Determinant biomechanical variables for each sprint phase performance in track and field: A systematic review

Sprint studies present several variables and methodologies for biomechanical analysis in different phases of running. The variability in the analysis of the sample and distance covered may impede the application of the results in track and field athletes. The objective of this systematic review was to characterize the determinant biomechanical variables analyzed in the literature in each sprint phase. Four electronic databases were used (MEDLINE, Web of Science, SportDiscus, and Scopus). Only biomechanical studies with track and field athletes were selected. After the identification, screening, and eligibility process, 109 studies were included for qualitative synthesis and analyzed by the risk of bias assessment. The studies were classified in different sprint phases, according to the sprint task described by the authors (sprint start = 27, acceleration = 32, constant speed = 8, deceleration = 4, and not specified = 38). Factors such as the center of mass position, contact time, force applied on the rear block, and athletes’ ability to generate high amounts of force in the shortest possible time influence the sprint start performance. The acceleration phase is characterized by step frequency and step length transition, propulsive force, and minimization of braking force. Consequently, directing the resulting force as vertically as possible in the braking phase and as horizontally as possible in the anterior direction during the propulsive phase is important during the constant speed phase. In the deceleration phase, the decrease in step frequency and the increase in contact time may influence speed maintenance and, consequently, the result.