Complement component C3 is associated with body composition parameters and sarcopenia in community-dwelling older adults: a cross-sectional study in Japan.

BACKGROUND: Chronic inflammation is a factor in the pathogenesis of sarcopenia, which is characterized by low muscle mass and reduced strength. Complement C3 is important in the management of the immune network system. This study seeks to determine the relationship between serum C3 levels and body composition and sarcopenia-related status in community-dwelling older adults. METHODS: Study participants were 269 older adults living in rural Japan. A bioelectrical impedance analysis device was used to measure body composition parameters including body mass index (BMI), body fat percentage, waist-hip-ratio, and appendicular skeletal muscle mass index (SMI). Muscle function was measured by handgrip strength and 6-m walking speed. The correlation coefficients for C3 level and measurements were calculated using Pearson correlation analysis. Participants were categorized into normal, pre-sarcopenia, dynapenia, or sarcopenia groups. Sarcopenia was defined according to 2019 Asian Working Group for Sarcopenia definition, dynapenia was defined as low muscle function without low muscle mass, and pre-sarcopenia was defined as the presence of low muscle mass only. The C3 threshold score for sarcopenia status was evaluated by receiver operating characteristic curve (ROC) analysis. RESULTS: Significant positive correlations were found between C3 and BMI, body fat percentage, and waist-hip ratio in both sexes, and further positive correlations with SMI were found in women. The relationship with body fat percentage was particularly strong. Body composition measurements (BMI, body fat percentage, and waist- hip ratio) and C3 levels were lowest in the sarcopenia group compared with the others. ROC analysis showed that the significant threshold of C3 for discriminating between the normal and sarcopenia groups was 105 mg/dL. Multiple logistic regression analysis showed that participants with C3 < 105 mg/dL had an odds ratio of 3.27 (95% confidence interval, 1.49-7.18) for sarcopenia adjusted by sex, age and body fat percentage. CONCLUSION: C3 levels are suggested to be related to body composition and pathophysiological functions of sarcopenia. C3 is expected to become a useful biomarker for sarcopenia, for predicting the onset of the disease and for predicting the effectiveness of interventions.

Association of depressive symptoms with Geriatric Locomotive Function Scale score in community-dwelling older adults living in the state of emergency.

BACKGROUND: Under the state of emergency, it has been reported that the amount of physical activity among community-dwelling older adults has decreased significantly due to refraining from going out, and there are strong concerns about the Geriatric Locomotive Function Scale and deterioration of mental health. Therefore, this study aimed to investigate whether the depressive state before the coronavirus disease 2019 (COVID-19) pandemic affected the 25-Geriatric Locomotive (GLFS) score during the COVID-19 pandemic among community-dwelling older adults. METHODS: The participants were 194 community-dwelling older adults (45 men, 149 women) with an average age of 75.5 ± 5.5 years who responded to a self-administered survey conducted three times (preliminary, second, and third) from before the 2018 COVID-19 pandemic to March 2021. Individuals with a score of ≥ 10 on the Geriatric Depression Scale 15 (GDS 15) were excluded. The survey items included the 25-question Geriatric Locomotive Function Scale (GLFS25), GDS 15, and other basic attributes. Those with scores of 5 to 9 on the GDS 15 and those with scores of 0 to 4 were assigned to the depressive symptoms (DS) group and the non-DS group, respectively. Statistical analysis was performed using two-way analysis of variance. The Mann-Whitney U test was used for comparisons between the groups. RESULTS: In total, 187 patients were included in the analysis, excluding 7 patients. GLFS 25 showed a significant increase in scores at the second and third time points compared with baseline, and a main effect was confirmed in both groups, with no interaction effect. The second time, the score was 10.0 ± 8.5 and 13.7 ± 10.5 in the non-DS and DS groups, respectively. The third time, the non-DS and DS groups scored 10.8 ± 10.5 and 14.9 ± 10.1 points, respectively, indicating a significant difference. CONCLUSIONS: Our results revealed that the increase in the GLFS 25 score in community-dwelling older adults during the COVID-19 pandemic was related to their DS during normal times before the pandemic. Evaluating such individuals and providing social support may effectively reduce the deterioration of the GLFS 25 score.

