Peer Review #1 of "Strategies of elite Chinese gymnasts in coping with landing impact from backward somersault (v0.1) (original) (raw)
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Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology, 2012
Gymnasts are exposed to a high incidence of impact landings due to the execution of repeated dismount performances. Biomechanical research can help inform recent discussions surrounding a proposed rule change in potentially injurious gymnastic dismounting. The review examines existing understanding of the mechanisms influencing the impact loads incurred in gymnastic-style landings achieved using biomechanical approaches. Laboratory-based and theoretical modelling research of inherent and regulatory mechanisms is appraised. The integration of the existing insights into injury prevention interventions studies is further considered in the appraisals. While laboratory-based studies have traditionally been favoured, the difficulty in controlling and isolating mechanisms of interest has partially restricted the understanding gained. An increase in the use of theoretical approaches has been evident over the past two decades, which has successfully enhanced insight into less readily modified mechanisms. For example, the important contribution of mass compositions and 'tuned' mass coupling responses to impact loading has been evidenced. While theoretical studies have advanced knowledge in impact landing mechanics, restrictions in the availability of laboratory-based input data have suppressed the benefits gained. The advantages of integrating laboratory-based and theoretical approaches in furthering scientific understanding of loading mechanisms have been recognised in the literature. Since a multi-mechanism contribution to impact loading has been evident, a deviation away from studies examining isolated mechanisms may be supported for the future. A further scientific understanding of the use of regulatory mechanisms in alleviating a performer's inherent injury predisposition may subsequently be gained and used to inform potential rule changes in gymnastics. While the use of controlled studies for providing scientific evidence for the effectiveness of gymnastics injury counter measures has been advocated over the past decade, a lack of information based on randomised controlled studies or actual evaluation of counter measures in the field setting has been highlighted. The subsequent integration of insight into biomechanical risk factors of landing with clinical practice interventions has been recently advocated.
Reducing ground reaction forces in gymnastics’ landings may increase internal loading
Journal of Biomechanics, 2009
The aim of this study was to use a subject-specific seven-link wobbling mass model of a gymnast, and a multi-layer model of a landing mat, to determine landing strategies that minimise ground reaction forces (GRF) and internal forces. Subject-specific strength parameters were determined that defined the maximum voluntary torque/angle/angular velocity relationship at each joint. These relationships were used to produce subject-specific 'lumped' linear muscle models for each joint. Muscle activation histories were optimised using a Simplex algorithm to minimise GRF or bone bending moments for forward and backward rotating vault landings. Optimising the landing strategy to minimise each of the GRF reduced the peak vertical and horizontal GRF by 9% for the backward rotating vault and by 8% and 48% for the forward rotating vault, compared to a matching simulation. However, most internal loading measures (bone bending moments, joint reaction forces and muscle forces) increased compared to the matching simulation. Optimising the landing strategy to minimise the peak bone bending moments resulted in reduced internal loading measures, and in most cases reduced GRF. Bone bending moments were reduced by 27% during the forward rotating vault and by 2% during the backward rotating vault landings when compared to the matching simulations. It is possible for a gymnast to modify their landing strategy in order to minimise internal forces and lower GRF. However, using a reduction in GRF, due to a change in landing strategy, as a basis for a reduction in injury potential in vaulting movements may not be appropriate since internal loading can increase.
Journal of Functional Morphology and Kinesiology
The crucial criteria when assessing technical performance in artistic gymnastics is the higher elevation of the gymnast’s body and a stable landing (i.e., stick-landing). The purpose of this study was to compare kinetic and kinematic parameters during the landing phase of standing back somersaults (SBS) following three technical arm-swing performed during the preparatory phase in high-level male gymnasts. The three different arm-swing pertain to three “gymnastics schools”, i.e., Russian, Chinese, and Romanian. Six high-level male gymnasts participated in this study. Three arm-swing with different angles (i.e., SBS270°, SBS180°, and SBS90°) were randomly performed. A 3D kinetic and kinematic analysis was conducted. Results showed significant variation in the landing angle (p = 0.009) across the three arm-swing techniques. The SBS90° arm-swing resulted in the closest angle to the vertical. Additionally, the SBS90° arm-swing technique induced the lowest horizontal and vertical force va...
