ABSTRACT
Sporadic inclusion body myositis (sIBM) is a muscle disease in older people and is characterized by inflammatory cell invasion into intact muscle fibers and rimmed vacuoles. The pathomechanism of sIBM is not fully elucidated yet, and controversy exists as to whether sIBM is a primary autoimmune disease or a degenerative muscle disease with secondary inflammation. Previously, we established a method of collecting CD56-positive myoblasts from human skeletal muscle biopsy samples. We hypothesized that the myoblasts derived from these patients are useful to see the cell-autonomous pathomechanism of sIBM. With these resources, myoblasts were differentiated into myotubes, and the expression profiles of cell-autonomous pathology of sIBM were analyzed. Myoblasts from three sIBM cases and six controls were differentiated into myotubes. In the RNA-sequencing analysis of these "myotube" samples, 104 differentially expressed genes (DEGs) were found to be significantly upregulated by more than twofold in sIBM, and 13 DEGs were downregulated by less than twofold. For muscle biopsy samples, a comparative analysis was conducted to determine the extent to which "biopsy" and "myotube" samples differed. Fifty-three DEGs were extracted of which 32 (60%) had opposite directions of expression change (e.g., increased in biopsy vs decreased in myotube). Apolipoprotein E (apoE) and transmembrane protein 8C (TMEM8C or MYMK) were commonly upregulated in muscle biopsies and myotubes from sIBM. ApoE and myogenin protein levels were upregulated in sIBM. Given that enrichment analysis also captured changes in muscle contraction and development, the triggering of muscle atrophy signaling and abnormal muscle differentiation via MYMK or myogenin may be involved in the pathogenesis of sIBM. The presence of DEGs in sIBM suggests that the myotubes formed from sIBM-derived myoblasts revealed the existence of muscle cell-autonomous degeneration in sIBM. The catalog of DEGs will be an important resource for future studies on the pathogenesis of sIBM focusing on primary muscle degeneration.
Subject(s)
Muscle Fibers, Skeletal , Myositis, Inclusion Body , Humans , Myositis, Inclusion Body/metabolism , Myositis, Inclusion Body/genetics , Myositis, Inclusion Body/pathology , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/pathology , Cell Differentiation , Aged , Female , Male , Cells, Cultured , Transcriptome , Myoblasts/metabolism , Myoblasts/pathology , Biopsy , Gene Expression Profiling , Middle AgedABSTRACT
Posterior dislocation of the shoulder joint is a rare condition. It is often misdiagnosed owing to a lack of evident clinical features compared with anterior shoulder dislocation, and inappropriate radiological examination. We present a case of chronic posterior fracture dislocation treated with greater tuberosity osteotomy. A 66-year-old man was injured in a fall while carrying a drone. He was referred to our hospital following 3 months of conservative treatment at a nearby clinic, without reduction of the posterior dislocation. Physical examination revealed a prominent reduction in shoulder joint range of motion and shoulder pain. Radiological examination revealed posterior shoulder dislocation associated with greater tuberosity malunion and a small bone fracture of the posterior portion of the glenoid. Open reduction and internal fixation, including greater tuberosity osteotomy, were performed. Although subluxation of the posterior dislocation persisted postoperatively, the humeral head gradually returned to its centric shoulder joint position owing to rotator cuff force coupling. At 24-month follow-up, the patient showed excellent shoulder results.
ABSTRACT
The physiological significance of skeletal muscle as a secretory organ is now well known but we can only speculate as to the existence of as-yet-unidentified myokines, especially those upregulated in response to muscle contractile activity. We first attempted to establish an "insert-chamber based in vitro exercise model" allowing the miniature but high cell-density culture state enabling highly developed contractile human myotubes to be readily obtained by applying electric pulse stimulation (EPS). By employing this in vitro exercise model, we identified R-spondin 3 (RSPO3) as a novel contraction-inducible myokine produced by cultured human myotubes. Contraction-dependent muscular RSPO3 mRNA upregulation was confirmed in skeletal muscles of mice subjected to sciatic nerve mediated in situ contraction as well as those of mice after 2 h of running. Pharmacological in vitro experiments demonstrated a relatively high concentration of metformin (millimolar range) to suppress the contraction-inducible mRNA upregulation of human myokines including RSPO3, interleukin (IL)-6, IL-8 and CXCL1. Our data also suggest human RSPO3 to be a paracrine factor that may positively participate in the myogenesis processes of myoblasts and satellite cells. Thus, the "insert chamber-based in vitro exercise model" is a potentially valuable research tool for investigating contraction-inducible biological responses of human myotubes usually exhibiting poorer contractility development even in the setting of EPS treatment.