Determination of individual factors associated with hallux valgus using SVM-RFE.

INTRODUCTION: This cross-sectional study aimed to determine the factors related to hallux valgus (HV) and their importance using support vector machine-recursive feature elimination (SVM-RFE). METHODS: A total of 864 participants aged ≥ 18 years were enrolled. The Manchester scale was used to determine the presence of HV (summed scores for both feet ≥ 4). The questionnaire included items such as age, sex, height, weight, and foot measurements. These internal factors were analyzed to determine if they are related to HV using SVM-RFE. RESULTS: The results of tenfold cross-validation using SVM-RFE revealed that the numbers of feature selections were 10, 10, and 9 for age, sex, and body weight, respectively, and these factors were shown to be related to HV. HV was found to be more common in women than in men (women, 24.9%; men, 7.6%), but the sex difference was not significant in older people. CONCLUSION: Age and sex were found to be important factors associated with HV identified via feature selection using SVM-RFE.

Ninjin'yoeito, a traditional Japanese medicine, attenuates age-related deficits of muscle performance, self-care motivation, and body temperature in C57BL/6 mice.

As both physiological and psychological factors influence age-associated declines in older people, the development of drug therapy with multifaceted effects is required. To investigate the utility of ninjin'yoeito (NYT) against geriatric syndromes, we evaluated the effects of NYT on age-related declines in old C57BL/6 mice (88-week-old) as a preclinical model of frailty progression. Here, we showed that NYT reversed the decline of rectal temperature in old mice and also improved forelimb grip strength compared with that in the old control group without affecting skeletal muscle loss. Moreover, NYT significantly increased the duration of grooming after a sucrose solution was sprayed, which reflected self-care motivation. Finally, we revealed the antioxidant effects of NYT using a cell-free assay. These results suggest that NYT can improve both physiological and psychological declines associated with aging, and the mechanism may include antioxidant effects. NYT may have potential utility for maintaining the health of older people.

Task-specific fear influences abnormal trunk motor coordination in workers with chronic low back pain: a relative phase angle analysis of object-lifting.

BACKGROUND: Pain-related fear influences impaired trunk movement (e.g., limited movement of range and velocity), but it is unclear how fear relates to trunk motor coordination (e.g., a more "in-phase" upper-lower trunk motion pattern). We conducted the present study to: (1) identify the motor coordination pattern of the in-phase upper-lower lumbar movements during the lifting, and (2) determine how pain-related fear is related to the trunk coordination pattern in workers with chronic low back pain (CLBP). METHODS: We examined 31 male workers with CLBP (CLBP group) and 20 healthy controls with no history of CLBP (HC group). The movement task was lifting a box, the weight of which was 10, 30%, or 50% of the subject's body weight. We used a 3D motion capture system to calculate the mean absolute relative phase angle (MARP) angle as an index of coordination and the mean deviation phase (DP) as an index of variability. We used a numerical rating scale to assess the subjects' task-specific fear. RESULTS: The MARP angle during trunk extension movement in the 50% condition was significantly decreased in the CLBP group compared to the HCs; i.e., the upper lumbar movement was more in-phase with the lower lumbar movement. The hierarchical multiple regression analysis results demonstrated that a decreased MARP angle was associated with high task-specific fear. CONCLUSIONS: A more 'in-phase' upper-lower lumbar movement pattern was predicted by task-specific fear evoked when performing a work-related activity. Our findings suggest that an intervention for task-specific fear may be necessary to improve an individual's impaired trunk motor coordination.

Association between serum insulin-like growth factor 1 and locomotive syndrome in community-dwelling older people.

