Training aids can play an important role in the training of athletes, but only if they assist in the learning of correct technique. The design of a training aid differs considerably from the design of other products because it is crucial that the mechanisms used in learning a skill must be taken into consideration. Research has shown that this can be achieved by: encouraging specific motor skills, providing feedback, providing support in a safe environment, permitting repetition, permitting progressive learning, or by providing some combination of these. For this to be possible an in-depth understanding of the biomechanical requirements of the sporting activity is essential. A study was carried out to determine the fundamental requirements of a training aid, and to then design and build two working prototype gymnastics training aids. Elite training sessions were observed and High Performance coaches were interviewed to establish the skills that required a training aid and the customer requirements for such a device. On the basis of this information two contrasting gymnastics skills were chosen. The first was a handstand on the rings, a complex motor control skill requiring the gymnast to balance on two moving pendulums, requested by 100% of the coaches interviewed. The second skill was a backward handspring, often the first backward dynamic skill most gymnasts will learn, requested by 89% of the coaches interviewed. The training aids were required to simplify the learning of the skill, whilst still utilising correct technique. The backward handspring aid was also required to effectively support the gymnast but not obstruct a good performance. A biomechanical analysis of each skill was carried out in order to inform the design of suitable training aids. The aids were designed and manufactured in accordance with British Standards, and were then biomechanically assessed to ensure that they correctly aided the learning of the skills. In order to assess the aids: displacement, force and muscle activation data were collected and were used to compare the gymnastics skills with and without the aids. The data showed that the training aids replicated the correct biomechanical requirements of the actual skills: the handstand aid was shown to utilise the same control mechanism as was observed on the rings, and the backward handspring aid permitted a unobstructed good performance and assisted in the learning of the skills with correct technique. Both aids were also demonstrated to out-perform any of the existing training aids.

A novel method of controlling miniature sensors using Handspring Visor Prism PDA has been implemented. A generic motherboard was developed to map the data and address lines from the Visor onto a Complex Programmable Logic Device (CPLD) to provide basic electrical signals to the sensor board. The sensor board housed the sensor and contained application specific circuitry. The PDA, the motherboard, and the sensor board completed the control mechanism for the sensor. Miniature sensors and PDA based control mechanism scaled down the size of the complete system making the unit portable. This unit facilitated a faster analysis of data on field. Two applications were targeted: Flurometer (bio-sensor) and Corner Cube Retroreflector (CCR-optical sensor for communication). A sensor board was developed to control a thermally regulated fluorometer undergoing the Nuclei Acid Synthesis Based Amplification (NASBA) process, which detected the fluorescence from the solution containing target RNA. NASBA runs were conducted using solution containing K. brevis- Red tide organisms to validate the interface of the PDA with a fluorometer. Real time fluorescence plot over time was obtained on the PDA indicating presence/absence of the target RNA; thus, it successfully interfaced the PDA with the fluorometer. Additionally, a sensor board was developed to control the electrostatic actuation mechanism of the MEMS based CCR. Efforts were made to fabricate the vertical mirrors of CCR using wet and dry fabrication techniques.

INTRODUCTION: Women’s gymnastics has the highest injury incidence rates for NCAA female college athletes. Gymnastics maneuvers may require support and transfer of the entire body weight from the feet to the hands. Such motions cause excessive loading and stress across joint surfaces which on occasion can exceed the mechanical strength of upper limb joints and supportive musculoskeletal structures, resulting in injuries ranging from acute fractures to chronic overuse injuries like osteochondritis dissecans. Recent technological advances have only now made it possible to analyze the complex and simultaneous motions in multiple planes required for evaluation of even the most basic gymnastic maneuvers like the round-off back handspring (ROBHS). OBJECTIVES: There is a paucity of data characterizing upper extremity injury causation and biomechanical risk factors in the small number of gymnastics studies conducted. The first hand contact for any gymnastics skill has never been quantitatively assessed. Therefore, the primary objective of this study is to perform a detailed 3D biomechanical characterization of the round-off back handspring (ROBHS) first hand contact and evaluate any potential correlations to upper extremity injury determinants. METHODS: A 3D motion capture camera and force plate system captured the relative positon of reflective markers affixed to 62 anatomical positions on subjects during performance of an ROBHS. A virtual model of each subject was constructed using Nexus C-motion software. Programming with Visual3D and MATLAB software was used to calculate desired force, kinematic and kinetic variables such as joint torques and angles. Past medical history questionnaires were administered, and clinical range of motion and strength measures were assessed. RESULTS: Compared with other factors analyzed, hand contact order appeared to have the highest degree of influence on upper extremity biomechanics at both the time of initial contact and throughout the entire movement sequence. The second contact limb was correlated with a larger average ground contact force, whereas while the first contact limb was related to a shorter time to peak force development and larger magnitude rotational kinematic variables, especially at the elbow—the primary site of upper extremity injury. For the first hand contact, torque development at the elbow and shoulder appeared to be related, and wrist and shoulder variables were presumably related to ground reaction force (GRF) development. The proposed literature elbow injury mechanism may need some adjustment to reflect the impact of elbow flexion angle on GRF and elbow valgus torque, key variables tied to chronic elbow joint capsule overload injuries. CONCLUSIONS: The novel information provided by this study can be used to guide future recommendations for the prevention of upper extremity injury in gymnastics training and competition. Improved understanding of associated force, kinetic, and kinematic biomechanical variables like joint torque could have implications for movement specific body positioning with the potential for extrapolation to gymnastics moves with similar loading patterns. Possible protective technique interventions based on study findings include increasing second hand elbow flexion during the round-off phase of motion or minimizing the time between hand contacts.