1.Effects of different obstacle height and movement pattern on supported leg sway during lateral stepping over in healthy young adults: Analysis using a small triaxial accelerometer
Takashi Sato ; Hideto Kanzaki ; Toshiaki Sato
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):355-362
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.
2.Equations to estimate visceral adipose tissue volume by a single-slice method
Kiyoji Tanaka ; Rina So ; Tomoaki Matsuo
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):335-344
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.
3.The effect of icing treatment on recovery process of damaged muscle in the rat
Kazumi Ikezaki ; Tsubasa Shibaguchi ; Takao Sugiura ; Hirofumi Miyata
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):345-354
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.
4.The role of sports medicine for athletes -protection of the athletes’ lifetime healthcare-
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):323-333
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.
5.Changes in the sagittal plane spinal alignment at the time of the cross-leg sitting position
Yukio Urabe ; Hiroshi Shinohara ; Takuya Takeuchi ; Shogo Tsutsumi
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):363-367
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.
6.Differences in body density and percent body fat found by different methods of evaluating body composition
Kayo Shitara ; Noriko Hakamada ; Takahiro Ohnishi ; Tatsuaki Ikeda
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(5):369-382
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.
7.Effects of acute aerobic repetition exercise on the vascular endothelial function
Yasuaki Tamura ; Hajime Miura ; Kenichi Deguchi ; Ayako Azuma ; Yuji Hashimoto ; Miduki Ishikawa
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(6):437-444
High-intensity interval exercise (IE) leads to greater improvements in the arterial function than continuous exercise at moderate intensity (CE). However, few studies have been performed on the effects of the repetition exercise (RE) on the vascular endothelial function. The purpose of this study was to compare the effects of CE vs. IE vs. RE during aerobic exercise on the vascular endothelial function determined by flow-mediated vasodilation (FMD). Ten healthy male subjects randomly performed 3 trials as follows: CE (20-min cycling at 50%Wmax), IE (10 × 1-min intervals cycling at 75%Wmax interspersed with 1-min intervals cycling at 25%Wmax), and RE (30 × 20-sec intervals cycling at 100%Wmax interspersed with 20-sec intervals at rest). FMD was assessed at rest and 30 and 60 min after each exercise, and then the normalized FMD (nFMD) was calculated from the peak shear rate. The nFMD (a.u.) significant increased 30 min after IE (1.2 ± 0.2 to 3.0 ± 1.0, p<0.05) and increased 30 min after CE (1.0 ± 0.2 to 1.4 ± 0.2, n.s.) and returned to baseline at 60 min after both exercises, while the nFMD decreased 30 min after RE (1.3 ± 0.2 to 1.2 ± 0.1, n.s.) and was sustained at 60 min. The nFMD value at 30 min after IE was significantly greater than that at 30 min after RE (3.0 ± 1.0 versus 1.2 ± 0.1, p<0.05). These results suggest that RE may lead to a less improvement in the vascular endothelial function than CE and IE.
8.Validity of moderate to vigorous physical activity according to the modified version of the International Physical Activity Questionnaire for Japanese Early Adolescents
Yoshitake Oshima ; Yuki Hikihara ; Ryoji Kasanami ; Norio Murase ; Kojiro Ishii
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(6):427-436
The International Physical Activity Questionnaire (IPAQ) is a self-reported questionnaire for assessment of physical activity and has been validated in many countries among adults. However, there are few studies about the validity of IPAQ for children. The purpose of this study was to investigate the validity of moderate to vigorous physical activity according to the modified version the IPAQ for Japanese Early Adolescents (IPAQ-JEA). Ninety-two adolescents aged 10-13 years participated in this study. The validity of the IPAQ-JEA criteria was tested using an activity monitor (Active style Pro, HJA-350IT; ASP). Daily physical activity was continuously monitored for one week by ASP. The participants were asked to complete the IPAQ-JEA after wearing the ASP. The epoch length of ASP was set at 1-min in this study (ASP1-min). According to the minute by minute METs values, time spent on moderate intensity physical activity (MPA, 3 to 6 METs), vigorous intensity PA (VPA, > 6 METs), and moderate to vigorous intensity PA (MVPA, > 3 METs) was calculated. In addition, we also calculated bout physical activity maintained for 10 minutes or longer (ASPbout). Weekly time spent on MVPA assessed by IPAQ-JEA (MVPA_IPAQ-JEA) was significantly correlated with that assessed by ASPbout (MVPA_ASPbout) (ρ=0.359, p<0.01) and ASP1-min (MVPA_ASP1-min) (ρ=0.399, p<0.01). However, MVPA_IPAQ-JEA was significantly higher than that of MVPA_ASPbout and MVPA_ASP1-min (p<0.001). Although time spent on VPA assessed by IPAQ-JEA (VPA_IPAQ-JEA) was also significantly correlated with that assessed by ASPbout (VPA_ASPbout) (ρ=254, p<0.05) and ASP1-min (VPA_ASP1-min) (ρ=438, p<0.01), time spent on VPA_IPAQ-JEA was significantly higher than that for VPA_ASPbout and VPA_ASP1-min (p<0.001). These results support the use of the IPAQ-JEA as a relative measure of physical activity among 10-13-year-old children.
