| Research Abstract |
A study was conducted to clarify the stepping motion and its rhythms characteristics as temporary factor. Twenty-four healthy male and female 66-90year old were recruited as subjects. Stepping motion with maximum effort during 15 seconds was recorded by a high speed video camera, and the leg strength was measured in the sitting position. Coordinates of body position were fed into a microcomputer using a digitizing method, and the frequency, movement time, displacement, velocity, power etc were analized. In order to clarify the stepping motion, the correlation between the performance and parameter of stepping motion, was calculated, along with the coefficient-variation of temporary parameters such as lcycle time(MT), contact time(CT), aerial time(AT), leg moving up time (MUT)and leg lowering time (LT)in the aerial phase. The results may be summarized as follows:
1 )Male' s parameters such as frequency, movement time, displacement, velocity, power, the leg strength in stepping motion were
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higher than those of females.
2) Among rhythmic characteristics of temporary parameters in stepping motion, the right and left MT were equal. The CT was longer than the AT (Male was longer AT than the female), and the MUT in the aerial phase was longer than the LT.
3) The results revealed a significant negative correlation between the frequency and the movement time, between the frequency and the CT, and a significant positive correlation was found between the frequency and velocity, between the velocity and the CT. However, there were no significant correlations between the frequency and the power, the leg strength.
4) The coefficient-variation (CV) of the frequency in stepping motion was small, and the CV of CT and AT was mid-range(the CV of AT was larger than CT). The CV of MUT and LT were also greater. This suggested the instability of the aerial phase.
5)Stepping motion was classified into three patterns, typel(stepping in place), type2(light hopping with lower knee lifting),type3(powerful hopping with higher knee lifting).Type 1 was frequent in female motion, while type3 was frequent in male motion. Less
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