of post-stroke complex regional pain syndrome.

This prospective cohort study aimed to identify the risk factors for post-stroke complex regional pain syndrome (CRPS) using a decision tree algorithm while comprehensively assessing upper limb and lower limb disuse and physical inactivity. Upper limb disuse (Fugl-Meyer assessment of upper extremity [FMA-UE], Action Research Arm Test, Motor Activity Log), lower limb disuse (Fugl-Meyer Assessment of lower extremity [FMA-LE]), balance performance (Berg balance scale), and physical inactivity time (International Physical Activity Questionnaire-Short Form [IPAQ-SF]) of 195 stroke patients who visited the Kishiwada Rehabilitation Hospital were assessed at admission. The incidence of post-stroke CRPS was 15.4% in all stroke patients 3 months after admission. The IPAQ, FMA-UE, and FMA-LE were extracted as risk factors for post-stroke CRPS. According to the decision tree algorithm, the incidence of post-stroke CRPS was 1.5% in patients with a short physical inactivity time (IPAQ-SF < 635), while it increased to 84.6% in patients with a long inactivity time (IPAQ-SF ≥ 635) and severe disuse of upper and lower limbs (FMA-UE score < 19.5; FMA-LE score < 16.5). The incidence of post-stroke CRPS may increase with lower-limb disuse and physical inactivity, in addition to upper-limb disuse. Increasing physical activity and addressing lower- and upper-limb motor paralysis may reduce post-stroke CRPS.

Decrease in current perception thresholds of A-beta fibers by subthreshold noise stimulation using transcutaneous electrical nerve stimulation.

Developing effective supplements and rehabilitation of the impaired tactile and proprioception sensation is a significant challenge. One potential method for improving these sensations in clinical practice is using stochastic resonance with white noise. While transcutaneous electrical nerve stimulation (TENS) is a simple method, the effect of subthreshold noise stimulation via TENS on sensory nerve thresholds is currently unknown. This study aimed to investigate whether subthreshold TENS can alter afferent nerve thresholds. The electric current perception thresholds (CPT) of A-beta, A-delta, and C fibers were assessed in 21 healthy volunteers during both subthreshold TENS and control conditions. Subthreshold TENS was found to have lower CPT values compared to the control condition for A-beta fibers. No significant differences were observed between subthreshold TENS and control for A-delta and C fibers. Our findings indicated that subthreshold TENS might selectively enhance the function of A-beta fibers.

Influence of Daily Aerobic Exercise Duration on Phase 2 Cardiac Rehabilitation at a Rehabilitation Hospital and Health-Related Quality of Life After Discharge.

Background: Phase 2 in-patient cardiac rehabilitation (CR) at a rehabilitation hospital is now added the medical service fees in Japan and in light of the recent reimbursement for CR, a study needed to be performed to determine exertional exercise on its effectiveness and benefits to patients. We examined the effects of daily aerobic exercise duration on health-related quality of life (HR-QoL) at 6 months after discharge from phase 2 CR. Methods: Of the 54 consecutive cardiovascular disease patients admitted to a rehabilitation hospital after acute care, 43 were considered acceptable candidates for enrollment according to predetermined inclusion and exclusion criteria. Of these, 40 patients completed study requirements, including return of a questionnaire on HR-QoL survey 6 months after discharge. The primary outcome was HR-QoL as evaluated using the EuroQol five-dimension five-level (EQ-5D-5L). Two multiple regression models were constructed to assess the influences of daily aerobic exercise duration (content of rehabilitation) and other clinicodemographic variables assessed during acute care (model 1) or at transfer from acute care to a rehabilitation hospital (model 2). Results: Both model 1, which included age, Barthel index of daily function before hospitalization, and daily aerobic exercise duration in the rehabilitation hospital (R2 = 0.553, P < 0.001), and model 2, which included New York Heart Association functional classification at transfer, Charlson comorbidity index at transfer, and daily aerobic exercise duration (R2 = 0.336, P = 0.002) identified aerobic exercise duration as a significant independent factor influencing HR-QoL at 6 months post-discharge (model 1: P = 0.041; model 2: P = 0.010). Conclusions: Enhanced daily aerobic exercise content during phase 2 in-hospital CR can significantly improve longer-term HR-QoL among cardiovascular disease patients independently of other clinicodemographic factors, including age, activities of daily living before treatment, and baseline condition at rehabilitation onset. These findings, that in the small sample size, support the continued expansion of phase 2 CR at a rehabilitation hospital in Japan.