BACKGROUND: Locomotive syndrome (LS) is a condition in which mobility decreases, and it is known as a risk factor for elderly persons needing care in connection with sarcopenia and frailty. Prevention or delay of the onset of these diseases is important for preventing the need for care, and identification of biomarkers as indicators for appropriate intervention is useful. The present study aimed to clarify whether the serum insulin-like growth factor 1 (IGF-1) level, which has been reported to be related to sarcopenia and frailty, is related to LS. METHODS: The study participants were 133 elderly people living in a rural area in Japan. LS was assessed using Locomo-25, which is a self-administered questionnaire, and LS was defined as a Locomo-25 score ≥ 7 points. Serum IGF-1 and albumin levels were measured. A self-completed medical history questionnaire was used. RESULTS: On multiple linear regression analysis, age, IGF-1, osteoporosis, and osteoarthritis were significantly associated with the Locomo-25 score. The receiver-operating characteristic curve analysis of the IGF-1 level showed a threshold value of 82.0 ng/mL for discriminating non-LS and LS. The logistic regression analysis adjusted for osteoporosis, osteoarthritis, and the propensity score estimated from sex, age, and BMI showed that the odds ratio (OR) of the IGF-1 level for LS was 1.019 (95% confidence interval [CI], 1.002-1.039; p = 0.027), and the OR of IGF-1 ≤ 82 ng/mL for LS was 2.275 (95% CI 0.993-5.324; p = 0.052). CONCLUSIONS: The present findings suggest that osteoporosis and osteoarthritis were associated with early LS, and a decrease of the serum IGF-1 level was a significant independent factor for early LS.

Does a combination of self-reported signs related to central sensitization and pressure pain threshold allow for a more detailed classification of pain-related characteristics in patients with chronic musculoskeletal pain?: A cross-sectional study.

OBJECTIVES: The clinical utility of combining the central sensitization (CS) inventory (CSI) with the pressure pain threshold (PPT) in assessing the effect of central sensitization on pain is unknown. This study aimed to investigate the effects of CSI, PPT, and their interaction on pain and the characteristics of clinical symptoms in patients with chronic musculoskeletal pain grouped according to the CSI score and PPT value. METHOD: A total of 187 participants with chronic musculoskeletal pain were recruited. PPT, brief pain inventory, widespread pain index, pain catastrophizing scale, EuroQol-5 dimension, and CSI were assessed. Multiple regression analyses were performed using pain intensity and interference scores as dependent variables and the CSI score and PPT value as independent variables. Hierarchical cluster analysis was also performed to classify the participants into subgroups according to the CSI score and PPT value. Following the classification, pain-related characteristics and health-related QOL were compared among the subgroups. RESULTS: Multiple regression analyses demonstrated that only the CSI score significantly affected pain intensity and interference. As a result of the cluster analysis, three groups were identified: cluster 1 (n = 61, CSI low/PPT low group), cluster 2 (n = 78, CSI low/PPT high group), and cluster 3 (n = 48, CSI high/PPT low group). The CSI high/PPT low group had a higher incidence of pain-related symptoms than the CSI low group regardless of the PPT value. CONCLUSIONS: Combined CSI and PPT may not fully allow a detailed classification of pain-related characteristics. The CSI may be clinically more useful for assessing the effect of CS on pain-related symptoms.

Effect of perioperative pain neuroscience education in patients with post-mastectomy persistent pain: a retrospective, propensity score-matched study.

PURPOSE: Central sensitization (CS)-related symptoms and pain catastrophizing contribute to persistent post-mastectomy pain (PPMP). Pain neuroscience education (PNE) is effective in reducing CS-related symptoms and pain catastrophizing in patients with chronic pain. However, to date, no intervention study of PNE has been conducted to patients with PPMP. This study was aimed to examine whether PNE is more effective than biomedical education (BME) for PPMP. METHODS: In this retrospective case-control study, 118 patients were included. We intervened different patients at different times as follows: (1) a BME group (n = 58) of patients who received BME combined with physiotherapy and (2) a PNE group (n = 60) of patients who received PNE combined with physiotherapy. One year after surgery, we assessed pain intensity and interference (brief pain inventory [BPI]), CS-related symptoms (central sensitization inventory [CSI]), and pain catastrophizing (pain catastrophizing scale [PCS]). Propensity score matching was used to reduce or minimize selection bias and confounding biases and to make the number of cases in both groups match 1:1. RESULTS: Propensity score matching generated the BME group (n = 51) and the PNE group (n = 51). The BPI score, CSI score, and PCS score were statistically significantly lower in the PNE group than in the BME group (all, p < 0.05). The effect sizes for the BPI intensity (r = 0.31) were moderate. CONCLUSIONS: PNE resulted in a better outcome of pain management with less functional disability and CS-related symptoms compared to BME after breast surgery.

