Acute effects of barefoot running and running requirement on lower-limb kinematics in habitually shod endurance runners

Abstract

The aim of this study was to analyse kinematic variables when running barefoot and when wearing conventional running shoes at comfortable and demanding running speeds. Sixty healthy recreational male runners (age = 35.6 ± 11.7 years old, body mass index = 22.9 ± 2.4 kg/m²) performed trials in shod/barefoot running conditions on a treadmill at self-selected comfortable and demanding speeds. Photogrammetric techniques (2D) were employed. In barefoot conditions, contact time was shorter (p < 0.001) at demanding speed, flight time was shorter at comfortable (p < 0.05) and demanding (p < 0.05) speeds, and there was greater stride frequency at both speeds (p < 0.001). In addition, in barefoot conditions, runners landed with significantly greater knee flexion (p < 0.05); lower ankle dorsiflexion (p < 0.001); and lower knee flexion in take-off at demanding speed (p = 0.002) compared with shod conditions. In conclusion, the current study has provided evidence to suggest that acute changes occur in the temporal variables and kinematics between shod/barefoot conditions at low and high speeds in habitually shod runners. Significant differences were found in spatial–temporal events between shod/barefoot conditions, with shorter times in barefoot conditions with greater knee flexion and ankle dorsiflexion. When speed was increased in barefoot conditions, duration of timing variables decreased significantly both comfortable and demanding speed (p < 0.001). Because of this, stride and gait cycle was significantly faster and thus there was a higher stride frequency.