L5.5.7.2.1: Posterior Upper Thigh (Buttocks)

• POSTERIOR UPPER THIGH (BUTTOCKS)

  [a] Gluteus Medius

  [b] Gluteus Maximus

  [c] Vastus Lateralis

  Hamstring Group:

  [d] Biceps Femoris

  [e] Semitendinosus

  [f] Semimembranosus

  [g] Adductor Magnus

  [g]

  
• Gluteus Medius

  ○ Runs from the ilium to the femur, beneath the gluteus maximus

  ○ Hip abductor

  ○ Important in steadying the pelvis during walking

  ○ Important site for giving intramuscular injections, particularly when administering more than 5 ml
• Biceps Femoris

  ○ Lies in the posterolateral aspect

  ○ Arises proximally by two heads; long head (superficial) and short head (deep)
• Semitendinosus

  ○ Located at the posterior and medial aspect of the thigh

  ○ Have a long tendon of insertion
• Semimembranosus

  ○ Relatively large muscle that originates from a small facet on the rough superolateral surface of the ischial tuberosity

  ○ Tendon of semimembranosus appears at the level of the mid-thigh and continues caudally toward the point of insertion at the medial condyle of the tibia
• Adductor Magnus

  ○ Large triangular muscle with a proximal tendinous attachment to the inferior ramus of the pubis, the ramus of the ischium, and the ischial tuberosity