Subject(s)
Muscle Contraction , Muscle Fibers, Skeletal , Thrombospondins , Animals , Electric Stimulation , Humans , Interleukin-6/genetics , Mice , Muscle Contraction/physiology , Muscle Fibers, Skeletal/physiology , Muscle, Skeletal/physiology , RNA, Messenger/genetics , Thrombospondins/geneticsABSTRACT
Contractile activity is a fundamental property of skeletal muscles. We describe the establishment of a "feeder-supported in vitro exercise model" using human-origin primary satellite cells, allowing highly-developed contractile myotubes to readily be generated by applying electrical pulse stimulation (EPS). The use of murine fibroblasts as the feeder cells allows biological responses to EPS in contractile human myotubes to be selectively evaluated with species-specific analyses such as RT-PCR. We successfully applied this feeder-supported co-culture system to myotubes derived from primary satellite cells obtained from sporadic inclusion body myositis (sIBM) patients who are incapable of strenuous exercise testing. Our results demonstrated that sIBM myotubes possess essentially normal muscle functions, including contractility development, de novo sarcomere formation, and contraction-dependent myokine upregulation, upon EPS treatment. However, we found that some of sIBM myotubes, but not healthy control myotubes, often exhibit abnormal cytoplasmic TDP-43 accumulation upon EPS-evoked contraction, suggesting potential pathogenic involvement of the contraction-inducible TDP-43 distribution peculiar to sIBM. Thus, our "feeder-supported in vitro exercise model" enables us to obtain contractile human-origin myotubes, potentially utilizable for evaluating exercise-dependent intrinsic and pathogenic properties of patient muscle cells. Our approach, using feeder layers, further expands the usefulness of the "in vitro exercise model".
Subject(s)
Muscle Contraction/physiology , Muscle, Skeletal/physiology , Satellite Cells, Skeletal Muscle/physiology , Animals , Cell Culture Techniques/methods , Cells, Cultured , Electric Stimulation/methods , Feeder Cells/metabolism , Humans , Mice , Models, Biological , Muscle Fibers, Skeletal/cytology , Myoblasts/cytology , Myositis, Inclusion Body/physiopathology , Sarcomeres/physiology , Satellite Cells, Skeletal Muscle/metabolismABSTRACT
PURPOSE: Intra-articular pathologies, such as labral and chondral lesions, are common in patients with frozen shoulder. This study evaluated the correlations between the range of motion and labral and chondral lesions in patients with frozen shoulder and investigated their pathophysiologies. METHODS: In total, 125 individuals (53 men and 72 women) who underwent arthroscopic pan-capsular release between 2014 and 2020 were included in the study. The range of motion was measured using scapular fixation and true glenohumeral motion under general anaesthesia. The American Shoulder and Elbow Surgeons Shoulder score and the Shoulder Rating Scale score of the University of California, Los Angeles were used to compare intra-articular pathologies. RESULTS: More than 80% of patients with frozen shoulder had labral pathologies, and nearly half of them had chondral pathologies. Labral lesions extending to the anterior rim of the glenoid had a greater range of motion and the greatest total American Shoulder and Elbow Surgeons Shoulder score. More severe chondral lesions had a lesser range of motion, but presented the greatest function scores and the lowest strength scores according to the Shoulder Rating Scale of the University of California, Los Angeles. The pain scores of the American Shoulder and Elbow Surgeons Shoulder score and the Shoulder Rating Scale of the University of California, Los Angeles were not correlated with the degree of these pathologies. The traction force affected the labrum during true range of motion, and the compression force occurred on the articular cartilage during internal rotation at 90° of forward flexion during diagnostic arthroscopy. CONCLUSION: Labral and chondral lesions are common in patients with frozen shoulder. Adherence to the capsulolabral complex induced a limited range of motion and labral and chondral pathologies. Diagnostic arthroscopy with motion is an important method of reproducing the pathogenesis of intra-articular structures for patients with frozen shoulder. LEVEL OF EVIDENCE: Level III.
