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[Purpose] The purpose of this study was to determine whether unilateral dominance exists in toe grip strength in Kendo players using a toe grip dynamometer. [Participants and Methods] In total, 15 male college Kendo players, who had no disability or pain in their feet, were included in the study. The participants completed a questionnaire to determine which foot the participants used as their front and rear foot while standing in Kendo. We measured toe grip strength three times on each side. We then extracted the maximum value of toe grip strength from the three measurements on each side and calculated the ratio of toe grip strength to body weight (%). [Results] All players used their right foot as the front foot. We found that the front foot toe grip strength was significantly stronger than the rear foot toe grip strength. [Conclusion] Our results suggest laterality of toe grip strength and the front foot toe grip strength is stronger than the rear foot toe grip strength in Kendo players.

[Purpose] The purpose of the present study was to confirm the relationships between shoulder strength (extensor strength and internal rotator strength) of the abducted position and swimming power during arm-only swimming. [Subjects and Methods] Fourteen healthy male collegiate swimmers participated in the study. Main measures were shoulder strength (strength using torque that was calculated from the upper extremity length and the isometric force of the abducted position) and swimming power. [Results] Internal rotation torque of the dominant side in the abducted external rotated position (r=0.85) was significantly correlated with maximum swimming power. The rate of bilateral difference in extension torque in the maximum abducted position (r=−0.728) was significantly correlated with the swimming velocity-to-swimming power ratio. [Conclusion] The results of this study suggest that internal rotator strength measurement in the abducted external rotated position and extensor strength measurement in the maximum abducted position are valid assessment methods for swimmers.

In this study, the finishing movement of front-crawl swimming upon reaching the goal was carried out by a unilateral forearm-amputee swimmer experimentally, and the difference between the finishing movements of the impaired side and the healthy side was compared in order to examine the effectiveness of each finishing movement. The subject was one female unilateral forearm-amputee swimmer (Impairment Classification S9) who has participated in Paralympic. The experiment practice was set that the subject carried out front-crawl swimming with the maximum effort without taking a breath from the 10 m point before the goal toward the goal wall. The practice conditions were set with four types, in order to verify with which arm the subject used to touch the goal wall (with the impaired side or the healthy side), and whether she touched the goal wall in the water or above the water. For evaluating a finishing movement, the standard value was set with the estimated time required when the swimmer touched the goal with her head top while maintaining the swimming speed when reaching the goal. And the difference between the standard time and the actual required time was calculated as the time loss (seconds). Among the four types of finishing movements evaluated in this research, the time loss during the finishing movement tends to decrease when the subject touched the goal with her healthy side in the water (-0.20 ± 0.01 seconds), while it tends to increase when she touched the goal with her impaired side in the water (0.08 ± 0.07 seconds). This result suggests the possibility that a unilateral forearm-amputee swimmer can expect better results by touching the goal with the healthy side in the water. For achieving this, the swimmer needs to adjust his/her strokes as making the finishing touch by the healthy side in the water.

[Purpose] The present study aimed to demonstrate the following by using measurements for the definite angles provided by the digital protractor: inter-rater reliability and validity in radiograph measurements and smartphone application measurements. [Subjects and Methods] The subject angles were 26 angles between 15° and 180° that were selected randomly using a computer. Three examiners measured the angles using the radiograph and smartphone application. The radiograph was obtained at a position 250 cm from the chest shooting cassette holder. The smartphone photograph was obtained at positions 50, 100, 150, 200, and 250 cm from the holder. [Results] Under all conditions, intra-class correlation coefficients showed 0.999. The correlation coefficient was 0.999 for all conditions. The mean absolute difference to the protractor was ≤0.28° for all conditions. [Conclusion] In comparison with the protractor, radiograph measurements and smartphone application measurements, the results of the present study showed high inter-rater reliability, validity, and small error. The results indicated that radiograph and smartphone application measurements could be used as criteria of validity in angle measurements. It supported the legitimacy of high-quality previous studies that used radiograph measurements as a criterion for validity.

BACKGROUND An increased femoral anteversion may be a risk factor for patellofemoral pain and is measured by Craig's Test clinically using a goniometer. However, its validity has not been examined. The purpose of the present study was to examine the validity of Craig's Test, with those measured using computed tomography (CT), and to investigate the relationship between femoral anteversion and knee external rotation. METHODS Twenty-six college students (13 men and 13 women) were measured their femoral anteversion values by Craig's Test (FACraig) and CT (FACT) and knee external rotation values by CT (KERCT). Multiple regression analysis to predict FACraig using FACT and sex was conducted. Mixed design (Measurements × sex) ANOVA examined the difference in FACraig and FACT. Pearson's correlation coefficients examined the relationships between FACT and KERCT for each sex. RESULTS FACT (B=0.41, P=0.014) and sex (B=-5.22, P=0.075) together explained 23.4% of the variance in FACraig (F=3.52, P=0.046). FACraig was significantly smaller than FACT in females while no significant difference was found in males. Greater FACT was significantly related with greater KERCT (r=0.47, P=0.02) in females only. CONCLUSIONS Craig's Test does not provide highly valid values to reflect the true femoral anteversion despite its clinical significance. Greater femoral anteversion may be associated with increased static knee external rotation, possibly resulting in increased quadriceps-angle and thus patellofemoral pain risk.

