Joint hemorrhage accelerates cartilage degeneration in a rat immobilized knee model.

BACKGROUND: Joint hemorrhage is caused by trauma, ligament reconstruction surgery, and bleeding disorders such as hemophilia. Recurrence of hemorrhage in the joint space induces hemosiderotic synovitis and oxidative stress, resulting in both articular cartilage degeneration and arthropathy. Joint immobilization is a common treatment option for articular fractures accompanied by joint hemorrhage. Although joint hemorrhage has negative effects on the articular cartilage, there is no consensus on whether a reduction in joint hemorrhage would effectively prevent articular cartilage degeneration. The purpose of this study was to investigate the effect of joint hemorrhage combined with joint immobilization on articular cartilage degeneration in a rat immobilized knee model. METHODS: The knee joints of adult male rats were immobilized at the flexion using an internal fixator from 3 days to 8 weeks. The rats were randomly divided into the following groups: immobilized blood injection (Im-B) and immobilized-normal saline injection (Im-NS) groups. The cartilage was evaluated in two areas (contact and non-contact areas). The cartilage was used to assess chondrocyte count, Modified Mankin score, and cartilage thickness. The total RNA was extracted from the cartilage in both areas, and the expression of metalloproteinase (MMP)-8, MMP-13, interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α was measured by quantitative real-time polymerase chain reaction. RESULTS: The number of chondrocytes in the Im-B group significantly decreased in both areas, compared with that in the Im-NS group. Modified Mankin score from 4 to 8 weeks of the Im-B group was significantly higher than that of the Im-NS group only in the contact area. The expression of MMP-8 and MMP-13 from 2 to 4 weeks and TNF-α from 2 to 8 weeks significantly increased in the Im-B group compared with those in the Im-NS group, but there was no significant difference in IL-1ß expression. CONCLUSIONS: The results showed that joint hemorrhage exacerbated immobilization-induced articular cartilage degeneration. Drainage of a joint hemorrhage or avoidance of loading may help prevent cartilage degeneration during joint immobilization with a hemorrhage.

Restriction in the hip internal rotation of the stride leg is associated with elbow and shoulder pain in elite young baseball players.

BACKGROUND: Evidence is scarce concerning the relationship of physical dysfunction of the trunk and lower extremities with elbow and shoulder pain in young baseball players. This study aimed to examine the association of joint flexibility of the trunk and lower extremities and dynamic postural control with elbow and shoulder pain among elite young baseball players. METHODS: We analyzed baseball players (aged 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival. Range of motion in external rotation and internal rotation (IR) of the hip, as well as the finger-to-floor distance and heel-to-buttock distance, was measured. The straight-leg-raise test was also conducted. Dynamic postural control was evaluated using the Star Excursion Balance Test. Multivariable logistic regression analyses were conducted to examine the association of physical function with the elbow or shoulder pain incidence. RESULTS: Of 210 players surveyed, 177 without elbow or shoulder pain were included in the analysis. Of the participants, 16 (9.0%) reported having elbow or shoulder pain during the tournament. Participants with the incidence of elbow or shoulder pain had a significant restriction in hip IR of the stride leg compared with those without pain (35.8° vs. 43.7°, P = .022). There were no significant associations of other joint flexibilities and the Star Excursion Balance Test with elbow or shoulder pain. CONCLUSION: Decreased hip IR range of motion of the stride leg was significantly associated with the elbow or shoulder pain incidence. Players, coaches, and clinicians should consider the physical function of the trunk and lower extremities for the prevention of elbow and shoulder pain.

RAGE-dependent NF-kB inflammation processes in the capsule of frozen shoulders.

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.

Musculoskeletal pain and new-onset poor physical function in elderly survivors of a natural disaster: a longitudinal study after the great East Japan earthquake.

