chapter 2: Biomechanics of the Patellofemoral Joint


"If we select any object from the whole extent of an¬imated nature, and contemplate it fully and in all its bearings, we shall certainly come to this conclu¬sion: that there is Design in the mechanical con¬struction, Benevolence in the endowments of the living properties, and that Good on the whole is the result."

—Sir Charles Bell (1774 1842) (The Hand, Its Mechanism and Vital Endowments as Evincing Design, Ch 1.)

Ultimately, health and disease of the patellofemoral joint must be understood in bio¬mechanical terms. In carrying out its functions, the patella must accommodate the forces that normal activity brings to bear on this joint. The capacity to accommodate these forces may be reduced by abnormalities of anatomy or disease, or overcome by injury or overloading. Alterations of the joint due to aging may also have an adverse effect. Understanding the failure to meet the mechanical demands of daily activity requires an understanding of how load is transmitted across the patellofemoral joint, how that joint is stabilized, and how the two parts of the joint move in relation to one another during function. It is not necessary to be an engineer or a mathematician to understand the basic mechanical principles governing the patellofemoral joint that play an important role both in pathology and rehabilitation.


Inside Chapter 2: