The frequency of one-legged stance and two-legged stance differs considerably among sports. We therefore expect the balance ability of athletes from different sports to vary. This study compared the sway characteristics during a static one-legged stance of soccer players, basketball players, swimmers, and non-athletes. The centre of pressure sway during one-legged stance of ten male participants representing each of the four groups was measured using a stabilometer. Centre of pressure sway was assessed by four sway factors: sway velocity, anterior-posterior sway, horizontal sway, and high-frequency sway. None of the four groups of participants showed significant differences in body sway between standing on the dominant leg and standing on the non-dominant leg. The soccer players had more high-frequency sway and less anterior-posterior sway and horizontal sway than the basketball players, swimmers, and non-athletes. These results suggest that soccer players have superior ability to maintain a stable one-legged stance. Further study is required to determine how much of the superior balance ability in soccer players is innate and how much is developed through training, as well as to determine the relationship between balance ability and playing performance.

The present study aimed to compare the accuracy of estimating the percentage of total body fat (%TBF) among three bioelectrical impedance analysis (BIA) devices: a singlefrequency BIA with four tactile electrodes (SF-BIA4), a single-frequency BIA with eight tactile electrodes (SF-BIA8) and a multi-frequency BIA with eight tactile electrodes (MF-BIA8). Dual-energy x-ray absorptiometry (DXA) and hydrostatic weighing (HW) were used as references for the measured values. Forty-five healthy college student volunteers (21 males: 172.9Ϯ5.5 cm and 65.8Ϯ9.1 kg and 24 females: 160.7Ϯ6.6 cm, 52.6Ϯ6.2 kg) were the subjects. Correlation coefficients between the BIA measurements and the references were calculated. The standard error of estimation (SEE) was calculated by regression analysis when estimating the reference measures (DXA and HW) from the predictor (SF-BIA4, SF-BIA8 and MF-BIA8). The differences in %TBF between the reference and the predictor, calculated by the reference minus the predictor, were plotted against the %TBF measured by the references. The MF-BIA 8 here showed the highest correspondence to the reference and the least estimation error compared with the other BIA methods. It is considered that there is a limit to directly estimate FFM from a regression equation using impedance, weight, height and age as independent variables, and that %TBF can be more accurately estimated by measuring segmental impedances using eight electrodes and multi-frequency electric currents and then estimating total body water from these impedances.

This study aimed to determine the factor structure of the center of foot pressure (CFP) movement during static upright posture, and to objectively categorize and summarize parameters to evaluate CFP movement. The subjects were 220 healthy young males and females. The measurement of CFP was carried out 3 times with 1 min rest and the mean of trials 2 and 3 was used for the analysis. The measurement device was an Anima's stabilometer G5500. The data sampling frequency was 20 Hz. Thirty-four parameters with high reliability were selected from the following 6 domains except for the center position which is a fundamental attribute: distance, distribution of amplitude, area, velocity, power spectrum, and body sway vector. Factor analysis (principal factor method and promax rotation) was applied to a correlation matrix consisting of 32 parameters. Four factors abstracted were interpreted as follows; unit time sway, front and back sway, left and right sway and high frequency band of power spectrum. The reliability coefficient (ICCϭ0.89-0.95) and the congruence coefficient (fϭ0.80-0.97) between factors abstracted from the original and the cross-validity groups were very high. It was considered that the CFP movement consists of the above 4 factors that evaluate the amount of body sway and can be synthetically evaluated by them.

This study aimed to comprehensively investigate the comprehensive relationships between depression and the characteristics of lifestyle and quality of life (QOL) of healthy, community dwelling elderly, and compare them according to gender and age groups. 1302 subjects (657 males and 645 females) were used for analysis. The investigators in this study were researchers working at universities in each prefecture. Data collection was conducted in a general delivery survey and interview setting or an education class setting. The geriatric depression scale (GDS) consisting of 15 items with a dichotomous scale was used to assess depression symptoms in the elderly. In addition, 16 items selected from the four factors of economic situation, physical health, social activity, and personal status were used to assess lifestyle. Furthermore, this study investigated life satisfaction, morale, and physical function with the LSI scale, PGC morale scale and the ADL scale of the Ministry of Education, Science and Culture, respectively. According to our results, depression characteristics of the elderly differ between gender and age groups. Depression increases in the old-old elderly rather than in the young-old elderly and is highest in old-old females. The factors significantly related to depression in community dwelling elderly were the number of friends and morale. In particular, an increase in the number of friends was related to a decrease in depression. Depression in the old-old elderly was more significantly related to many lifestyle items compared with the young-old elderly, and especially in the old-old elderly, the extent of social activities related to a decrease in depression.

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The purposes of this study were to clarify the kinetics of muscle oxygenation (Oxy-Hb, Deoxy-Hb) by near infrared spectroscopy (NIR) in the decreasing force phase, especially the pre-and post-phases of the inflection point, in sustained maximal static gripping (SSG), and to examine the relationship between kinetics of muscle oxygenation and forcedecreasing parameters. The experiment was conducted on 20 male subjects aged 15-18 years. The time at the lowest Oxy-Hb value (20.5Ϯ5.5 s) significantly correlated with the decreasing times of forces of 40, 60 and 80% of maximal voluntary contraction (MVC), and the rate of decreasing force for 0-1 min (rϭ.60, .53, .49, and Ϫ.63 respectively). These parameters reflect the decreasing force based on the oxygenation deficiency into the muscle with the obstruction of the blood flow. The time of reaching the highest Deoxy-Hb value (46.8Ϯ15.0 s) and the regression coefficient in the Deoxy-Hb decreasing phase correlated significantly with the decrement for 1-2 min. This parameter evaluates the phase where resumption of the blood flow began, and Deoxy-Hb in the tissue was eliminated. The inflection point of the gripping force is related to the time at the highest Deoxy-Hb, and reflects the beginning and the resumption of the blood flow. The decrement for 2-3 min and the regression coefficient of post-inflection point evaluate the steady state phase of force decreasing, in which oxygen is sufficiently supplied to active muscles.

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