Research On The Protective Performance Of Knee Pad And Product Development Based On Inverse Dynamics Analysis

Falling refers to that any part of the body loses balance and falls down on the ground or some other lower place.In addition to the hip and wrists,in the process of falling,knee injuries easily.At present,the researches of domestic and foreign markets mainly focus on the medical protection of the knee joint,the detection of the people's motion state and the development of the knee pad.Currently,the knee pads on the market are divided into non-packed ones and packed ones.The main function of the non-packed knee pad is to keep warm and reduce the damage of joint torsion,over extension and bending during the movement of the knee.The packed knee pad mainly uses polyurethane and sponge,which both have good impact resistance,but are not good to absorb moisture.Knee protective products currently on the market don't mention to protective level.Both at home and abroad,people study the protective performance of knee pad only in the fabric performance not from the actual effect in the perspective of biomechanics research.For this vacancy,combining the characteristics of seamless knitted products with good wet absorption,numerous three-dimensional structures,the author of this paper tries to find out the knee pad which has good protective ability which is suitable for people.Based on the theory of knee injury and through 3D dynamic capture system,the study accurately captures the falling gesture in the process of human knees trajectory,using the principle of inverse dynamics to analyze the stress state of the knee and judge knee impact resistant performance of some groups.At last,it uses performance testing and comprehensive performance evaluation.The paper sets up a whole system from the human body motion dynamic capture to the seamless knee design and development.Firstly,the study builds a theoretical system for knee protection based on the theory of human biomechanics,knee injury,analysis of the causes and protective methods of the people falling.Then it establishes sample plan and basic parameters.From the point of view that the three-dimensional fabric tissue has excellent protection performance,and the anti-impact property of the fabric,through the literature research and market research,the orthogonal experiment design is used to establish the sample plan,with the seamless production process,nine experimental fabrics were made.Basic parameters of test experimental fabric(density,square gram weight,thickness).Then we test the impact resistance of sample using 3D dynamic capture system.The study captured people's falling movements by tag markers on thehuman body to measure motion track of the human knee joint in the process of movement,by inverse dynamics,movement human knee motion parameters could be converted to the various mechanical parameters,in order to analyze the force of the knees and judge the quality of protective performance of samples.The relationship between basic parameters and impact resistance of knitted fabrics is studied by orthogonal test.The results show that the main factors affecting the braking performance of fabric are density,structure and material.The higher the density,the better the braking performance.Rib tissue> suspension tissue > staggered tissue.The braking performance of 8tex/100 f polyester +20D spandex /50 D polyamide coated yarn is superior to that of 14 tex polyester viscose blended yarn+20D spandex /30 D polyamide coated yarn and 7tex/144 f polyester +20D spandex/30 D polyamide wrap yarn.The material is 8tex/100 f polyester +20D spandex /50 D polyamide wrap yarn,and the rib body has the best performance.The results showed that the main factors affecting impact resistance of knitted fabrics are density,organization structure and material.8tex/100 f polyester +20D spandex /50 D polyamide coated yarn,the organization structure is staggered organization,the density is tight fabric to resist impact performance is the best.The tests were performed on the elasticity,deformation rate,moisture permeability and permeability of 9 samples.Using entropy and TOPSIS method of 9 kinds of comprehensive evaluation of the experimental sample ordering,the raw material of 8 Tex / 100 f polyester + 20/50 nylon bag yarn,organization as the rib,the density of the fabric is tense has the best comprehensive performance.The results of this paper knee pad products for seamless knitting technology of health care market development provides new ideas.This subject theoretically proves the mechanism affecting the protection effect of the knee protector and builds a complete research system to develop protective sportswear,the system contains human biomechanics,sports injury theoretical knowledge,motion capture,clothing materials test and fashion design.It provides some reference for the textile and garment industry to produce better knee pad products.