Knee Joint Models for Kneeling Biomechanics - Computational Biomechanics of the Musculoskeletal System - page 83

7 Knee Joint Models for

Kneeling Biomechanics

Yuxing Wang, Yubo Fan, and Ming Zhang

ContentS
Summary .......................................................................................................................................... 83
7.1 Introduction ............................................................................................................................. 83
7.2 Development of a Kneeling Model ......................................................................................... 84
7.2.1 Material Properties ...................................................................................................... 86
7.2.2 Loading and Boundary Conditions ............................................................................. 87
7.3 Determining the Mechanical Status of Kneeling .................................................................... 88
7.3.1 Stress Distribution of Cartilage................................................................................... 88
7.3.2 Stress Distribution of Menisci and Bones................................................................... 89
Acknowledgments ............................................................................................................................ 90
References ........................................................................................................................................ 90

Summary
Kneeling is a common movement required for both occupational and cultural reasons and has been
shown to be associated with an increased risk of knee disorders. Since excessive stress is considered
to be a possible aggressor, it is important to determine the mechanical features of this posture. Models
of the knee joint can provide this information, particularly the stress distribution within the inner
region, which is very difficult to measure through experimental approaches. In this chapter, a three-
dimensional finite element (FE) model of the human knee joint in a kneeling position, flexed through
90 degrees, was developed from magnetic resonance images. The bones, cartilages, and ligaments
were incorporated into the model, with relevant interaction between cartilage, ligaments, and bone.

7.1 IntroduCtIon
Kneeling is required by many occupations, such as mining, baggage handling, building construc-
tion, and agricultural work. It is also a critical part of life in the Middle East and Asia for religious or
cultural reasons. Since kneeling is an important and common activity, it is natural that people have
a desire to investigate its effects on the health of the knee joint. Previous studies have shown that
kneeling and crouching can increase the risk of knee injuries (Jensen and Eenberg 1996; Coggon
et al. 2000; McMillan and Nichols 2005). A dose-response relationship between kneeling and knee
disorders has also been reported (Jensen 2005; Klussmann et al. 2010). While the exact mechanisms
for these diseases are not clear, excessive cartilage stress could be one explanation. Therefore, the
determination of stress distribution plays an important role in understanding and preventing knee
injuries associated with kneeling.
FE analysis is a useful tool for investigating the mechanical status of joints. Using this approach,
many researchers have studied the stress within and around the knee under different situations. For
example, investigators have reported on the stress and strain values of loaded knee cartilage, the effects
of different loading conditions, and run parametric analyses after changing the material properties

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