Video-Analysis of "High-Risk" on-field Movements Biomechanics in Amateur Male Futsal Players: Preliminary Findings

BACKGROUND: Landings, decelerations, and changes of direction are key movements in Futsal matches. These playing situations can be associated with non-contact lower limb injuries, ranging from an ankle sprain to ACL tear, due to biomechanical risk factors, such as dynamic knee valgus. Evidence indicates that the identification of sport-specific Biomechanics is a necessary step to investigate the players' movement quality and implement injuries prevention programs. AIM: The main goal of the present study is to propose an affordable video-analysis methodology to identify biomechanical variables, useful to understand the biomechanical effects of a 4-week multifaceted training program intervention, which looked for modifying injury risk in sport-specific tasks. MATERIALS AND METHODS: In RCT study, 44 amateur Futsal players were equally divided into two groups: Intervention Group (IG, N=22), and Control Group (CG, N=22). The IG attended a 4-week intervention program, 2 times per week, with each session lasting up to 1 hour. An on-the field setting was used to deliver a threetask test to each group: Single-Leg Hop (SLH), Deceleration (DEC), and 90 degrees Changing of Directions ( COD). For each participant, bilaterally, pre-to-post intervention, we video-analyzed: seven variables for the SLH and DEC frames, including four frontal stability angles (trunk, hip, knee, and ankle), two sagittal flexion angles (hip and knee), the body Centre of Mass difference (.CM) in centimetres (cm) between landing and standing position, and the body mean acceleration on the x-axis during the deceleration. In addition, for the final-foot contact (FFC) frame during COD, we considered three frontal stability angles (trunk, knee, foot), two sagittal flexion angles (hip, knee) and the distance in cm between the FFC and the body CM on the y-axis. RESULTS: IG compared to the CG at T1 showed a significant improved frontal stability, in COD Knee angle, and foot angle; and a significant improved Hip and Knee co-flexion, in landing Hip Flexion, in landing Knee Flexion, and in COD Knee Flexion. IG, pre-to-post intervention, showed a significant improved frontal stability in landing Knee angle, in DEC Knee angle; and a significant improved Hip and Knee co-flexion, in SLH.CM, in DEC both Hip and Knee Flexion angles, in COD Knee Flexion angles. CONCLUSIONS: These results provide coaches with an affordable and feasible video-analysis methodology based on an on-the field setting to screen biomechanical variables in futsal-specific movements.