Effect of muscle load tasks with maximal isometric contractions on oxygenation of the trapezius muscle and sympathetic nervous activity in females with chronic neck and shoulder pain.

BACKGROUND: Sympathetic nervous activity contributes to the maintenance of muscle oxygenation. However, patients with chronic pain may suffer from autonomic dysfunction. Furthermore, insufficient muscle oxygenation is observed among workers with chronic neck and shoulder pain. The aim of our study was to investigate how muscle load tasks affect sympathetic nervous activity and changes in oxygenation of the trapezius muscles in subjects with chronic neck and shoulder pain. METHODS: Thirty females were assigned to two groups: a pain group consisting of subjects with chronic neck and shoulder pain and a control group consisting of asymptomatic subjects. The participants performed three sets of isometric exercise in an upright position; they contracted their trapezius muscles with maximum effort and let the muscles relax (Relax). Autonomic nervous activity and oxygenation of the trapezius muscles were measured by heart rate variability (HRV) and Near-Infrared Spectroscopy. RESULTS: Oxyhemoglobin and total hemoglobin of the trapezius muscles in the pain group were lower during the Relax period compared with the control group. In addition, the low frequency / high frequency (LF/HF) ratio of HRV significantly increased during isometric exercise in the control group, whereas there were no significant changes in the pain group. CONCLUSIONS: Subjects with neck and shoulder pain showed lower oxygenation and blood flow of the trapezius muscles responding to isometric exercise, compared with asymptomatic subjects. Subjects with neck and shoulder pain also showed no significant changes in the LF/HF ratio of HRV responding to isometric exercise, which would imply a reduction in sympathetic nervous activity.

Predictive Value of Pain Sensitization Associated with Response to Exercise Therapy in Patients with Knee Osteoarthritis: A Prospective Cohort Study.

Purpose: Knee osteoarthritis (KOA) is a degenerative disease with inflammation, becoming persistent as it progresses, resulting in reduced quality of life. Exercise is the recommended treatment for KOA; however, the extent of pain reduction with exercise is heterogeneous and the prognostic implications of baseline factors in patients undergoing exercise are still unknown. This study examined the association between the response to exercise therapy and clinical outcomes, radiologic severity, and pain sensitization, and investigated the optimal predictive value for the effectiveness of exercise. Patients and Methods: Demographics, radiologic severity, pressure pain threshold (PPT), and temporal summation of pain (TSP) at the knee, tibia, and forearm were assessed at baseline. The pain numeric rating scale (NRS) was assessed before and after 12 weeks of exercise. Patients were divided into responder/non-responder groups according to recommended criteria: responder, ≥30% reduction in pain; non-responder, <30% reduction in pain, and each variable was compared between the groups. The area under the curve (AUC) and cutoff points were determined by receiver operating characteristic curve analysis. Results: Sixty-five patients were categorized as responders and 26 as non-responders. In the non-responder group, baseline NRS (P<0.01), pain duration (P<0.01), and TSP at the knee (P<0.001) and tibia (P<0.05) were significantly higher, and PPT at the knee (P<0.001), tibia (P<0.001), and forearm (P<0.001) were significantly lower, than those in the responder group; however, no significant differences between groups were found in other demographics and radiologic severity. The variables that showed moderate or better predictive ability (AUC≥0.7) were PPT at the knee (cutoff points: 241.5 kPa), tibia (307.5 kPa), forearm (318.5 kPa), and TSP at the knee (15.5 mm). Conclusion: Our findings suggest that pain sensitization is associated with the response to exercise therapy. Furthermore, we provide clinically predictive values for PPT and TSP in predicting the outcome to exercise in KOA.

