Quantification of Extramyocellular Lipids and Intramuscular Fat from Muscle Echo Intensity in Lower Limb Muscles: A Comparison of Four Ultrasound Devices against Magnetic Resonance Spectroscopy.

This study aimed to compare different ultrasound devices with magnetic resonance spectroscopy (MRS) to quantify muscle lipid content from echo intensity (EI). Four different ultrasound devices were used to measure muscle EI and subcutaneous fat thickness in four lower-limb muscles. Intramuscular fat (IMF), intramyocellular (IMCL) and extramyocellular lipids (EMCL) were measured using MRS. Linear regression was used to compare raw and subcutaneous fat thickness-corrected EI values to IMCL, EMCL and IMF. IMCL had a poor correlation with muscle EI (r = 0.17-0.32, NS), while EMCL (r = 0.41-0.84, p < 0.05-p < 0.001) and IMF (r = 0.49-0.84, p < 0.01-p < 0.001) had moderate to strong correlation with raw EI. All relationships were improved when considering the effect of subcutaneous fat thickness on muscle EI measurements. The slopes of the relationships were similar across devices, but there were some differences in the y-intercepts when raw EI values were used. These differences disappeared when subcutaneous fat thickness-corrected EI values were considered, allowing for the creation of generic prediction equations (r = 0.41-0.68, p < 0.001). These equations can be used to quantify IMF and EMCL within lower limb muscles from corrected-EI values in non-obese subjects, regardless of the ultrasound device used.

Interaction Between Sarcopenic Obesity and Nonlocomotive Physical Activity on the Risk of Depressive Symptoms in Community-Dwelling Older Adult Japanese Women.

This study aimed to investigate the interaction between sarcopenic obesity and locomotive and nonlocomotive physical activity (PA) on the risk of depressive symptoms in community-dwelling older Japanese women. Participants were 143 community-dwelling older women aged 64-94 years. PA was measured using a three-axis accelerometer. Participants were classified according to two levels of total, locomotive, and nonlocomotive PA. Depressive symptoms were assessed by a self-administered survey consisting of the 15-item Japanese version of the Geriatric Depression Scale (GDS-15-J). The interaction between sarcopenic obesity groups and total or locomotive PA did not affect GDS-15-J scores. However, the interaction between sarcopenic obesity groups and nonlocomotive PA significantly affected GDS-15-J scores (p < .05). Moreover, sarcopenic obesity in the low PA group had significantly higher GDS-15-J scores compared with sarcopenic obesity in the high PA group (p < .05). We concluded that sarcopenic obesity combined with low nonlocomotive PA may exacerbate depressive symptoms in older women.

Point Prevalence of the Biomechanical Dimension of Dysfunctional Breathing Patterns Among Competitive Athletes.

ABSTRACT: Shimozawa, Y, Kurihara, T, Kusagawa, Y, Hori, M, Numasawa, S, Sugiyama, T, Tanaka, T, Suga, T, Terada, RS, Isaka, T, and Terada, M. Point prevalence of the biomechanical dimension of dysfunctional breathing patterns among competitive athletes. J Strength Cond Res 37(2): 270-276, 2023-There is growing evidence of associations between altered biomechanical breathing patterns and numerous musculoskeletal and psychological conditions. The prevalence of dysfunctional and diaphragmatic breathing patterns is unknown among athletic populations. The purpose of this study was to examine the prevalence of dysfunctional and diaphragmatic breathing patterns among athletic populations with a clinical measure to assess the biomechanical dimension of breathing patterns. Using a cross-sectional design, 1,933 athletes across multiple sports and ages were screened from 2017 to 2020. Breathing patterns were assessed using the Hi-Lo test in the standing position. Scores of the Hi-Lo test were determined based on the presence or absence of abdominal excursion, anterior-posterior chest expansion, superior rib cage migration, and shoulder elevation. The Hi-Lo test scores were used to categorize observational breathing mechanics as dysfunctional and diaphragmatic breathing patterns. The prevalence of athletes with dysfunctional breathing patterns was 90.6% (1,751 of 1,933). Athletes with diaphragmatic breathing patterns accounted for 9.4% of all athletes in our sample (182 of 1,933). There were no differences in the proportion of breathing patterns between male and female athletes ( p = 0.424). Breathing patterns observations were associated with sport-setting categories ( p = 0.002). The highest percentages of dysfunctional breathers were in middle school student athletes (93.7%), followed by elementary school student athletes (91.2%), high school student athletes (90.6%), professional/semiprofessional athletes (87.5%), and collegiate athletes (84.8%). The current study observed that dysfunctional breathing patterns (90.6%) in the biomechanical dimension were more prevalent than diaphragmatic breathing pattern (9.4%) among competitive athletes. These results suggest that clinicians may need to consider screening breathing patterns and implementing intervention programs aimed to improve the efficiency of biomechanical dimensions of breathing patterns in athletic populations. This study may help raise awareness of impacts of dysfunctional breathing patterns on athletes' health and performance.

