Sports medicine has played a role in athlete safety, strengthening physical ability, improving sports performance, and players’ life extension. Recently, sports medicine is adding some roles to provide lifetime healthcare for athletes including children in the development stage, active players and retired players. Concussion in sport, the effects of exercising in childhood on bone and joint health, and female athlete triad are described in this review paper. Some proposals for protection of the athletes’ lifetime healthcare are also discussed.
Although it is common to assess visceral adipose tissue (VAT) by CT and MRI with a single slice at the umbilicus or the fourth and fifth lumbar vertebrae (L4-L5), recent studies reported that this single-slice method for determining an individual’s VAT may be inaccurate. Therefore, VAT accumulation should be based on total volume and determined with multiple slices rather than by cross-sectional area. However, obtaining multiple slices is burdensome for both subjects and analysts and lacks versatility despite its accuracy. The purpose of this study was to develop a new equation model for predicting VAT volume while maintaining the measurement accuracy of the multiple-slice method. We analyzed data from 214 Japanese male adults (48.5±9.3 years) and developed multiple, stepwise, linear regressions with VAT volume as a dependent variable and age, BMI, waist circumference and VAT areas (the standard L4-L5 measurement site 0 cm, +5 cm, +10 cm) as independent variables. From these results, we determined the best prediction equation for VAT volume as follows: VAT volume = (30.4×BMI) + (17.9×VAT area at L4-L5+10 cm) – 501.5. The model explained 93.1% of VAT variance and the predicted VAT volume significantly correlated with the measured VAT volume (r=0.97). This study developed a new VAT assessment method with a high level of accuracy. The method is significantly less burdensome in measurement and analysis than the multiple-slice method. Researchers can use this equation when they require an accurate evaluation of VAT accumulation. However, they should bear in mind that this equation was derived from data acquired from middle-aged, overweight and obese male subjects.
Although icing treatment has been well accepted as aftercare in sports fields, the detailed mechanisms of the treatment is not fully understood. In this study, we investigated the effect of icing treatment on the recovery process of rat plantaris muscles with artificially induced muscle damage. Sixty male Wistar rats (8-weeks-old) were randomly assigned to three groups; control (CTL), bupivacaine-injected (BPVC), and icing treatment after BPVC (ICE). Icing treatment was applied for 20 min immediately after BPVC, and the treatment was used once per day for 3 days. The plantaris muscles were removed at 3, 7, 15, and 28 days after the muscle damage, then immunohistochemical and real time RT-PCR analysis were performed. In histochemical analysis, although significant changes were found in the relative muscle weight, cross-sectional area of muscle fiber, percentage of muscle fiber with central nuclei, and expressed immature myosin heavy chain isoforms after muscle damage, as compared to the CTL group, no differences were found between BPVC and ICE groups. In mRNA expression analysis, the ICE group had a significantly lower value of MyoD than the BPVC group at 3 days after the damage. Expression of IL-6 mRNA, which relates to muscle inflammation, indicated significantly higher value in BPVC, but not in ICE, than CTL groups at 7days after the damage. Furthermore, BKB2 receptor, which relates to acute muscle soreness, indicated a significantly higher expression in BPVC than ICE groups at 3 days after the damage. These results suggest that icing treatment is effective to suppress muscle inflammation and soreness at an early stage of recovery from damage, but not effective for muscle regeneration at a later stage.
The purpose of this study was to determine sway characteristics of a supported leg during a lateral stepping over obstacle task with different obstacle height and movement patterns, using a small triaxial accelerometer. We examined 20 healthy young adults to assess their trochanter malleolar distance traveled during a lateral stepping over obstacle task with obstacle heights of 30%, 50%, and 70%. The lateral stepping over tasks revealed flexion and extension patterns. We directed the subjects to grasp a forward handrail, perform the lateral step, and subsequently step over to the side. We calculated synthetic acceleration (SA) from acceleration data measured using two small triaxial accelerometers and two web cameras. We calculated supporting leg sway; RMS phases of X-, Y-, and Z-axes; and SA data. The subjects showed increased RMS of Y-axis and SA according to the obstacle height for the flexion pattern; however, they did not show change in RMS of Y-axis and SA according to the obstacle height for the extension pattern. During lateral stepping over, the RMS of Y-axis and SA for the flexion pattern were higher than for the extension pattern. The findings for the flexion pattern suggest that the center of gravity shifts higher according to increased obstacle height; consequently, the supporting leg becomes unstable. The findings for the extension pattern suggest that the “screw-home” rotation effect of the supporting leg during movement can support lateral stepping over better than the flexion pattern.
Cross-leg sitting is locus posture performed well in Asian area, and a lifestyle and culture are thought to affect it. It is usually essential to cross-leg sitting carried out in the case of Zen meditation to maintain cross-leg sitting locus in a relaxed state to perform locus posture in floor, and to perform it in hip joint flexion of bilateral feet, abduction, and lateral rotation position in the meditation for a long time. The spinal column of cross-leg sitting was intended that aligning it confirmed backbone in lumbar vertebrae being displaced than rest standing position in the kyphosis direction or raising a bearing surface whether aligning it changed into lordotic projection from the lumbar vertebrae kyphosis direction. The thoracic vertebra angle and the lumbar vertebrae angle measured it using SpinalMouse®. We decided to measure a thoracic vertebra angle, a lumbar vertebrae angle when we changed the height of the target rest standing position and the bearing surface of cross-leg sitting. The thoracic vertebra angle did not change by raising the bearing surface of cross-leg sitting, however the lumbar vertebrae angle changed. It showed a significant correlation between hip joint flexion, abduction, an external rotation angles and the change of the lumbar vertebrae angle. Results of this study suggested that lumbar, aligning it changed to lordosis in the high cross-leg sitting thing that we changed. The quantity that aligning it biases into lordosis of the lumbar part is related to the flexion of the hip joint, abduction, external rotation flexibility.
The objectives of this study were 1) to quantify the differences in body densities and percent body fat using various methods for evaluating body composition (e.g., underwater weighing (UWW), air displacement plethysmography (ADP), skinfold caliper (SKF) measurement, ultrasound (US), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA)), and 2) to examine the relationship between trends of the differences in body density and percent body fat obtained by these methods and characteristics of morphology and body composition. To this end, the body compositions of 73 healthy male adults were measured using UWW, ADP, SKF, US, and BIA. Twenty-seven of these 73 subjects underwent further measurement using DXA. Differences in body densities determined with ADP, SKF, and US were compared with those measured using UWW as a reference, and the differences in percent body fat estimated with UWW, ADP, SKF, US and BIA were compared with those measured by DXA as a reference. The results of this study indicate that 1) ADP is useful as a method for evaluating body density, as the results differed insignificantly from the reference method and showed no systematic errors due to differences in morphological characteristics and body composition, and 2) UWW measurements exhibited the smallest difference in percent body fat from the reference method, however, more than in any other method, there were systematic errors due to differences in morphological characteristics and body composition, specifically, trunk composition.
October 05, 2017 Due to the maintenance‚following linking services will not be available on Oct 18 from 10:00 to 19:00 (JST)(Oct 18‚ from 1:00 to 10:00(UTC)). We apologize for the inconvenience. a)reference linking b)cited-by linking c)linking to J-STAGE with JOI/OpenURL
May 18, 2016 We have released “J-STAGE BETA site”.
May 01, 2015 Please note the "spoofing mail" that pretends to be J-STAGE.