Subject(s)
Bursitis , Shoulder Joint , Arthroscopy , Bursitis/surgery , Female , Humans , Joint Capsule/surgery , Male , Range of Motion, Articular , Shoulder Joint/surgery , Treatment OutcomeABSTRACT
BACKGROUND: The Simple Shoulder Test (SST) is a widely used patient-reported outcome assessment. The purpose of this study was to develop and validate a Japanese version of the SST (SST-Jp). METHODS: A two-stage observational study was conducted to validate the cross-cultural adaptation of the SST. A total of 100 patients with shoulder disorders completed the SST-Jp; the Disability of Arm, Shoulder, and Hand assessment; and the Medical Outcomes Short-Form 36 (SF-36) at an initial visit. Thirty-four of the patients repeated the SST-Jp one week after the first examination. The test-retest reliability was quantified using the interclass correlation coefficient, and Cronbach's alpha (α) was calculated to assess internal consistency. Construct validity was assessed using Spearman's rank correlation coefficient. RESULTS: The internal consistency of the SST-Jp was very high (α = 0.826). The interclass correlation coefficient of the SST-Jp was also high (0.859). There was a strong, positive correlation between the Disability of Arm, Shoulder, and Hand and the SST-Jp (r = 0.717, P < .001). The SST-Jp was significantly correlated with most of the SF-36 subscales. The correlations of the SST-Jp with physical subscales of the SF-36 were stronger than those with the other subscales. CONCLUSIONS: The SST-Jp was found to be a valid and reliable measurement for shoulder joint pain and function assessment among the Japanese population.
Subject(s)
Bursitis , Joint Capsule Release , Bursitis/surgery , Humans , Range of Motion, ArticularABSTRACT
Myofascia, deep fascia enveloping skeletal muscles, consists of abundant collagen and elastin fibres that play a key role in the transmission of muscular forces. However, understanding of biomechanical dynamics in myofascia remains very limited due to less quantitative and relevant approaches for in vivo examination. The purpose of this study was to evaluate the myofascial fibril structure by means of a quantitative approach using two-photon microscopy (TPM) imaging in combination with intravital staining of Evans blue dye (EBD), a far-red fluorescence dye, which potentially labels elastin. With focus on myofascia of the tibial anterior (TA) muscle, the fibril structure intravitally stained with EBD was observed at the depth level of collagen fibrous membrane above the muscle belly. The EBD-labelled fibril structure and orientation in myofascia indicated biomechanical responses to muscle activity and ageing. The orientation histograms of EBD-labelled fibrils were significantly modified depending upon the intensity of muscle activity and ageing. Moreover, the density of EBD-labelled fibrils in myofascia decreased with habitual exercise but increased with muscle immobilization or ageing. In particular, the diameter of EBD-labelled fibrils in aged mice was significantly higher. The orientation histograms of EBD-labelled fibrils after habitual exercise, muscle immobilization and ageing showed significant differences compared to control. Indeed, the histograms in bilateral TA myofascia of exercise mice made simple waveforms without multiple sharp peaks, whilst muscular immobilization or ageing significantly shifted a histogram with sustaining multiple sharp peaks. Therefore, the dynamics of fibre network with EBD fluorescence in response to the biomechanical environment possibly indicate functional tissue adaptation in myofascia. Furthermore, on the basis of the knowledge that neutrophil recruitment occurs locally in working muscles, we suggested the unique reconstruction mechanism involving neutrophilic elastase in the myofascial fibril structure. In addition to the elastolytic susceptibility of EBD-labelled fibrils, distinct immunoreactivities and activities of neutrophil elastase in the myofascia were observed after electric pulse stimulation-induced muscle contraction for 15 min. Our findings of EBD-labelled fibril dynamics in myofascia through quantitative approach using TPM imaging and intravital fluorescence labelling potentially brings new insights to examine muscle physiology and pathology.