9.Effects of community-based intervention on cognitive function and hand finger dexterity in older adults at different levels of time to go out
Noriko Ogawa ; Mami Fujibayashi ; Chika Tanaka Nanayama ; Masato Nishiwaki
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(6):455-465
The present study aimed to examine the effects of community-based intervention on cognitive function and hand finger dexterity in older adults at different levels of time to go out. Forty men and women (age, 73 ± 1 years) participated in supervised group activity and seated exercise for 60 min per session, once each week during an 8-week intervention. The participants wore an activity monitor for 1 week to determine baseline values and for the 8 weeks of intervention. Mini-mental state examination (MMSE) and pegboard test, which is related to cognitive function, were assessed before and after the intervention. Based on the total time to go out at baseline, the participants were assigned to Control group (> 60 min/day, n = 18) or Short group (≦ 60 min /day, n = 22), and then analyzed. After the 8 weeks of intervention, the Control and Short groups improved physical fitness parameters such as handgrip strength. Although MMSE in the both groups did not reach statistically significant level, these values tended to increase slightly from the baseline. Interestingly, two-way repeated-measures analysis of variance indicated significant interaction of pegboard test, and the score significantly increased only in the Short group. Total physical activity and moderate-vigorous physical activity in the both groups did not change significantly between the baseline and intervention periods. Therefore, these results suggest that the trainability of pegboard test, which is an index of hand finger dexterity and is related to cognitive function, would differ depending on the time to go out at baseline in older adults.
10.Influence of exercising condition and degree of improvement in sit-to-stand power index during a 12-week Chokin exercise program on exercise continuation after one year
Naoko Yanagawa ; Shigeru Inoue ; Yumiko Ohya ; Teruichi Shimomitsu ; Masashi Kawanishi ; Tetsuo Fukunaga ; Shiho Sawai ; Hiroaki Kanehisa
Japanese Journal of Physical Fitness and Sports Medicine 2017;66(6):445-453
We aimed to elucidate the impact of the conducting state in exercise programs and the degree of improvement in sit-to-stand power index (STS-PI) on the continuation of Chokin exercise by participants one year from the completion of the intervention period. Subjects participated in a 12-week Chokin exercise class for the elderly, which consisted of 10 body mass-based exercises. As variables indicating exercise conditions, the number of exercise days weekly and the total number of sets performed during the intervention period were adopted. STS-PI was calculated using the time required to perform 10-times-repeated sit-to-stand task, and its relative change (%∆STS-PI) was used to represent the degree of improvement in physical function. Among 52 men and 129 women who responded to the inquiry about the continuation of Chokin exercise one year from the completion of the intervention period, 32 men and 93 women confirmed continuation of the exercise program. Logistic regression analysis showed that %∆STS-PI for men, as well as %∆STS-PI and the number of exercise days weekly for women, were factors associated with the decision of subjects to continue the Chokin exercise. These results indicate that the degree of improvement in STS-PI associated with the Chokin exercise class is a factor for continuing the exercise program one year from the completion of the intervention period, at least in elderly men and women. Furthermore, high exercise frequency during the intervention period may be associated with the decision to continue Chokin exercise after the completion of the intervention among women.