Examining Movement Patterns, Skeletal Muscle Mass, and Hip Mobility in Office Workers With or Without Lower Back Pain: An Analytical Cross-Sectional Study.

OBJECTIVES: The purpose of this study was to clarify the relationship between Functional Movement Screen (FMS), skeletal muscle mass, and hip mobility in office workers with or without chronic lower back pain (LBP), as well as to determine whether the above items differed between office workers with or without chronic LBP. METHODS: This study utilized an analytic cross-sectional design. The participants were 35 office workers (14 in the LBP group and 21 in the non-lower back pain group, or NLBP) who were willing to cooperate with the request for cooperation in this study. Movement patterns were assessed by FMS and skeletal muscle mass was measured by bioelectrical impedance analysis. Hip mobility was measured by prone hip extension (PHE) and straight leg raising. The correlations between each item and differences in the presence or absence of LBP were analyzed. RESULTS: The LBP and NLBP groups showed different correlations (p<0.05) between total and subcategory scores and skeletal muscle mass. Total FMS score (p=0.02, r=-0.40) and PHE angle (p=0.01, r=0.43) were significantly higher in the LBP group than in the NLBP group. CONCLUSIONS: The FMS shows different relationships between total and subcategory scores and skeletal muscle mass for office workers with or without LBP. In addition, office workers with LBP may have different movement patterns and greater hip extension range of motion than those without LBP.

Characteristics of injuries related to Kin-Ball sport in Japan: A questionnaire study.

INTRODUCTION: The number of Kin-Ball sport participants is expected to increase in the future. However, there is no report on the characteristics of the injuries associated with Kin-Ball sport. OBJECTIVE: The purpose of this study was to describe the characteristics of injuries relate to Kin-Ball sport. DESIGN: Observational study. SETTING: A self-administered questionnaire was used for data collection. PARTICIPANTS: One hundred ninety Kin-Ball sport participants were included in this study. MAIN OUTCOME MEASURES: The questionnaire was designed based on physical characteristics, participation in Kin-Ball sport, and Kin-Ball sport injuries. Participation in Kin-Ball sport includes the length of time spent playing Kin-Ball sport as well as the playing categories (junior, friendly, champion challenge, champion, over 40). Kin-Ball sport injuries include the presence or absence of injury experience, the site, type, situation, and current injuries or pain associated with Kin-Ball sport. RESULTS: One hundred fifty-two players (80%) of Kin-Ball sport participants were injured. The ankle was the most frequently visited body site (60; 22.1%), and the elbow was the second most visited body site (40; 14.8%). Sprains were the most common type of injury. CONCLUSION: This is the first study to describe the characteristics of injuries relate to Kin-Ball sport. The findings of this study could be beneficial for athletes, coaches, trainers, and clinicians to prevent, or treatment of the injuries.

The Components of Lumbar Motor Control Are Not Inter-related.

OBJECTIVES: To verify the relationship between the indicators of components of lumbar motor control and determine the factors related to the indicators to each of these components. METHODS: Twenty-five healthy university students were included in the study. The lumbar spine and hip kinematic parameters of posterior/anterior pelvic tilt (mobility and smoothness), ball catching (reactivity), and forward/backward rocking (adaptive stability) were measured as indicators of lumbar motor control. Lumbar proprioception, trunk muscle strength, and lower trunk muscle thickness were also measured. Kinematic parameters of the lumbar spine and hip were measured using a small accelerometer. The data verified the relevance of indicators of lumbar motor control and the relationship with relevant factors. RESULTS: No significant correlations were found for most lumbar motor control indicators. Lumbar proprioception and rectus abdominis muscle thickness were identified as relevant indicators of lumbar motor control. CONCLUSIONS: Each component of lumbar motor control is independent and must be evaluated for the component whose function is required. Additionally, some components of lumbar motor control are associated with lumbar proprioception and rectus abdominis muscle thickness; thus, evaluation of these components is necessary when evaluating lumbar motor control.

Effects of 6 weeks of whole-body vibration training on ankle motor control: a randomized controlled trial.

