294 



THE ARTICULATIONS 



and extension movements at the elbow which is due to the oblique direction of the articular 

 surfaces of the bones. 



4. The antero-posterior spiral curve of the femoral condyles is such that the anterior part 

 is an arc of a greater circle than the posterior; hence certain ligaments which are tightened during 



Fig. 326. — Section of Knee, showing Crucial Ligaments in Extension. 



Anterior crucial ligament 



Intercondyloid eminence of tibia 



Transverse ligament 



Slip from lateral meniscus to femur 



(ligament of Wrisberg) 

 Posterior crucial ligament 



Latetal meniscus 



Coronary ligament 



Anterior tibio-fibular ligament 



extension are relaxed during flexion, and thereby a considerable amount of rotatory movement 

 is permitted in the flexed position. The axis of this rotation is vertical, and passes through the 

 medial intercondyloid tubercle of the tibia, so that the lateral condyle moves in the arc of a 

 larger circle than does the medial, and is therefore required to move more freely and easily; 



Fig. 327. — Crucial Ligaments in Flexion. 



Posterior crucial 



Anterior crucial 

 Medial meniscus 



Transverse ligament 



Slip from lateral cartilage to femur 

 Lateral meniscus 



Anterior tibio-fibular ligament 



hcjiro the shape of the lateral articular facet and the loose connection of the lateral meniscus 

 which i.s aduptcd to it. 



In extension, all the ligaments are on the stretch with the exception of the ligamentum 

 patolla; anfi front of the capHule. Kxtcii.sion is checked by both the crucial ligaments and the 

 collateral ligaments (figs. 325, A, B, and 320). 