Subject(s)
Fascia/physiology , Neutrophils/physiology , Physical Conditioning, Animal/physiology , Aging/physiology , Animals , Evans Blue , Fascia/diagnostic imaging , Fascia/ultrastructure , Leukocyte Elastase/metabolism , Male , Mice, Inbred C57BL , Microscopy, Fluorescence , Muscle ContractionABSTRACT
BACKGROUND: The Shoulder Pain and Disability Index (SPADI) is a simple disease specific questionnaire that is used to evaluate the impact of shoulder disorders. The purpose of this study was to translate the SPADI into Japanese (SPADI-Jp) and evaluate its reliability and validity in Japanese patients with shoulder disorders. METHODS: Cross-cultural adaptation of the SPADI was performed according to international guidelines. A total of 100 patients with shoulder disorders participated in this study. Each participant was asked to finish the SPADI-Jp, Disability of Arm, Shoulder and Hand (DASH), and the Short-Form 36 (SF-36) at the initial visit. Thirty-four patients repeated the SPADI-Jp to assess the test-retest reliability. The test-retest reliability was quantified using the interclass correlation coefficient (ICC), while Cronbach's alpha was calculated to assess the internal consistency. The construct validity was assessed using Spearman's rank correlation coefficients. RESULTS: Internal consistency in the SPADI-Jp was very high (0.969), as measured by the Cronbach's alpha. The ICC of the SPADI-Jp was 0.930. There was a strong, positive correlation between the DASH and the SPADI-Jp (r = 0.837, p < 0.001). The SPADI-Jp was significantly correlated with most of the SF-36 subscales. The correlations of the SPADI-Jp with physical subscales of the SF-36 were stronger than those with the other subscales. CONCLUSIONS: We demonstrated that the SPADI-Jp is a reliable and valid self-assessment tool. Because cross-cultural adaptation, validation, and reliability of the disease-specific questionnaire for shoulder pain and disability have not been evaluated in Japan, the SPADI-Jp can be useful for evaluating such patients in the Japanese population.
Subject(s)
Disability Evaluation , Shoulder Pain , Cross-Sectional Studies , Humans , Japan , Reproducibility of Results , Shoulder Pain/diagnosis , Surveys and QuestionnairesABSTRACT
Sporadic inclusion body myositis (sIBM) is the most common idiopathic inflammatory myopathy, and several reports have suggested that mitochondrial abnormalities are involved in its etiology. We recruited 9 sIBM patients and found significant histological changes and an elevation of growth differential factor 15 (GDF15), a marker of mitochondrial disease, strongly suggesting the involvement of mitochondrial dysfunction. Bioenergetic analysis of sIBM patient myoblasts revealed impaired mitochondrial function. Decreased ATP production, reduced mitochondrial size and reduced mitochondrial dynamics were also observed in sIBM myoblasts. Cell vulnerability to oxidative stress also suggested the existence of mitochondrial dysfunction. Mitochonic acid-5 (MA-5) increased the cellular ATP level, reduced mitochondrial ROS, and provided protection against sIBM myoblast death. MA-5 also improved the survival of sIBM skin fibroblasts as well as mitochondrial morphology and dynamics in these cells. The reduction in the gene expression levels of Opa1 and Drp1 was also reversed by MA-5, suggesting the modification of the fusion/fission process. These data suggest that MA-5 may provide an alternative therapeutic strategy for treating not only mitochondrial diseases but also sIBM.
