Papers by Ryoichi Nagatomi
Journal of Bone and Mineral Metabolism, 2010
Although there is ample evidence supporting the effectiveness of physical activity in the prevent... more Although there is ample evidence supporting the effectiveness of physical activity in the prevention and treatment of osteoporosis, there are no previous studies to examine the effect of office-based brief high-impact exercise (HIE) on bone mineral density (BMD) in healthy premenopausal women. This study evaluated the effects of office-based HIE on BMD in healthy premenopausal Japanese women. Ninety-one healthy premenopausal women were randomized to receive stretching exercise (SE) or HIE (stretching, along with up to 5 9 10 vertical and versatile jumps) for 12 months. The BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. Several cardiovascular risk factors and leg strength also were assessed. An accelerometer-based recorder was used to measure daily impact loading in four 1-week samples. The progression of the HIE program was ensured by the accelerometer. Thirty-three women (71.7%) in the SE group and 34 (75.6%) in the HIE group completed the study. There was a significant difference in the change in the femoral neck BMD between the groups in favor of the HIE group [0.6% (95% CI:-0.4, 1.7) vs.-1.0% (95% CI:-2.2, 0.2)]. Adiponectin, LDL, HDL, and the leg strength of participants in both the groups improved during the intervention. These finding suggested that office-based brief HIE can be recommended for premenopausal women for preventing bone mineral loss. Keywords Osteoporosis Á Impact exercise Á Bone mineral density Á Accelerometer Trial Registration: http://www.umin.ac.jp/ctr/index.htm Identifier: UMIN000000533.
Applied Sciences
We conducted a review to collect the validated basketball-specific physical field tests and to pr... more We conducted a review to collect the validated basketball-specific physical field tests and to provide practical advice for their appropriate selection and application. A comprehensive electronic literature search was performed via three electronic databases (PubMed, GoogleScholar, and SportDiscuss). Results of 93 studies provided recommendations for seven test packages and eighteen individual tests that have already been validated for basketball players. Although there is a lack of standardized, widely, and systematically used test protocols for testing the fitness levels of basketball players, standardized, normative data from NBA Combine Testing and other basketball-specific tests have the potential to help coaches compare their players with elite basketball players. Our review indicated that agility and reactive agility are fundamental skills in basketball; however, linear sprinting ability should not be considered a determining factor of success for basketball players. Finally,...
Applied Sciences
Basketball is one of the most popular team sports in the world. A wide variety of athletic skills... more Basketball is one of the most popular team sports in the world. A wide variety of athletic skills can be valuable indicators of a talented player. Testing these skills help trainers and scouts to make the best decisions during both youth and adult player selection of different competitive levels and field positions. However, scientific data regarding the association between field tests results and match statistics is sparse. We conducted a systematic review to logically summarize the physical field tests of athletic abilities and anthropometric measures used in basketball in different player positions at different levels, and to determine whether test results may correlate with match statistics. A comprehensive electronic literature search was performed via three electronic databases (PubMed, GoogleScholar, SportDiscus). The CASP checklist was used for checking the quality of reporting for all included articles. Based on 39 studies, it could be supported that the agility, speed and ...
Frontiers in Physiology
Background: Low back pain (LBP) is a common health problem — sitting on a chair for a prolonged t... more Background: Low back pain (LBP) is a common health problem — sitting on a chair for a prolonged time is considered a significant risk factor. Furthermore, the level of LBP may vary at different times of the day. However, the role of the time-sequence property of sitting behavior in relation to LBP has not been considered. During the dynamic sitting, small changes, such as slight or big sways, have been identified. Therefore, it is possible to identify the motif consisting of such changes, which may be associated with the incidence, exacerbation, or improvement of LBP.Method: Office chairs installed with pressure sensors were provided to a total of 22 office workers (age = 43.4 ± 8.3 years) in Japan. Pressure sensors data were collected during working days and hours (from morning to evening). The participants were asked to answer subjective levels of pain including LBP. Center of pressure (COP) was calculated from the load level, the changes in COP were analyzed by applying the Toepl...
