Landing-Takeoff Asymmetries Applied to Running Mechanics: A New Perspective for Performance

Elastic bouncing is a physio-mechanical model that can elucidate running behavior in different situations, including landing and takeoff patterns and the characteristics of the muscle-tendon units during stretch and recoil in running. An increase in running speed improves the body's elastic mechanisms. Although some measures of elastic bouncing are usually carried out, a general description of the elastic mechanism has not been explored in running performance. This study aimed to compare elastic bouncing parameters between the higher- and lower-performing athletes in a 3000 m test.

Thirty-eight endurance runners (men) were divided into two groups based on 3000 m performance: the high-performance group (P_high; n = 19; age: 29 ± 5 years; mass: 72.9 ± 10 kg; stature: 177 ± 8 cm; 3000_time: 656 ± 32 s) and the low-performance group (P_low; n = 19; age: 32 ± 6 years; mass: 73.9 ± 7 kg; stature: 175 ± 5 cm; 3000_time: 751 ± 29 s). They performed three tests on different days: (i) 3000 m on a track; (ii) incremental running test; and (iii) a running biomechanical test on a treadmill at 13 different speeds from 8 to 20 km h^-1. Performance was evaluated using the race time of the 3000 m test. The biomechanics variables included effective contact time (t _ce), aerial time (t _ae), positive work time (t _push), negative work time (t _break), step frequency (f _step), and elastic system frequency (f _sist), vertical displacement (S _v) in t _ce and t _ae (S _ce and S _ae), vertical force, and vertical stiffness were evaluated in a biomechanical submaximal test on treadmill.

The t _ae, f _sist, vertical force and stiffness were higher (p < 0.05) and t _ce and f _step were lower (p < 0.05) in P_high, with no differences between groups in t _push and t _break.

The elastic bouncing was optimized in runners of the best performance level, demonstrating a better use of elastic components.