| It is easy to cause damage to human body joints,ligaments and muscles when landing from high altitude.Of all the injuries,ankle sprain is the most common one.In addition,varus ankle sprain accounted for a major proportion in all the cases of ankle sprain.According to the survey,wearing ankle brace significantly improves the protective effect as well as reducing the risks on ankle sprain.Moreover,compared with the flexible ankle brace,the semi-rigid ankle brace produces better performance in ankle protection.However,the most common ankle braces on the market today,are the symmetrical protective flexible ankle brace,symmetrical and asymmetric rehabilitation rigid ankle brace,and a small number of asymmetric ankle braces.Protective semi-rigid ankle braces specifically for the ankle inversion is rare,which offers limited protection and fails to meet the diverse demands.In light of all above,this paper conducted researches on an asymmetric semi-rigid protective ankle brace from the following four aspects:1.The asymmetry anatomy structure of human ankle joint and the ankle joint injury mechanism were studied,then a complementary asymmetric ankle brace was designed accordingly.2.Polymer films and plastic materials were applied in multiple preparation methods to manufacture a variety of types of ankle brace.3.The structural parameters and mechanical properties of each type of ankle braces were tested systematically.4.Human trails were conducted to evaluate the performance of ankle braces on ankle protection.The results showed that an asymmetric ankle braces with flexible inner part,plasticity bottom and lateral parts can be manufactured from EVA,silicone film and woven metal mesh.The results of human trials showed that the asymmetric semi-rigid ankle brace produced outstanding performance in ankle protection.The lateral shape retention property was remarkably improved compared with the inner side,and the tensile breaking strength of lateral side reached beyond 12 MPa.Although the tensile elongation was decreased compared with the inside part,this result is in favor of protective effect.Fatigue test showed that the ankle brace was stable in structure,high resilient and low plastic deformable under fixed load.Moreover,the permeability of the three kinds of coated fabrics showed that even in simulated perspiration,the maximum air permeability was(2102±14)L·m-2· s-1,much higher than the requirement in personal clothing.Wet friction excelled dry friction,contributing to the promotion of protective effect.The result of gait test showed that the silicone material semi-rigid ankle brace had significant effect on tibialis anterior muscle and lateral gastrocnemius muscle,and the tibialis anterior muscle was more active than barefoot state.In addition,EVA film semi-rigid ankle brace had a significant effect on the tibialis anterior,and biceps femoris was active.There was significant gender difference in the protection of tibialis anterior muscle with semi-rigid ankle brace.The protective effect on male is better,which is consistent with the literature report.The high jump experimental results showed that the EMG of the lateral gastrocnemius was significantly different on both sides.Specifically,the EMG of the dominant side(right side)was significantly greater than the non-dominant side(left side).In addition,the EMG of the lateral gastrocnemius was significantly different between the different protective states,and the EMG of the dominant side lateral gastrocnemius was maximized by the silicone membrane ankle brace.In summary,the asymmetric semi-rigid protective ankle brace produced positive effect on ankle protection.Nevertheless,this study needs further exploration to optimize the materials and process details to provide reference for the development of related products. |
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