Associations of muscle volume of individual human plantar intrinsic foot muscles with morphological profiles of the foot.

Human plantar intrinsic foot muscles consist of 10 muscles that originate and insert within the sole of the foot. It is known that the anatomical cross-sectional area (ACSA) and muscle thickness of two plantar intrinsic foot muscles, the flexor hallucis brevis (FHB) and abductor hallucis (ABH), associate with morphological parameters of the foot, such as total and truncated foot length and navicular height. However, it is unclear how the size for each of the plantar intrinsic foot muscles associates with various morphological profiles of the foot. This study aimed to elucidate this subject. By using magnetic resonance imaging (MRI), serial images of the right foot were obtained in 13 young adult men without foot deformities. From the obtained MR images, ACSA for each of the individual plantar intrinsic foot muscles was analyzed along the foot length, and then its muscle volume (MV) was calculated. The analyzed muscles were the abductor digiti minimi (ABDM), ABH, adductor hallucis oblique head (ADDH-OH), adductor hallucis transverse head (ADDH-TH), flexor digitorum brevis (FDB), FHB, and quadratus plantae (QP). Furthermore, MV of the whole plantar intrinsic foot muscle (WHOLE) was defined as the total MVs of all the analyzed muscles. As morphological parameters, total foot length, truncated foot length, forefoot width, ball circumference, instep circumference, navicular height, great toe eversion angle, and little toe inversion angle were measured using a laser three-dimensional foot scanner in standing and sitting conditions. In addition, navicular drop (ND) and normalized truncated navicular height (NTNH) were also calculated as medial longitudinal arch (MLA) height indices. The MV of WHOLE was significantly associated with the forefoot width, ball circumference, and instep circumference (r = 0.647-0.711, p = 0.006-0.013). Positive correlations were found between the forefoot width and MV of FHB, FDB, and QP (r = 0.564-0.653, p = 0.015-0.045), between the ball circumference and MV of QP (r = 0.559, p = 0.047), between the instep circumference and MV of FHB (r = 0.609, p = 0.027), and between the little toe inversion angle and MV of QP (r = 0.570, p = 0.042). The MVs of ABH, ABDM, and ADDH-OH were not significantly correlated with any morphological parameters of the foot. Similarly, no significant correlations were found between MV of each muscle and either of the MLA height indices (ND and NTNH). Thus, the current results indicate that forefoot width and circumferential parameters (instep and ball circumference), not MLA height, associate with the size of the whole plantar intrinsic foot muscles, especially those specialized in toe flexion (FHB, FDB, and QP).

Lycopene-Family Carotenoids Confer Thermostability on Photocomplexes from a New Thermophilic Purple Bacterium.

Blastochloris tepida is a newly described thermophilic purple bacterium containing bacteriochlorophyll b. Using purified light-harvesting 1 reaction center (LH1-RC) core complexes from Blc. tepida, we compared the biochemical, spectroscopic, and thermal denaturation properties of these complexes with those of its mesophilic counterpart, Blc. viridis. Besides their growth temperature optima, a striking difference between the two species was seen in the carotenoid composition of their LH1-RC complexes. The more thermostable Blc. tepida complex contained more carotenoids with longer conjugation lengths (n > 9), such as lycopenes (n = 11), and had a total carotenoid content significantly higher than that of the Blc. viridis complex, irrespective of the light intensity used for growth. The thermostability of LH1-RCs from both Blc. tepida and Blc. viridis decreased significantly in cells grown in the presence of diphenylamine, a compound that inhibits the formation of highly conjugated carotenoids. In contrast to the thermophilic purple bacterium Thermochromatium tepidum, where Ca2+ is essential for LH1-RC thermostability, Ca2+ neither was present in nor had any effect on the thermostability of the Blc. tepida LH1-RC. These results point to a mechanism that carotenoids with elongated conjugations enhance hydrophobic interactions with proteins in the Blc. tepida LH1-RC, thereby allowing the complexes to withstand thermal denaturation. This conclusion is bolstered by a structural model of the Blc. tepida LH1-RC and is the first example of photocomplex thermostability being linked to a carotenoid-based mechanism.

