Duda G N, Schneider E, Chao E Y
Biomechanics Section, Technical University Hamburg-Harburg, Germany.
J Biomech. 1997 Sep;30(9):933-41. doi: 10.1016/s0021-9290(97)00057-2.
The forces exerted by the soft and hard tissues of the thigh together represent a system in equilibrium. This balance of loads must be considered when the system components are examined independently. However, in many biomechanical analyses of the thigh, the femur is studied without considering soft tissue loading. To improve the understanding of femoral loading a three-dimensional model was developed. Taking into account all thigh muscles, body weight and contact forces at the hip, patello-femoral and knee joints, the internal loads of the bone were calculated. Internal loads of the femur decreased as a result of muscle activity from proximal to distal at the hip and from distal to proximal at the knee. The load reduction could be up to 50% of the internal forces at the hip, depending on gait phase. Maximal forces were found between 40 and 60% of the stance phase, whereas maximal torsional moments occurred shortly after heel strike. This model demonstrated that muscles play a substantial role in balancing the loads within the femur. In general, the bone is loaded axially, rather than in bending, with maximum shear forces at the proximal and distal ends. Bending moments are relatively small compared to models which do not consider muscle activity. From one gait phase to another, the femur experiences alternating, rather than one-sided bending load.
大腿的软组织和硬组织共同施加的力构成一个平衡系统。在单独检查系统组件时，必须考虑这种负载平衡。然而，在许多对大腿的生物力学分析中，研究股骨时并未考虑软组织负荷。为了更好地理解股骨负荷，开发了一个三维模型。该模型考虑了所有大腿肌肉、体重以及髋部、髌股关节和膝关节处的接触力，计算了骨骼的内部负荷。由于肌肉活动，股骨的内部负荷在髋部从近端到远端、在膝关节从远端到近端逐渐降低。根据步态阶段，负荷降低幅度可达髋部内力的50%。最大力出现在站立阶段的40%至60%之间，而最大扭矩出现在足跟触地后不久。该模型表明，肌肉在平衡股骨内的负荷方面起着重要作用。一般来说，骨骼承受轴向负荷，而非弯曲负荷，近端和远端的剪切力最大。与不考虑肌肉活动的模型相比，弯矩相对较小。从一个步态阶段到另一个步态阶段，股骨承受的是交替负荷，而非单侧弯曲负荷。