Impact of Phase Angle on Physical Function in Patients with Acute Stroke.

OBJECTIVE: Phase angle, an assessment of muscle quality, might be a possible predictor of physical function in patients with an acute stroke; however, the evidence for the same is limited. Therefore, this study aimed to investigate whether phase angle is associated with improved physical function at discharge. METHODS: In this observational cohort study, we determined the phase angle in patients with an acute stroke using a portable, noninvasive multifrequency bio-impedance device. The primary objective was the assessment of physical function using the Functional Independence Measure motor (FIM-motor) at discharge in the acute phase. The secondary outcome was home discharge. Multiple regression analysis was used to determine the association between phase angle, FIM-motor score, and home discharge. RESULTS: The study included 129 patients (78 men; mean age 75.2 years). Multiple linear regression analysis showed that the phase angle was independently associated with FIM-motor score at discharge in all models (Model 1: ß= 0.27, p < 0.001; Model 2: ß = 0.234, p < 0.001; Model 3: ß = 0.201, p = 0.017). However, multiple logistic regression analysis showed that the phase angle was not associated with home discharge (p = 0.464). CONCLUSIONS: The phase angle at the onset of a stroke, is an independent predictor of physical function at discharge in the acute phase. Our findings highlight the importance of determining the phase angle in patients with an acute stroke.

Increased anxiety about falls and walking ability among community-dwelling Japanese older adults during the COVID-19 pandemic.

BACKGROUND: Understanding the physical and mental changes in community-dwelling elderly people is very important during the coronavirus disease 2019 (COVID-19) pandemic when considering preventive measures. The purpose of this study was to clarify the changes of physical function and anxiety for activities of daily living in community-dwelling older adults, focusing on locomotor function during the COVID-19 pandemic. METHODS: The study participants were 127 older people who participated in successive surveys, in the summers of 2019 and again in 2020, after the state of emergency. The Locomo 25 questionnaire, Geriatric Depression Scale-15 (GDS-15) questionnaire, medical history, and number of people living together were self-reported. The Locomo 25 covers six aspects of physical pain, movement-related difficulty, usual care, daily activity, social activities, and anxiety. RESULTS: The paired samples t-test revealed that Locomo 25 total scores in 2020 were significantly higher than those in 2019. The GDS-15 score showed no significant difference. The comparison of scores for each item of the Locomo 25 revealed significantly higher scores in 2020 on Q21 ('difficult to perform sports activity', P = 0.0021), Q22 ('restricted from meeting own friends', P < 0.001), Q23 ('restricted from joining social activities', P < 0.001), Q24 ('anxious about falling in own house', P = 0.0023), and Q25 ('anxious about being unable to walk in the future', P = 0.0016). CONCLUSIONS: About 2 months after declaration of the first state of emergency due to the COVID-19 pandemic in Japan, social activity was severely restricted. Older adults showed almost no changes in body pain and locomotive disabilities, but increases in their anxieties about walking ability and falling were remarkable.

Combination of Pain Location and Pain Duration is Associated with Central Sensitization-Related Symptoms in Patients with Musculoskeletal Disorders: A Cross-Sectional Study.

OBJECTIVES: Increased evidence indicates that pain location affects central sensitization (CS)-related symptoms. In addition, pain location and pain duration may be intricately related to CS-related symptoms. However, these factors have been investigated separately. This study aimed to investigate the association between CS-related symptoms and pain location and/or pain duration in patients with musculoskeletal disorders. METHODS: Six hundred thirty-five participants with musculoskeletal disorders were included in this cross-sectional study. All participants were assessed for pain location, pain duration, central sensitization inventory (CSI), EuroQol-5 dimension, and brief pain inventory. The participants were categorized into 3 groups based on pain location (spinal, limb, and both spinal and limb pain) and into 2 groups based on pain duration (acute and chronic pain). RESULTS: The interaction between pain location and pain duration were not significant on CSI score (P > 0.05). The odds ratio for higher CSI score (≥ 40) in patients with both spinal and limb pain vs. those with spinal or limb pain was 2.64 (P < 0.01) and that in patients with chronic pain vs. those with acute pain was 1.31 (P = 0.52). In addition, the prevalence of higher CSI scores in the combination of chronic and "both spinal and limb" pain was high (23.1%, adjusted residual = 4.48). CONCLUSIONS: Pain location independently influenced CSI scores, and the combination of both spinal and limb pain and chronic pain indicated high CSI scores. The combination of pain location and pain duration is an important clue that points to CS-related symptoms.