Inhibition of current perception thresholds in A-delta and C fibers through somatosensory stimulation of the body surface.

Somatosensory stimulation of the body surface, such as through tactile and noxious stimulation, is widely known to inhibit pain. However, no studies have measured the threshold changes due to somatosensory stimulation of each nerve fiber (Aß, Aδ, and C) separately. We examined the changes in the current perception thresholds of Aδ, C, and Aß fibers induced by non-noxious and noxious somatosensory stimulation of the body surface. The current stimuli were sinusoidal waves at frequencies of 2000 Hz, 250 Hz, and 5 Hz, which selectively stimulated the Aß, Aδ, and C fibers, respectively. In the case of non-noxious stimulation, lightly rubbing the dorsal side of the forearm with a brush showed no significant physiological or clinical changes in the current perception thresholds of the Aδ, and C fibers; a significant increase was observed only in the Aß fibers. However, applying noxious stimulation to the body surface through hand immersion in cold water increased pain thresholds in both the Aδ and C fibers, and sensory threshold of the Aß fibers; changes in tactile thresholds were not significant. Inhibition of sensory information by nociceptive inputs may selectively suppress nociceptive stimuli.

Pain Sensitization and Neuropathic Pain-like Symptoms Associated with Effectiveness of Exercise Therapy in Patients with Hip and Knee Osteoarthritis.

Pain sensitization and neuropathic pain-like symptoms are some of the common pain symptoms in patients with lower limbs, including hip and knee, osteoarthritis (HOA/KOA). Exercise therapy has been the first-line treatment; however, the effects differ for each patient. This prospective cohort study investigated the relationship between the effectiveness of exercise therapy and pretreatment characteristics (radiologic severity, pain sensitization, and neuropathic pain-like symptoms) of patients with HOA/KOA. We assessed the pain intensity using a numerical rating scale (NRS) before and after 12 weeks of exercise therapy in patients with HOA/KOA (n = 101). Before treatment, the Kellgren-Lawrence (K-L) grade; minimum joint space width (mJSW); pressure pain threshold (PPT) and temporal summation of pain (TSP) at the affected joint, tibia, and forearm; Central Sensitization Inventory-9; and painDETECT questionnaire (PDQ) were assessed. Cluster analysis was based on the pretreatment NRS and change in NRS with exercise therapy to identify the subgroups of pain reduction. The pretreatment characteristics of each cluster were compared. According to the results of the cluster analyses, patients in cluster 1 had severe pain that did not improve after exercise therapy, patients in cluster 2 had severe pain that improved, and those in cluster 3 had mild pain that improved. The patients in cluster 1 exhibited lower PPT at all measurement sites, higher TSP at the affected joint, and higher PDQ scores than those in other clusters. There was no difference in the K-L grade and mJSW among the clusters. The subgroup with severe pain and pain sensitization or neuropathic pain-like symptoms at pretreatment, even with mild joint deformity, may have difficulty in achieving improvement in pain after 12 weeks of exercise therapy. These findings could be useful for prognosis prediction and for planning exercise therapy and combining with other treatment.

Post-Stroke Complex Regional Pain Syndrome and Upper Limb Inactivity in Hemiplegic Patients: A Cross-Sectional Study.

