Athletic event-specific characteristics in floating toes during the static standing posture.

[Purpose] We aimed to determine the cause of floating toe syndrome, along with methods for correction and prevention. [Participants and Methods] We recruited 93 Japanese male students. Participants were grouped, according to primary sport, as Sprinters (SPR), Swimmers (SWM), Gymnasts (GYM), Kendoists (KND) and Controls (CON). Degree of floating toe syndrome was measured according to whether any toe was not in full contact with the ground in a static standing posture-the Floating Toe Point (FTP). Two points were given for each toe that was not at the FTP. The sum of the FTP was defined as the Floating Toes Score (FTS), and was classified as follows: Normalcy (over 18 points), Incomplete Contact (between 10 and 17 points), and Floating Toes (Under 9 points). [Results] The mean FTS for all participants (10.40 ± 5.803) met the criteria for Floating Toes. Scores were highest for SWMs (13.46 ± 5.710), followed by GYMs (13.26 ± 4.505), and SPRs (12.00 ± 4.870), who all met the criteria for Incomplete Contact. Both KNDs (6.55 ± 5.409) and CONs (9.45 ± 4.824) met the criteria for Floating Toes. [Conclusion] SWMs had the highest FTSs, followed by GYMs, and SPRs. KNDs had the lowest FTS. However, no group was classified as Normal. We suggest that athletes who practice or train with bare feet do not necessarily have higher FTSs, if evaluated in the standing posture.

Development of biotin-prototrophic and -hyperauxotrophic Corynebacterium glutamicum strains.

To develop the infrastructure for biotin production through naturally biotin-auxotrophic Corynebacterium glutamicum, we attempted to engineer the organism into a biotin prototroph and a biotin hyperauxotroph. To confer biotin prototrophy on the organism, the cotranscribed bioBF genes of Escherichia coli were introduced into the C. glutamicum genome, which originally lacked the bioF gene. The resulting strain still required biotin for growth, but it could be replaced by exogenous pimelic acid, a source of the biotin precursor pimelate thioester linked to either coenzyme A (CoA) or acyl carrier protein (ACP). To bridge the gap between the pimelate thioester and its dedicated precursor acyl-CoA (or -ACP), the bioI gene of Bacillus subtilis, which encoded a P450 protein that cleaves a carbon-carbon bond of an acyl-ACP to generate pimeloyl-ACP, was further expressed in the engineered strain by using a plasmid system. This resulted in a biotin prototroph that is capable of the de novo synthesis of biotin. On the other hand, the bioY gene responsible for biotin uptake was disrupted in wild-type C. glutamicum. Whereas the wild-type strain required approximately 1 µg of biotin per liter for normal growth, the bioY disruptant (ΔbioY) required approximately 1 mg of biotin per liter, almost 3 orders of magnitude higher than the wild-type level. The ΔbioY strain showed a similar high requirement for the precursor dethiobiotin, a substrate for bioB-encoded biotin synthase. To eliminate the dependency on dethiobiotin, the bioB gene was further disrupted in both the wild-type strain and the ΔbioY strain. By selectively using the resulting two strains (ΔbioB and ΔbioBY) as indicator strains, we developed a practical biotin bioassay system that can quantify biotin in the seven-digit range, from approximately 0.1 µg to 1 g per liter. This bioassay proved that the engineered biotin prototroph of C. glutamicum produced biotin directly from glucose, albeit at a marginally detectable level (approximately 0.3 µg per liter).

A Survey of the Menstrual Status of Female College Students.

Education about menstruation is a sensitive topic for young female students; providing appropriate knowledge is essential for maintaining and improving their health. The present study was conducted to collect data corresponding to different factors affecting health among young individuals; the menstrual status, exercise habits, sleep status, and body composition of these individuals as well as the relationships among these factors, were evaluated. Altogether, 200 female students responded to the survey; 129 completed all the physical measurement items. As a case study, face-to-face interviews regarding menstrual symptoms were conducted. Results showed that 49/200 (25%) and 120/200 (60%) participants experienced moderate or severe pain before and during menstruation, respectively. The degree of pain one week before menstruation and during menstruation were significantly positively correlated (r = 0.573, p < 0.01). When analyzed as group data, it was difficult to identify the relationship between menstrual status, exercise habits, and sleep status; these were found to be intricately associated with various factors. The case study analysis confirmed that some individuals experienced physical and psychological symptoms, such as irregular menstrual cycles, premenstrual syndrome, and severe menstrual cramps.

Differences in sprinting performance and kinematics between preadolescent boys who are fore/mid and rear foot strikers.

The purpose of this study was to clarify whether foot strike patterns are associated with different sprint performance and kinematics in preadolescent boys. The study enrolled 24 healthy 10-11-year-old boys in the fifth grade at public elementary schools in Japan. The participants performed the 50-m sprint with maximum effort. Sprint motion was recorded using a high-speed video camera (120 fps) placed in the sagittal plane on the left side of a line drawn at 35-m from the start line. Kinematic variables were calculated based on manually digitized body landmark coordinates. The participants were categorized into two groups according to their foot strike pattern (rearfoot strikers, RF group, n = 12; forefoot or midfoot strikers, FF/MF group, n = 12). The time taken to complete the 50-m sprint in the FF/MF group (9.08±0.52 s) was faster than that in the RF group (9.63±0.51 s). The FF/MF group had greater sprint speed, higher step frequency, and shorter foot contact time than the RF group. Regarding the association between foot strike pattern and sprint kinematics, we found that the RF group had a greater range of knee flexion during the support-leg phase, whereas the FF/MF group had shorter horizontal distance from the heel of the support leg to the centre of mass at the touchdown, greater maximal knee flexion velocity during the swing-leg phase, and higher the maximum hip extension velocity during the support-leg phase. The current results suggested that, in preadolescent boys, forefoot or midfoot strike (rather than rearfoot strike) is effective for obtaining a higher step frequency and sprint speed through greater magnitude of knee flexion and hip extension movement velocities during the swing and support phases, respectively. The current findings will be useful for understanding the characteristics of the development of sprinting performance in preadolescent children.

Profile of match performance and heart rate response in Japanese amputee soccer players.

BACKGROUND: The purpose of this study was to profile the match performance and heart rate response in Japanese amputee soccer players. METHODS: Twelve amputee soccer players participated in this study. Match data were collected 20 samples in 4 matches. Match performances data such as total distance, high-intensity running (HIR: ≥13 km·h-1) were collected using a global positioning systems technology. Heart rate (HR) was recorded using short-range radio telemetry. In addition, the rating of perceived exertion (RPE) was assessed immediately using Borg's original after the first half and the second half. RESULTS: This study showed that the distance covered over the 50 minutes of the match was 2984.2±56.1 m, and it was significantly shorter in the second half than the first half (P<0.05). The distance covered by HIR was 205.3±100.5 m, and there was no significant difference between the first half and the second half. Moreover, the mean HR during match was 176.8±7.9 beats·min-1, which corresponded to 96.3% of HRmax. RPE was a high value of more 15 in both of the first half and the second half. CONCLUSIONS: This study was the first to evaluate competitive performance during matches in amputee soccer. Results of this study indicated that the exercise intensity was high in amputee soccer. It would be considered that causes were amputee soccer own rules and exercise style. These findings would serve as the reference when advance the future studies of amputee soccer.