Relationship between transverse arch height and foot muscles evaluated by ultrasound imaging device

Abstract

[Purpose] Few studies on the transverse arch (TA) in the forefoot have been conducted. The forefoot is where pains occur most frequently and is related to walking and balance; hence, paying attention to TA is vital. However, the relationship between TA and foot muscles has not been investigated. Therefore, this study aims to investigate muscles related to TA. [Subjects and Methods] Nineteen healthy young males were included. Measurements of their feet, excluding one foot with recent foot pain (n=37), were obtained. The height of TA (TAH) was measured in two ways: during 10% and 90% loading of body weight. The cross-sectional area and thickness of five muscles were measured: flexor digitorum longus, peroneus longus and brevis, flexor hallucis brevis, flexor digitorum brevis (FDB) and abductor hallucis (ABH). All measurements were performed with an ultrasound device. [Results] FDB and ABH were correlated with TAH during 10% and 90% loading after removing the effect of body mass index and age. The greater FDB and ABH, the higher TAH. [Conclusion] As FDB becomes larger, the second, third and fourth metatarsal heads are raised more. Furthermore, the height of the first metatarsal head is lowered by a larger ABH. These mechanisms may increase TAH.

Comparison of the Changes in the Structure of the Transverse Arch of the Normal and Hallux Valgus Feet under Different Loading Positions

“…Based on the study by Uritani et al [18], feet with an HV angle lower than 20 degrees were assigned to the Without-HV group and those with an HV angle equal or higher than 20 degrees were assigned to the With-HV group. US images were taken by the customized machine WBPUID that allows taking images in a weight-bearing position [9,19] using an US diagnostic device (Noblus, Hitachi Aloka Medical, Tokyo, Japan) at B-mode US with a frequency of 9.0 MHz [9]. WBPUID was previously tested to evaluate the structure of the transverse arch in the coronal plane, and its images were in agreement with computed tomography ultrasonograms [14].…”

“…First, body weight was measured, and calculations were done. Next, the therapist placed the tested foot on the US probe opening and confirmed the configuration of the lowest points of the epiphysis of the medial sesamoid bone (MS), the lateral sesamoid bone (LS), the second metatarsal head bone (2MTH), and the fifth metatarsal head bone (5MTH) [9]. For the 90% W.S.…”

“…All participants were able to maintain this posture independently. A similar 90% weight-loading positioning and the WBPUID parameters were previously used and validated by our laboratory members [9,19]. participants from getting injured, we instructed them to shift their weight on the tested foot until the scale under the not-tested foot showed 10% of their body weight, and to sway their bodies forward.…”

“…All participants were able to maintain this posture independently. A similar 90% weight-loading positioning and the WBPUID parameters were previously used and validated by our laboratory members [9,19]. where an ultrasound probe is located and a scale and connected to the ultrasound device.…”

“…These arches work together and respond to the weight put on the foot while walking by providing shock absorption [8]. This study focuses on the transverse arch, which is in the forefoot [9], and is formed by the five metatarsal heads (MTHs) ( Figure 1). As HV deformity causes the medial shifting of the first MTH, and because the first MTH itself is a part of the transverse arch, we hypothesized that feet with HV deformity would have a different transverse arch structure compared to feet without HV deformity.…”