Facile synthesis of size- and shape-controlled freestanding Au nanohole arrays by sputter deposition using anodic porous alumina templates.

To fabricate a freestanding through-hole Au membrane using an anodic porous alumina template, Au was deposited on the outermost surface of an anodic film followed by the removal of the template. Alumina templates with different dimensions (e.g. diameters and number of pores) were prepared by two-step anodization in the range of 40-80 V and pore-widening. The Au thin films were deposited onto alumina templates with well-controlled surface morphologies by sputter deposition using a commercially available ion sputter coater. After the removal of the alumina template, a variety of Au membranes with nanoholes, nanotubes, or branched pores were obtained, which reflect the morphology of the alumina template. When the sputtered Au penetrates the pores of the alumina film, Au nanotube arrays with an aspect ratio of ∼3 can be fabricated. The present method is much simpler than the traditional template process involving multi-step replication because there is no need to separate the alumina template from the aluminum substrate before Au deposition.

Development of More Precise Measurement to Predict Pain 1 Month Postoperatively Based on Use of Acute Postoperative Pain Score in Patients With Distal Radial Fracture.

BACKGROUND: A method for modeling the acute pain trajectory using the simple linear fit of an individual's pain intensity scores after surgery was developed and affords more precise measurement than conventional pain assessment. However, the method has the disadvantage of using only the slope without considering the intercept. The purpose of this study was to verify our modification of the pain trajectory model including slope and intercept and to identify clusters. METHODS: The pain intensity was measured in 60 patients after surgery, and we calculated their pain trajectories. The pain trajectory normally resolves in intensity over a period of days, and the linear fit of an individual patient's pain intensity score defines the trajectory. In this simple linear model (x axis, days; y axis, pain intensity), each patient's trajectory has the slope and the intercept. A multiple regression analysis model known as structural equation modeling was used to predict postoperative pain at 30 days after surgery. Finally, we performed hierarchical cluster analysis using the pain trajectory. RESULTS: The slope and intercept model was the best fit among the models. Based on cluster analysis results, we created 4 pain trajectory groups (slope and intercept). CONCLUSION: Our results suggest that the pain trajectory using the slope and intercept is quite useful for predicting postoperative pain at 30 days after surgery. Additionally, patients were classified into 4 groups using the slope and intercept. By considering both the slope and intercept, clinicians may be able to detect the risk for prolonged pain earlier than other methods.

Excitability of oxytocin neurons in paraventricular nucleus is regulated by voltage-gated potassium channels Kv4.2 and Kv4.3.

Oxytocin is produced by neurons in the paraventricular nucleus (PVN) and the supraoptic nucleus in the hypothalamus. Various ion channels are considered to regulate the excitability of oxytocin neurons and its secretion. A-type currents of voltage-gated potassium channels (Kv channels), generated by Kv4.2/4.3 channels, are known to be involved in the regulation of neuron excitability. However, it is unclear whether the Kv4.2/4.3 channels participate in the regulation of excitability in PVN oxytocin neurons. Here, we investigated the contribution of the Kv4.2/4.3 channels to PVN oxytocin neuron excitability. By using transgenic rat brain slices with the oxytocin-monomeric red fluorescent protein 1 fusion transgene, we examined the excitability of oxytocin neurons by electrophysiological technique. In some oxytocin neurons, the application of Kv4.2/4.3 channel blocker increased firing frequency and membrane potential with extended action potential half-width. Our present study indicates the contribution of Kv4.2/4.3 channels to PVN oxytocin neuron excitability regulation. Abbreviation: PVN, paraventricular nucleus; Oxt-mRFP1, Oxt-monometric red fluorescent protein 1; PaTx-1, Phrixotoxin-1; TEA, Tetraethylammonium Chloride; TTX, tetrodotoxin; aCSF, artificial cerebrospinal fluid;PBS, phosphate buffered saline 3v, third ventricle.