Subject(s)
Indoleacetic Acids/therapeutic use , Mitochondria, Muscle/metabolism , Myositis, Inclusion Body/drug therapy , Phenylbutyrates/therapeutic use , Adenosine Triphosphate/biosynthesis , Aged , Aged, 80 and over , Buthionine Sulfoximine/pharmacology , Cell Survival/drug effects , Cells, Cultured , DNA, Mitochondrial/genetics , Drug Evaluation, Preclinical , Dynamins/biosynthesis , Dynamins/genetics , Female , Fibroblast Growth Factors/blood , Fibroblasts/drug effects , GTP Phosphohydrolases/biosynthesis , GTP Phosphohydrolases/genetics , Growth Differentiation Factor 15/biosynthesis , Growth Differentiation Factor 15/blood , Growth Differentiation Factor 15/genetics , Humans , Indoleacetic Acids/pharmacology , Male , Middle Aged , Mitochondria, Muscle/pathology , Myoblasts/drug effects , Myoblasts/metabolism , Myoblasts/ultrastructure , Myositis, Inclusion Body/metabolism , Myositis, Inclusion Body/pathology , Oxygen Consumption , Phenylbutyrates/pharmacology , Reactive Oxygen Species/metabolism , Retrospective StudiesABSTRACT
BACKGROUND: We aimed to retrospectively determine the effects of arthroscopic pan-capsular release with or without entire coracohumeral ligament (CHL) release and diabetes mellitus (DM) in patients with frozen shoulder (FS). METHODS: The study included 34 patients (20 male and 14 female patients) who underwent arthroscopic pan-capsular release without entire CHL release (group 1) and 26 patients (6 male and 20 female patients) who underwent entire CHL release for FS (group 2). Patients with a minimum of 12 months of follow-up were included, and range of motion (ROM) and the shoulder rating scale of the University of California at Los Angeles (UCLA) scoring system were evaluated. RESULTS: In group 2, external rotation and hand-behind-the-back (HBB) ROMs were significantly increased compared with group 1 at the final follow-up (external rotation, 53.1° ± 15.2° vs. 41.3° ± 20.5° [P = .044]; HBB level, T6 [interquartile range, T5-T9] vs. T11 [interquartile range, T8-L4] [P < .001]). Total UCLA scores and UCLA scores for pain (9.2 ± 1.5 vs. 10.0, P = .003), function (8.5 ± 1.4 vs. 10.0, P < .001), and active forward flexion (4.6 ± 0.6 vs. 4.9 ± 0.2, P < .011) were significantly greater in group 2 at the final follow-up. Patients without DM tended to have greater recovery of forward flexion and HBB ROMs and better total, pain, and function UCLA scores compared with those with DM. In group 2, there were no significant differences in ROMs and UCLA scores between the patients with DM and those without DM. CONCLUSION: Arthroscopic entire CHL release is an essential treatment option for FS patients to regain ROMs and function and to reduce pain.
ABSTRACT
BACKGROUND: Proximal humeral fractures are one of the most common fractures in adults. Some patients treated operatively have restriction in range of motion (ROM) after surgery. This study aimed to evaluate arthroscopic pancapsular release in patients with severe stiffness after treatment with intramedullary nailing for proximal humeral fractures. METHODS: This study included 12 patients (7 women and 5 men) who underwent arthroscopic pancapsular release in the beach-chair position between May 2015 and February 2018. Intraoperative findings were recorded, and ordinary (with scapulothoracic motion) and true (without scapulothoracic motion) glenohumeral ROMs were measured with a goniometer. The American Shoulder and Elbow Surgeons shoulder score, Shoulder Rating Scale score of the University of California, Los Angeles scoring system, and Constant score were compared before and after the release. The Wilcoxon signed rank and Mann-Whitney U tests were used to analyze data. RESULTS: The average age of the patients was 65.1 years (standard deviation, 9.5 years), and the mean follow-up period after the release was 30.6 months (standard deviation, 11.7 months). All ROMs on the affected side after surgery were significantly greater than those before surgery in all directions. However, ROMs in forward flexion, lateral elevation, and external rotation with the arm at the side and at 90° of forward flexion on the affected side postoperatively were significantly lower than those on the unaffected side. All scores were significantly greater after surgery than before surgery. CONCLUSION: Arthroscopic pancapsular release is effective for patients with proximal humeral fractures treated with intramedullary nailing.
