Efficacy Research Of Different Unstable Soles Support

Objective: Sole structure variety can alter foot specific region’s plantar pressure, which havebeen proven by many previous study and this method has been widely used in motion control. Thegait kinematic parameters and muscle activation level are taken as qualitative indicators ofinstability to provide a reference for serving unstable shoes as a tool to enhance treatment ofstability for the future study. One purpose of this study is to identify the integral unstable degree inthe dynamic test and analyze the impact of sole structure on the instability and muscle activity withutilizing the changes of gait parameters in kinematics and EMG caused by unstable trainingdevices.Methods: In this study, based on the flat sole, select heel and forefoot regions adding unstablestructural elements. Meanwhile, unstable elements in the coronal plane of forefoot have beenadjusted to find the resulting changes in lower extremity kinematics, plantar dynamics and muscleactivities.22healthy female subjects(age:22.5±1.26years, height:162.9±1.2cm, weight:56±2.4kg,BMI:22.1±0.8kg/m2, shoes size:37) participated in the study, walking with different experimentshoes under their self-selected speed. Kinematics and surface electromyography measurementswere carried out simultaneously. For each heel, medial midfoot, lateral midfoot, metatarsal I,metatarsal II-III, metatarsal IV-V, big toe and other toe region, mean values for the22subjectsfor peak pressure, pressure–time integral and contact area were calculated.Results: The results showed all three experiments shoes can effectively lead to knee abduction,internal rotation and hip rotation amplitude increased significantly. In addition, ankle varus andinternal rotation amplitude were reduced, causing activation levels of small muscle(TA-tibialisanterior, PL-peroneus longus, LG-lateral gastrocnemius) group significantly increased. Theadjustment of forefoot unstable structure could make change of lower limb kinematics and musclesactivation level. Statistically significant increscent of heel peak pressure and pressure–time integralwas provided by the3experiment shoe.Conclusions: Thus, approach by adding instability element in the sole structure to regulatehuman postural control and lower limb muscles is feasible. Adjust the unstable structural elementsin metatarsal coronal plane position can significantly change the distribution of plantar pressure,and peak pressure and pressure–time integral was significantly higher in the append region ofunstable structural elements, and append distal region tends to decrease significantly. Thevariability promote the postural control system by adjusting CNS(center nerve system), proprioceptive ability, neuromuscular ability and sensorimotor ability. It proposed a trainingequipment which would enhance postural control by adjusting lower extremity kinematics andreorganizing muscle activity. More descending research can be conducted to testify the feasibilityof unstable shoes construction on human postural control and gait, even instruct training, injuryprevention and rehabilitation.