Shear cushions reduce the impact loading rate during walking and running.
In addition to vertical ground reaction force (GRF), anterior-posterior GRF with a greater external moment arm may be another repetitive impact force that contributes to overuse running injuries. In this study, a shear cushion device was placed between the sole of a shoe and the ground to reduce not only the vertical loading, but also the anterior-posterior loading while walking and running. For this study, 15 healthy male runners classified as heel strikers (height: 173.2 +/- 4.7 cm, mass: 68.5 +/- 5.6 kg) were recruited. Participants were required to walk (2.5 m/s), jog (3.5 m/s), and run (4.2 m/s) while wearing shoes with three different sole groove designs (conventional, straight groove, and 45 degrees groove). Both the straight and 45 degrees groove soles provided significant shear shift during walking, jogging, and running, as well as delayed the time to first peak anterior-posterior GRF during walking. The straight groove sole reduced the vertical loading rate during jogging (p = 0.010) and running (p = 0.010), and delayed the time to first peak vertical GRF in all gait conditions. These findings suggest that the vertical loading rate and the time to the first peak anterior-posterior GRF can be changed by the sole groove design under various gait conditions.
Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan.
Ming-Sheng
MS
Chan
Graduate Institute of Sports Equipment Technology, Taipei Physical Education College, Taipei, Taiwan.
Shu-Ling
SL
Huang
Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan.
Yo
Y
Shih
Department of Physical Education, National Taiwan Normal University, Taipei, Taiwan.
Chia-Hsiang
CH
Chen
Department of Athletic Performance, National Taiwan Normal University, Taipei, Taiwan.
Tzyy-Yuang
TY
Shiang
D000704:Analysis of Variance; D004867:Equipment Design; D061826:Foot Orthoses; D006801:Humans; D008297:Male; D012420:Running / Q000502:physiology*; D012775:Shoes; D016138:Walking / Q000502:physiology*; D055815:Young Adult