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 con-trol 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. Results: 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). Conclusion: 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.