Minimising peak forces at the shoulders during backward longswings on rings

Abstract

Many elite gymnasts perform the straight arm backward longswing on rings during their competition routines in order to satisfy specific judging requirements. Measured peak combined cable tension during a backward longswing is typically in excess of 9 bodyweights (Nissinen, 1983) and forces of this magnitude have been associated with an increased risk of injury to gymnasts' shoulders (Carraffa et al., 1996). This study investigated the contribution of longswing technique and the elasticity of the gymnast and rings apparatus to minimising loading at the shoulders. A three-dimensional video and cable tension analysis was conducted on a backward longswing performed by an elite gymnast. This analysis provided information regarding the motion of the rings cables, the gymnast's technique and the elasticity of the rings apparatus. A three-dimensional five segment computer simulation model of a gymnast swinging on rings was developed. The inertial characteristics for the model were determined from anthropometric measurements of the gymnast and measurements taken directly from the rings apparatus. The simulation model was evaluated by comparing the backward longswing from the data collection with a simulation of the same performance. The root mean squared differences between the actual performance of the longswing and the evaluated simulation for cable tension and orientations of the gymnast and rings cables were 6.2%, 1.0% and 1.9% respectively. During the evaluated longswing the peak combined force at the shoulders was 8.5 bodyweights. Modifications to the evaluated simulation of the longswing were used to determine the effect of the gymnast's technique, his elasticity and that of the rings apparatus on peak net shoulder forces. Altering the gymnast's technique, by fixing the gymnast in a straight body configuration throughout the swing, increased the peak shoulder force by 2.56 bodyweights. Removing lateral arm movements, which form part of the gymnast's technique, also resulted in an increased peak shoulder force (0.73 bodyweights). Removing the elasticity of the apparatus and gymnast in turn resulted in smaller increases in peak shoulder force (0.62 and 0.53 bodyweights). When both aspects of technique were altered the increase in peak shoulder force was 2.5 times greater than when both components of elasticity were removed. Although the elasticity of the gymnast and apparatus contribute to minimising peak shoulder forces, this study shows that the contribution of a gymnast's technique is considerably greater.

Optimised performance of the backward longswing on rings

“…(1989), and the non-linear damped spring used to represent shoulder compliance. While these factors have all been shown to be important in altering peak loading at the shoulders during longswings, increasing apparatus elasticity produces only a small reduction in peak force at the shoulders (Brewin et al, 2000).…”

Advances in the development of whole body computer simulation modelling of sports technique

“…They have also been used in other activities, such as high bar circling (Yeadon and Hiley, 2000) or long swings on rings (Brewin, Yeadon and Kerwin, 2000), by limiting the joint torques to prevent unrealistic movements. Most force-driven or torque-driven simulation models have been used to represent relatively simple jumping movements where the body can be represented using simplified planar two-dimensional models.…”

Biomechanical analysis of cross on training and competition

“…Other gymnastics studies concerned about measuring and diminish shoulder loads on rings (BREWIN; YEADON; KERWIN, 2000), or analysed the combined kinetics with inverse dynamics analysis on floor exercise movements (FARANA; JANDACKA; IRWIN, 2013;FARANA et al, 2014;FARANA et al, 2015).…”

“…Thus, the measured tension in one cable was doubled to provide combined cable tension in long swings (BREWIN; YEADON; KERWIN, 2000). For strength exercises, force plates were used to measure the combined forces which were necessary to the gymnast to perform the cross (DUNLAVY et al, 2007) and the swallow (CAMPOS; SOUSA; LEBRE, 2011).…”

“…Most biomechanical analysis on rings relies on handstand (BREWIN; YEADON; KERWIN, 2000;SANDS, 2009;SPRIGINGS et al, 1998), evaluating the movement techniques and torque on shoulder and hips in dynamic situations. There is a lack of knowledge about the gymnasts' upper limb forces during the strength and resistance skills.…”