HIP-JOINT. 



299 



second phalanges than between the second and third. The movement of flexion 

 is very considerable, but the extension is limited by the anterior and lateral 

 ligaments. 



ARTICULATIONS OF THE LOWEE EXTREMITY. 



The Articulations of the Lower Extremity comprise the following groups: 



I. Hip-joint. V. Articulations of the Tarsus. 



II. Knee-joint. VI. Tarso-metatarsal Articulations. 



III. Articulations between the Tibia YII. Metatarso-phalangeal Articula- 



and Fibula. tions. 



IV. Ankle-joint. VIII. Articulations of the Phalanges. 



I. HIP-JOINT. (Fio. 205.) 



This articulation is an enarthrodial, or ball-and-socket joint, formed by the 

 reception of the head of the femur into the cup-shaped cavity of the acetabulum. 

 The articulating surfaces are covered with cartilage, that on the head of the 

 femur being thicker at the centre than at the circumference, and covering the 



Fig. 205. Left Hip-joint laid open, 



entire surface with the exception of a depression just below its centre for the 

 ligamentum teres ; that covering the acetabulum is much thinner at the centre 

 than at the circumference, being deficient in the situation of the circular de- 

 pression at the bottom of the cavity. The ligaments of the joint are the 



Capsular. Teres. 



Ilio-femoral. Cotyloid. 



Transverse. 



The Capsular Ligament is a strong, dense, ligamentous capsule, embracing 

 the margin of the acetabulum above, and surrounding the neck of the femur 

 below. Its upper circumference is attached to the acetabulum two or three 



