Effects of digital filtering on peak acceleration and force measurements for artistic gymnastics skills.

Low-pass filters are ideal when filtering human movements, however the effectiveness of such filters relies on the correct selection of the cut-off frequency. The aim of this study was to determine the most appropriate filter cut-off for acceleration- and force-time data when measuring peak resultant acceleration (PRA) and ground reaction force (PRGRF) during gymnastics landings. Sixteen gymnasts executed backward handsprings and backward somersault landings onto a matted force plate while wearing four inertial measurement units (IMUs). Acceleration- and force-time data were filtered using a fourth-order Butterworth filter at different cut-off frequencies ranging from raw through to 250 Hz. Residual analysis plots were produced, and the PRGRF and PRA for all IMUs were calculated for each participant and skill at all cut-off frequencies. Descriptive statistics, model II linear regressions and Bland-Altman plots were conducted. Results indicated that a minimum 85 Hz cut-off is optimal. High cut-off frequencies (>80 Hz) showed good linear relationships and had minimal mean bias compared with raw values, indicating that either filtered (above ~85 Hz) or raw signals can be used. It is suggested that for applied sports settings no filtering is needed, however a minimum cut-off of 85 Hz should be implemented for research purposes.

Injury epidemiology and risk factors in competitive artistic gymnasts: a systematic review.

BACKGROUND: Artistic gymnastics is reported to have some of the highest injury rates in sports, which limits participation and often involves considerable medical expenses. PURPOSE: To critically appraise the epidemiological literature on injury patterns and risk factors in competitive artistic gymnastics. STUDY DESIGN: Systematic review. METHODS: Six databases were searched for articles that investigated injuries in competitive artistic gymnasts. Injury incidence, prevalence and risk factor data were extracted, alongside information on injury location, type, severity, nature and mechanism of injury. Quality and level of evidence were assessed using a modified Downs and Black quality index checklist and the Oxford Centre for Evidence-based Medicine guidelines. RESULTS: The search identified 894 articles, with 22 eligible for inclusion. Descriptive analysis showed that injury incidence and prevalence varied from 0.3 to 3.6 injuries per gymnast (female=0.3-3.6, male=0.7) and 2.0-2.3 (female=2.0-2.3, male=2.0), respectively. Male gymnasts sustained mostly upper limb injuries, while female gymnast reported lower limb injuries. Floor was associated with the greatest number of injuries for both male and female gymnasts. Higher competitive level and exposure to competition were risk factors for gymnastics injury: age, body mass, body size, training duration and life stress were significant associated factors. CONCLUSION: Injury incidence and prevalence results are substantial among artistic gymnasts of all competitive levels. Gymnasts who train at highly competitive levels and are exposed to competition environments are a greater risk of injury. Future researchers should implement consistent reporting methods.

The use of inertial measurement units to quantify forearm loading and symmetry during gymnastics vault training sessions.

The upper limbs are important in gymnastics vaulting, as the success of the flight phase is dependent on a quick and forceful push-off from the vault. This places the upper limbs under stress, which has been associated with pain and injury. This study aimed to quantify forearm segmental loading and symmetry when performing foundation to advanced-level vaulting skills during training. Twelve advanced-level artistic gymnasts (female, n = 6; male, n = 6) wore bilaterally forearm-mounted inertial measurement units while completing their vaulting sessions. The peak resultant acceleration for the leading and non-leading forearms during contact were calculated. Female gymnasts performed variations of Yurchenko vaults, while male gymnasts performed Handspring and Tsukahara vaults. Descriptive statistics (median and inter-quartile range), symmetry index scores, and total session impact load (measure of cumulative loading) were calculated between the lead and non-lead forearms. High asymmetrical loading was identified for some Yurchenko, Handspring, and Tsukahara vaults, with large variations identified between gymnasts. Some gymnasts experienced greater loading at their lead forearm, while others experienced greater loading at their non-lead forearm. Results indicate that limb loading patterns in advanced gymnastics are highly individualised, indicating that individual analysis is needed to identify gymnasts (or limbs) at an increased risk for overuse injury.