BACKGROUND: Interventions on ankle motor control are important to prevent recurrent ankle sprains. Training using whole-body vibration may easily and effectively improve ankle motor control, but the effects have not been investigated. Therefore, this study aimed to clarify the effects of 6 weeks of training with whole-body vibration on ankle motor control in a dynamic movement task among healthy participants. METHODS: Twenty healthy university students (6 males and 14 females) were randomly allocated to whole-body vibration training and control groups, with 10 participants in each group. The training was performed twice a week for 6 weeks in both groups. Primary outcome was mean ankle angular jerk cost in the star excursion balance test. Secondary outcomes were maximum ankle motion angle and maximum reach distance in the star excursion balance test, ankle proprioception, and range of ankle dorsiflexion motion in the loaded position. RESULTS: There was a significant group × period (pre- and postintervention) interaction for mean ankle angular jerk cost in the direction of ankle abduction/adduction during posterolateral reaching, which was significantly lower at postintervention than that at preintervention in the whole-body vibration group In the whole-body vibration group, the maximum ankle dorsiflexion motion angle during anterior and posterolateral reaching was significantly higher at postintervention than that at preintervention. CONCLUSIONS: Training with whole-body vibration improves ankle motor control in dynamic movement tasks, although the direction of reach and plane of motion are limited. Additionally, training with whole-body vibration is also effective in increasing the ankle dorsiflexion angle during dynamic movement tasks.

The Effects of Aging on Sarcoplasmic Reticulum-Related Factors in the Skeletal Muscle of Mice.

The pathogenesis of sarcopenia includes the dysfunction of calcium homeostasis associated with the sarcoplasmic reticulum; however, the localization in sarcoplasmic reticulum-related factors and differences by myofiber type remain unclear. Here, we investigated the effects of aging on sarcoplasmic reticulum-related factors in the soleus (slow-twitch) and gastrocnemius (fast-twitch) muscles of 3- and 24-month-old male C57BL/6J mice. There were no notable differences in the skeletal muscle weight of these 3- and 24-month-old mice. The expression of Atp2a1, Atp2a2, Sln, and Pln increased with age in the gastrocnemius muscles, but not in the soleus muscles. Subsequently, immunohistochemical analysis revealed ectopic sarcoplasmic reticulum calcium ion ATPase (SERCA) 1 and SERCA2a immunoreactivity only in the gastrocnemius muscles of old mice. Histochemical and transmission electron microscope analysis identified tubular aggregate (TA), an aggregation of the sarcoplasmic reticulum, in the gastrocnemius muscles of old mice. Dihydropyridine receptor α1, ryanodine receptor 1, junctophilin (JPH) 1, and JPH2, which contribute to sarcoplasmic reticulum function, were also localized in or around the TA. Furthermore, JPH1 and JPH2 co-localized with matrix metalloproteinase (MMP) 2 around the TA. These results suggest that sarcoplasmic reticulum-related factors are localized in or around TAs that occur in fast-twitch muscle with aging, but some of them might be degraded by MMP2.

Action Sequence Learning Is Impaired in Genetically Modified Mice with the Suppressed GABAergic Transmission from the Thalamic Reticular Nucleus to the Thalamus.

The thalamic reticular nucleus (TRN) is a thin sheet of GABAergic neurons surrounding the thalamus, and it regulates the activity of thalamic relay neurons. The TRN has been reported to be involved in sensory gating, attentional regulation, and some other functions. However, little is known about the contribution of the TRN to sequence learning. In the present study, we examined whether the TRN is involved in reward-based learning of action sequence with no eliciting stimuli (operant conditioning), by analyzing the performance of male and female Avp-Vgat-/- mice (Vgatflox/flox mice crossed to an Avp-Cre driver line) on tasks conducted in an operant box having three levers. Our histological and electrophysiological data demonstrated that in adult Avp-Vgat-/- mice, vesicular GABA transporter (VGAT) was absent in most TRN neurons and the GABAergic transmission from the TRN to the thalamus was largely suppressed. The performance on a task in which mice needed to press an active lever for food reward showed that simple operant learning of lever pressing and learning of win-stay and lose-shift strategies are not affected in Avp-Vgat-/- mice. In contrast, the performance on a task in which mice needed to press three levers in a correct order for food reward showed that learning of the order of lever pressing (action sequence learning) was impaired in Avp-Vgat-/- mice. These results suggest that the TRN plays an important role in action sequence learning.

Effects of Aging on Collagen in the Skeletal Muscle of Mice.