Kinesiophobia modulates lumbar movements in people with chronic low back pain: a kinematic analysis of lumbar bending and returning movement.

PURPOSE: We aimed to kinematically analyze lumbar bending and returning movements and clarify the relationship between fear of movement and kinematic output. METHODS: We recruited 45 participants with CLBP (i.e., > 6 months) and 20 healthy control (HC) participants with no history of CLBP. We used the numerical rating pain scale (NRS), Tampa Scale for Kinesiophobia (TSK-11), and Pain Self-Efficacy Questionnaire (PSEQ-2) as qualitative outcome measurements. CLBP participants were divided into two subgroups (high- and low-fear groups) based on the median split of the total TSK-11 score. In the kinematic recording session, a starting-cue beep signaled participants to bend forward using the lumbar region of their spine and then return to an upright posture, and we used a flexible twin-axis electrogoniometer to record the lumbar movements. The time series of lumbar movements was divided into four phases according to lumbar movement velocity, and we calculated the length (sec) of each phase. RESULTS: Phase 1 (duration prior to cue-induced movement initiation) and phase 3 (switch in the direction of lumbar movement from forward to backward) were significantly longer in the CLBP high-fear group compared with those in the CLBP low-fear group and HC group (p < 0.05). The increased lengths of these two phases were positively correlated with not only pain intensity but also TSK-11 scores (p < 0.05). CONCLUSIONS: These results represent evidence of a particular lumbar movement pattern associated with kinesiophobia. These results might help to identify psychological factors that impact lumbar movement patterns in individuals with CLBP. These slides can be retrieved under Electronic Supplementary Material.

Correction to: Kinesiophobia modulates lumbar movements in people with chronic low back pain: a kinematic analysis of lumbar bending and returning movement.

In the figure 2, "CLBP Low fear" located at the right end of Time of Phase 1 is wrong. The correct statement is "CLBP High fear". The complete correct figure 2 is given below.

[6]-gingerol and [6]-shogaol, active ingredients of the traditional Japanese medicine hangeshashinto, relief oral ulcerative mucositis-induced pain via action on Na+ channels.

The traditional Japanese herbal medicine hangeshashinto (HST) has beneficial effects for the treatment of oral ulcerative mucositis (OUM) in cancer patients. However, the ingredient-based mechanism that underlies its pain-relieving activity remains unknown. In the present study, to clarify the analgesic mechanism of HST on OUM-induced pain, we investigated putative HST ingredients showing antagonistic effects on Na+ channels in vitro and in vivo. A screen of 21 major ingredients using automated patch-clamp recordings in channel-expressing cells showed that [6]-gingerol and [6]-shogaol, two components of a Processed Ginger extract, considerably inhibited voltage-activated Na+ currents. These two ingredients inhibited the stimulant-induced release of substance P and action potential generation in cultured rat sensory neurons. A submucosal injection of a mixture of [6]-gingerol and [6]-shogaol increased the mechanical withdrawal threshold in healthy rats. In a rat OUM model, OUM-induced mechanical pain was alleviated 30min after the swab application of HST despite the absence of anti-bacterial and anti-inflammatory actions in the OUM area. A swab application of a mixture of [6]-gingerol and [6]-shogaol induced sufficient analgesia of OUM-induced mechanical or spontaneous pain when co-applied with a Ginseng extract containing abundant saponin. The Ginseng extract demonstrated an acceleration of substance permeability into the oral ulcer tissue without an analgesic effect. These findings suggest that Na+ channel blockage by gingerol/shogaol plays an essential role in HST-associated analgesia of OUM-induced pain. This pharmacological mechanism provides scientific evidence supporting the use of this herbal medicine in patients suffering from OUM-induced pain.

Effect of illusory kinesthesia on hand function in patients with distal radius fractures: a quasi-randomized controlled study.