Journal of Cellular Physiology
The Tohoku Journal of Experimental Medicine
Motor skill practice improves performance not only in the trained-but also in the untrained contr... more Motor skill practice improves performance not only in the trained-but also in the untrained contralateral limba phenomenon called as interlimb transfer. Handedness affects motor skill acquisition and interlimb transfer, but it remains unknown whether handedness affects interlimb transfer when practicing with the dominant or non-dominant limb. We have hypothesized that interlimb transfer of skill acquisition differs between left-and right-handed participants, and that right-as compared with left-hand motor skill practice shows greater interlimb transfer, regardless of handedness. Strongly left-hand (n = 12, aged 27.3 ± 4.4 years; 3 female) and right-hand dominant (n = 12, 20.7 ± 3.8 years; 5 female) subjects with no history of neurological or orthopedic disorders performed the grooved pegboard test before and after 4 blocks of practice on the same apparatus. Subjects were timed on their speed of the task. Right-handed subjects failed to improve manual performance in their right hand after right-or left-hand motor practice. In contrast, they showed improvement on the left hand in each condition. These data suggest greater interlimb transfer after right-hand motor skill practice, but no interlimb transfer after left-hand practice. On the other hand, our results show consistent interlimb transfer effects in left-handed subjects, irrespective of whether the dominant left or the non-dominant right arm has been initially trained. In conclusion, our results add to the body of literature by detecting the differences in the magnitude of motor skill acquisition and interlimb transfer between left-and right-handed subjects after short-term unilateral motor skill practice.
Journal of Epidemiology
Background: There is scarce epidemiological evidence regarding the relationships of the consumpti... more Background: There is scarce epidemiological evidence regarding the relationships of the consumption of different types of vegetables or fruits with change in skeletal muscle strength. We prospectively examined the relationships among Japanese adults, using handgrip strength to assess skeletal muscle strength. Methods: A 3-year study was carried out with 259 Japanese adults who were 22-68 years of age. The frequency of consumption of different types of vegetables or fruits were obtained using a validated self-administered dietary history questionnaire. Handgrip strength was measured with a handheld digital Smedley dynamometer. Results: After adjustment for confounding factors, the mean change in handgrip strength in participants stratified according to the level of tomato and tomato product consumption at baseline were −3.2 (95% confidence interval [CI], −4.0 to −2.3) for <1 time=week, −2.7 (95% CI, −3.6 to −1.8) for 1 time=week, −1.6 (95% CI, −2.5 to −0.8) for 2-3 times=week, and −1.7 (95% CI, −2.8 to −0.7) for ≥4 times=week, (P for trend = 0.022). However, the significant relationships of consumption of other types of vegetables and different types of fruits with change in handgrip strength were not observed. Conclusion: Higher consumption of tomato and tomato product at baseline was significantly associated with reduced decline in handgrip strength among Japanese adults over a 3-year follow-up period. This study suggests that consumption of tomato and tomato product could be protective against the decline in skeletal muscle strength associated with aging.
Nutrition Journal
Background This prospective cohort study aimed to investigate the association between daily seawe... more Background This prospective cohort study aimed to investigate the association between daily seaweed intake and depressive symptoms. Methods In a prospective study conducted between 2008 and 2011, 500 Japanese adult employees aged 20–74 years participated and were included in the final analysis. Consumption of seaweed was assessed using a brief self-administered diet history questionnaire, and changes in seaweed consumption were divided into three categories (decreased, unchanged, and increased). Depressive symptoms were assessed using a Japanese version of the Self-Rating Depression Scale (SDS). Depressive symptoms were defined as an SDS score of ≥50 in the present study. Results At the 3-year follow-up, 46 participants (9.2%) showed depressive symptoms. Multivariate analysis showed that baseline seaweed intakes were not significantly associated with the incidence of depressive symptoms (p for trend = 0.501). Conversely, odds ratios (95% CI) for depressive symptoms were lower in the...
