Elite long jumpers with below the knee prostheses approach the board slower, but take-off more effectively than non-amputee athletes

Steffen Willwacher,Kai Heinrich,Alena M Grabowski,Ralf Müller,Wolfgang Potthast,Gert-Peter Brüggemann,Johannes Funken,Hiroaki Hobara

doi:10.1038/s41598-017-16383-5

Abstract

The use of technological aids to improve sport performance (‘techno doping’) and inclusion of Paralympic athletes in Olympic events are matters of ongoing debate. Recently, a long jumper with a below the knee amputation (BKA) achieved jump distances similar to world-class athletes without amputations, using a carbon fibre running-specific prosthesis (RSP). We show that athletes with BKA utilize a different, more effective take-off technique in the long jump, which provided the best athlete with BKA a performance advantage of at least 0.13 m compared to non-amputee athletes. A maximum speed constraint imposed by the use of RSPs would indicate a performance disadvantage for the long jump. We found slower maximum sprinting speeds in athletes with BKA, but did not find a difference in the overall vertical force from both legs of athletes with BKA compared to non-amputees. Slower speeds might originate from intrinsically lower sprinting abilities of athletes with BKA or from more complex adaptions in sprinting mechanics due to the biomechanical and morphological differences induced by RSPs. Our results suggest that due to different movement strategies, athletes with and without BKA should likely compete in separate categories for the long jump.

Highlights

Jumping for distance may be one of the most traditional competitive events in sports, with potentially the earliest use of performance enhancing technical aids; first performed during the Ancient Greek Olympic Games[1]
The record distance of male athletes with below the knee amputation (BKA) using running-specific prosthesis (RSP) (8.40 m) has improved by 2.60 m (45%) since 1996; a resulting jump distance similar to those of current world-class non-amputee athletes, whose records have not changed during the same period
The purpose of the present study was to identify the key biomechanical differences in maximum effort long jumps between athletes with BKA and non-amputee athletes

Summary

Introduction

Jumping for distance may be one of the most traditional competitive events in sports, with potentially the earliest use of performance enhancing technical aids (handheld weights); first performed during the Ancient Greek Olympic Games[1]. Athletes with BKA elicit lower anterior ground reaction forces and have longer contact times during the push-off from the starting blocks and the first step of the acceleration phase compared to non-amputees[10,11,12]. This indicates a performance disadvantage during maximum acceleration tasks compared to non-amputees; potentially due to the missing muscles and reduced capacity for positive power generation and other constraints imposed by the use of RSPs10–13. Maximizing ASFs during short contact times is crucial for attaining fast maximum sprinting speed

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Conclusion