Aging affects several tissues in the body, including skeletal muscle. Multiple types of collagens are localized in the skeletal muscle and contribute to the maintenance of normal muscle structure and function. Since the effects of aging on muscle fibers vary by muscle fiber type, it is expected that the effects of aging on intramuscular collagen might be influenced by muscle fiber type. In this study, we examined the effect of aging on collagen levels in the soleus (slow-twitch muscle) and gastrocnemius (fast-twitch muscle) muscles of 3-, 10-, 24-, and 28-month-old male C57BL/6J mice using molecular and morphological analysis. It was found that aging increased collagen I, III, and VI gene expression and immunoreactivity in both slow- and fast-twitch muscles and collagen IV expression in slow-twitch muscles. However, collagen IV gene expression and immunoreactivity in fast-twitch muscle were unaffected by aging. In contrast, the expression of the collagen synthesis marker heat shock protein 47 in both slow- and fast-twitch muscles decreased with aging, while the expression of collagen degradation markers increased with aging. Overall, these results suggest that collagen gene expression and immunoreactivity are influenced by muscle fiber type and collagen type and that the balance between collagen synthesis and degradation tends to tilt toward degradation with aging.

Effects of Obesity in Old Age on the Basement Membrane of Skeletal Muscle in Mice.

Obesity and aging are known to affect the skeletal muscles. Obesity in old age may result in a poor basement membrane (BM) construction response, which serves to protect the skeletal muscle, thus making the skeletal muscle more vulnerable. In this study, older and young male C57BL/6J mice were divided into two groups, each fed a high-fat or regular diet for eight weeks. A high-fat diet decreased the relative gastrocnemius muscle weight in both age groups, and obesity and aging individually result in a decline in muscle function. Immunoreactivity of collagen IV, the main component of BM, BM width, and BM-synthetic factor expression in young mice on a high-fat diet were higher than that in young mice on a regular diet, whereas such changes were minimal in obese older mice. Furthermore, the number of central nuclei fibers in obese older mice was higher than in old mice fed a regular diet and young mice fed a high-fat diet. These results suggest that obesity at a young age promotes skeletal muscle BM formation in response to weight gain. In contrast, this response is less pronounced in old age, suggesting that obesity in old age may lead to muscle fragility.

Effects of stretching on the basement membrane structure in the soleus muscle of Wistar rats.

The basement membrane (BM), mainly composed of collagen IV, plays an important role in the maintenance, protection, and recovery of muscle fibers. Collagen IV expression is maintained by the balance between synthetic and degradative factors, which changes depending on the level of muscle activity. For example, exercise increases collagen IV synthesis, whereas inactivity decreases collagen IV synthesis. However, the effects of stretching on the BM structure remain unclear. Therefore, to investigate the effects of stretching on the BM of the skeletal muscle, we continuously applied stretching to the rat soleus muscle and examined the altered expression of BM-related factors and structure using quantitative polymerase chain reaction (qPCR), western blotting, zymography, immunohistochemistry, and electron microscopy. The results show that stretching increased the matrix metalloproteinase 14 (MMP14) expression and MMP2 activity, and decreased the collagen IV expression and width of the lamina densa in the soleus muscle. These results suggest that stretching promotes BM degradation in the rat soleus muscle. The findings of this study indicate a new influence of stretching on skeletal muscles, and may contribute to the new use of stretching in rehabilitation and sports fields.

Relationship between ankle-joint angle during dynamic balance task and ankle-joint proprioception in chronic ankle-instability individuals.

BACKGROUND: Chronic ankle instability (CAI) is a major condition in athletes. It is known that both ankle joint proprioception and joint motion control are important for the improvement of CAI, but the relationship between the two has not been clarified. The purpose of this study was to compare ankle-joint angle in dynamic balance tasks and ankle-joint proprioception in healthy and CAI individuals and to verify the relationship between ankle-joint angle in dynamic balance tasks and ankle-joint proprioception in individuals with CAI. METHODS: The participants were 27 females (age 20.3±0.9 years, healthy group: 15, CAI group: 12). The star excursion balance test (SEBT) was used for the dynamic balance task, and the ankle joint angles were measured with a small accelerometer during the movement. The error of the active joint repositioning test (AJRT) was measured to test the proprioception. RESULTS: There was no significant difference in the error in AJRT between the groups, but the joint angle in SEBT was significantly lower in the CAI group than in the healthy group for ankle dorsiflexion only. The error in AJRT of ankle inversion was correlated with the ankle inversion/eversion angle of the SEBT, and the error in AJRT of ankle plantar flexion was correlated with the ankle-dorsiflexion angle of the SEBT. CONCLUSIONS: CAI individuals showed no difference in ankle-joint proprioception compared to healthy individuals, but their ankle-joint-dorsiflexion angle in the dynamic balance task was smaller. Ankle-joint proprioception in CAI individuals was related to the ankle-joint angle in the dynamic balance task.