ABSTRACT
BACKGROUND: A thickened joint capsule is believed to be one of the most specific manifestations of and the primary restraint against range of motion (ROM) in frozen shoulders. The purpose of this study was to evaluate the relationship among ROMs under general anesthesia before surgery and the effects of each joint capsular release on ROM. METHODS: ROM was measured using a goniometer with scapular fixation. Arthroscopic pan-capsular release was performed with the patient in the beach-chair position in the following order: (1) rotator interval, (2) coracohumeral ligament, (3) superior capsule, (4) middle glenohumeral ligament, (5) anterior inferior glenohumeral ligament, and (6) posterior inferior glenohumeral ligament. ROMs in forward flexion (FF), lateral elevation (LE), external rotation with the arm at the side (ER1), external rotation at 90° of LE (ER2), internal rotation at 90° of LE (IR2), horizontal flexion, external rotation at 90° of FF (ER3), and internal rotation at 90° of FF (IR3) were evaluated before and after each release. RESULTS: A total of 32 consecutive shoulders were included. After each capsular release, the ROM recovered; the final ROM was significantly greater on the affected side than on the unaffected side. Significant correlations were found between FF and LE, FF and ER1, ER1 and ER2, ER1 and ER3, ER2 and ER3, and IR2 and IR3 on both sides, regardless of surgery. CONCLUSION: Each segment of the joint capsule affected ROM in all directions, supporting the need for whole-joint capsular release; ROM was significantly greater on the affected side than on the unaffected side after surgery.
Subject(s)
Bursitis/surgery , Joint Capsule Release , Range of Motion, Articular/physiology , Shoulder Joint/surgery , Arthroscopy , Bursitis/physiopathology , Humans , Ligaments, Articular/physiopathology , Ligaments, Articular/surgery , Prospective Studies , Rotation , Shoulder Joint/physiopathologyABSTRACT
BACKGROUND: The etiology of frozen shoulder (FS) remains uncertain. Advanced glycation end-products (AGEs) cause the cross-linking and stabilization of collagen and are increased in FS. The purpose of this study was to elucidate the pathogenesis of FS by evaluating the receptor of AGE (RAGE)-dependent pathways. METHODS: Tissue samples of the coracohumeral ligament (CHL) and anterior inferior glenohumeral ligament (IGHL) were collected from 33 patients with FS, with severe stiffness, and 25 with rotator cuff tears (RCTs) as controls. Gene expression levels of RAGE, high-mobility group box 1 (HMGB1), Toll-like receptor 2 (TLR2), TLR4, nuclear factor-kappa B (NF-kB), and cytokines were evaluated using a quantitative real-time polymerase chain reaction. The immunoreactivities of carboxymethyllysine (CML), pentosidine, and RAGE were also evaluated. CML and pentosidine were further evaluated using high-performance liquid chromatography. RESULTS: Gene expression levels of RAGE, HMGB1, TLR2, TLR4, and NF-kB were significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group. Immunoreactivities of RAGE and CML were stronger in the CHLs and IGHLs from the FS group than in those from the RCT group. Pentosidine was weakly immunostained in the CHLs and IGHLs from the FS group. CML using high-performance liquid chromatography was significantly greater in the CHLs and IGHLs from the FS group than in those from the RCT group. CONCLUSIONS: AGEs and HMGB1 might play important roles in the pathogenesis of FS by binding to RAGE and activating NF-kB signaling pathways. Suppression of these pathways could be a treatment option for FS.
