Combined effects of foot placement technique and sport specific habitual training on landing mechanics

Abstract

Correct technique that provides e cient and safe dissipation of ground reaction forces (GRF) is crucial during landing motions. Parkour practitioners (traceurs) intrinsically developed a landing technique in which they solely land on their forefoot (FFL) to counter extreme loading demands of their practice. Traceurs attenuate impact forces substantially during FFL compared to traditionally used toe-heel landing (THL). However, traceurs are already expected to execute their habitual foot placement technique (FPT), FFL, more e ciently via favorable adaptations in their musculoskeletal and neuromuscular system. Up till now, it has not been tested speci cally if FFL is superior over THL in shock absorption, regardless of performers habitual and/or preferred FPT. Additionally, it is not known how sport speci c habitual training (SSHT) in FPT a ects landing mechanics. Presently, to ll those gaps FFL and THL mechanics were analyzed during drop landings from 75 cm in three groups (n = 3 x 12); (1) traceurs (habitual FFL practice), (2) basketball players (habitual THL practice) and (3) nonathletes (no habitual training). GRF metrics, lower body joint kinematics, activation patterns of tibialis anterior (TA) and gastrocnemius medialis (GM) muscles, and mechanical characteristics of the Achilles tendon (AT), TA and GM were measured to examine the e ects of FPT and SSHT on landing mechanics. Results indicate that FFL is considerably advantageous than THL for shock absorption, independently of SSHT and preferred FPT. Furthermore, kinematic and neuromuscular strategies were altered between groups to achieve similar shock attenuation for each technique, based on the potential adaptive e ects of their SSHT. These ndings present valuable insights into the e ects of FPT on landing mechanics which may have practical implications for every practitioner and trainer whether in sports or recreational activities.|Keywords : Parkour, Forefoot, Ankle, GRF, Kinematic, EMG, Sti ness, Recoil.