 The small saphenous vein ( SSV ) , runs along the posterior aspect of the leg as far as the popliteal region , in the upper calf . Here it enters the popliteal space which is located between the two heads of the gastrocnemius muscle where it usually drains above the knee joint in the popliteal vein or a little less often in the great saphenous vein ( GSV ) or other deep muscular veins of the thigh . The use of ultrasonography has allowed a number of variations to be shown at this level ; when no contact is made with the popliteal vein it might be seen to drain in the GSV , at a variable level ; or , it may merge with the Giacomini vein and drain in the GSV at the superior 1 / 3 of the thigh . It can also but rarely , drain in the vein of the semimembranosus ( thigh muscle ) ( shown below ) . Usually though , it connects with a perforator vein at its middle 1 / 3 . To check for insufficiency , the Paraná maneuver is very useful . 
