Long jumpers with and without a transtibial amputation have different three-dimensional centre of mass and joint take-off step kinematics

• Main Authors: Johannes Funken, Steffen Willwacher, Kai Heinrich, Ralf Müller, Hiroaki Hobara, Alena M. Grabowski, Wolfgang Potthast
• Format: Article
• Language: English
• Published: The Royal Society 2019-04-01
• Series: Royal Society Open Science
• Subjects: joint angle; paralympics; locomotion; prosthetics; performance analysis; adaptation
• Online Access: https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.190107

Long jumpers with below the knee amputation (BKA) have achieved remarkable performances, yet the underlying biomechanics resulting in these jump distances are unknown. We measured three-dimensional motion and used multi-segment modelling to quantify and compare the centre of mass (COM) and joint kinematics of three long jumpers with BKA and seven non-amputee long jumpers during the take-off step of the long jump. Despite having the same jump distances, athletes with BKA, who used their affected leg for the take-off step, had lower sagittal plane hip and knee joint range of motion and positioned their affected leg more laterally relative to the COM compared to non-amputee athletes. Athletes with BKA had a longer compression phase and greater downward movement of their COM, suggesting that their affected leg (lever) was less rigid compared to the biological leg of non-amputees. Thus, athletes with BKA used a different kinematic mechanism to redirect horizontal to vertical velocity compared to non-amputee athletes. The specific movement patterns of athletes with BKA during the take-off step were constrained by the mechanical properties of the prosthesis. These results provide a basis for coaches and athletes to develop training protocols that improve performance and inform the design of future prostheses.