72 ANTHROPOLOGY. 



leading from the lesser troctianter to the linea aspera. Use : to adduct and 

 flex the thigh and to rotate it inwards. 



Triceps adductor femoris consists of the three following portions, which 

 pass in distinct laminae from the pelvis to the thigh : 



Adductor longus, flat and triangular, situated at the upper and internal 

 part of the thigh, arising from the anterior surface of the pubes, and inserted 

 into the middle third of the linea aspera. 



Adductor brevis, arising from the anterior inferior surface of the pubes, 

 and inserted into the superior third of the internal root of the linea 

 aspera. 



Adductor magnus, the largest and longest of the three, arising from the 

 anterior surface of the descending ramus of the pubes, and from the ramus 

 of the ischium, and inserted into the rough ridge leading from the great 

 trochanter to the linea aspera. The three adductors, in addition to adduct- 

 ing the limb, can rotate it outwards. They also serve to support and 

 steady the pelvis on the thigh ; likewise to flex and extend the thigh on the 

 pelvis. 



3. Muscles of the back part of the Thigh. They are only three in 

 number, and are commonly called hamstrings ; the semi-tendinosus and 

 semi-membranosus form the inner, the biceps the outer hamstring. 



Biceps flexor cruris consists of a long and a short head. The former arises 

 from the outer and back part of the tuber ischii in common with the semi- 

 tendinosus, and about the inferior third of the thigh it joins the short head 

 which arises from the linea aspera. The tendon of the common muscle 

 descends behind the knee, then turning forwards and outwards, is inserted 

 into the head of the fibula. Use : to flex the knee joint, to extend the 

 thigh, and rotate the limb outwards. It also assists in raising the body 

 when bent in, and in maintaining the erect posture. 



Semi-tendinosus arises from the tuberosity of the ischium, and is inserted 

 into the anterior angle of the tibia below its tubei'cle. Use: to flex the 

 knee, and rotate the leg inwards ; also to extend the thigh, to support the 

 pelvis, and prevent the trunk from bending forwards. 



Semi-membranosus^ beneath the preceding, arises from the upper and outer 

 part of the tuber ischii, and descending ends in a tendon, which passes 

 behind the internal condyle and divides into three processes. The first is 

 inserted into the external condyle of the femur ; the second is inserted into 

 the posterior part of the tibia and fibula, and is also continuous with the 

 deep fascia of the leg ; the third is inserted into the head of the tibia. Use: 

 to extend the thigh on the leg, to flex and rotate the knee, and to strengthen 

 the back part of the joint. 



4. Muscles of the anterior and external part of the Leg. The 

 muscles on the fore part of the leg are four in number, viz. the tibialis anti- 

 cus, extensor pollicis, extensor communis digitorum, and peronseus tertius. 

 Those on the outer side of the leg are the peronseus longus and brevis. 



Tibialis anticus, on the outer side and next to the tibia, arises from the 

 outer part of the superior two thirds of the tibia, from the head of the fibula, 

 and from the interosseous ligament; it is inserted into the inner side of the 

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