The relationship between scapular position and glenohumeral rotational range of motion in high school baseball players.

BACKGROUND: Past research indicated that scapular malposition is related to the glenohumeral internal rotation deficit (GIRD). However, there is no research examining the effect of throwing-related pain on this relationship. This study investigated the relationship between scapular position and range of motion (ROM) and compared the difference in this relationship between with and without throwing-related pain. METHODS: Forty male baseball players in high school were recruited for this study. The existence and degree of throwing-related pain were obtained from a questionnaire. Participants were divided into 2 groups according to the presence or absence of the pain. Glenohumeral internal and external rotation ROM (abduction internal rotation angle and abduction external rotation angle [ABER], respectively) were measured using a digital inclinometer. The pectoralis minor muscle length was measured using a vernier caliper and scapula index, which indicated the scapular position, measured using a measuring tape. All these measurements were taken on both dominant and nondominant sides. The GIRD and total motion arc (TMA) deficit were calculated from the ROM measurements. Groups were compared using a mixed-model analysis of variance. RESULTS: There was a significant interaction between group and ABER dominance. Other variables were not seen as the interaction effect. There was a significant positive correlation between the scapula index and TMA (r = 0.47, P = .02) and a negative correlation between the scapula index and GIRD (r = -0.65, P < .01) in the dominant side of the pain group. In addition, in the nondominant side of the pain group, the scapula index and ABER were significantly correlated (r = 0.43, P = .04). CONCLUSIONS: The results of this study indicate that the scapular position is associated with the glenohumeral ROM in high school baseball players. In addition, this study demonstrated that the scapular internally rotated position was correlated with the GIRD and TMA deficit in high school baseball players who had throwing-related pain. On the other hand, the scapular externally rotated position was correlated with increased ABER, mainly in the pain-free baseball players or on the nondominant side. These results indicated that the scapular position might affect the glenohumeral rotational ROM in high school baseball players.

Reliability of lower leg muscle thickness measurement along the long axis of the muscle using ultrasound imaging, in a sitting position.

[Purpose] To verify the reliability and validity of lower leg muscle thickness (MT) assessment along the muscle's long axis using ultrasound imaging (USI) in a sitting position. [Participants and Methods] Twenty healthy adult female participants (aged, 20.3 ± 0.9 years) were included in the study. Intra- and inter-examiner reliability of the proximal, middle, and distal MT of the tibialis anterior (TA) and medial head of the gastrocnemius (GM) were verified using USI in a sitting position. Additionally, the relationship between MT measurement using USI and muscle cross-sectional area (MCSA) measurement using magnetic resonance imaging (MRI), as well as the ankle joint's maximum muscle strength, were examined. [Results] The reliability of TA and GM MT measurement using USI was high for all regions. The relationship between MCSA measurement using MRI and MT measurement using USI showed a significant correlation in all the regions for both muscles. The relationship between ankle muscle strength and USI of MT was not significantly correlated in any region for both muscles. [Conclusion] Measurement of MT using USI is reliable and valid for MCSA, but must be combined with assessments of other factors for muscle strength.

Effects of aging on basement membrane of tibialis anterior muscle during recovery following muscle injury in rats.

We investigated the effect of aging on the basement membrane (BM) during postinjury muscle recovery. Using a rat model, we found that aging delayed muscle fiber and BM recovery. In addition, expression of BM-related factors peaked 7 days after muscle injury among both young and older rats. Peak expression of collagen IV synthetic factors decreased with age, whereas expression of the degradative factor was unaffected by age. These results suggest that age-related delays in postinjury muscle fiber and BM recovery may be related to the suppression of collagen IV synthetic factors.

Advantage of a higher position of the tracheostoma with glottic closure for preventing complications related to tracheostomy tube: a retrospective cohort study.

