<italic><bold>Context</bold>:</italic> This study aimed to examine the differences in electromyographic (EMG) activity of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles, break-point angle (BPA), and the angle at peak BFlh EMG activity between bilateral and unilateral Nordic hamstring exercise (NHE) on a sloped platform. <italic><bold>Design</bold>:</italic> This study was designed as a case-control study. <italic><bold>Methods</bold>:</italic> Fourteen men participated in the study. The participants initially performed maximum voluntary isometric contraction (MVIC) on the prone leg curl to normalize the peak hamstring EMG amplitude as the %MVIC. Then, participants were randomized to perform the following 3 variations of NHE: bilateral (N40) or unilateral (N40U) NHE with a platform angle of 40°, and unilateral NHE with a platform angle of 50° (N50U). The EMG activities of the BFlh and ST and the knee flexion angle during the NHE variations were recorded to calculate the EMG activity of the BFlh and ST in terms of the %MVIC, the angle at peak BFlh EMG, and BPA. <italic><bold>Results</bold>:</italic> The BFlh %MVIC was significantly higher in N40U (<italic>P</italic> &lt; .05) and N50U (<italic>P</italic> &lt; .05) than in N40. A significant difference in BFlh %MVIC and ST %MVIC was observed between N40U (<italic>P</italic> &lt; .05) and N50U (<italic>P</italic> &lt; .05). The mean values of BPA and the angle at peak BFlh EMG were &lt;30° for all NHE variations. <italic><bold>Conclusions</bold>:</italic> In the late swing phase of high-speed running, BFlh showed higher EMG activity; thus, unilateral NHE may be a specific hamstring exercise for hamstring injury prevention.

The purpose of this study was to examine whether the NHE with an increased lower leg slope angle would enhance hamstring EMG activity in the final phase of the descend. The hamstring EMG activity was measured, the biceps femoris long head (BFlh) and the semitendinosus (ST). Fifteen male volunteers participated in this study. Subjects performed a prone leg curl with maximal voluntary isometric contraction to normalize the hamstring EMG activity. Subsequently, subjects performed the NHE, with the help of a certified strength and conditioning specialist, while the lower leg slope angle were randomly set at 0° (NH), 20° (N20), and 40° (N40). To compare hamstring EMG activity during the NHE variations, the knee flexion angle was set in the range from 0° to 50°, divided into five phases (0-10°, 10-20°, 20-30°, 30-40° and 40-50°), where 0° indicated that the knee was fully extended. To calculate the knee extension angular velocity, the knee flexion angle divided by time, and break point angle (BPA) was the angle at which 10°/s was exceeded. In the statistical analysis, a two-way repeated measures ANOVA was used for the hamstring EMG activity and a one-way repeated measures ANOVA was used for the BPA. The EMG activity of the BFlh and the ST in N20 and N40 was significantly higher than in NH at knee flexion angle of 0-20° (p < 0.05). For the BPA, NH (57.75° ± 13.28°), N20 (36.27° ± 9.89°) and N40 (16.26° ± 9.58°) were significantly higher in that order (p < 0.05). The results of this study revealed that the NHE with an increased lower leg slope angle shifted the BPA to the lower knee flexion angle and enhanced the hamstring EMG activity in the final phase of the descent.

The differences in physical activity for opponentchanges remain unclear for all organized sports. Thisstudy aimed to investigate the relationship between game results and activityprofiles of the national men’s lacrosse team during the2018 Federation of International Lacrosse World Championship. The study population included all twenty-one lacrosseplayers (five attacks: ten midfielders, and six defenses) of one team that participatedin the Championship. The results revealed that in seven internationalmatches, the distance was significantly greater in the higher-ranked group (the higher-ranked four teams of this study opponent)than in the lower-ranked group (thelower-ranked three teams of this study opponent),as was also the case for the walk and sprint distances (p &lt; 0.05 forboth comparisons). The sprint and high-speed running distances in thepreliminary group (the team that competedin the qualifier) were significantly shorter thanthose in the final round group (theteam that competed in the knockout phase)(p &lt; 0.01 for both comparisons). The midfield group’s top speed andsprint distance were significantly greater than those of the attack and defensegroups (p &lt; 0.001). Multiple comparison tests showed that distanceand jog distance in the 4th quarter (4Q) were significantly greater than those in1Q–3Q (p &lt; 0.01).Run and sprint distances and medium-intensity decelerations were significantlygreater than in the 2Q (p &lt;0.001, p =0.02 and p=0.049, respectively). The 4Q had significantlygreater low-intensity accelerations and decelerations than the 2Q and 3Q (p &lt; 0.05 for both comparisons).The differences in the opponent’s physical data can help coaches adjust trainingand conditioning before a match.