Stem Cell Reports
Adult muscle stem cells (satellite cells) are required for adult skeletal muscle regeneration. A ... more Adult muscle stem cells (satellite cells) are required for adult skeletal muscle regeneration. A proper balance between quiescence, proliferation, and differentiation is essential for the maintenance of the satellite cell pool and their regenerative function. Although the ubiquitin-proteasome is required for most protein degradation in mammalian cells, how its dysfunction affects tissue stem cells remains unclear. Here, we investigated the function of the proteasome in satellite cells using mice lacking the crucial proteasomal component, Rpt3. Ablation of Rpt3 in satellite cells decreased proteasome activity. Proteasome dysfunction in Rpt3-deficient satellite cells impaired their ability to proliferate, survive and differentiate, resulting in defective muscle regeneration. We found that inactivation of proteasomal activity induced proliferation defects and apoptosis in satellite cells. Mechanistically, insufficient proteasomal activity upregulated the p53 pathway, which caused cell-cycle arrest. Our findings delineate a critical function of the proteasome system in maintaining satellite cells in adult muscle.
PloS one, 2018
We determined the effects of wearing an above-knee compression garment (CG) on knee joint positio... more We determined the effects of wearing an above-knee compression garment (CG) on knee joint position sense. Healthy young adults (n = 24, age = 27.46 ± 4.65 years) performed a passive knee position-matching task on an isokinetic dynamometer with each leg separately. We determined the magnitude of compression by measuring anatomical thigh cross sectional area (CSA) in standing using magnetic resonance imaging. Wearing the CG compressed CSA by 2% (t = 2.91, p = 0.010, Cohen's d = 0.68). Repeated measures ANOVA (rANOVA) with three repetition factors (condition: CG, no CG; leg: right dominant, left non-dominant; and target angles: 30°, 45°, 60°) revealed an effect of angles (p < 0.001), where the matching of knee joint position was more accurate at 60° compared to 30° and 45° (p < 0.001). However, CG did not reduce passive joint position sense errors. In fact, joint position error was less without CG (p = 0.014). In conclusion, while CG does compress the thigh it does not afford...
BMC oral health, Dec 29, 2017
Sports-related dental injuries, such as tooth fracture, loosening, and avulsion, are a major conc... more Sports-related dental injuries, such as tooth fracture, loosening, and avulsion, are a major concern among young athletes because they directly impair oral function. Although the preventive efficacy of mouthguards has been well established, the prevalence of sports-related dental injuries remains high among young athletes. The aim of this study is to identify the variables contributing to the risk of sports-related dental injuries by conducting a survey on large population of young athletes in Miyagi prefecture. A cross-sectional study was conducted with school-aged athletes (aged 6-15 years, n = 5735) using a self-reported questionnaire. The questionnaire examined general variables, including sex, age, and body mass index; sports-related variables, including sports-type, team level, activity schedule, break time, and verbal/physical abuse by coaches; and lifestyle variables related to free time, including screen-time and sleep duration. Their associations with sports-related dental...
The Tohoku journal of experimental medicine, Apr 1, 2018
Verbal or physical abuse from coaches has a negative impact on young athletes. To prevent abuse a... more 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' ...
Journal of epidemiology, May 25, 2017
The "Physical Activity Reference for Health Promotion 2013" provides "fit" re... more The "Physical Activity Reference for Health Promotion 2013" provides "fit" reference values for cardiorespiratory fitness (CRF) for good health. The importance of achieving a fit CRF level for several years on the subsequent prevention of type 2 diabetes mellitus (T2DM) remains to be clarified. This cohort study was conducted in 2,235 nondiabetic males aged 21 to 59 years, enrolled in April 1986 through March 1987. We calculated the ratio of the area under the curve (AUCratio) for actual measured values and the AUC for the reference values of CRF in each individual during an 8-year measurement period before the baseline. According to whether they met a fit CRF level or not, participants were categorized into groups based on the AUCratio (FitAUC or UnfitAUC) and initial CRF (Fitinitial or Unfitinitial), respectively. T2DM was evaluated on health checkups until March 2010. During the follow-up period, 400 men developed T2DM. After adjustment for confounders, as com...