Relationship between Trunk Muscularity and Club Head Speed in Male Golfers.

This study examined how the volume of trunk muscles and its bilateral asymmetry are related to club head speed in golfers. Fourteen right-handed male golfers performed five driver shots, and the club head speed for each trial was calculated from a three-dimensional reflective marker position of the club head immediately before impact. The volume of each side of the rectus abdominis, erector spinae, psoas major, quadratus lumborum, lateral abdominal wall muscle, and multifidus was determined using magnetic resonance imaging. For each muscle, the ratio of the larger to smaller side in muscle volume was calculated to assess bilateral asymmetry. The club head speed correlated positively with the volume of each side of the rectus abdominis and erector spinae, left quadratus lumborum, and the asymmetric ratio of the psoas major (r=0.595-0.747), but negatively with the asymmetric ratio of the quadratus lumborum (r=-0.641). Multiple regression analysis revealed that the right erector spinae volume and the asymmetric ratio of the psoas major were significant contributors for the club head speed (R2=0.797). These results indicate that the variation in the club head speed can be strongly explained by the absolute volume and bilateral asymmetry of specific trunk muscles.

Adverse effects of the coexistence of locomotive syndrome and sarcopenia on the walking ability and performance of activities of daily living in Japanese elderly females: a cross-sectional study.

[Purpose] The aim of this study was to investigate whether the coexistence of locomotive syndrome and sarcopenia is associated with the risk of fall or performance of activities of daily living in elderly females. [Participants and Methods] We categorized 112 Japanese elderly female participants under three groups: control, locomotive syndrome, and locomotive syndrome and co-existing sarcopenia. We compared the groups based on the mean scores of anthropometric and physical function measurements, the Timed Up and Go test, and the Tokyo Metropolitan Institute of Gerontology Index of Competence to evaluate activities of daily living. [Results] The Timed Up and Go test score significantly differed among the groups. The score of the Timed Up and Go test significantly correlated with scores of the skeletal muscle mass index, skeletal muscle strength grading, and usual gait speed. The total score of the Tokyo Metropolitan Institute of Gerontology Index of Competence significantly decreased in all the groups. [Conclusion] The coexistence of locomotive syndrome and sarcopenia is associated with an increased risk of fall and worsened performance of activities of daily living. Further, the risk of fall is associated with the skeletal muscle mass, skeletal muscle strength, and gait speed. It seems likely that, compared to sarcopenia, locomotive syndrome is more sensitive to lower limb dysfunctions.

Impact of Six Consecutive Days of Sprint Training in Hypoxia on Performance in Competitive Sprint Runners.

Kasai, N, Mizuno, S, Ishimoto, S, Sakamoto, E, Maruta, M, Kurihara, T, Kurosawa, Y, and Goto, K. Impact of six consecutive days of sprint training in hypoxia on performance in competitive sprint runners. J Strength Cond Res 33(1): 36-43, 2019-The purpose of this study was to determine the effects of 6 successive days of repeated sprint (RS) training in moderate hypoxia on anaerobic capacity in 100-200-m sprint runners. Eighteen male sprint runners (age, 20.0 ± 0.3 years; height, 175.9 ± 1.1 cm; and body mass, 65.0 ± 1.2 kg) performed repeated cycling sprints for 6 consecutive days in either normoxic (NOR; fraction of inspired oxygen [FiO2], 20.9%; n = 9) or hypoxic conditions (HYPO; FiO2, 14.5%; n = 9). The RS ability (10 × 6-second sprints), 30-second maximal sprint ability, maximal oxygen uptake ((Equation is included in full-text article.)max), and 60-m running time on the track were measured before and after the training period. Intramuscular phosphocreatine (PCr) content (quadriceps femoris muscle) was measured by P-magnetic resonance spectroscopy (P-MRS) before and after the training period. Both groups showed similar improvements in RS ability after the training period (p < 0.05). Power output during the 30-second maximal sprint test and (Equation is included in full-text article.)max did not change significantly after the training period in either group. Running time for 0-10 m improved significantly after the training period in the HYPO only (before, 1.39 ± 0.01 seconds; after, 1.34 ± 0.02 seconds, p < 0.05). The HYPO also showed a significant increase in intramuscular PCr content after the training period (before, 31.5 ± 1.3 mM; after, 38.2 ± 2.8 mM, p < 0.05). These results suggest that sprint training for 6 consecutive days in hypoxia or normoxia improved RS ability in competitive sprint runners.

