Research On Motor Control Ability Of The Elderly When Stepping Over Obstacles

ObjectiveAgeing is now a global problem. Falls is a major threat to the health of the elderly. The present study intends to explore the potential perilous factors causing the old people's falls while stepping over obstacles from kinesiology and dynamics features reflected in process of healthy women stepping over obstacles, and combined with tendencies towards sensory integration ability to change as the age increases. Therefore, it will be helpful in putting forward precautionary measures as well as a proposal of improvement in future.MethodsWe have selected 140 female in different age groups in the Beijing community. Participants'fine physical conditions without obvious wound or disease is ensured in the process of addressing a questionnaire. By using Good Balance system, the author tests the participants'centre-of-gravity trace respectively under the four different posture modes, including standing on two legs with eyes open, standing on two legs with eyes closed, linear step with eyes open, and standing on one leg with eyes open. We record the participants'movements while they surmount three lightweight obstacles with different height (10cm,15cm,20cm) by using one Kistler three-dimensional force plate and camera system. We carry out a plane fixed-point and multi-point analysis of the recording by using Vision system, together with an analysis of the dynamical parameter by using Kistler software in order to get the indices of kinesiology and dynamics. we make a variance analysis concerning single factor by putting these indices into different categories according to different age groups.Results:1. Most of the differences between the relevant age groups are shown in the mode of standing on one leg alone with eyes open and the indices in path length on the X and Y axis. The differences between the participants aging 70 and the rest are quite obvious. The curves of all tested indices go downward gradually in the following sequence, standing on one leg alone with eyes open, linear step with eyes open, standing on two legs with eyes closed and standing on two legs with eyes open.2. In the analysis of participants'moves in stepping over obstacles, we find that the differences are all significant between the age group of 70 and that of 20,50 in surmounting the mentioned three obstacles of various heights. However, the above differences disapear after normalized with the participants'height. The curve about changes of the indices along with the increases of age indicates that there is a tendency of the old people to have a longer gait period, the decreasing cadence, a shorten stride,and slower velocity.3. While the old people are stepping over obstacles, their double support phase percent of cycle is longthen, joint angle of lower limb is reducing with aging, and their stride shortens, together with the lead-heel distance's narrower and the trial-toe clearance's insufficient raise.Concluion:1. In the test of static balance, with a long trace on the X axis and a long trace on the Y axis, the mode of standing on one leg with eyes open shows a clearer distinction between different age groups and better reflects the changes of one's static balance capacity as age increases.2. All the features of the gait and moves to surmount obstacles indicate the fact that the lack of muscle strength and the limited extent of joint's activities are common to the old people. The insufficient raise of leg is one of the reasons why the old people are liable to be tripped down while they step over obstacles, as well as a reference to the index of tumble risk prediction in sports.3. Results of the gait research indicate that the age of 50 is the turning point, beyond which the failing speed of one's control of his/her moves accelarates. The curves about changes of the indices as the age increases all indicate that the age of 50 is the point of inflection, beyond which the gradient of all curves become steep. This shows that the failing speed of relevant abilities accelarates. This reminds us that the age of 50 is the turning point of senility of men's body, which should be regarded as crucial and sensitive in taking precautions against stumble of the old people.