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A computer simulation model of an International Gymnastics Federation (F.I.G.) landing mat and a gymnast was developed to investigate the mechanics of landing from the gymnastics vault. The landing mat model incorporated the multilayer design of the landing mat and its deformation characteristics were based upon experimental data. The gymnast model was based upon an elite level gymnast and contained subject-specific parameters. The gymnast was modelled as a seven-segment link system with 'lumped' muscles producing joint rotation at the hip, knee and ankle. Wobbling masses were included within the trunk, thigh and shank segments to represent soft tissue movement. A two segment bone within the shank and thigh provided estimates of bone bending moments and bone deformations. Joint torques were based upon the torque / angle / angular velocity relationship established during isokinetic dynamometry testing of the subject. The muscle forces were calculated from the joint torques and from moment arm data taken from the literature and scaled to the subject. The gymnast–mat model was evaluated using the kinetic, kinematic and EMG data collected from actual vaults performed by the subject. Evaluation results showed good agreement between the simulations and the actual performances with difference scores between 10.1 % and 23.6 %. The landing strategy and landing mat were optimised to minimise the ground reaction forces and bone bending moments. Optimised landing strategy results suggest that modifications to the gymnast's landing strategy could reduce the peak ground reaction forces but this may not decrease the peak internal joint forces. Optimised landing mat parameter results suggest that a landing mat with 20 % more damping could reduce the peak ground reaction forces and internal joint forces but this may increase the initial impact force between the foot and the mat's surface.

Technique selection is fundamental to Women’s Artistic Gymnastics with rapidly evolving difficulty and complexity; a result of changes in the scoring system and apparatus design. The aim of this research was to increase knowledge and understanding of the biomechanics underpinning female longswing techniques to determine effective technique selection. Five progressive themes addressed this aim; contemporary trend analysis, biomechanical conceptual approach, method validation, biomechanical musculoskeletal approach and biomechanical energetic approach. Elite competition provided the basis to the thesis with a strong ecologically valid trend analysis reporting the straddle Tkachev as the most frequently performed release skill preceded by three distinct longswing techniques; arch, straddle, pike. Quantifying each technique through a biomechanical conceptual approach enumerated differences observed and examined their influence on key release parameters. Significant differences (p≤0.05) were reported in the initiation and joint angular kinematics within the functional phases; however not for release parameters. Further examination into the joint kinetics and energetic demands of the gymnast were required to explain technique selection. Non-invasive methods of joint kinetic data collection are challenging within the elite competitive environment; therefore indirect methods were validated to provide confidence in the subsequent musculoskeletal approach. Inverse dynamic estimations were most sensitive to kinematic inputs with field versus lab comparisons highlighting systematic differences in joint moments (0.8%RMSD in consistency). Joint kinetics provided new knowledge of the underlying biomechanics of varying techniques, specifically greater shoulder joint moments and hip joint powers during the pike longswing. Examining gymnast energetic contribution to the total gymnast-high-bar energy system developed a novel effectiveness score highlighting the potential energy excess available to the arch (30%) and straddle (2%) techniques, indicating the potential to develop more complex versions of skills. This research provides coaches and scientists with specific physical preparation requirements for varying longswing techniques and insight into the need for customised technique selection.

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A computer simulation model of the table contact phase of gymnastics vaulting was developed to gain an understanding of the mechanics of this phase of the vault. The model incorporated a gymnast and a vaulting table, and used a novel two-state contact phase representation to simulate the interaction between these two bodies during the table contact phase. The gymnast was modelled in planar form using seven segments, with torque generators acting at the wrist, shoulder, hip and knee joints. The model also allowed for shoulder retraction and protraction, displacement of the glenohumeral joint centre and flexion/extension of the fingers. The table was modelled as a single rigid body that could rotate. The model was personalised to an elite gymnast so that simulation outputs could be compared with the gymnast's performance. Kinematic data of vaulting performances were obtained using a optoelectronic motion capture system. Maximal voluntary joint torques were also measured using an isovelocity dynamometer, and a torque - angle - angular velocity relationship was used to relate joint torques to joint angles and angular velocities. A set of model system parameters was determined using a gymnast-specific angle-driven model by matching four simulations to their respective performances concurrently. The resulting parameters were evaluated using two independent trials, and found to be applicable to handspring entry vaults. The torque-driven model was successfully evaluated, and shown to produce realistic movements, with mean overall differences between simulations and recorded performances of 2.5% and 8.6% for two different handspring entry vaults. The model was applied to further understanding of the mechanics of the table contact phase of gymnastics vaulting. Optimisation showed that there was limited potential (1.3%) for the gymnast to improve performance through technique changes during the table contact phase. However, with additional changes in configuration at table contact post-flight rotation could be increased by 9.8% and post-flight height could be increased by 0.14m. Angular momentum was found to always decrease during the table contact phase of the vault, although the reductions were less when maximising post-flight rotation.