The purpose of this study was to examine the relationship between static balance ability and lower limb muscle strength in elderly people of differing body mass index. One-hundred and fifty-two elderly female individuals, aged over 75 yrs., were divided into three groups: the low weight group (BMI≦20 kg/m2), normal weight group (20<BMI <25 kg/m2), and obese group (BMI≧25 kg/m2 group). We measured the unipedal standing time with eyes open as static balance ability, and the force generated by foot-gripping and isometric knee extension as lower limb muscle strength. The low weight group demonstrated a significantly longer unipedal standing time (32.5 ±32.4 sec.) than both the normal weight (19.2±18.0 sec.) and obese (12.9±15.5 sec.) groups. A significant correlation between the unipedal standing time and relative foot-gripping force (strength to body weight) was observed in the low weight group and the normal weight group. On the other hand, the relative knee extension force (strength to body weight) and unipedal standing time was only significantly correlated in the normal weight group. These findings suggest that the contribution of leg muscle strength to static balance ability in elderly individuals is affected by physique.
This study examined the associations among the time needed to walk 5 m at the maximum velocity (5-m walking time) and physical, cognitive, and mental functions to confirm the usefulness of measuring such a time for active elderly individuals. The 5-m walking time, lower-limb muscle strength, and standing balance representing physical functions, as well as those representing cognitive and mental functions, were measured, involving 351 elderly females who were actively participating in a health-promoting group for the elderly to perform Tai Chi and muscle strength training. Through multiple regression analysis, the following factors showing associations, independently of the 5-m walking time, were extracted: the 30-second chair-stand test score, height, quadriceps femoris muscle strength, duration of standing on one leg with the eyes open, and Geriatric Depression Scale-5 score. In this respect, the 5-m walking time may be a useful index even for active elderly individuals to evaluate not only their physical functions, represented by the lowerlimb muscle strength and balance ability, but also mental functions.
The purpose of this study was to biologically clarify the effect of stretching exercise on the hemodynamic of the gastrocnemius. The subjects were the40right legs of40 healthy male students. Under two conditions of stretching and no stretching, the hemodynamics of the popliteal artery were investigated and compared, between the conditions and before and after stretching, using the arterial diameter and blood flow velocity evaluated by ultrasound. No significant difference was found between the conditions in the arterial diameter, but after stretching, a significant increase in the blood flow velocity, suggests the possibility that it temporarily increases the volume of the bloodflowinthemuscle it controls.
This study aimed to clarify the influences of a dual-task on elderly community residentsʼgait parameter values. The gait parameter values of 35 elderly females were compared between single-task (ST: walking as usual) and dual-task (DT: walking while performing a mental calculation) walking. The gait velocity, cadence, and step and stride lengths were markedly reduced with significant increases in the durationsofthestance phase and double-support when performing DT compared with ST. On examiningtheir percentages, the step and stride lengths decreased to 89.9 and 90.9%, respectively, while the durations of the stance phase and double-support increased to 166.6 and 200.0%, respectively. There were no significant differences in the step width or toe angle. Based on the results, decreases in the cadence and step and stride lengths, as well as increases in the durations of the stance phase and double-support, may influence the gait velocity when performing DT, and the latter may be associated particularly closely with a reduced gait velocity.
This study examined the influences of heel heights on gait parameters and lower-limb muscle activity, involving 14 healthy adult females. On comparison of gait parameters and lower-limb muscle activity during gait among shoes without heels and with heel heights of 3 and 7 cm, the values representing the gait velocity, step, and stride length were significantly lower when wearing shoes with a heel height of 7 cm. There were no marked differences in these gait parameters between shoes without heels and with a heel height of 3 cm. The double support phase significantly shortened when wearing shoes with heel heights of 3 and 7 cm compared with those without heels, while the swing phase markedly extended in the latter. Significant differences in lower-limb muscle activity were not observed in any of the 4 muscles measured. Based on these results, heel heights greater than 3 cm are likely to affect the stance and swing phases during gait,while the influences of a heel height of 3 cm or less on the gait velocity, step, or stride length may be slight.
This study examined the effects of original insoles to improve the toe grip function, involving 50 healthy adult females (20.1±1.1), with the aim of introducing them. Fluctuations in the center of gravity were measured under 3 conditions to compare the total trace length and outer peripheral area: barefoot, using general insoles (general), and using those to improve the toe grip function (study). In multiple comparisons, the total trace length was significantly shorter under the general and study compared with barefoot condition (p<0.01). The outer peripheral area was markedly smaller under the study compared with barefoot condition (p<0.01). It was demonstrated that the insoles to improve the toe grip function positively influence the standing balance. The significance of conducting studies based on intervention or involving the elderly was also indicated.