Subject(s)
Bursitis/metabolism , Ligaments, Articular/metabolism , NF-kappa B/metabolism , Receptor for Advanced Glycation End Products/metabolism , Adult , Aged , Case-Control Studies , Female , Gene Expression , HMGB1 Protein/genetics , HMGB1 Protein/metabolism , Humans , Immunohistochemistry , Male , Middle Aged , NF-kappa B/genetics , Real-Time Polymerase Chain Reaction , Receptor for Advanced Glycation End Products/genetics , Retrospective Studies , Signal Transduction , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolismABSTRACT
CONTEXT: Range of motion (ROM) in the glenohumeral joint decreases with age in healthy subjects; however, the underlying mechanism remains unclear. The process of aging of the joint capsule, including the coracohumeral ligament (CHL), could affect ROM limitation. OBJECTIVE: This study investigated correlations between elasticity of the CHL, evaluated by means of shear-wave elastography, and age, side dominance, and ROM in healthy individuals. DESIGN: Experimental study. SETTING: Laboratory. SUBJECTS: Eighty-four healthy volunteers (39 men and 45 women, mean age: 42.6 y) were included. MAIN OUTCOME MEASURES: Subjects were divided into 3 age groups: younger (20-39 y), middle (40-59 y), and older (≥60 y) age groups. With participants in the supine position, CHL elasticity in both shoulders was evaluated in both neutral and 30° external rotation, with arms at the sides. ROM, including forward flexion, lateral elevation, external rotation, 90° abduction with external rotation, and hand behind the back were measured with participants in the standing position. RESULTS: The CHL elastic modulus was higher in the older group than in the younger group in the neutral (78.4 kPa [SD: 37.1] and 56.6 kPa [SD: 31.7], respectively) and 30° external rotation positions (135.5 kPa [SD: 63.5] and 71.4 kPa [SD: 32.2], respectively). Negative correlations were found between the CHL elastic modulus and ROM in terms of 30° external rotation and both external rotation (R = -.59, P = .02) and 90° abduction with external rotation (R = -.71, P = .003) in the older group, with correlation coefficients increasing with age. CONCLUSIONS: Significant correlations were identified between CHL elasticity and ROM in both external rotation and 90° abduction with external rotation with increasing age. Decreased CHL elasticity was strongly associated with decreased shoulder ROM in middle-aged and older individuals.
ABSTRACT
Verbal or physical abuse from coaches has negative effects on young athletes, and the parents of athletes also have an influence on the sports environment. It is therefore important to understand parents' attitudes towards abuse against their children from the coaches. This study aimed to elucidate the characteristics of parents who accept the infliction of verbal or physical abuse on their children from coaches of youth sports teams. A cross-sectional study using self-report questionnaires was conducted with parents of young athletes (n = 6,493). Multivariate logistic regression models were used to assess the factors associated with parents' acceptability of verbal or physical abuse against their children. The proportion of parents who were accepting of verbal or physical abuse was 21.5%. Acceptability of verbal or physical abuse was significantly associated with male (odds ratio: 1.67, 95% confidence interval: 1.43-1.95), younger age (1.24, 1.09-1.41), lower educational attainment (1.32, 1.17-1.50), smoking habits (1.42, 1.23-1.63), experience of playing on a team with high levels of competition during their junior or high school days (1.31, 1.15-1.50), and experience of verbal and physical abuse by their own former coaches (3.59, 3.03-4.26 and 1.17, 1.02-1.35). About 58% and 28% of parents had experienced verbal and physical abuse from their own former coaches, and parents who had experienced verbal abuse themselves were most likely to be accepting of verbal or physical abuse towards their children. Educating parents is considered to be important for preventing and eradicating abuse against young athletes.
Subject(s)
Child Abuse/psychology , Mentoring , Parents/psychology , Youth Sports , Adult , Child , Confidence Intervals , Female , Humans , Male , Odds RatioABSTRACT
OBJECTIVE: Prolonged periods of living in prefabricated houses (PHs) may increase the risk of musculoskeletal (MSK) symptoms; however, the association is not clear. This study aimed to investigate the association between continued residence in PHs and MSK pain in a population affected by a natural disaster, the Great East Japan Earthquake (GEJE) survivors. DESIGN, SETTING AND PARTICIPANTS: A panel study was conducted including 1059 and 792 survivors at 2 and 4 years, respectively, after the GEJE, using a self-reported questionnaire. Those with no response on living status and those who did not live in a PH were excluded. Participants were classified into two groups by living status: continued residence in a PH (lived in a PH during both periods) or moving out of a PH (lived in a PH in the first period and did not live in a PH in the second). PRIMARY OUTCOME MEASURE: MSK pain included lower back, shoulder, knee, hand or foot, and neck pain. Changes in the occurrence of MSK pain during the two periods were assessed and defined as 'new-onset' and 'continuing' MSK pain. Multiple logistic regression analysis was used to examine the influence of continued residence in a PH on new-onset and continuing MSK pain. RESULTS: Continued residence in a PH was significantly associated with new-onset MSK pain, even after adjustment for covariates (adjusted OR 2.18, 95% CI 1.25 to 3.79, p=0.006). Participants who continued living in a PH had higher rates of continuing MSK pain than those who moved out; however, the difference was not significant (adjusted OR 1.69, 95% CI 0.94 to 3.05, p=0.079). CONCLUSION: Continued residence in a PH was associated with new-onset MSK pain among survivors. Public support should be provided to such people to ensure a more comfortable life.
