Biomechanical Analysis of Performance and Asymmetry During Bend Sprinting

  • Jonathan David White

    Student thesis: Doctoral Thesis

    Abstract

    This thesis aimed to understand the drivers of performance and inter‑limb asymmetry during bend sprinting under conditions representative of competition. To inform methods of data collection and processing, a validation study was conducted which found differing methods as the most accurate detection of touchdown for the left (L‑R) and right (R‑L) steps.
    The main body of work was split into two phases. Phase 1 investigated the effects of lane radius and lateral banking on step characteristics and lower extremity joint kinematics in conditions representative of indoor competition. Lateral banking increased step velocities primarily through enabling longer step lengths whilst tighter radii did not result in faster step velocities than less tight bend radii, suggesting the need for familiarisation with banked bends. Compared to flat bends, lateral banking decreased the magnitudes of body lateral lean, hip abduction/adduction and ankle eversion/inversion for the L‑R and R‑L steps. Despite these reductions in frontal and transverse plane joint angles, trends for increased inter‑limb differences were observed on the banked bends.
    Phase 2 investigated the drivers of performance during bend sprinting on radii representative of outdoor competition. Step length and peak inward force in the L‑R step, and step frequency and duration of propulsive force generation for the R‑L step were key determinants of step velocity. Novel insights were gained into the R‑L step's role in generating inward and vertical forces during early stance, with minimised hip and knee flexion angles at touchdown aiding the generation of sufficient angular velocities throughout stance. For the L‑R step, peak inward force and inward impulse related to step velocity and step length, respectively, reinforcing the L‑R steps role in inward force generation. Therefore, in addition to optimising sagittal plane angles and angular velocities, to produce greater inward force athletes minimised hip adduction velocities at touchdown and peak knee adduction during stance whilst maximising ankle external rotation and inversion velocities. These findings highlight the need to stabilise in the frontal plane in addition to optimal sagittal plane angular velocities.
    This thesis has provided new understanding of biomechanics of indoor bend sprinting, and the drivers of bend sprinting step velocities. While asymmetry in kinetics did not directly relate to performance, inter‑limb differences were observed throughout the thesis. Plyometric drills, use of wearable resistance on the bend, and exercises inducing body lateral lean may have the potential to develop the kinetics and kinematics found to correlate with step velocity and or determinants of step velocity that are highlighted in this thesis.
    Date of Award7 Jan 2025
    Original languageEnglish
    Awarding Institution
    • University of Portsmouth
    SupervisorTimothy Exell (Supervisor), Joe Moore (Supervisor) & Cassie Wilson (Supervisor)

    Cite this

    '