[Purpose] Although a correlation has been reported between shoulder strength and maximum swimming power during arm-only swimming, the correlation between shoulder strength and maximum swimming power during front crawl swimming remains unclear. This study aimed to confirm the validity of a clinical assessment method for shoulder strength related to front crawl swimming power. [Participants and Methods] Study participants included 9 healthy male collegiate swimmers. Shoulder strength, including extension and internal rotation torque and swimming power, were measured. [Results] Maximum swimming power was significantly correlated with extension torque in the position of maximum shoulder abduction on the dominant side (r=0.844). No significant correlations were observed between the swimming velocity-to-swimming power ratio and the rate of bilateral differences in extension torque in the position of maximum shoulder abduction. [Conclusion] The extensor strength in the position of maximum shoulder abduction was significantly correlated with the maximum swimming power, suggesting that this assessment method is useful for front crawl swimmers. Notably, measurements on the dominant side may provide useful data that are essential in training to improve front crawl swimming propulsion.

[Purpose] The purpose of present study was to establish the same-session and between-day intra-rater reliability of measurements of extensor strength in the maximum abducted position (MABP) using hand-held dynamometer (HHD). [Subjects] Thirteen healthy volunteers (10 male, 3 female; mean ± SD: age 19.8 ± 0.8 y) participated in the study. [Methods] Participants in the prone position with maximum abduction of shoulder were instructed to hold the contraction against the ground reaction force, and peak isometric force was recorded using the HHD on the floor. Participants performed maximum isometric contractions lasting 3 s, with 3 trials in one session. Between-day measurements were performed in 2 sessions separated by a 1-week interval. Intra-rater reliability was determined using intraclass correlation coefficients (ICC). Systematic errors were assessed using Bland-Altman analysis for between-day data. [Results] ICC values for same-session data and between-day data were found to be “almost perfect”. Systematic errors not existed and only random error existed. [Conclusion] The measurement method used in this study can easily control for experimental conditions and allow precise measurement because the lack of stabilization and the impact of tester strength are removed. Thus, extensor strength in MABP measurement is beneficial for muscle strength assessment.

[Purpose] The purpose of the present study was to establish the intra- and inter-rater reliability of measurement of extensor strength in the maximum shoulder abducted position and internal rotator strength in the 90° abducted and the 90° external rotated position using a hand-held dynamometer. [Subjects and Methods] Twelve healthy volunteers (12 male; mean ± SD: age 19.0 ± 1.1 years) participated in the study. The examiners were two students who had nonclinical experience with a hand-held dynamometer measurement. The examiners and participants were blinded to measurement results by the recorder. Participants in the prone position were instructed to hold the contraction against the ground reaction force, and peak isometric force was recorded using the hand-held dynamometer on the floor. Reliability was determined using intraclass correlation coefficients. [Results] The intra- and inter-rater reliability data were found to be "almost perfect". [Conclusion] This study investigated intra- and inter-rater reliability and reveald high reliability. Thus, the measurement method used in the present study can evaluate muscle strength by a simple measurement technique.

[Purpose] The purpose of this study was to confirm the correlation between racket velocity during the forehand smash movements with shoulder extensor strength and internal rotator strength in the neutral and abducted positions. [Subjects and Methods] Fourteen collegiate badminton players participated in the study. Measurements were performed shoulder strength, using torque calculated from the upper extremity length and the isometric force, and racket velocity during the forehand smash movements. The shoulder extensor strength and internal rotator strength were measured in the neutral and abducted positions. [Results] The extension torque and internal rotation torque of the shoulder in the neutral position were not significantly correlated with racket velocity. Additionally, correlations between extension torque of the shoulder in the maximum abducted position and racket velocity were insignificant. However, the internal rotation torque of the shoulder in the abducted external rotated position was significantly correlated with racket velocity (r=0.652). [Conclusion] The shoulder internal rotator strength in the abducted external rotated position are suitable measurements for evaluating badminton players.