2014
The main goal of this work is the computerized video analysis of the characteristic key technical elements of the double somersault dismount off uneven bars in the basic specialization stage in women's artistic gymnastics. The study was conducted during the Masters National Championships, One ti, 16-18 November, 2012. The subjects of the research were 7 female gymnasts, 12 to 14 years old, members of the Junior Olympic Team in Deva and finalists on this apparatus. The biomechanical analysis was performed by means of a specialized program called Physics ToolKit Version 6.0, focusing on the key elements of the technique (as per Boloban, V., 1990): starting position (SP), multiplication of body position (MP) and final position (FP) of the body. The biomechanical analysis of double somersault dismount off uneven bars highlighted the characteristics of the key elements and the influence of the biomechanical indicators on the technical execution of the dismount. The analysis of the execution of the dismount in comparison with the requirements of the technical regulations of the International Code of Points for uneven bars will generate new methodological guidelines meant to improve and correct executions, thus confirming the hypotheses proposed and the performances achieved in competition.
Journal of applied biomechanics
The link between static and dynamic landing lumbar postures, when gymnasts are exposed to large ground reaction forces, has not been established. This investigation aimed to (a) determine if a relationship exists between sagittal static and dynamic landing lumbar spine angles at peak ground reaction force (GRF) and (b) quantify how close to end-range postures the gymnasts were at landing peak GRF. Twenty-one female gymnasts' upper and lower lumbar spine angles were recorded: statically in sitting and standing, during landing of three gymnastic skills, and during active end-range lumbar flexion. Pearson's correlations were used to investigate relationships between the angles in different postures. Significant correlations (r = .77-.89, p <.01) were found between all the static/dynamic postures in the lower lumbar spine angle, while fewer and less significant upper lumbar spine correlations were reported. Thirty percent of gymnasts landed a backsault with their lower lumbar...
Journal of Electromyography and Kinesiology, 2017
The purpose of this study was to examine the biomechanics of the lower limb, during landing in female prepubertal gymnasts and prepubertal untrained girls, aged 9-12 years. Ten healthy participants were included in each group and performed five landings from 20, 40, and 60 cm. Kinematics, ground reaction forces (GRF) and electromyogram (EMG) from the lateral gastrocnemius, tibialis anterior, and vastus lateralis are presented. Gymnasts had higher vertical GRF and shorter braking phase during landing. Compared to untrained girls, gymnasts exhibited for all examined drop heights more knee flexion before and at ground contact, but less knee flexion at maximum knee flexion position. Especially when increasing drop heights the gymnasts activated their examined muscles earlier, and generally they had higher pre-and post landing EMG amplitudes normalized to the peak EMG at 60 cm drop height. Furthermore, gymnasts had lower antagonist EMG for the tibialis anterior compared to untrained girls, especially when landing from higher heights. It is concluded that the landing strategy preferred by gymnasts is influenced by long-term and specialized training and induces a stiffer landing pattern. This could have implications in injury prevention, which requires further investigation.
Single-leg jump landing is a complex task. This study investigated lower extremity motion and vertical ground reaction force (GRF) during jump landing between dominant (DL) and non-dominant (NDL) limbs. Five female athletes performed the single leg jump-landing test from a 30 cm height platform in four directions; forward (0°), 30° diagonal, 60° diagonal, and lateral (90°) directions. The findings showed that jump-landing direction significantly influenced hip and knee flexion angles at initial contact phase, hip flexion and ankle dorsiflexion angles, at peak vertical GRF phase, and the peak value of vertical GRF. Female athletes exhibited a trend of using an ankle strategy in multidirections of landing that is similar to stiff landing. An increase of hip and knee flexion should be suggested during landing to increase a soft landing.
2010
T he research aims to develop insight into inherent mechanisms and regulatory strategies contributing to the physical demands of gymnastic-style landings. The use of a modelling approach to examine the interaction of: 1. a performer’s physical profile and self-selected landing strategy and 2: local mass distribution and mass tuning effects on impact loading is presented. Strategy adjustments accommodating inherent physical profiles were found to be essential in ensuring effective load attenuation but were acknowledged as potentially incompatible with current constraints in gymnastic scoring systems. Mass tuning partially alleviated the loading effects of inherent local mass profiles and was considered achievable without substantial alterations in the regulatory movement patterns.