Research On Static Balance Ability Evaluation Based On Somatosensory Interaction

Balance ability is one of the indicators of physical fitness. Static balance has an important impact on sports skills and health development. It is the important guarantee to keep postures and complete various actions stability. Static balance is the ability to maintain static posture stability and control the center of gravity to maintain a stable state in the support surface. The static balance measurement methods are evaluated by variation characteristics of the center of pressure (COP) without the center of gravity(COG). There are many evaluation indicators but not unified and lack of high reliability and validity of indicators. A single task or a single indicator is commonly evaluated without comprehensive evaluation indicators.In order to solve the problems in the resent research, according to the theory of static balance measurement, this study designed four projects of double feet standing with eyes opened (DFEO), double feet standing with eyes closed (DFEC), single foot standing with eyes opened (SFEO) and single foot standing with eyes closed (SFEC)under the somatosensory interactive environment to test the static balance. Then, we developed a static balance evaluation system based on somatosensory interaction device Kinect. The system could record the positions of 25 joints and COG in real time.The static balance ability was evaluated by the swinging length (SL), the swinging velocity (SV), the swinging amplitude (SA) and the swinging envelope area (SEA) of COG and other 10 indicators. The test results were presented to the user to achieve a process and real-time feedback evaluation. In order to verify the reliability and validity of the evaluation indicators, the repeated measurements and simultaneous measurements were designed and implemented with 14 healthy college students. The results showed that the static balance test based on somatosensory interaction device Kinect had good internal consistency reliability, retest reliability and concurrent validity.The evaluation indicators had preferable reliability and validity. They could be used to evaluate static balance reliably and effectively.In order to evaluate static balance more comprehensively and objectively, we built a comprehensive evaluation indicator model of static balance based on the above 10 indicators and four projects. First of all, this study calculated the weight of different projects and indicators with the coefficient of variation of 55 students’ results from Nanjing Garden Middle School. Then, the comprehensive evaluation indicator model was established with weighted linear addition method to synthesize each task and indicator. At last, the validity of the model was tested by comparison with the expert’s score. The results showed that the comprehensive evaluation indicator model could evaluate the static balance effectively, and the distinction of the comprehensive evaluation indictor model was better than experts. The model was more accurate in predicting the better of static balance ability. The distinction and sensitivity of the model were better.The static balance ability evaluation method based on somatosensory interaction was completed by variation characteristics of COG. The comprehensive evaluation indicator model was established to realize objective quantitative evaluation. It provides the basis of evaluation and more accurate evaluation methods for the balance development and physical health of students. The method is not only a reasonable price and simple operation, but also free and non-contact evaluation. It could be widely used in primary and secondary balance ability test.