A device for characterising the mechanical properties of the plantar soft tissue of the foot.
The plantar soft tissue is a highly functional viscoelastic structure involved in transferring load to the human body during walking. A Soft Tissue Response Imaging Device was developed to apply a vertical compression to the plantar soft tissue whilst measuring the mechanical response via a combined load cell and ultrasound imaging arrangement. Accuracy of motion compared to input profiles; validation of the response measured for standard materials in compression; variability of force and displacement measures for consecutive compressive cycles; and implementation in vivo with five healthy participants. Static displacement displayed average error of 0.04 mm (range of 15 mm), and static load displayed average error of 0.15 N (range of 250 N). Validation tests showed acceptable agreement compared to a Houndsfield tensometer for both displacement (CMC > 0.99 RMSE > 0.18 mm) and load (CMC > 0.95 RMSE < 4.86 N). Device motion was highly repeatable for bench-top tests (ICC = 0.99) and participant trials (CMC = 1.00). Soft tissue response was found repeatable for intra (CMC > 0.98) and inter trials (CMC > 0.70). The device has been shown to be capable of implementing complex loading patterns similar to gait, and of capturing the compressive response of the plantar soft tissue for a range of loading conditions in vivo.
School of Health Sciences, University of Salford, UK. Electronic address: D.j.parker1@salford.ac.uk.
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Parker
School of Engineering, Manchester Metropolitan University, UK. Electronic address: G.Cooper@mmu.ac.uk.
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Cooper
School of Health Sciences, University of Salford, UK. Electronic address: S.Pearson@Salford.ac.uk.
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Pearson
School of Health Sciences, University of Salford, UK. Electronic address: G.Crofts@Salford.ac.uk.
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Crofts
School of Computing, Science & Engineering, University of Salford, UK. Electronic address: D.Howard@Salford.ac.uk.
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Howard
College of Science & Technology, University of Salford, UK. Electronic address: P.Busby@Salford.ac.uk.
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Busby
School of Health Sciences, University of Salford, UK.
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Nester
D000328:Adult; D001696:Biomechanical Phenomena; D002138:Calibration; D004867:Equipment Design; D005260:Female; D005528:Foot / Q000000981:diagnostic imaging* / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D009038:Motion; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods; D016138:Walking / Q000502:physiology; D055815:Young Adult
Biomechanics; Dynamic testing; Foot; Gait simulation; Soft tissue mechanics; Ultrasound