BACKGROUND: Surgery to prevent aspiration has complications related to tracheostomy tube, such as the trachea-brachiocephalic artery fistula. Glottic closure procedure makes tracheostoma at a position higher than the first ring of the trachea and theoretically has a potential to prevent such complications owing to a longer distance between the tip of tracheostomy tube and the tracheal membrane adjacent to the brachiocephalic artery. Our aim is to evaluate the safety of glottic closure in neurologically impaired patients by comparing outcomes with laryngotracheal separation. METHODS: This study is a single-center retrospective study from 2004 to 2019, using data of 15 and 12 patients who underwent glottic closure (GC) and laryngotracheal separation (LTS). The primary outcome was the incidence of postoperative complications induced by tracheostomy tube placement and adjustment of the tracheostomy tube position to prevent these complications, such as by converting to a length-adjustable tube and/or placing gauze between the skin and tube flange. Additionally, we analyzed the anatomical relationship between the tracheostomy tube tip and brachiocephalic artery and measured the distance between them using postoperative CT images. RESULTS: No patients in either group had trachea-brachiocephalic artery fistula. Erosion or granuloma formation occurred in 1 patient (7%) and 4 patients (33%) in the GC and LTS groups, respectively. Adjustment of the tracheostomy tube was needed in 2 patients (13%) and 6 patients (50%) in the GC and LTS groups. CT revealed a higher proportion of patients with the tracheostomy tube tip superior to the brachiocephalic artery in GC than LTS group. The mean tracheostoma-brachiocephalic artery distance was 40.8 and 32.4 mm in the GC and LTS groups. CONCLUSIONS: Glottic closure reduces the risk of postoperative complications related to a tracheostomy tube. This may be due to the higher position of the tracheostoma at the level of the cricoid cartilage, increasing the distance between the tracheostoma and brachiocephalic artery.

Outcomes of Aspiration Prevention Surgery: A Retrospective Cohort Study Using a Japanese Claims Database.

Aspiration prevention surgeries, such as laryngotracheal separation and total laryngectomy are performed to prevent aspiration pneumonia. We aimed to investigate the outcomes of surgery for intractable aspiration and relevant factors. This retrospective cohort study used a nationwide insurance claims database that included company employees and their family members aged < 75 years in Japan. We extracted the data of patients who underwent aspiration prevention surgeries between January 2005 and March 2019. We identified 127 patients (males, 55.9%), of whom 59.8% were aged < 18 years at the surgery. The most common comorbidity was neurological disease (99.2%). The frequency of pneumonia episodes decreased by 1.5 per year after surgery compared with before surgery (p < 0.001). Among patients who received parenteral and enteral nutrition before surgery (n = 92), the adjusted hazard ratio (aHR) for oral intake without parenteral and enteral nutrition was lower in the longer preoperative duration (≥ 14.7 months) for the parenteral and enteral nutrition. However, the difference was not statistically significant (aHR 0.55; 95% confidence interval: 0.15-2.08, p = 0.38). The aHR for oral intake was higher in the ≥ 30 years group than in the < 30 years group (aHR 13.76; 95% confidence intervals: 4.18-42.24; p < 0.001). This study demonstrated that postoperative oral intake was achieved more frequently in patients aged ≤ 30 years than in those aged > 30 years, and supported the effectiveness of aspiration prevention surgery for reducing aspiration pneumonia. Further research is necessary to investigate factors related to postoperative oral intake.

Effects of Endurance Exercise on Basement Membrane in the Soleus Muscle of Aged Rats.

The basement membrane (BM)-related factors, including collagen IV, are important for the maintenance and recovery of skeletal muscles. Aging impairs the expression of BM-related factors during recovery after disuse atrophy. Muscle activity facilitates collagen synthesis that constitutes the BM. However, the effect of endurance exercise on the BM of aged muscles is unclear. Thus, to understand the effect of endurance exercise on the BM of the skeletal muscle in aged rats, we prescribed treadmill running in aged rats and compared the differences in the expression of BM-related factors between the aged rats with and without exercise habits. Aged rats were subjected to endurance exercise via treadmill running. Exercise increased the mRNA expression levels of the BM-related factors, the area and intensity of collagen IV-immunoreactivity and the width of lamina densa in the soleus muscle of aged rats. These finding suggests that endurance exercise promotes BM construction in aged rats.

Effects of aging on basement membrane-related gene expression of the skeletal muscle in rats.

The basement membrane (BM), with collagen IV as a major component, plays an important role in the maintenance of muscle structure and its robustness. To investigate the effects of aging on factors related to BM construction, we compared the expression status of these factors in 3- and 20-month-old male Wistar rats. The expression levels of Col4a1 and Col4a2 (encoding collagen IV), Sparc (involved in collagen IV functionalization), and Mmp14 (a collagen IV degradation factor) were decreased. These results suggest that aging suppresses collagen IV synthetic and degradative factors and affects BM-related factors in the steady state.

