Introduction: Advanced footwear technology shoes (AFTs) with a carbon-fiber plate embedded in the resilient midsole has been shown to enhance the efficiency and economy of plantar flexor muscles (Nigg et al., Citation2020), reducing their activation during running. Unlike running, race walking represents an uncommon form of human locomotion, that is the leg must be straightened during the initial contact with the ground until a vertical upright position at a high speed to ensure no loss of contact. Thus, race walkers heavily rely on the plantar flexor muscles for energy generation to maintain proper technique, producing greater metabolic effort compared to running (Hanley & Bissas, Citation2013). To date, no studies have investigated the effect of AFTs on the biomechanical characteristics and muscular mechanics of the lower limb in race walking. An approach to access muscle activation is to utilise magnetic resonance (MR) imaging, which detects increases in skeletal muscle proton transverse relaxation time (T2) post-exercise, reflecting activated muscle fibres with exceptional spatial resolution. Purpose of the study: This study aimed to investigate the effect of AFTs on the lower limb muscle activation after near-maximal effort race walking using T2-weighted MR imaging, and to analyse the lower limb joint kinematics between AFTs and traditional shoes (TRADs). Methods: Six elite race walkers (age: 21.17 ± 3.13y, weight: 57.8 ± 3.6 kg, height: 171.1 ± 4:0cm, 10 km personal record: 40:44 ± 1:34min:s; mean ± SD) performed a 10-min race walk on the treadmill at near-maximal effort (100% their 10 km personal record) with randomly assigned shoes at four separate visits. The sagittal lower limb joint kinematics were captured using a high-speed camera at 240 frames per second during the last 2-min in the race walk. Before and immediately after exercise, the T2-weighted MR images were obtained from the lower limb in a random order, and the T2 were calculated from the image. Results: The joint angle was not significantly different between shoe conditions, while the ankle and metatarsophalangeal (MTP) joint were significantly lower in AFTs compared with TRADs (p < 0.05). Regarding the T2, there was a significant Shoes × Time interactions in the medial gastrocnemius (p < 0.05, n2:0.179) lateral gastrocnemius (p < 0.05, n2:0.216), soleus (p < 0.05, n2:0.351), and biceps femoris (p < 0.05, n2:0.349). Post-hoc statistical analyses revealed that after race walking, T2 was significantly lower in AFTs than in TRADs in the soleus (-7.20%), lateral gastrocnemius (-8.09%), and medial gastrocnemius (-7.26%), except for the biceps femoris.
© Copyright 2025 Footwear Science. Taylor & Francis. Alle Rechte vorbehalten.