Aerobic exercise training-induced changes in serum C1q/TNF-related protein levels are associated with reduced arterial stiffness in middle-aged and older adults.

Adiponectin regulates endothelial nitric oxide synthase in endothelial cells, and body fat loss by aerobic exercise training promotes adiponectin secretion. Recently, C1q/tumor necrosis factor-related proteins (CTRPs) have been identified as novel adipokines and are paralogs of adiponectin, but the association between exercise training-induced reduction of arterial stiffness and circulating CTRPs levels remains unclear. This study aimed to clarify whether the reduction of arterial stiffness in middle-aged and older adults is associated with the change in serum levels of CTRPs induced by exercise training. A total of 52 middle-aged and older participants were randomly divided into two groups: a training group ( n = 26) and a sedentary control group ( n = 26). Participants in the training group completed 8 wk of aerobic exercise training (60-70% peak oxygen uptake for 45 min, 3 days/wk). The reduction of percent whole body fat, abdominal visceral fat area, and carotid-femoral pulse-wave velocity (cfPWV) was significantly greater in the training group than in the control group ( P < 0.05). Moreover, the increase in serum adiponectin, CTRP3, and CTRP5 from baseline to 8 wk was significantly higher in the training group compared with the control group ( P < 0.05). Additionally, the training-induced change in cfPWV was negatively correlated with the training-induced change in serum adiponectin, CTRP3, and CTRP5 levels ( r = -0.51, r = -0.48, r = -0.42, respectively, P < 0.05), and increased plasma nitrite/nitrate level by exercise training was correlated only with adiponectin levels ( r = 0.41, P < 0.05). These results suggest that the exercise training-induced increase in serum CTRPs levels may be associated with the reduction of arterial stiffness in middle-aged and older adults.

Bilateral deficit of spring-like behaviour during hopping in sprinters.

PURPOSE: Unilateral leg stiffness is a key contributor to sprint running speed, thereby great bilateral deficit (BLD) of leg stiffness would be expected to be observed in sprinters. However, it remains clear only BLD of leg stiffness at the preferred hopping frequency in non-sprinters. The purpose of this study was to clarify the BLD of spring-like behaviour in hopping at various frequencies and the effect of chronic adaptation via sprint running experience on BLD during the hopping. METHODS: Fifteen male experienced sprinters and 12 male novices participated in this study. They were instructed to hop in place at three frequencies (2.0, 2.5, and 3.0 Hz), and to perform hopping with maximal effort. Ground reaction forces (GRF) of both legs during the hopping were recorded using two force plates. RESULTS: At higher hopping frequencies during the unilateral and bilateral hopping, smaller peak value of vertical GRF (F max) and greater leg stiffness (K leg) were significantly observed. The BLD index of F max and the BLD index of K leg were significantly smaller at higher hopping frequencies. No significant differences of BLD index of F max and BLD index of K leg were observed between sprinters and novices. CONCLUSION: Our results demonstrate that neuromuscular inhibition in the contralateral leg changes during the hopping based on hopping frequency. This suggests that plyometric training in the beginning of rehabilitation should involve bilateral jumping at a high frequency. In experienced sprinters, detailed mechanics of chronic neuromuscular adaptation via unilateral facilitation of spring-like behaviour should be assessed by measuring electromyographic activity.