OBJECTIVES: We investigated the effects of the illusion of motion through tendon vibration on hand function in patients with distal radius fractures. SETTING: Kawachi General Hospital, Japan. SUBJECTS: A total of 22 patients with distal radius fractures were divided into either an illusory kinesthesia group ( n = 11) or a control group ( n = 11). INTERVENTION: We performed the intervention for seven consecutive days after surgery. Evaluations were performed at one day, seven days, one month, and two months postsurgery. MAIN MEASURES: Data were collected on pain at rest and pain during movement. The Patient-Rated Wrist Evaluation and Pain Catastrophizing Scale were also used. RESULTS: The illusory kinesthesia group showed significantly better scores on Patient-Rated Wrist Evaluation ( p < 0.01) compared with the control group at seven days, one month, and two months postsurgery. The mean (SD) of the Patient-Rated Wrist Evaluation total score was 97.6 (2.2) at one day postsurgery and 9.1 (5.3) at seven days postsurgery in the illusory kinesthesia group, while the Patient-Rated Wrist Evaluation total score was 96.3 (4.4) at one day postsurgery and 20.1 (17.0) at seven days postsurgery in the control group. CONCLUSION: Our results indicate that illusory kinesthesia is an effective postsurgery management strategy not only for pain alleviation, but also hand function in patients with distal radius fractures. Furthermore, the significant improvements persisted for up to two months after intervention in the illusory kinesthesia group, but not in the control group. In addition, patients in the kinesthetic illusions group showed increased use of the affected limb in daily living.

The influence of trait anxiety and illusory kinesthesia on pain threshold.

[Purpose] It has also been reported that decreased activity in the reward pathway causes a decrease in brain activity in the descending pain control system in people with high trait anxiety. Activation of this system is dependent on both the reward pathway and motor areas. Recently, studies have also shown that motor areas are activated by illusory kinesthesia. It was aimed to explore whether anxiety trait modulates the influence of illusory kinesthesia on pain threshold. [Subjects and Methods] The pain threshold and trait anxiety at rest before vibratory tendon stimulation (the task) were measured. After the task, the pain threshold, the illusory kinesthesia angle, and the intensity of illusory kinesthesia for patients with and without illusory kinesthesia were measured. A total of 35 healthy right-handed students participated, among whom 22 and 13 were included in the illusion and no-illusion groups, respectively. [Results] There was a significant increase in the pain threshold after task completion in both groups; however, there was no statistically significant difference between the two groups. Correlational analysis revealed that State-Trait Anxiety Inventory-trait score correlated negatively with the pain threshold in the no-illusion group, but there was no correlation in the illusion group. [Conclusion] The pain threshold improved regardless of the size of trait anxiety in the illusion group, but did not improve merely through sensory input by vibratory stimulation in the no-illusion group. Thus, illusory kinesthesia has effect of increasing the pain threshold.

EEG frequency analysis of cortical brain activities induced by effect of light touch.

In human postural control, touching a fingertip to a stable object with a slight force (<1 N) reduces postural sway independent of mechanical support, which is referred to as the effect of light touch (LT effect). The LT effect is achieved by the spatial orientation according to haptic feedback acquired from an external spatial reference. However, the neural mechanism of the LT effect is incompletely understood. Therefore, the purpose of this study was to employ EEG frequency analysis to investigate the cortical brain activity associated with the LT effect when attentional focus was strictly controlled with the eyes closed during standing (i.e., control, fixed-point touch, sway-referenced touch, and only fingertip attention). We used EEG to measure low-alpha (about 8-10 Hz) and high-alpha rhythm (about 10-12 Hz) task-related power decrease/increase (TRPD/TRPI). The LT effect was apparent only when the subject acquired the stable external spatial reference (i.e., fixed-point touch). Furthermore, the LT-specific effect increased the high-alpha TRPD of two electrodes (C3, P3), which were mainly projected from cortical brain activities of the left primary sensorimotor cortex area and left posterior parietal cortex area. Furthermore, there was a negative correlation between the LT effect and increased TRPD of C3. In contrast, the LT effect correlated positively with increased TRPD of P3. These results suggest that central and parietal high-alpha TRPD of the contralateral hemisphere reflects the sensorimotor information processing and sensory integration for the LT effect. These novel findings reveal a partial contribution of a cortical neural mechanism for the LT effect.