Subject(s)
Earthquakes , Musculoskeletal Pain/epidemiology , Public Housing/statistics & numerical data , Survivors/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Japan/epidemiology , Logistic Models , Longitudinal Studies , Male , Middle Aged , Surveys and Questionnaires , Young AdultABSTRACT
Contraction of cultured myotubes with application of electric pulse stimulation (EPS) has been utilized for investigating cellular responses associated with actual contractile activity. However, cultured myotubes derived from human subjects often exhibit relatively poor EPS-evoked contractile activity, resulting in minimal contraction-inducible responses (i.e. myokine secretion). We herein describe an "in vitro exercise model", using hybrid myotubes comprised of human myoblasts and murine C2C12 myoblasts, exhibiting vigorous contractile activity in response to EPS. Species-specific analyses including RT-PCR and the BioPlex assay allowed us to separately evaluate contraction-inducible gene expressions and myokine secretions from human and mouse constituents of hybrid myotubes. The hybrid myotubes, half of which had arisen from primary human satellite cells obtained from biopsy samples, exhibited remarkable increases in the secretions of human cytokines (myokines) including interleukins (IL-6, IL-8, IL-10, and IL16), CXC chemokines (CXCL1, CXCL2, CXCL5, CXCL6, CXCL10), CC chemokines (CCL1, CCL2, CCL7, CCL8, CCL11, CCL13, CCL16, CCL17, CCL19, CCL20, CCL21, CCL22, CCL25, CCL27), and IFN-γ in response to EPS-evoked contractile activity. Together, these results indicate that inadequacies arising from human muscle cells are effectively overcome by fusing them with murine C2C12 cells, thereby supporting the development of contractility and the resulting cellular responses of human-origin muscle cells. Our approach, using hybrid myotubes, further expands the usefulness of the "in vitro exercise model".
Subject(s)
Hybrid Cells/physiology , Models, Biological , Muscle Contraction/physiology , Muscle Fibers, Skeletal/physiology , Myoblasts/physiology , Animals , Cell Fusion , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Electric Stimulation , Exercise , Humans , Male , Mice , Middle Aged , Satellite Cells, Skeletal Muscle/cytologyABSTRACT
Verbal and physical abuse from coaches has negative effects on young athletes. Although the abuse can lead to the athletes' dropping out, no studies have reported on this topic. The purpose of this study was to elucidate the association between experience of verbal or physical abuse from coaches and loss of motivation for the present sport in young athletes. School-aged athletes (age range, 6-15 years, n = 6,791) were assessed using a self-reported questionnaire. Multivariate logistic regression models were used to assess the association between experience of verbal or physical abuse and loss of motivation for the present sport. Variables considered in the models were sex, age, body mass index, presence of bodily pain, team levels, number of training days per week, number of training hours per day on weekdays and weekends, and frequency of participation in games. The prevalence of loss of motivation for the present sport was 8.1%. Experience of verbal or physical abuse was significantly associated with loss of motivation for the present sport and the adjusted odds ratios (95% confidence intervals) were 1.93 (1.54-2.42, p < 0.001) for verbal abuse and 1.76 (1.27-2.42, p = 0.001) for physical abuse. Findings of this study suggest that experience of verbal or physical abuse from coaches is associated with loss of motivation for the present sport. Eradication of verbal and physical abuse from coaches is important for young athletes to continue sport participation.