BACKGROUND: Functional disability is a significant problem after natural disasters. Musculoskeletal pain is reported to increase after disasters, which can cause functional disability among survivors. However, the effects of musculoskeletal pain on functional decline after natural disasters are unclear. The present study aimed to examine the association between musculoskeletal pain and new-onset poor physical function among elderly survivors after the Great East Japan Earthquake. METHODS: A longitudinal study was conducted on survivors aged ≥65 years at three and 4 years after the Great East Japan Earthquake. A total of 747 persons were included in this study. Physical function was assessed using the Kihon Checklist. New-onset poor physical function was defined as low physical function not present at 3 years but present at 4 years after the disaster. Knee, hand or foot, low back, shoulder, and neck pain was assessed using a self-reported questionnaire and was defined as musculoskeletal pain. Musculoskeletal pain at 3 years after the disaster was categorized according to the number of pain regions (0, 1, ≥ 2). Multiple logistic regression analyses were performed to calculate the odds ratio (OR) and 95% confidence interval (95% CI) for new-onset poor physical function due to musculoskeletal pain. RESULTS: The incidence of new-onset poor physical function was 14.9%. New-onset poor physical function was significantly associated with musculoskeletal pain. Compared with "0" musculoskeletal pain region, the adjusted ORs (95% CI) were 1.39 (0.75-2.58) and 2.69 (1.52-4.77) in "1" and "≥ 2" musculoskeletal pain regions, respectively (p for trend = 0.003). CONCLUSIONS: Musculoskeletal pain is associated with new-onset poor physical function among elderly survivors after the Great East Japan Earthquake. Monitoring musculoskeletal pain is important to prevent physical function decline after natural disasters.

Parents' Own Experience of Verbal Abuse Is Associated with their Acceptance of Abuse towards Children from Youth Sports Coaches.

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.

Verbal Abuse from Coaches Is Associated with Loss of Motivation for the Present Sport in Young Athletes: A Cross-Sectional Study in Miyagi Prefecture.

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.

Knee pain is associated with lower back pain in young baseball players: a cross-sectional study.

PURPOSE: Considerable research has focused on shoulder and elbow injuries among baseball players; however, although lumbar spine and knee injuries are commonly experienced, they are less frequently studied. During common motions in baseball, such as throwing, hitting, and running, energy is transferred from the lower extremities through the lower back to the upper body. Lower extremity pain, as well as lower back pain (LBP), can disrupt the kinematic chain, and it is important to understand the association between lower extremity complaints and LBP. The purpose of this study was to elucidate the association between knee pain and LBP among young baseball players. METHODS: A cross-sectional study was conducted with young baseball players (aged 6-15 years, n = 1,609) using a self-reported questionnaire. Multivariate logistic regression models were used for analyses. Variables considered in the models were sex, age, body mass index, team levels, number of days of training per week, number of hours in practice per day on weekdays and weekend, frequency of participation in games, practice intensity, and player position. RESULTS: The point prevalence of LBP and knee pain was 8.4% and 13.1%, respectively. Knee pain was significantly associated with LBP. Using the absence of knee pain as a reference, the adjusted odds ratio (95% confidence interval) for LBP was 5.83 (3.93-8.65) (p < 0.001) in the presence of knee pain. CONCLUSIONS: Knee pain was associated with LBP among young baseball players. Clinicians should pay attention to knee complaints to prevent and treat LBP among young baseball players. LEVEL OF EVIDENCE: III.

The characteristics of coaches that verbally and physically abuse young baseball players using a self-reported questionnaire.

