Effects of Barefoot and Shod on the In Vivo Kinematics of Medial Longitudinal Arch During Running Based on a High-Speed Dual Fluoroscopic Imaging System

Abstract

Shoes affect the biomechanical properties of the medial longitudinal arch (MLA) and further influence the foot’s overall function. Most previous studies on the MLA were based on traditional skin-marker motion capture, and the observation of real foot motion inside the shoes is difficult. Thus, the effect of shoe parameters on the natural MLA movement during running remains in question. Therefore, this study aimed to investigate the differences in the MLA’s kinematics between shod and barefoot running by using a high-speed dual fluoroscopic imaging system (DFIS). Fifteen healthy habitual rearfoot runners were recruited. All participants ran at a speed of 3 m/s ± 5% along with an elevated runway in barefoot and shod conditions. High-speed DFIS was used to acquire the radiographic images of MLA movements in the whole stance phase, and the kinematics of the MLA were calculated. Paired sample t-tests were used to compare the kinematic characteristics of the MLA during the stance phase between shod and barefoot conditions. Compared with barefoot, shoe-wearing showed significant changes (p < 0.05) as follows: 1) the first metatarsal moved with less lateral direction at 80%, less anterior translation at 20%, and less superiority at 10–70% of the stance phase; 2) the first metatarsal moved with less inversion amounting to 20–60%, less dorsiflexion at 0–10% of the stance phase; 3) the inversion/eversion range of motion (ROM) of the first metatarsal relative to calcaneus was reduced; 4) the MLA angles at 0–70% of the stance phase were reduced; 5) the maximum MLA angle and MLA angle ROM were reduced in the shod condition. Based on high-speed DFIS, the above results indicated that shoe-wearing limited the movement of MLA, especially reducing the MLA angles, suggesting that shoes restricted the compression and recoil of the MLA, which further affected the spring-like function of the MLA.

In-shoe multi-segment foot kinematics measurement during the stance phase of running using a stretch strain sensor

“…However, these experimental designs may not fully reproduce foot motion during shod running because the integrity of the shoe is compromised. In contrast, measurement with high-speed dual fluoroscopic imaging systems allows for the investigation of foot motion with a complete shoe [ 10 ]. However, these methods are not simple and difficult to use in a clinical setting.…”

“…Shod running showed significantly a lower STR signal compared to barefoot running at 30%–100 % stance. In a previous study reported that shod running reduces the magnitude of medial longitudinal arch compression during from 0% to 70 % stance [ 10 ]. According to this result, the STR does not reflect differences from 0% to 20 % stance phase.…”

“…Previous studies have evaluated foot kinematics while wearing modified shoes (i.e., making holes) [ [6] , [7] , [8] ] or sandals [ 9 ] using a three-dimensional motion capture system or wearing complete shoes using high-speed dual fluoroscopic imaging systems [ 10 ]. Based on these analyses, footwear reportedly reduces the magnitude of medial longitudinal arch compression [ [10] , [11] , [12] ] and greatly restricts forefoot and midfoot motions during running [ 6 ]. Detecting differences in intra-foot kinematics between barefoot and shoe conditions requires high-spec equipment.…”

Adaptive Changes in Longitudinal Arch During Long-distance Running

“…This arch undergoes a dynamic cycle of compression and elongation, followed by elevation and contraction within the gait cycle, enabling efficient energy storage and release [4]. Studies suggest that the arch's functionality can contribute great effort toward the reduction of energy expenditure during running, underpinning investigations in running kinematics, dynamics, and footwear innovation [5][6][7][8]. Understanding the LA's behavioral changes during running is thus crucial for advancing biomechanical research and applications.…”