Biomechanical comparisons between straight and bend sprinting in athletic sprint events

During bend sprinting, the continuous need to change direction affects athletes' whole-body mechanics. Continuously changing direction results in athletes not being able to achieve the same velocities on the bend as seen during straight-line sprinting. The aim of this thesis was to identify technique and performance differences between bend and straight-line sprinting. Two studies were conducted, one empirical study with experienced bend sprinters and one scoping review synthesising the existing bend sprinting literature. No differences were found in performance, push time, or most kinetic variables when analysing the effect of the bend during block starts compared with straight-line sprinting. However, there were reductions in vertical force on the bend compared with straight-line sprinting, which may negatively impact initial steps after block exit by reducing step length. Therefore, the bend reduces performance in subsequent race phases after block exit, potentially because athletes line their blocks up straight to increase anterior velocity. The results from the scoping review found that the effectiveness of strength training, which targets the performance descriptors, lower body kinematics, and ground reaction forces, should be further explored. A focus should be how athletes can better maintain variables closer to those during straight-line sprinting. Determining which variables are closely related to performance in sprinters who have greater velocities on the bend, and sprinters who can better maintain their velocity on the bend compared with straight-line sprinting, would help improve all bend sprinters. Additionally, statistical analysis such as statistical parametric mapping would provide additional information on the characteristics of the waveform that differentiate performers that may be lost when analysing discrete variables. Finally, advancements in technology should be explored by biomechanists to capture data ecologically during training and competition. Overall, changes in performance on the bend occur post block exit. However, a decrease in vertical force may impact the first few steps by reducing step length and, therefore, velocity. Variables related to better bend sprinters need to be identified using statistical analysis such as parametric mapping and advances in technology. An intervention study could then evaluate the effectiveness of strength training targeting the performance descriptors, lower body kinematics, and ground reaction forces, providing insights into improving bend sprinting performance.