Controlling Anterior Shear During lsokinetic Knee Extension Exercise.
The purpose of this paper is to present a means of controlling anterior shear force at the knee during isokinetic exercise. A dual-pad attachment to existing exercise equipment allows selection of the degree of anterior shear placed on the knee during exercise, ranging from a value which apparently places minimal stress on ligamentous restraints, through intermediate shear levels, to a value nearly that of standard exercise equipment. The special problems associated with anterior cruciate ligament (ACL) involvement are reviewed in terms of ACL function, failure, and healing. Calculated loading configurations illustrate the effect on shear afforded by the device. A pilot roentgenographic study indicates restoration of normal tibiofemoral alignment and joint surface velocity vectors during isometric extension with the device. This preliminary finding correlates with clinical observation. Clinical application includes isokinetic exercise of the chronically lax knee and rehabilitation of the knee after ACL repair or reconstruction. J Orthop Sports Phys Ther 1982;4(1):23-31.
Johnson
D
D