Purpose: The purpose of this study was to investigate the prevalence of post-stroke complex regional pain syndrome (CRPS) and to examine the characteristics of inactivity status of the upper limb in post-stroke CRPS patients. In addition, as a sub-analysis, the association between the upper limb inactivity status and pain intensity was investigated in post-stroke CRPS patients. Patients and Methods: This cross-sectional study included 102 patients with first-ever stroke between April 2019 and February 2020. Each patient was allocated into one of two groups based on the presence or absence of CRPS. Demographic data (age, sex, stroke etiology, lesion side, and number of days since stroke onset) were collected. The following evaluations were performed in all patients: Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Motor Activity Log (MAL). The numerical rating scale (NRS) to determine pain intensity was assessed only in patients with post-stroke CRPS. Results: Nineteen and 83 patients were assigned to the post-stroke CRPS and control group, respectively. The prevalence of post-stroke CRPS was 18.6% (19/102). FMA, ARAT, and MAL scores were significantly lower in patients with post-stroke CRPS than those without it. FMA and ARAT scores were significantly correlated with NRS scores, but MAL was almost zero-scored in patients with post-stroke CRPS. Conclusion: The study results indicated that activity status of the affected upper limb was severely deteriorated, and more inactivity of the upper limb was associated with higher pain intensity in patients with post-stroke CRPS. Thus, our results suggest that post-stroke CRPS may be influenced by the degree of upper limb inactivity after stroke.

Effects of Exercise-Induced Hypoalgesia at Different Aerobic Exercise Intensities in Healthy Young Adults.

Purpose: Exercise-induced hypoalgesia (EIH) is a reduction in pain sensitivity that occurs following a single bout of exercise. However, little research has compared the EIH effects of exercise at different intensities, including low intensity, in the same participant. It is unclear as to which exercise intensities demonstrate EIH more effectively. The aim of this study was to examine and compare the effect of different intensities of exercise on pain sensitivity in the same participant. Methods: We included 73 healthy young adult volunteers (35 female and 38 male) in this experimental cross-over study. Each participant completed four experimental sessions of 30 min, consisting of aerobic exercise at 30% heart rate reserve (HRR), aerobic exercise at 50% HRR, aerobic exercise at 70% HRR, and quiet rest. EIH was assessed using the pressure pain threshold (PPT) and temporal summation of pain (TSP) in the quadriceps, biceps, and trapezius. Results: Low- and moderate-intensity exercise increased the multisegmental PPT and reduced TSP (all P < 0.05). High-intensity exercise increased the multisegmental PPT (all P < 0.05), but decreased TSP in only the quadriceps and biceps (P < 0.05), not the trapezius (P = 0.13). We found no difference in relative PPT and TSP changes between exercise intensities (P > 0.05) except for relative PPT change at the quadriceps (P < 0.05). Conclusion: Our results show that not only moderate- and high-intensity exercise, but also low-intensity exercise can produce a hypoalgesic response.

Comparative effects of acupressure at local and distal acupuncture points on pain conditions and autonomic function in females with chronic neck pain.

Acupressure on local and distal acupuncture points might result in sedation and relaxation, thereby reducing chronic neck pain. The aim was to investigate the effect of acupressure at local (LP) and distal acupuncture points (DP) in females with chronic neck pain. Thirty-three females were assigned to three groups: the control group did not receive any stimuli, the LP group received acupressure at local acupuncture points, GB 21, SI 14 and SI 15, and the DP group received acupressure at distal acupuncture points, LI 4, LI 10 and LI 11. Verbal rating scale (VRS), Neck Disability Index (NDI), State-Trait Anxiety Inventory (STAI), muscle hardness (MH), salivary alpha-amylase (sAA) activity, heart rate (HR), heart rate variability (HRV) values and satisfaction due to acupressure were assessed. VRS, NDI, STAI and MH values decreased after acupressure in the LP and the DP group. HR decreased and the power of high frequency (HF) component of HRV increased after acupressure in only the LP group. Although acupressure on not only the LP but also the DP significantly improved pain conditions, acupressure on only the LP affected the autonomic nervous system while acupuncture points per se have different physical effects according to location.