Non-linear growth trends of toe flexor muscle strength among children, adolescents, and young adults: a cross-sectional study.

PURPOSE: There are only a few studies on the muscular strength of the foot in children and adolescents; thus, the developmental pattern and normative data of these populations during growth are unclear. We sought to elucidate the developmental pattern of the foot muscle strength among children, adolescents, and young adults compared with that of the hand. METHODS: A total of 747 children, adolescents, and young adults participated in this study, and their maximum isometric toe flexor strength (TFS), hand grip strength (HGS), and foot length were measured. RESULTS: TFS was correlated with HGS (r = 0.785), age (r = 0.659), height (r = 0.757), body mass (r = 0.737), and foot length (r = 0.594). Multiple regression analyses revealed that TFS was correlated with age (ß = 0.243 in boys; ß = 0.461 in girls), squared value of age (age2; ß = - 0.296 in boys; ß = - 0.260 in girls), and body mass (ß = 0.256 in boys; ß = 0.311 in girls) in both sexes, indicating a non-linear relationship between age and TFS development. In a regression model for HGS, age was a significant variable, but not age2. HGS increased linearly from childhood until young adulthood, whereas TFS increased from childhood until adolescence and then levelled off. CONCLUSION: Our results demonstrate that TFS has a different developmental pattern compared with HGS.

The effects of low-repetition and light-load power training on bone mineral density in postmenopausal women with sarcopenia: a pilot study.

BACKGROUND: Age-related reduction in bone mineral density (BMD) is generally accelerated in women after menopause, and could be even more pronounced in individuals with sarcopenia. Light-load power training with a low number of repetitions would increase BMD, significantly reducing bone loss in individuals at risk of osteoporosis. This study investigated the effects of low-repetition, light-load power training on BMD in Japanese postmenopausal women with sarcopenia. METHODS: The training group (n = 7) followed a progressive power training protocol that increased the load with a weighted vest, for two sessions per week, over the course of 6 weeks. The training exercise comprised five kinds of exercises (squats, front lunges, side lunges, calf raises, and toe raises), and each exercise contained eight sets of three repetitions with a 15-s rest between each set. The control group (n = 8) did not undergo any training intervention. We measured BMD, muscle strength, and anthropometric data. RESULTS: Within-group changes in pelvis BMD and knee extensor strength were significantly greater in the training group than the control group (p = 0.029 and 0.030 for pelvis BMD and knee extensor strength, respectively). After low-repetition, light-load power training, we noted improvements in pelvis BMD (1.6%) and knee extensor strength (15.5%). No significant within- or between-group differences were observed for anthropometric data or forearm BMD. CONCLUSIONS: Six weeks of low-repetition, light-load power training improved pelvis BMD and knee extensor strength in postmenopausal women with sarcopenia. Since this training program does not require high-load exercise and is therefore easily implementable as daily exercise, it could be an effective form of exercise for sedentary adults at risk for osteoporosis who are fearful of heavy loads and/or training that could cause fatigue. TRIAL REGISTRATION: This trial was registered with the University Hospital Medical Information Network on 31 October 2016 ( UMIN000024651 ).

Serum C1q as a novel biomarker of sarcopenia in older adults.

Aging-induced elevation in C1q secretion activates the Wnt signaling pathway in muscles, leading to the development of muscle fibrosis. However, the association between serum C1q level and muscle mass and strength remains unclear in humans. The aim of the study was to elucidate whether serum C1q level is associated with aging- and resistance training-induced changes in muscle mass and strength. First, in a cross-sectional study, we investigated the association between serum C1q level and muscle mass and strength in 131 healthy subjects, aged 20-81 yr. Second, in an intervention study, we examined the association between the effects of serum C1q level and muscle mass and strength on 12 wk resistance training in 11 healthy older adults (60-81 yr). In the cross-sectional study, serum C1q level increased with aging and was negatively correlated with muscle mass and strength. Furthermore, 12 wk resistance training in older adults reduced the age-associated elevation in serum C1q levels. The training effect of serum C1q level significantly correlated with the change in the cross-sectional area of the thigh (r = -0.703; P < 0.01). Serum C1q level may reflect loss of muscle mass; therefore, C1q may be a novel biomarker of sarcopenia.

