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H. Shinohara1, F. Obata2, S. Kobayashi3, M. Kobayashi2, Y. Urabe4
1Aomori University of Health and Welfare, Physical Therapy, Aomori, Japan, 2Takarazuka University of Medical and Health Care, Physical Therapy, Takarazuka, Japan, 3Takarazuka University of Medical and Health Care, Faculty of Wakayama Health Care Science, Physical Therapy, Wakayama, Japan, 4Graduate School of Biomedical and Health Sciences at Hiroshima University, Physical Therapy, Hiroshima, Japan
Background: In normal feet, medial longitudinal arch (MLA) rises and falls periodically within the walking cycle, and has a structure that absorbs local loads caused by loading. Depression of the MLA under loading conditions has been reported for some time, but there is no clarity on whether this behavior of the arch differs between people with flatfoot and healthy subjects. We devised can measure not only the height of the medial cuneiform but also the angle of the medial cuneiform, so that the degree of pronation of the tarsal bone can be known.
Purpose: The purpose of this study was to clarify how the behavior at the time of depression differs between high and low MLA using an ultrasonic diagnostic imaging system.
Methods: The subjects were 19 university students (total, 38 feet). All the participants were women. When the ultrasound apparatus was used, the height of the navicular and medial cuneiform were measured in both standing and sitting position. The sample was divided into two groups according to MLA height, a high arch group (HAG) and a low arch group (LAG). At the same time, the arch height ratio (N-MLA, C-MLA) and the angle of the medial cuneiform bone were measured.
Results: In both groups, the arch height was depressed by the load, and the arch height ratio (C-MLA, N-MLA) also reduced. In LAG, the variation in the heights of the medial cuneiform and navicular and the variation in the medial cuneiform angle from the sitting position to the standing position were significantly correlated (r = −.74, P < .001; r = −.50, P = .027). Conversely, HAG showed no significant correlation (r = −.12, P = .596; r = .17, P = .498).
Conclusion(s): The arch heights in both LAG and HAG decreased by the load. Moreover, the variation in the pronation angle of the medial cuneiform was larger in the LAG and was significantly correlated with the variation in the arch height of the medial cuneiform and navicular. The results of this study suggest that those with low MLAs have a different behavior of depressing the arch under load and also suggest that this phenomenon can be evaluated using an ultrasonic imaging system. Future research may use a training program to examine this in more detail than before, and an even better training method can be proposed. We hope that the method used in this study will assist in choosing appropriate clinical training.
Implications: This study is important for prevention and treatment of flatfoot and foot function.
Funding, acknowledgements: The authors express his appreciation to Mr. Shouichi Takagi for his contribution to the make the apparatus.
Keywords: Medial longitudinal arch, flatfoot, Ultrasonography
Topic: Musculoskeletal: lower limb
Did this work require ethics approval? Yes
Institution: Takarazuka University of Medical and Health Care
Committee: Takarazuka University of Medical and Health Care
Ethics number: 1802211
All authors, affiliations and abstracts have been published as submitted.
