Effects of advanced footwear technology shoes on lower limb muscle activation in race walking using T2-weighted magnetic resonance imaging: a pilot study

Given the established effects of advanced footwear technology shoes (AFTs) on lower limb kinematics and muscle activation in running, similar effects may be expected in race walking. This pilot study aimed to examine the effect of AFTs on lower limb muscle activation using proton transverse relaxation time (T2)-weighted magnetic resonance (MR) imaging following near-maximal effort race walking, and investigate lower limb kinematics, compared with traditional shoes (TRADs). Six elite race walkers performed a 10-min race walk on the treadmill at 100% of their season-best 10-km pace (average speed: 14.8 km/h) at four separate visits, wearing either TRADs or AFTs. Sagittal joint kinematics were determined using a high-speed camera at 240 fps during the last 2-min of the race walk. For each visit, the T2-weighted MR images of either the shank or thigh were obtained in randomised order before and immediately after exercise, and the T2 values were calculated from the images. Two-way analysis of variance showed a significant Shoes × Time interaction in the soleus (p < 0.05, η2: 0.351), lateral gastrocnemius (p < 0.05, η2: 0.216), medial gastrocnemius (p < 0.05, η2: 0.179), and the biceps femoris (p < 0.05, η2: 0.349). The T2 values were significantly lower in these muscles when wearing AFTs compared with TRADs after race walking. In contrast, lower limb kinematics remained unchanged between AFTs and TRADs during race walking. These findings suggest that AFTs may reduce the exercise-induced metabolic response in the activated posterior lower limb muscles without affecting kinematics during near-maximal effort race walking.