BACKGROUND: Because the relationship between coaches and athletes is unequal, verbal and physical abuse remains a common problem among sports coaches. We aimed to elucidate the characteristics of baseball coaches who verbally/physically abuse young baseball players. METHODS: A cross-sectional study was conducted on youth sports team coaches in Miyagi prefecture, Japan (n = 380), using a self-reported questionnaire. Multivariate logistic regression models were used for the analyses, evaluating the following variables: sex, age, educational level, smoking habits, years of coaching, level of baseball-playing experience, personal experience with verbal/physical abuse by former coaches, satisfaction with athletes' attitudes, number of athletes on the team, team competition level, awareness of the recommendations of the Japanese Society of Clinical Sports Medicine, limitations in the total pitch count, difficulty in coaching in other positions, number of games per year, and acceptance of former verbal/physical abuse. RESULTS: The prevalence of verbal/physical abuse toward young athletes was 74.5% (n = 283) and 6.6% (n = 25), respectively. Verbal abuse was significantly associated with personal experience of verbal abuse by former coaches (odds ratio [OR]: 2.00, 95% confidence interval [95% CI]: 1.04-3.85), and acceptance of verbal/physical abuse (OR: 2.61, 95% CI: 1.34-5.10). Physical abuse was significantly associated with greater than 10 years of coaching experience (OR: 7.16, 95% CI: 1.36-37.78), personal experience with physical abuse by former coaches (OR: 4.25, 95% CI: 1.23-14.70), and acceptance of verbal/physical abuse (OR: 3.85, 95% CI: 1.51-9.84). CONCLUSIONS: Coaches' experiences with verbal/physical abuse by former coaches negatively affected young athletes. Breaking this cycle is necessary to keep athletes active and interested in playing baseball. LEVEL OF EVIDENCE: Level III.

Involvement of neutrophils and interleukin-18 in nociception in a mouse model of muscle pain.

Muscle pain is a common condition that relates to various pathologies. Muscle overuse induces muscle pain, and neutrophils are key players in pain production. Neutrophils also play a central role in chronic pain by secreting interleukin (IL)-18. The aim of this study was to investigate the involvement of neutrophils and IL-18 in a mouse model of muscle pain. The right hind leg muscles of BALB/c mice were stimulated electrically to induce excessive muscle contraction. The left hind leg muscles were not stimulated. The pressure pain threshold, number of neutrophils, and IL-18 levels were investigated. Furthermore, the effects of the IL-18-binding protein and Brilliant Blue G on pain were investigated. In stimulated muscles, pressure pain thresholds decreased, and neutrophil and IL-18 levels increased compared with that in non-stimulated muscles. The administration of IL-18-binding protein and Brilliant Blue G attenuated hyperalgesia caused by excessive muscle contraction. These results suggest that increased IL-18 secretion from larger numbers of neutrophils elicits mechanical hyperalgesia.

Late bedtimes, short sleeping time, and longtime video-game playing are associated with low back pain in school-aged athletes.

PURPOSE: Low back pain is a significant problem for school-aged athletes. Although some risk factors relating to sports activities have been reported, the effect of lifestyles on low back pain in school-aged athletes is not clear. The purpose of this study was to elucidate the association between lifestyles, such as wake-up time, bedtime, sleeping time, and TV-viewing or video-game-playing time per day and low back pain of school-aged athletes. METHODS: A cross-sectional study was conducted with school-aged athletes (aged 6-15 years, n = 6441) using a self-reported questionnaire and multivariate logistic regression models were used for analyses. Variables considered in the models were gender, age, body mass index, team levels, number of days in practice per week, number of hours in practice per day, and lifestyles. RESULTS: The frequency of low back pain was 5.0% (n = 322). Late bedtime, short sleeping time, and long video-game-playing time per day were significantly associated with low back pain. There was no significant association between low back pain and wake-up time or TV-viewing time per day. CONCLUSION: Unhealthy life-style choices, such as late bedtimes, short sleeping time, and longtime video-game playing, were associated with low back pain in school-aged athletes.

Sleep Disturbance Is Associated with New Onset and Continuation of Lower Back Pain: A Longitudinal Study among Survivors of the Great East Japan Earthquake.

