Shock absorption properties of synthetic sports surfaces: A review

Abstract

Repeated impact loading during running is a risk factor in the etiology of overuse injuries. Shock absorption can reflect the degree of force attenuation when the heel lands first during movement. This study summarizes the major achievements in the existing literature regarding shock absorption from the engineering perspective and then suggests directions for further investigation. Studies have explained the influencing factors related to shock absorption from the synthetic sports surface itself. Some special measurement methods that can be used to assess vertical and horizontal shock absorption simultaneously are discussed. Numerical simulations related to shock absorption are reviewed, including how to acquire a constitutive model of the sports surface and simulate the manner of loading. Future work should aim to build "player movement-surface structure and material-player performance" relationship systems, with more accurate measurements of shock absorption properties in the vertical and horizontal directions and numerical models that can truly reflect actual movements. Solving these problems can strengthen the theoretical and practical understanding of the relationship between synthetic sports surfaces and injury, and athletes can develop more expert performance with fewer injuries. KEYWORDSforce reduction, measurement, shock absorption, simulation, synthetic sports surface | INTRODUCTIONThe overall yearly incidence rate for running injuries varies between 37% and 56%. 1 Hence, related to bodily injury, the performance of synthetic running track surfaces, which are used for indoor and outdoor recreational or game surfaces, is always valued.There are mainly two collision ways between foot and ground in running, including a rear-foot strike (RFS) (Figure 1A and 1B) and a Nomenclature: b, stiffness coefficients; C 1 ,C 2 ,C 3 , instantaneous elastic constants; C 10 ,C 01 , material parameters within the small-strain limit; E, elastic modulus; E * (ω), complex modulus in uniaxial tension/compression; E′(ω), storage modulus; E ′′ (ω), loss modulus; F, force applied to the specimen; f, frequency; f c , force generated by the nonlinear viscous element; f k , force generated by the nonlinear elastic element; G(i), amplitude; G(t), the reduced relaxation function; G∞, the long term modulus once the material is totally relaxed; k, stiffness constant which depends on the surface's elastic modulus and the geometry of the impactor; k0, p0,p1,c0,c1,c2,r0,r1,r2,q0,q1,q2, undetermined coefficients; L,L0, the current and initial lengths of the material specimen; m, mass of test foot; n, nonlinearity coefficient; r, the radius of the hammer head; t, time; u, viscosity coefficients; x, deformation; _ x, deformation velocity; € x, deformation acceleration; β, undetermined coefficients; β i , the decay rate of relaxation; δ(ω), the phase shift angle between the stress and the applied strain; ε, strain; ε(t), stress with time; ε 0 , amplitude; λ, the stretch ratio; μ, the elastic parameter; σ, the tensile stress; σ e (ε), the inst...

Influence of bonding condition on mechanical performance of synthetic sports surfaces by FEM

“…Based on two types of modern synthetic sports track surfaces: precast sheets and in-situ systems, different construction schemes have different types of surfaces (Wang et al, 2019). The base layer is always asphalt concrete regardless of constructional solutions of the modern synthetic athletic tracks (Wang et al, 2019).…”

“…Based on two types of modern synthetic sports track surfaces: precast sheets and in-situ systems, different construction schemes have different types of surfaces (Wang et al, 2019). The base layer is always asphalt concrete regardless of constructional solutions of the modern synthetic athletic tracks (Wang et al, 2019). In prefabricated sheets systems, the synthetic surface and asphalt base layer are bonded by a weather-sensitive adhesive (World Athletics, 2019; Wang et al, 2019).…”

“…The base layer is always asphalt concrete regardless of constructional solutions of the modern synthetic athletic tracks (Wang et al, 2019). In prefabricated sheets systems, the synthetic surface and asphalt base layer are bonded by a weather-sensitive adhesive (World Athletics, 2019; Wang et al, 2019). In the in-situ systems, synthetic surfaces are paved above the asphalt base layer directly (World Athletics, 2019; Wang et al, 2019).…”

“…In prefabricated sheets systems, the synthetic surface and asphalt base layer are bonded by a weather-sensitive adhesive (World Athletics, 2019; Wang et al, 2019). In the in-situ systems, synthetic surfaces are paved above the asphalt base layer directly (World Athletics, 2019; Wang et al, 2019). There should be no water or steam in the construction when the related synthetic material is paved accordingly with construction regulations.…”