MUSCULAR AND TIBIOFEMORAL JOINT FORCES DURING ISOKINETIC CONCENTRIC KNEE EXTENSION

The purpose of this study was the examination of muscular and tibiofem oral forces during concentric isokinetic knee extension at angular vel ocities ranging from 30 to 210 deg s(-1) using a two-dimensional biome chanical model. Five males without knee joint injury history participa ted in the study. The maximum moment ranged from 226.2 Nm at 30 deg s( -1) to 166.4 Nm at 210 deg s(-1). The maximum muscular force ranged fr om 7.5 times body weight at 30 deg s(-1) to 5.7 at 210 deg s(-1). The compressive tibiofemoral force ranged from 7.5 times body weight at 30 deg s(-1) to 5.7 at 210 deg s(-1) and the shear tibiofemoral force ra nged from 0.9 to 0.8 times body weight respectively, These results ind icate that the forces developed during maximal isokinetic knee extensi on are significantly reduced relative to other powerful dynamic activi ties but are higher than joint forces during simple walking and cyclin g activities. Appropriate precautions and adjustment of the isokinetic protocol are required in the final phases of joint injury rehabilitat ion.