Lower back pain (LBP) is a common health problem after natural disasters. Although some related factors have been reported, the effect of sleep disturbances on LBP is not clear. The purpose of this study was to elucidate the influence of sleep disturbances on LBP after the Great East Japan earthquake (GEJE). A panel study was conducted with the survivors of the GEJE (n = 2,295) at three and four years after the disaster using self-reported questionnaires. The changes in the presence of LBP during the two periods were assessed; LBP was characterized as either new onset or continuation of LBP. The participants' sleep conditions were assessed, and the changes in sleep disturbances during the two periods were classified into four groups: absence, new onset, improvement, and continuation. Multivariate logistic regression models were used to analyze the association of the changes in sleep disturbance with new onset and continuation of LBP. The rates of new onset and continuation of LBP were 14.1% and 55.1%, respectively. The changes in sleep disturbances were significantly associated with new-onset and continuing LBP. Using "absence" as a reference for the change of sleep disturbance, the adjusted ORs (95% CI) for new-onset LBP were 2.19 (1.42-3.38) in "new onset," 1.38 (0.83-2.30) in "improvement," and 2.17 (1.50-3.15) in "continuation," and those for continuing LBP were 1.42 (0.71-2.84) in "new onset," 0.98 (0.55-1.74) in "improvement," and 1.60 (1.01-2.51) in "continuation." Careful attention should be paid to sleep disturbances to prevent and improve LBP after natural disasters.

Higher Incidence of Sleep Disturbance among Survivors with Musculoskeletal Pain after the Great East Japan Earthquake: A Prospective Study.

Sleep disturbance is a common symptom after natural disasters. Although musculoskeletal pain also increases after natural disasters, its relation to sleep disturbance is not clear. The purpose of this study was to determine the influence of musculoskeletal pain on new-onset sleep disturbance among survivors after the Great East Japan Earthquake (GEJE). A prospective cohort study was conducted with the survivors of the GEJE at two and three years after the earthquake. New-onset sleep disturbance was defined as sleep disturbance absent at two years and present at three years after the earthquake. The sites of musculoskeletal pain included low back, shoulder, knee, and hand or foot. The number of musculoskeletal pain sites at two years after the earthquake was divided into three categories (0, 1, and 2 or more). Univariate and multivariate logistic regression models were used to calculate the odds ratio (OR) and 95% confidence interval (95%CI) for new-onset sleep disturbance according to the number of musculoskeletal pain sites. A total of 1,102 survivors were included in this study and 14.6% of the participants reported new-onset sleep disturbance. Using "0" as a reference, the adjusted ORs (95% CI) for new-onset sleep disturbance were 2.43 (1.55-3.80) in "1" and 2.96 (1.88-4.64) in "2 or more", respectively (P for trends < 0.001). In conclusion, this is the first study showing higher incidence of sleep disturbance among survivors with musculoskeletal pain after the GEJE. Care for musculoskeletal pain is important to prevent sleep disturbance after natural disasters.

The Characteristics of Coaches that Verbally or Physically Abuse Young Athletes.

Verbal or physical abuse from coaches has a negative impact on young athletes. To prevent abuse against young athletes, it is important to know the characteristics of abusive coaches. This study aimed to elucidate the characteristics of coaches who commit verbal or physical abuse in youth sports teams. A cross-sectional study was conducted with coaches of youth sport teams in Miyagi prefecture, Japan (n = 1,283), using a self-reported questionnaire (response rate was 24.0%). Multivariate logistic regression models were used for analyses. The prevalence of verbal and physical abuse towards young athletes was 64.7% (n = 830) and 6.2% (n = 79), respectively. Verbal abuse was significantly associated with lower educational attainment (odds ratio (OR): 1.32, 95% confidence interval (95% CI): 1.03-1.69), experiences of verbal abuse by own coaches (OR: 1.85, 95% CI: 1.37-2.50), acceptability for verbal or physical abuse (OR: 2.53, 95% CI: 1.82-3.52), and dissatisfaction with athletes' attitude (OR: 1.62, 95% CI: 1.26-2.07). Physical abuse was significantly associated with experiences of physical abuse by respondents' coaches (OR: 2.71, 95% CI: 1.50-4.92), acceptability for verbal or physical abuse (OR: 3.89, 95% CI: 2.39-6.33), and longer experience of coaching in years (OR: 2.45, 95% CI: 1.20-4.98). The results of this study show that coaches who commit verbal or physical abuse had typically experienced abuse from their former coaches, and adopted a similar style. Breaking the negative cycle of verbal and physical abuse is necessary to eliminate the abuse of young athletes.