Basement membrane recovery process in rat soleus muscle after exercise-induced muscle injury.

Purpose: Collagen IV is a component of the basement membrane (BM) that provides mechanical support for muscle fibers. In addition, transcription factor 4 (TCF4) is highly expressed in muscle connective tissue fibroblasts and regulates muscle regeneration. However, the expression of collagen IV and TCF4 (+) cells in response to exercise-induced muscle injury is not well known. Here, we investigated the expression and localization of collagen IV and TCF4 (+) cells during the recovery process after muscle injury induced by different exercise loads.Materials and Methods: Muscle injury was observed in the soleus muscle of young Wistar rats after 12 or 18 sets-downhill running (DR) on a treadmill. After running, the rats were permitted to recover for a period of 0.5 days, 2 days, or 7 days.Results: Ectopic localization of collagen IV in injured muscle fibers was observed after DR, and the number increased at 0.5 days after 18 sets DR and at 2 days after 12 or 18 sets DR as compared to the number observed at baseline. BM disruption was observed after DR. TCF4 (+) cells appeared in the inside and around injured muscle fibers at 0.5 day of recovery. After 18 sets DR, TCF4 (+) cells were more abundant for a longer period than that observed after 12 sets DR.Conclusions: DR induces BM disruption accompanied by muscle fiber damage. It is possible that BM destruction may be accompanied by muscle damage and that TCF4 (+) cells contribute to muscle fiber and BM recovery.

Indications and postoperative outcomes of surgery for laryngotracheal stenosis: A descriptive study.

OBJECTIVE: Tracheal reconstruction is a rare surgical procedure and the actual incidence of or indications for this procedure have not been thoroughly elucidated. We performed the nationwide database analysis to clarify the real-world situation of laryngotracheal surgery requiring cervical tracheal reconstruction. METHODS: Patients who underwent surgical treatment for laryngotracheal stenosis or defect from 2008 to 2016 were identified from the Diagnosis Procedure Combination inpatient database, collected from 270 acute care hospitals in Japan. Patients were divided into two groups based on presence/absence of malignancy, and T-tube or tracheotomy dependence at 6 months after surgery was compared between the two groups. RESULTS: One hundred and thirty-four patients (75 males) were identified. The median age at surgery was 65.5 years. The most common indication for surgery was malignancy (n = 60, 44.8%), followed by iatrogenic (n = 25, 18.6%), trauma (n = 6, 4.5%), malformation of the larynx and trachea (n = 6, 4.5%), and chronic inflammatory disease (n = 4, 2.8%). Thyroid cancer was the most common malignancy (n = 38). Thirty patients (22.4%) failed to decannulate within 6 months and malignancy was associated with a lower dependence on T-tube or tracheotomy at 6 months after surgery (adjusted odds ratio: 0.25, 95% confidence interval: 0.08-0.79). CONCLUSION: A Japanese health insurance claims database provided a useful overview of the clinical features and outcomes of patients who underwent cervical tracheal reconstruction surgery for laryngotracheal stenosis or defect.

Hyperactive sensorimotor cortex during voice perception in spasmodic dysphonia.

Spasmodic dysphonia (SD) is characterized by an involuntary laryngeal muscle spasm during vocalization. Previous studies measured brain activation during voice production and suggested that SD arises from abnormal sensorimotor integration involving the sensorimotor cortex. However, it remains unclear whether this abnormal sensorimotor activation merely reflects neural activation produced by abnormal vocalization. To identify the specific neural correlates of SD, we used a sound discrimination task without overt vocalization to compare neural activation between 11 patients with SD and healthy participants. Participants underwent functional MRI during a two-alternative judgment task for auditory stimuli, which could be modal or falsetto voice. Since vocalization in falsetto is intact in SD, we predicted that neural activation during speech perception would differ between the two groups only for modal voice and not for falsetto voice. Group-by-stimulus interaction was observed in the left sensorimotor cortex and thalamus, suggesting that voice perception activates different neural systems between the two groups. Moreover, the sensorimotor signals positively correlated with disease severity of SD, and classified the two groups with 73% accuracy in linear discriminant analysis. Thus, the sensorimotor cortex and thalamus play a central role in SD pathophysiology and sensorimotor signals can be a new biomarker for SD diagnosis.