膝十字靭帯と大腿筋との機能的連携作用

大腿筋力と前十字靭帯伸び特性に関する3次元モデル解析

抄録

The objective of this study is to perform mathematical model analysis mainly dealing with the anterior cruciate ligament's (ACL) strain elicited by the thigh muscles' contraction, attempting to get a picture of the ligament-muscle synergism in the knee. A 3-D mathematical model taking into account movements and forces of the patellofemoral and tibiofemoral joints was described. Simulation was performed to determine a direct relationship between the thigh muscles' forces and ACL strain as a function of knee angle. The simulation results demonstrated that quadriceps contraction can result in an anterior displacement of the tibia in the range of 0 to 75° of flexion and a posterior displacement over 75°, and hamstrings contraction always causes a posterior displacement of the tibia irrespective of any knee flexion angles. The results on the influence of thigh muscle contraction on ACL strain were also obtained and it was concluded that quadriceps contraction has direct impact on ACL strain, and relatively low and variable levels of hamstrings co-activation can effectively reduce ACL strain. Furthermore it was found that the antagonistic effect of the hamstrings co-contraction is small as long as the knee angle is small. These results suggested that a reflex are between ACL and hamstrings could exist.