Excessive game playing is associated with musculoskeletal pain among youth athletes: a cross-sectional study in Miyagi prefecture.

Youth athletes are known to be at high risk of musculoskeletal (MSK) injuries. Children in developed countries are increasingly adopting a sedentary lifestyle. Although some risk factors related to sports activities have been reported, the effect of lifestyle (i.e. screen time behaviour) on MSK pain in youth athletes is not well known. This study aimed to examine the association of game playing and TV viewing with MSK pain among youth athletes. A self-administered questionnaire was mailed to youth athletes belonging to the Miyagi Amateur Sports Association. The final study population included 6,143 youth athletes (male, 71.1%; age range, 6-15 years). Multiple logistic regression analysis was used to examine the association of game playing and TV viewing behaviour with MSK pain. The point prevalence of MSK pain was 25.5%. The longest category of game playing time (≥3 h) was significantly associated with MSK pain as compared with the shortest category (<1 h) (odds ratio, 1.39; 95% confidence interval, 1.12-1.73, p = 0.003). There was no significant association between TV viewing time and MSK pain. These results suggest that game playing time might be an associated factor for MSK pain among youth athletes.

Youth baseball players with elbow and shoulder pain have both low back and knee pain: a cross-sectional study.

PURPOSE: Serious arm injuries in youth baseball players have been increasing. Though a breakage in the kinetic chain could affect arm injuries, an association between arm injuries and insufficient support of the trunk and lower extremities is not well understood. The purpose of this study was to investigate the association of low back and knee pain with elbow and/or shoulder complaints among youth baseball players. METHODS: A self-administered questionnaire and document informed consent were mailed to youth athletes belonging to the Miyagi Amateur Sports Association. Multiple logistic regression analysis was used to examine the association of low back and knee pain with elbow and/or shoulder pain at the time of the questionnaire. Variables considered in the models were as follows: sex, age, BMI, years of athletic experience, position, team level, the amount of practice, participating day in team practice and game per week, frequency of participation in games, and practice intensity. RESULTS: The final study population was comprised 1582 youth baseball players (aged 6-15 years old, male 95.6 %) who had responded to the questionnaire. A total of 24.8 % (n = 381) had elbow and/or shoulder pain, whereas 8.5 % (n = 130) had low back pain and 13.1 % (n = 201) had knee pain. The prevalence of elbow and/or shoulder pain with concomitant low back and knee pain was 61.2 % (n = 82) and 51.9 % (n = 108) (p < 0.001), respectively. The presence of low back and knee pain was significantly associated with the prevalence of elbow and/or shoulder pain among youth baseball players [adjusted odds ratio (ORs): 4.31, 95 % confidence interval (95 % CI): 2.86-6.51, p < 0.001, and ORs: 2.92, 95 % CI: 2.09-4.09, p < 0.001, respectively]. For other variables, older age (10- and 11-year old: ORs: 1.73, 95 % CI 1.10-2.73, p = 0.018; 12-15 year old: ORs: 1.62, 95 % CI: 1.18-2.58, p = 0.006), pitcher (ORs: 1.46, 95 % CI: 1.10-1.94, p = 0.009), catcher (ORs: 1.69, 95 % CI: 1.24-2.31, p = 0.001,), and practice intensity (ORs: 1.58, 95 % CI: 1.22-2.06, p = 0.001) were significantly associated with elbow and/or shoulder pain. CONCLUSION: Both low back and knee pain were significantly associated with elbow and/or shoulder pain in youth baseball players. Clinicians should check the complaints of the trunk and lower extremities as well as those of the elbow and shoulder for preventing severe injuries in youth baseball players. Level of Evidence III.

