Does “transition shoe” promote an intermediate biomechanical condition compared to running in conventional shoe and in reduced protection condition?

- TrS led to changes in VGRF variables and lower limbs kinematics.
- TrS promoted an intermediate biomechanical condition only for VGRF variables.
- Running in TrS is not the same of running in CS or MS for impact force variables.
- TrS arises as an option to transition and achieve minimal running.

This study evaluated if running in a “transition shoe” commercially available results in intermediate mechanical load upon lower extremities compared to conventional shoe and minimalist shoe/barefoot. Kinematic and kinetic parameters while running in different shoe conditions were compared. Fourteen runners (12 men, 2 women; age = 28.4 ± 7.3 years), inexperienced in minimalist shoes and barefoot running, ran on an instrumented treadmill within four experimental conditions (conventional shoe - CS, transition shoe - TrS, minimalist shoe - MS, and barefoot - BF). Running was performed at 9 km/h for 10 min in each experimental condition. Vertical ground reaction force (VGRF) and two-dimensional kinematic variables of lower limbs (both legs) were recorded. Nine data acquisitions (10 s) were conducted for each footwear condition. Transition shoe lead to significant changes in VGRF variables related to impact control, while kinematic parameters were little affected. The TrS had smaller first peak of VGRF (Fy1) than CS (p ≤ 0.001) and higher than MS (p = 0.050) and BF (p ≤ 0.001). Time to first peak of VGRF (tFy1) of TrS was smaller than CS (p ≤ 0.001) and higher than MS (p ≤ 0.001) and BF (p ≤ 0.001). The TrS and MS induced to lesser knee flexion (p < 0.001) and greater dorsiflexion (p < 0.001) than CS and BF. Thus, results suggest the transition shoe (TrS) tested seem to promote an intermediate mechanical load condition only for VGRF parameters, presenting values of impact forces between those found for conventional shoe and minimalist shoe/barefoot. Such knowledge could be useful for the transition process from conventional running shoe to minimalist shoe/barefoot.