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Shinohara H1, Kobayashi S1, Obata F1, Kobayashi M1, Urabe Y2
1Takarazuka University of Medical and Health Care, Takarazuka, Japan, 2Hiroshima University, Hiroshima, Japan
Background: The windlass mechanism is a phenomenon in which the medial longitudinal arch of the foot (MLA) rises during toe extension, which is thought to be caused by a pull on the plantar aponeurosis. Previous studies have revealed the phenomenon by using a foot model during walking.
Purpose: The purpose of this study is to clarify the influence of the load amount on the windlass mechanism by measuring navicular and medial cuneiform height in sitting and standing positions by using ultrasound. We hypothesize that MLA height will decrease with increased load from sitting to standing.
Methods: The subjects were 20 university students (total, 40 feet). All the participants were women. The navicular (N-MLA) and medial cuneiform (C-MLA) height were determined through ultrasound. A specially made instrument was used, which made a probe move horizontally when the ultrasound was used. MLA was measured at 0°, 10°, 20°, 30°, 40°, 50°, and 60° of toe extension and compared to the value at 0°. Additional comparisons were made in the same angle between sitting and standing.
Results: Both N-MLA and C-MLA increased with toe extension. In the comparison between sitting and standing positions, a significant difference was observed in all angles, but values in the standing position tended to change more than in sitting. In the sitting position, C-MLA at 0° was 34.4 %, and at 60° it was 42.9 %, thus increasing by 8.5 %. The N-MLA at 0° was 26.7 %, and at 60° it was 35.0 %, thus increasing by 8.3 %. In the standing position, C-MLA at 0° was 26.5 %, and at 60° it was 40.0 %, this increasing by 13.5 %. The N-MLA was 20.9 %, and at 60° it was 33.0 %, thus increasing by 12.1 %.
Conclusion(s): We clarify the influence of the load amount on the windlass mechanism. Medial longitudinal arch (MLA) of the foot develops with changes in the human gait. MLA increased in sitting and standing positions with increased toe extension angle.
Implications: This study showed that the MLA increases by extending the toes, more notably so in standing than in sitting. We think that the results of this study will provide the basic data necessary for understanding the windlass mechanism.
Keywords: Windlass mechanism, Medial longitudinal arch, Ultrasonography
Funding acknowledgements: The authors express his appreciation to Mr. Shouichi Takagi for his contribution to the make the apparatus.
Purpose: The purpose of this study is to clarify the influence of the load amount on the windlass mechanism by measuring navicular and medial cuneiform height in sitting and standing positions by using ultrasound. We hypothesize that MLA height will decrease with increased load from sitting to standing.
Methods: The subjects were 20 university students (total, 40 feet). All the participants were women. The navicular (N-MLA) and medial cuneiform (C-MLA) height were determined through ultrasound. A specially made instrument was used, which made a probe move horizontally when the ultrasound was used. MLA was measured at 0°, 10°, 20°, 30°, 40°, 50°, and 60° of toe extension and compared to the value at 0°. Additional comparisons were made in the same angle between sitting and standing.
Results: Both N-MLA and C-MLA increased with toe extension. In the comparison between sitting and standing positions, a significant difference was observed in all angles, but values in the standing position tended to change more than in sitting. In the sitting position, C-MLA at 0° was 34.4 %, and at 60° it was 42.9 %, thus increasing by 8.5 %. The N-MLA at 0° was 26.7 %, and at 60° it was 35.0 %, thus increasing by 8.3 %. In the standing position, C-MLA at 0° was 26.5 %, and at 60° it was 40.0 %, this increasing by 13.5 %. The N-MLA was 20.9 %, and at 60° it was 33.0 %, thus increasing by 12.1 %.
Conclusion(s): We clarify the influence of the load amount on the windlass mechanism. Medial longitudinal arch (MLA) of the foot develops with changes in the human gait. MLA increased in sitting and standing positions with increased toe extension angle.
Implications: This study showed that the MLA increases by extending the toes, more notably so in standing than in sitting. We think that the results of this study will provide the basic data necessary for understanding the windlass mechanism.
Keywords: Windlass mechanism, Medial longitudinal arch, Ultrasonography
Funding acknowledgements: The authors express his appreciation to Mr. Shouichi Takagi for his contribution to the make the apparatus.
Topic: Musculoskeletal: lower limb; Orthopaedics; Sport & sports injuries
Ethics approval required: Yes
Institution: Takarazuka University of Medical and Health Care
Ethics committee: Ethics Committee of Takarazuka University of Medical and Health Care
Ethics number: Number: 1802211
All authors, affiliations and abstracts have been published as submitted.