Comparative proteome analysis of the capsule from patients with frozen shoulder.

BACKGROUND: The etiology of frozen shoulder (FS) is unclear. Accordingly, this study used a label-free quantitative shotgun proteomic approach to elucidate the pathogenesis of FS based on protein expression levels. METHODS: Tissue samples from the rotator interval (RI), middle glenohumeral ligament (MGHL), and anterior-inferior glenohumeral ligament (IGHL) were collected from 12 FSs with severe stiffness and 7 shoulders with a rotator cuff tear (RCT) as controls. Protein mixtures were digested and analyzed by nano-liquid chromatography/electrospray ionization-tandem mass spectrometry. Relative protein expression levels were calculated by the signal intensity of identified peptide ions on mass spectra. Differentially expressed proteins between FS and RCT samples were evaluated by a gene enrichment analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. RESULTS: We identified 1594 proteins, 1358 of which were expressed in all 6 tissue groups. We detected more upregulated proteins in the upper (RI and MGHL) FS groups and the lower (IGHL) RCT group than in the comparative groups, respectively. Various proteins with functions in tissue repair, collagen metabolism and fibrillation, cell-cell and cell-matrix adhesion, blood coagulation, and the immune response were expressed more highly in the RI and MGHL FS groups than in the RCT group. Proteins with functions in phagocytosis, glutathione metabolism, retinoid metabolism, and cholesterol metabolism were expressed more highly in the IGHL RCT group than in the FS group. CONCLUSIONS: The pathophysiology of FS differs between the upper and lower parts of the joint capsule. Different treatment strategies for FS may be appropriate, depending on the location.

Playing video games for more than 3 hours a day is associated with shoulder and elbow pain in elite young male baseball players.

BACKGROUND: The effect of lifestyle factors on elbow or shoulder pain in young baseball players remains unclear. This study examined the association of game playing and television viewing with elbow or shoulder pain among elite young baseball players. METHODS: Study participants were young baseball players (age, 9-12 years) who participated in the National Junior Sports Clubs Baseball Festival in 2017. The national tournament invited 16 teams (totaling 210 players) selected based on the results of the regional qualifying tournaments. Self-reported questionnaires were mailed to all players before the tournament. Multiple logistic regression analyses were used to assess the association of video game playing and television viewing behavior with elbow or shoulder pain. RESULTS: Among the 210 players polled, 200 male players were included in the analysis. The prevalence of elbow or shoulder pain was 30.0%. Playing video games for ≥3 hours/day was significantly associated with elbow or shoulder pain vs. spending <1 hour/day playing video games (odds ratio, 5.59; 95% confidence interval, 1.44-21.64; P = .013). The amount of time spent watching television was not significantly associated with the prevalence of elbow or shoulder pain. CONCLUSIONS: Playing video games for ≥3 hours/day was associated with elbow or shoulder pain among elite young male baseball players. These findings highlight the effect of lifestyle on elbow and shoulder pain and should be taken into consideration by players, coaches, parents, and clinicians for the prevention of elbow and shoulder pain.

Association between sleep disturbance and new-onset subjective knee pain in Great East Japan Earthquake survivors: A prospective cohort study in the Miyagi prefecture.