New ultrasonography-based method for predicting total skeletal muscle mass in male athletes.

[Purpose] This study aimed 1) to assess whether a prediction model for whole body skeletal muscle mass that is based on a sedentary population is applicable to young male athletes, and 2) to develop a new skeletal muscle mass prediction model for young male athletes. [Subjects and Methods] The skeletal muscle mass of 61 male athletes was measured using magnetic resonance imaging (MRI) and estimated using a previous prediction model (Sanada et al., 2006) with B-mode ultrasonography. The prediction model was not suitable for young male athletes, as a significant difference was observed between the means of the estimated and MRI-measured skeletal muscle mass. Next, the same subjects were randomly assigned to a development or validation group, and a new model specifically relevant to young male athletes was developed based on MRI and ultrasound data obtained from the development group. [Results] A strong correlation was observed between the skeletal muscle mass estimated by the new model and the MRI-measured skeletal muscle mass (r=0.96) in the validation group, without significant difference between their means. No bias was found in the new model using Bland-Altman analysis (r=-0.25). [Conclusion] These results validate the new model and suggest that ultrasonography is a reliable method for measuring skeletal muscle mass in young male athletes.

Resistance training restores muscle sex steroid hormone steroidogenesis in older men.

Skeletal muscle can synthesize testosterone and 5α-dihydrotestosterone (DHT) from dehydroepiandrosterone (DHEA) via steroidogenic enzymes in vitro, but hormone levels and steroidogenic enzyme expression decline with aging. Resistance exercise has been shown to increase in plasma sex steroid hormone levels. However, it remains unclear whether resistance training can restore impaired steroidogenic enzyme expressions in older individuals. Six young and 13 older men were recruited, and muscle biopsies were taken from the vastus lateralis at basal state. The same group of older subjects underwent resistance training involving knee extension and flexion exercises for 12 wk, and post-training biopsies were performed 4-5 d after the last exercise session. Muscular sex steroid hormone levels and sex steroidgenesis-related enzyme expressions were significantly lower in older subjects than younger ones at baseline, but 12 wk of resistance training significantly restored hormone levels (DHEA: 432±26 at baseline, 682±31 pg/µg protein, DHT: 6.2±0.9 at baseline, 9.8±1.4 pg/µg protein). Furthermore, the steroidogenesis-related enzymes such as 3ß-hydroxysteroid dehydrogenase (HSD), 17ß-HSD, and 5α-reductase expressions were significantly restored by resistance training. We conclude progressive resistance training restores age-related declines in sex steroidogenic enzyme and muscle sex steroid hormone levels in older men.

Tendon Cross-Sectional Area is Not Associated With Muscle Volume.

Recent studies have reported that resistance training increases the cross-sectional areas (CSAs) of tendons; however, this finding has not been consistently observed across different studies. If tendon CSA increases through resistance training, resistance-trained individuals should have larger tendon CSAs as compared with untrained individuals. Therefore, in the current study, we aimed to investigate whether resistance training increases tendon CSAs by comparing resistance-trained and untrained individuals. Sixteen males, who were either body builders or rugby players, were recruited as the training group, and 11 males, who did not participate in regular resistance training, were recruited into the control group. Tendon CSAs and muscle volumes of the triceps brachii, quadriceps femoris, and triceps surae were calculated from images obtained by using magnetic resonance imaging. The volumes of the 3 muscles were significantly higher in the training group than in the control group (P < .001 for all muscles). However, a significant difference in tendon CSAs was found only for the distal portion of the triceps surae tendon (P = .041). These findings indicate that tendon CSA is not associated with muscle volume, suggesting that resistance training does not increase tendon CSA.

Toe Flexor Strength, Flexibility and Function and Flexor Hallucis Longus Tendon Morphology in Dancers and Non-Dancers.

