Elsevier

Clinical Biomechanics

Volume 22, Issue 2, February 2007, Pages 221-229
Clinical Biomechanics

Nonlinear finite element analysis for musculoskeletal biomechanics of medial and lateral plantar longitudinal arch of Virtual Chinese Human after plantar ligamentous structure failures

https://doi.org/10.1016/j.clinbiomech.2006.09.009Get rights and content

Abstract

Background

Musculoskeletal diseases of the foot such as stress fractures, tendonitis and subsequent pain are commonly associated with elevated stresses/strains of abnormal plantar arch after plantar ligamentous structure failures. The goal of this study was to develop anatomically detailed, finite element models of the medial and lateral plantar longitudinal arch, and to investigate bone and muscle stresses resulting from plantar fasciotomy and major plantar ligament injuries.

Methods

Nonlinear finite element models of the second ray and the fifth ray of plantar longitudinal arches were constructed on the basis of CT and MR images of Virtual Chinese Human “female No. 1”. The models assumed a balanced standing load configuration. Three different degrees of passive intrinsic muscle tensions (weak, moderate, or severe) were used in conjunction with simulations of plantar fasciotomy and major plantar ligament injury.

Findings

Plantar fasciotomy caused von Mises stress increases in the bones and plantar ligaments while major plantar ligament injuries caused stress increases in the bones, flexor tendons, and plantar fascia. Increasing intrinsic muscle passive tensions decreased stress/strain levels in the medial and lateral arch, and adjusted abnormal tension/compression stress flows of both arches to close to the normal biomechanical states.

Interpretation

This study shows that plantar longitudinal arches are concordant combination of bony structures, intrinsic muscles, plantar fascia and ligaments. After plantar ligamentous structure failures, intrinsic muscles have to contribute to stabilize the plantar arches. This mechanism may reduce the risk of developing stress fractures, tendonitis and pain syndrome.

Introduction

Stress fractures and tendonitis occurred in the foot, as well as painful foot syndrome are commonly associated with tissues pathological changes evocated by abnormal internal stresses/strains in the plantar arches (Gao, 2004, Mann et al., 2003, Prior and Tollafield, 1997). Previous investigations demonstrate that plantar longitudinal arch is a concordant musculoskeletal system of multiple factors (Simon et al., 2000). Failures of plantar flexors and plantar fascia will cause elevated metatarsal strains, which are regarded as pathological causes of stress fractures (Donahue and Sharkey, 1999, Sharkey et al., 1995). In addition, plantar ligament injuries after high-energy impact will increase dorsiflexion deformations of the foot, and may result in arch instability (Huang et al., 1993, Kitaoka et al., 1997, Mann et al., 2003). Some scholars indicate that plantar fasciitis or plantar fasciotomy leads to multiple internal stress transfer in bony structures and soft tissues of the ankle–foot complex (Cheung et al., 2004, Gefen, 2002), thus follows the intrinsic muscles assisting to stabilize the plantar arches during standing posture (Simon et al., 2000). However, the quantitative mechanism of internal stresses/strains adjusted by intrinsic muscles, plantar fascia and ligaments remains unclear.

Finite element (FE) method has been used to investigate the internal stresses/strains of the plantar arch. Two-dimensional (2D) FE models (Gefen, 2002, Lemmon and Cavanagh, 1997, Nakamura et al., 1981) and three-dimensional (3D) FE models (Cheung et al., 2005, Gefen et al., 2000) of the foot have been reported to predict plantar pressures and bone stresses, which considered nonlinear material characteristics for plantar soft tissues. However, at present, for lack of high-resolution anatomical experimental dataset of musculoskeletal system of human foot (Zhong et al., 2003), Finite element modelling had to ignore the effects of anatomical characteristics and mechanical properties of both bone trabecula and muscles on biomechanical responses of the ankle–foot complex (Cheung et al., 2005, Gefen, 2002, Lemmon and Cavanagh, 1997).

The objective of the present study is to establish anatomically detailed FE models of the medial plantar longitudinal arch (MPLA) and lateral plantar longitudinal arch (LPLA) of Virtual Chinese Human (VCH) “female No. 1”. The models are used to investigate bone stresses/strains, muscle stresses, arch tension/compression stress flows resulting from plantar fasciotomy and major plantar ligament injuries.

Section snippets

Anatomy and geometry

The geometry of the computer model of skeleton–skin complex was taken from 3D reconstruction of Computer tomography (CT) images of 1mm intervals from the left foot of VCH “female No. 1” (the digitized model of a cadaver whose age 19, height 155 cm, weight 46 kg, length of the second foot ray 23.6 cm, length of the fifth foot ray 20.8 cm) (Zhong et al., 2003). The 3D anatomic structure of the plantar arch comprises MPLA (the first, second, third ray) and LPLA (the fourth, fifth ray), while calcaneal

FE models of plantar longitudinal arches of VCH “female No. 1”

A geometrical accurate 3D model of skeleton–skin complex of left foot of Virtual Chinese Human “female No. 1” was developed (Fig. 1(a)). An anatomically detailed FE model of the second ray of MPLA was established (Fig. 1(b)), involving 8 tissues, 3267 elements, 7330 nodes. Another anatomically detailed FE model of the fifth ray of LPLA was developed (Fig. 1(c)), involving 8 tissues, 2689 elements, 5938 nodes. All anatomic components of two models were marked in detail while load configurations

Discussion

Anatomically detailed FE models of MPLA and LPLA in sagittal planes were developed by using CT and MR images of VCH “female No. 1”. The models incorporating geometric and material nonlinear characteristics contained eight tissue materials, such as cortical bone, trabecular bone, cartilage, tendon, ligament, plantar fascia, intrinsic muscle and fat pad. The parametric effects of increasing passive intrinsic muscle passions on biomechanical responses of plantar longitudinal arches were quantified

Conclusions

The predictions of anatomically detailed FE models of the second and the fifth foot ray demonstrated that the plantar longitudinal arch was a concordant combination of bones, intrinsic muscles, plantar fascia and ligaments. Plantar fasciotomy or major plantar ligament injuries resulted in peak stress/strain increase of both MPLA and LPLA. Whereas strengthening passive intrinsic muscle tensions decreased stress/strain levels in the abnormal arches. This quantified mechanism may reduce the risk

Acknowledgements

This work was supported by the China Postdoctoral science foundation project (No. 2004035047). The author would like to thank the Institute of Clinical Anatomy, First Military Medical University, Guangzhou, China for sharing experimental dataset of Virtual Chinese Human “female No. 1”. The author also thanks two reviewers very much.

References (31)

  • J.L. Crary et al.

    The effect of plantar fascia release on strain in the spring and long plantar ligaments

    Foot Ankle Int.

    (2003)
  • S.W. Donahue et al.

    Strains in the metatarsals during the stance phase of gait: Implications for stress fractures

    J. Bone Joint Surg. Am.

    (1999)
  • S.L. Gao

    Atlas of Practical Anatomy of Lower Limb

    (2004)
  • A. Gefen et al.

    Biomechanical analysis of the three-dimensional foot structure during gait: a basic tool for clinical applications

    J. Biomech. Eng.

    (2000)
  • C.K. Huang et al.

    Biomechanical evaluation of longitudinal arch stability

    Foot Ankle

    (1993)
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