BACKGROUND: The Great East Japan Earthquake (GEJE) and Tsunami devastated the northeastern coast of Japan on March 11, 2011. This study aimed to determine whether sociopsychological factors, such as sleep disturbance and psychological distress, influenced new-onset subjective knee pain in survivors during the post-disaster phase of the GEJE. METHODS: From November 2012 to February 2013 (2 years after the GEJE) and from November 2013 to February 2014 (3 years after the GEJE), survivors (≥18 years) completed self-reported questionnaires. A total of 1470 survivors responded to the questionnaires and were included in this study. New-onset subjective knee pain was defined as knee pain by encircled response absent at 2 years but present at 3 years after the GEJE. Two years after the GEJE, ≥10/24 points on the Kessler Psychological Distress Scale, and ≥6/24 points on the Athens Insomnia Scale defined the presence of psychological distress and sleep disturbance, respectively. Multiple logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) of the association between new-onset subjective knee pain and psychological distress or sleep disturbance. RESULTS: Among the participants, 10.9% (160/1470) reported experiencing new-onset subjective knee pain. Sleep disturbance was significantly associated with new-onset subjective knee pain (OR, 1.57, 95% CI, 1.08-2.29, P = 0.017); however, psychological distress was not (OR, 1.07, 95% CI, 0.65-1.78, P = 0.80). CONCLUSIONS: This is the first study to indicate an association between sleep disturbance and new-onset subjective knee pain among survivors of the GEJE. 247/300.

Influence of subjective economic hardship on new onset of neck pain (so-called: katakori) in the chronic phase of the Great East Japan Earthquake: A prospective cohort study.

BACKGROUND: Studies have suggested that musculoskeletal symptoms increase after natural disasters. The Great East Japan Earthquake (GEJE) and accompanying tsunami placed a huge financial burden on the local population. This study determined whether subjective economic hardship influenced the new onset of neck pain (katakori) in the chronic phase after the GEJE. METHODS: This study used longitudinal data from 1359 adults who had responded to the self-report questionnaire at 2 and 3 years after the GEJE. New-onset neck pain was defined as neck pain absent at 2 years and present at 3 years. Subjective economic hardship at 2 years after the GEJE was categorized into 4 groups: "normal," "a little bit hard," "hard," and "very hard." Multiple logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI) in order to examine the association between subjective economic hardship and new-onset neck pain. RESULTS: Among the participants, 12.9% (n = 175) reported new-onset neck pain. A significantly higher rate of new-onset neck pain was observed in participants who considered their subjective economic hardship to be "hard" (OR = 2.10, 95% CI = 1.34-3.30) or "very hard" (OR = 3.26, 95% CI = 1.83-5.46; p for trend <0.001) compared with those who considered their hardship to be "normal." CONCLUSIONS: Subjective economic hardship was significantly associated with new-onset neck pain in the chronic phase of the GEJE. (228/300).

Coexistence of Trunk or Lower Extremity Pain with Elbow and/or Shoulder Pain among Young Overhead Athletes: A Cross-Sectional Study.

Elbow or shoulder injuries are common in overhead sports. Because energy derived from the lower extremity passes through the trunk to the upper extremity in overhead motion, a break in such a kinetic chain could lead to arm injuries. However, there is only limited information about the role of the trunk and lower extremity support in preventing elbow or shoulder injuries. This study aimed to explore the association of trunk and lower extremity pain with elbow/shoulder pain among young overhead athletes. We conducted a cross-sectional study using self-reported questionnaires mailed to young athletes belonging to the Miyagi Amateur Sports Association. The final study population comprised 2,215 young athletes playing baseball (n = 1,422), volleyball (n = 546), softball (n = 14), handball (n = 28), tennis (n = 110), or badminton (n = 95). The median age of the participants was 11 years (range: 6 to 15 years). Multiple logistic regression analysis revealed the higher prevalence of elbow and/or shoulder pain in athletes with back pain (OR = 5.52, 95% CI = 3.51-8.69), hip pain (OR = 6.13, 95% CI = 3.35-11.22), knee pain (OR = 2.28, 95% CI = 1.48-3.51), and foot pain (OR = 3.03, 95% CI = 1.95-4.72), compared with those without pain. We propose that trunk or lower extremity pain is significantly associated with elbow or shoulder pain among young overhead athletes. Assessing for pain in trunk or lower extremity, as well as elbow and/or shoulder pain, may help prevent serious injuries in young overhead athletes.