Effect of Tai-chi exercise on lower limb muscle strength, bone mineral density and balance function of elderly women.

To study the effect of Tai-chi exercise on lower limb muscle strength, bone mineral density and balance function of elderly female, 105 urban elderly women, who do insufficient exercise in daily life, are selected as the subject and randomly divided into an observation group (Tai Chi Group), a control group I (Dance Group) and a control group II (Walking Group). Each group is consists of 35 women. Among them, the women in the observation group do Tai-chi exercise once a day, while the women in the control group I dance once a day and in the control group II stick to brisk walking once a day. All women in the three groups do the above said exercises for 40 minutes and the exercise intensity is controlled to be medium. At the time of selection and after 4, 8 and 12 months upon their exercises, respectively detect and compare the lower limb skeletal muscle mass, lower limb muscle strength, bone mineral density and balance function of the subject.At the time of selection, the general information of the subjects in the three groups show no significant difference (P > 0.05); however, after 4 months' exercise, most of the study indexes in the control group I and group II are improved significantly (P < 0.05), while most of the study indexes in the observation group show no significant difference (P > 0.05) in comparison with those at the time of selection and their general improvement effect is slightly lower than that in the control group; after 8 months, relevant study indexes of the subjects in the three groups are significantly improved (P < 0.05) in comparison with those at the time of selection, especially, the effect in the observation group is more obvious and is better than that of the control group II (P < 0.05). 12 months later, the effect of the observation group is improved significantly from day to day when comparing to theose in the control group I and group II (P < 0.05 or P < 0.01).Compared with the senile dance and walking exercises, the short-term Tai-chi exercise effect is not obvious, however, once the exercise period is extended, that is, continuous exercise for 8 months or even above 12 months, the advantage of Tai Chi is more and more significant. The study suggests that as a fitness measure, Tai Chi is more suitable for long-term exercise and its short-term effect is not obvious.