Abstract
The aim of this study was to compare young and adult sprinters on several biomechanical parameters that were previously highlighted as performance-related and to determine the behaviour of several muscle–tendon units (MTU) in the first stance phase following a block start in sprint running. The ground reaction force (GRF) and kinematic data were collected from 16 adult and 21 young well-trained sprinters. No difference between the groups was found in some of the previously highlighted performance-related parameters (ankle joint stiffness, the range of dorsiflexion and plantar flexor moment). Interestingly, the young sprinters showed a greater maximal and mean ratio of horizontal to total GRF, which was mainly attributed to a greater horizontal GRF relative to body mass and resulted in a greater change in horizontal centre of mass (COM) velocity during the stance phase in the young compared with the adult sprinters. Results from the MTU length analyses showed that adult sprinters had more MTU shortening and higher maximal MTU shortening velocities in all plantar flexors and the rectus femoris. Although previously highlighted performance-related parameters could not explain the greater 100 m sprinting times in the adult sprinters, differences were found in the behaviour of the MTU of the plantar flexors and rectus femoris during the first stance phase. The pattern of length changes in these MTUs provides ideal conditions for the use of elastic energy storage and release for power enhancement.
Highlights
Sprint performance depends on an effective start followed by achievement and maintenance of the highest possible running velocity [1]
As the highest centre of mass (COM) acceleration during a sprint occurs during the first stance phase [2], it is not surprising that the ability to generate maximal external power during this phase is linked to overall sprint performance [3,4]
The first stance phase has been highlighted as a critical segment of the acceleration phase and studying this will increase our overall knowledge about sprint performance
Summary
Sprint performance depends on an effective start followed by achievement and maintenance of the highest possible running velocity [1]. Previous research has highlighted the important contribution of several biomechanical parameters during the first stance phase to sprint performance These parameters include a high ratio of forces (RF) in percentage of horizontal to resultant ground reaction force (GFR) [5,6], high ankle joint stiffness [7] and a reduction in range of dorsiflexion, which requires high plantar flexor moments [8]. Debaere et al [9] have shown that there is a significant difference between young and adult well-trained sprinters in specific technical skills They highlighted a difference in relative joint power contribution to total power generation between the two groups. The adult sprinters relied more on knee joint power generation, whereas the young sprinters had more relative contributions from their hip joint [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