Tendinopathy of the flexor hallucis longus (FHL), colloquially referred to as "dancer's tendinitis," is a common condition in dancers and attributed to high demand on this muscle in positions of extreme ankle plantarflexion and metatarsophalangeal (MTP)) flexion and extension. Despite such a high prevalence, there has been little research into preventative or nonsurgical interventions. As a means to identify potential targets for prevention and intervention, this study aimed to characterize toe flexors in dancers by measuring strength, flexibility, function, and FHL tendon morphology. Dancers (n=25) were compared to non-dancers (n=25) in toe flexor isometric strength, first MTP joint range of motion, foot longitudinal arch flexibility, balance ability, endurance during modified heel raises without use of the toes, and FHL tendon thickness, cross-sectional area, and peak spatial frequency. Significant differences were found in functional first MTP joint extension (dancers 101.95°, non-dancers 91.15°, p<0.001), balance ability during single-leg stance on the toes (dancers 11.43 s, non-dancers 5.90 s, p=0.013), and during modified heel raises (dancers 22.20 reps, non-dancers 28.80 reps, p=0.001). Findings indicate that dancers rely on toe flexors more than non-dancers to complete balance and heel raise tasks. Efficacy of using this modified heel raise task with the toes off the edge of a block as a means to train larger plantarflexors and as a nonsurgical intervention should be studied in the future. Improving interventions for FHL tendinopathy will be impactful for dancers, in whom this condition is highly prevalent.

Effect of expertise on 3D force application during the starting block phase and subsequent steps in sprint running.

In sprinters with different levels of block acceleration, we investigated differences in their three-dimensional force application in terms of the magnitude, direction, and impulse of the ground reaction force (GRF) during the starting block phase and subsequent two steps. Twenty-nine participants were divided into three groups (well-trained, trained, and nontrained sprinters) based on their mean anteroposterior block acceleration and experience with a block start. The participants sprinted 10 m from a block start with maximum effort. Although the mean net resultant GRF magnitude did not differ between the well-trained and trained sprinters, the net sagittal GRF vector of the well-trained sprinters was leaned significantly further forward than that of the trained and nontrained sprinters during the starting block phase. In contrast, during the starting block phase and the subsequent steps, the transverse GRF vectors which cause the anteroposterior and mediolateral acceleration of the whole-body was directed toward the anterior direction more in the well-trained sprinters as compared with the other sprinters. Therefore, a more forward-leaning GRF vector and a greater anteroposterior GRF may particularly allow well-trained sprinters to generate a greater mean anteroposterior block acceleration than trained and nontrained sprinters.

[Outcome of schizophrenia in Asia: from the viewpoint of comparison between developed and developing countries].

The majority of the population in Asia lives in developing countries. Large-scale, international outcome studies coordinated by the WHO concluded that outcomes for schizophrenia in developing countries were better than those in developed countries. However, hospital-based outcome studies in Asian countries do not consistently support this finding, illustrating the diversity of outcomes in schizophrenia Moreover, community-based outcome studies in developing Asian countries highlight the fact that there are many individuals with schizophrenia who have never been treated, and that outcomes for this group are poor if they remain untreated. Furthermore, some studies in these countries have reported high mortality rates associated with schizophrenia Future studies in Asian countries should further investigate the relationship of accessibility of mental health services and sociocultural factors to the prognosis of schizophrenia. Research should also explore strategies for providing appropriate treatment for individuals with schizophrenia.

Vortex structure and fluid force changed by altering whole-body kinematic parameters during underwater undulatory swimming.

Swimmers generate vortices around their bodies during underwater undulatory swimming (UUS). Alteration of UUS movement would induce changes in vortex structure and fluid force. This study investigated whether a skilled swimmer's movement generated an effective vortex and fluid force for increasing the UUS velocity. A three-dimensional digital model and kinematic data yielded during UUS with maximum effort were collected for one skilled and one unskilled swimmer. The skilled swimmer's UUS kinematics were input into the skilled swimmer's model (SK-SM) and unskilled swimmer's model (SK-USM), followed by the kinematics of the unskilled swimmer (USK-USM and USK-SM, respectively). The vortex area, circulation, and peak drag force were determined using computational fluid dynamics. A larger vortex with greater circulation at the ventral side of the trunk and a greater circulation vortex behind the swimmer were observed in SK-USM compared to USK-USM. USK-SM generated a smaller vortex on the ventral side of the trunk and behind the swimmer, with a weaker circulation behind the swimmer compared to SK-SM. The peak drag force was larger for SK-USM than for USK-USM. Our results indicate that an effective vortex for propulsion was generated when a skilled swimmer's UUS kinematics was input in the other swimmer's model.