The Tohoku journal of experimental medicine, Nov 1, 2017
Elbow or shoulder injuries are common in overhead sports. Because energy derived from the lower e... more 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 ...
European Spine Journal
Low back pain is a significant problem for school-aged athletes. Although some risk factors relat... more 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. 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. 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. 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.
Archives of Pharmacal Research
Rhinoviral infection is associated with an increased risk of asthma attacks. The macrolide clarit... more Rhinoviral infection is associated with an increased risk of asthma attacks. The macrolide clarithromycin decreases cytokine production in nasopharyngeal aspirates from patients with wheezing, but the effects of macrolides on cytokine production in nasal epithelial cells obtained from asthmatic subjects remain unclear. Here, human nasal epithelial cells were infected with type-14 rhinovirus (RV14), a major RV group. Titers and RNA of RV14 and cytokine concentrations, including IL-1β and IL-6, were higher in the supernatants of the cells obtained from subjects with bronchial asthma (asthmatic group) than in those from the non-asthmatic group. Pretreatment with clarithromycin decreased RV14 titers, viral RNA and cytokine concentrations, and susceptibility to RV14 infection. Pretreatment with clarithromycin also decreased IL-33 production, which was detected after infection. Pretreatment with clarithromycin decreased the expression of intercellular adhesion molecule-1, the receptor for RV14, after infection, the number and fluorescence intensity of the acidic endosomes through which RV RNA enters the cytoplasm, and the activation of nuclear factor kappa-B proteins in nuclear extracts. These findings suggested that RV replication and cytokine production may be enhanced in nasal epithelial cells obtained from subjects with bronchial asthma and may be modulated by clarithromycin.
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, Jan 22, 2016
Serious arm injuries in youth baseball players have been increasing. Though a breakage in the kin... more 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. 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. The final study p...
The Tohoku journal of experimental medicine, Feb 1, 2017
Dental problems among athletes have been cautioned due to negative impacts not only on their oral... more Dental problems among athletes have been cautioned due to negative impacts not only on their oral health but also on athletic performance. Acquirement of appropriate oral health behavior mainly composed of toothbrushing in childhood can be one of the most important strategies for advancing children's athletic possibilities. Although habits of screen viewing, including game playing, and TV viewing have direct impacts on children's health and behavioral development, little is known about the association between these habits and toothbrushing frequency. A cross-sectional survey examining sports activities was conducted using a self-report questionnaire among school-aged athletic children belonging to the Miyagi Amateur Sports Association (n = 6,658). All statistical analyses were performed with SPSS, and P-values less than 0.05 were considered statistically significant. The association between a lower brushing frequency (< 2 times a day) and screen-viewing behavior was exami...
Social psychiatry and psychiatric epidemiology, Jan 9, 2017
Dairy products have been reported to have various beneficial effects on human health. Although so... more Dairy products have been reported to have various beneficial effects on human health. Although some previous studies have shown relationships between dairy consumption and depressive symptoms, the results of these studies were not consistent. This study aimed to investigate the association between frequency of low- and whole-fat dairy consumption, and depressive symptoms. This cross-sectional study enrolled 1159 Japanese adults aged 19-83 years. Dietary intake was assessed using a brief self-administered diet history questionnaire. Depressive symptoms were evaluated by a self-rating depression scale (SDS) (the presence of depressive symptoms was defined as an SDS score ≥45 points). Logistic regression models were used to analyze the association between the frequency of low- and whole-fat dairy consumption and depressive symptoms. Higher frequency of low-fat dairy consumption was associated with a lower prevalence of depressive symptoms. In the final adjusted model, the odds ratios a...
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Papers by Ryoichi Nagatomi