BACKGROUND: Evaluation of the effect of a pad on foot morphologies in patients with medial tibial stress syndrome (MTSS)requires more reliable and objective methods, rather than conventional subjective observations.OBJECTIVE: The objective of this study was to investigate the effect of pads on foot morphologies during quiet standing inathletes with MTSS.METHODS: We measured three-dimensional foot morphologies in 30 feet with MTSS and 40 healthy feet.RESULTS: The analysis showed that Hallux valgus degree, calcaneal angle, arch height, and arch height ratio differed significantlyas a result of the pad support, compared to no pad support in the MTSS group. The pad support only resulted in significantdifferences in arch height, compared to no support in the control group. Furthermore, thumb side angle, calcaneal angle, and archheight ratio were significantly different between the MTSS and control groups.CONCLUSIONS: Our study results suggest that changes in foot morphologies because of the use of a pad can be measuredobjectively in patients with MTSS.

本研究は脛骨内側ストレス症候群（以下，MTSS）を有した選手を対象とし、インソールによる静止立位時における足部形態の変化について検討することを目的とした。MTSS群患者20名および健常者20名を対象とし、静止立位時の3次元足部形態計測を行った。解析の結果、MTSS群においてno supportに比べてsupportはThumb side angle, Calcaneal angle, archheight, arch height ratioに有意差が生じた。健常群においてnosupportに比べてsupportはarch heightに有意差が生じた。さらにMTSS群と健常群の間でThumb side angle, Calcaneal angle, arch height ratioに有意差が生じた．本研究によって足底板による脛骨内側ストレス症候群患者の足部形態の変化を客観的に抽出することが可能となった。

本研究はラクロス選手のMFのポジションを役割の違いで2つに分けた（フルフィールドミッドフィルダー：FFMFとハーフミッドフィルダー：HMF）際に出場時間や運動負荷に差が見られるか検討を行った．対象者は男子ラクロス日本代表に選ばれた32人のMFのラクロス選手（HMF：19人，FFMF：13人）を対象として実験を行った．データは5試合の国際試合に関して，心拍計・加速度計が同期されているGPS装置を各選手の胸部に装着して取得した. 分析項目は心拍数，出場時間，休息時間，最高速度，スピード区間毎の走行距離（歩行(0–7.19 km/h), ジョギング(7.2–14.39 km/h), ランニング(14.4–21.59 km/h), スプリント(≧21.6 km/h)），加速度のゾーン毎の発揮回数（低強度 (0–1.99 m/s2)の加速度と減速度の回数, 中強度 (2.0–3.99 m/s2) の加速度と減速度の回数, 高強度 (≧4.0 m/s2) の加速度と減速度の回数）とした．結果は1play当たりと総playの出場時間において，HMFはFFMFに比べて有意に少なかった．総playの走行距離と出場回数において，HMFはFFMFに比べて有意に少なかった．総playの加速度の回数において低強度の加・減速度，中強度の加・減速度，高強度の加・減速度の回数において，HMFはFFMFに比べて有意に少なかった．以上より， HMFに必要な試合中のコンディショニングレベルはFFMFに比べて低回数のハイパワー発揮能力が必要であることが明らかとなった．

BACKGROUND: This study was designed toquantify the relationship between the relation between physical tests and gameactivity.METHODS: we measured physical ability (20m dash, 50 m dash, proagility shuttle, 12 minutes test, agility T-test). Then,we investigated the activity profiles of 24 men’s lacrosse players [attack(AT): 5, midfield (MD): 13, defense (DF): 6] using a global positioning system(GPS) and a player acceleration apparatus to determine their movement andphysiological load.RESULTS: The study revealed that in 13matches (n = 302), top speed was significantly correlated with the 20 m dash,the 50 m dash, and the proagility shuttle (statistical significance: 0.05%).Distance, walk distance, and jog distance for the AT and DF groups weresignificantly greater than those of the MD group, but the MD group’s top speedand sprint distance were the highest. Multiple-comparison tests showed that topspeed, run distance, and sprint distance in the third and fourth quarters weresignificantly smaller than in the first quarter.CONCLUSIONS: The development of physicalqualities likely helps improve the in-game performance of lacrosse players.Particularly, an intermittent method congruent with exercise patterns in actualcompetitions should be used in training, and this study is useful in developingtraining programs for game tactics according to positional characteristics.