股関節に疾患を有し腰痛を合併している6症例に対して、腰仙椎アライメントと腰痛との関係について検討した. X線像を基に静的立位での仙椎傾斜角と腰椎前弯角を測定した. その結果、仙椎傾斜角は増大傾向を認め、仙椎傾斜角と腰椎前弯角との間には正の相関を認めた. 腰椎前弯角が増大すると腰部に加わる力学的ストレスが大きくなるとされていることから、仙椎傾斜角の増大に伴う腰椎前弯角の増大により腰痛を併発したと推察される., In six cases with coxarthrosis, the relationship between alignment of the lumbosacral spine and lumbago was investigated. The sacral inclination angle and the lumbar lordosis angle at a stationary standing position was measured from radiograph. The sacral inclination was showed a tendency to increase. It is approved that there is a positive correlation between the sacral inclination and the lumbar lordosis. It is stated that when the angle of the lumbar lordosis increases, the dynamic stress loaded on the lumbar region increases. Therefor, it was speculated that in the case with increased sacral inclination, the angle of the lumbar lordosis increases, that may cause lumbago.

[Purpose] There are no recent studies investigating the incidence of jumper's knee and knee contusions in volleyball players. A lack of understanding of knee contusions suffered by players (liberos) receiving the ball has lead doctors to diagnose jumper's knee. There have been no studies distinguishing between jumper's knee and knee contusions, which present similar symptoms. The purpose of this study was to investigate and correlate the two conditions of jumper's knee and knee contusions. [Subjects and Methods] Thirty-one female volleyball players were assessed for their maximum jumping power, body weight, whether they performed broad (slide) spikes, and whether they often hit their knees and so on. [Results] Jumper's knee was found in either or both knees of 12 (57%) of 21 spikers. For knee contusions, symptoms were found in 5 of the 10 liberos and setters, who were confirmed to actually hit their knees by observing videotapes of their practice. [Conclusion] Symptoms resembling jumper's knee were discovered in 4 of 6 liberos. It was difficult to distinguish between jumper's knee and knee contusions in terms of their symptoms, except through observation of the players' actual performance. It is important to discriminate between the two conditions clinically for treatment (including physical therapy) and prevention.

[Purpose] Kendo practitioners often suffer from left low back pain. The present study was undertaken to analyze the features of range of motion (ROM) of the hip joint of kendo practitioners and their relation to prevention of lower back pain. [Subjects and Methods] The study involved 37 male university kendo practitioners: 26 kendo practitioners having a history of lower back pain, 11 kendo practitioners having no history of lower back pain. In accordance with the method of ROM measurement set forth by the Japanese Orthopaedic Association, the same examiner measured hip joint ROM during passive flexion/extension and internal/external rotation. [Results] In the low back pain group, no laterality was noted in the ROM of the external rotation. However, ROM of the internal rotation was significantly smaller on the left side than on the right side. The range of rotation was significantly smaller on the left side than on the right side. [Conclusion] The ROM of hip rotation on the left side was significantly diminished (less than 90 degrees) only in the low back pain group, and the laterality in ROM of left hip rotation was significantly greater in the low back pain group than in the non-low back pain group (p

[Purpose] Lower back pain is a characteristic of Kendo practitioners which is often encountered clinically. The present study was undertaken to analyze the features of the spinal alignment in Kendo practitioners and their relation to lower back pain. [Subjects and Methods] Of the 32 Kendo practitioners who consulted our hospital with a complaint of lower back pain and received physical therapy during the two years and three months from January 2005 to April 2007, On X-ray, the degree of eight kendo practitioners' spinal curvature was measured by Cobb's method. Inclination and rotation were measured at each intervertebral level of the lumbar spine. The angle of inclination at each intervertebral space (L1/2, L2/3, L3/4 and L4/5) was measured. In one of the kendo practitioners, the motion of stepping forward to make a frontal thrust was analyzed three-dimensionally. [Results] During the forward-stepping motion, the thoracic spine showed right convex curvature and the lumbar spine showed left convex curvature, with Cobb's angle being 12.4 ± 2.5 degrees for the thoracic spine and 13.7 ± 1.7 degrees for the lumbar spine. [Conclusions] These results suggest that shear stress at the left intervertebral joint at the L3/4 and L4/5 levels and stress of the facet joint capsule are involved in lower back pain.

本研究の目的は，健常な成人男性20名を対象に，静的立位における矢状面での腰仙椎アライメントを測定し，体幹筋力ならびに下肢筋伸張性との関係を検討することである。腰仙椎アライメントは，Ｘ線像を基に仙椎傾斜角と腰椎前弯角を測定した。体幹筋力は，体幹屈曲ならびに伸展の最大等尺性筋力を測定した。また，体幹伸展/屈曲筋力比（E/F比）についても求めた。下肢筋伸張性は，大腿直筋とハムストリングの伸張性を測定した。結果，腰仙椎アライメントは，体幹筋力ならびに下肢筋伸張性との関係を認めなかった。ただし，腰仙椎アライメントとE/F比との間には正の相関を認める傾向にあった。これは，腰仙椎アライメントの変化が体幹の筋活動に変化を生じさせ，その結果，E/F比にも変化が及んだものと考えた。