A NEW METHOD FOR ASSESSMENT OF FUNCTIONAL STABILITY AT THE KNEE JOINT

Abstract

INTRODUCTION: Muscle forces are transmitted by the joints to the movement of the body. Sometimes high muscle forces are used, especially in sports practice. To stabilize the arthron, it is necessary to train the musculature in a functional way. Knowledge of the stability of the arthron during its function in athletic use is helpful to prevent the arthron from overuse or injury. The knee joint frequently becomes unstable due to disruption of the cruciate ligaments. Several methods and devices were developed to test the amount of the tibial translation. Among other things, tibial translation depends on the status of the cruciate ligaments. When the cruciate ligaments are examined, the patient usually sits down or lies on the back with the leg unloaded and the knee joint muscles relaxed (DANIEL et al. 1985, ANDERSON/LIBSCOMP 1989). The examination focuses on the passive stability of the knee joint. Measurement of the passive stability of the ankle joint cannot give an exact description of the active stability of the ankle joint during functional situations (GOLLHOFER et al. 1993, LOHRER et al. 1993, SCHEUFFELEN et al. 1993). Measurement of the functional stability of the knee joint gets more and more a subject of interest (LYSHOLM et al. 1994, PFEIFFER et al. 1996). At the same time the examination methods that are used remain the same as those used during examination of passive stability. We have developed a device to measure the tibial translation of the knee joint. The purpose of the study was to test our new device and the corresponding method in a simple functional situation like standing and to measure the functional stability of the knee joint. We measured the size of the tibial translation and the reflex activities of the knee joint muscles in dependence on aclstatus, load of the leg and size and dynamic of the applied mechanical stimulus.