Pelvis contents

• Psoasorigin, insertion, joint crossed, position, and action


  • Ant. & lat. lumbar spine
  • Lesser trochanter of femur
  • Hip
  • Ant. & vertical, therefore flexion (sag. plane)
• Iliacusorigin, insertion, joint crossed, position, and action


  • Ant aspect of iliac bone
  • Lesser trochanter of femur
  • Hip
  • Ant. & vertical, therefore flexion (sag. plane)
• Obturator internusorigin, insertion, joint crossed, position, and action


  • Internal surface of obturator membrane
  • Trochanteric fossa or posterior aspect of greater trochanter of femur
  • Hip
  • Horizontal & posterior, therefore external rotation
• Piriformisorigin, insertion, joint crossed, position, and action


  • Interior aspect of sacrum
  • Greater trochanter of femur
  • Hip
  • Horizontal & posterior, therefore external rotation
• Pelvic openings to lower limb(4)

  • Posterior: lesser sciatic foramen, greater sciatic foramen
  • Anterior: deep to inguinal ligament
  • Medial: obturator canal
• Lesser sciatic foramen communication


  Communicates between perineum and true pelvis
• Greater sciatic foramen communication

  Communicates between true pelvis and gluteal region (post. thigh)
• Anterior opening deep to inguinal ligament communication

  Communicates between false pelvis and ant. thigh
• Obturator canal communication


  Communicates between true pelvis and med. thigh
• External iliac vein origin, termination, and relationships


  • Origin: tributary of common iliac vein (V3)
  • Termination: continuation to femoral vein proximal to inguinal ligament (V3)
  • Relationships: through false pelvis, accompanies external iliac artery & femoral nerve (V4)
• Major nerves (4) and their ventral rami

  • Femoral (posterior L2-L4)
  • Obturator (anterior L2-L4)
  • Common peroneal (posterior L5-S2)
  • Tibial (anterior L5-S3)
• Relocation of major muscle groups

  • Extensor (dorsal) muscles to anterior surface
  • Flexor (ventral) muscles to posterior surface
• Femoral nerve (post. division of ant. rami)


  Exits deep to inguinal ligament, innervates muscles in anterior thigh, major action is to extend knee
• Obturator nerve (ant. division of ant. rami)


  Exits obturator canal, innervates muscles in medial thigh, major action is to adduct hip
• Superior gluteal nerve (post. division of ant. rami)

  Exits greater sciatic foramen, innervates muscles in gluteal region, major action is to abduct hip
• Inferior gluteal nerve (post. division of ant. rami)

  Exits greater sciatic foramen, innervates muscles in gluteal region, major action is to extend hip
• Tibial nerve (ant. division of ant. rami)


  Exits greater sciatic foramen, innervates muscles in posterior thigh/leg, major actions are to flex knee and ankle
• Common peroneal nerve (post. division of ant. rami)


  Exits greater sciatic foramen, innervates muscles in anterior leg, major action is to dorsiflex (extend) ankle
• Contents of pelvic exits (to lower limb)

  • Deep to inguinal ligament: femoral & lymphatics, femoral nerve, LCNT, iliopsoas
  • Obturator canal: obturator & lymphatics, obturator nerve
  • Greater sciatic foramen: gluteal & lymphatics, sciatic, gluteal nerves, PCNT, n. obt int, n. quadratus femoris, piriformis
  • Lesser sciatic foramen: obturator internus
• Patient A has numbness of the skin over posterior thigh and weakness of ankle plantar flexors. Spinal level affected: S2
• Patient B has pins & needles of the skin over anteromedial shin and a diminished knee jerk reflex. Spinal level affected: L3
• Femoral artery


  Located on flexor surface of the hip joint, travels through femoral triangle bordered by inguinal ligament, stories muscle, and adductor longus muscle
• Popliteal artery

  Situated on flexor surface of knee joint, travels through popliteal fossa
• Dorsalis Pedi artery


  Situated on flexor surface of ankle joint, travels through tarsal tunnel, aka flexor retinaculum
• In a limb, major arteries are situated on the flexor surface of joints.
• External iliac artery


  Origin – Branch of common iliac a. at level L5-S1 IVD
• Femoral artery

  Origin- External iliac artery as it passes beneath the inguinal ligament
• Body wall and limbs have superficial and deep drainage systems in both venous and lymphatic systems
• Small/short saphenous vein


  Origin – lateral aspect of dorsal venous arch of foot, travels within subcutaneous layer of skin on posterior aspect of leg, Termination – drains into the popliteal v. at the popliteal fossa
• Great saphenous vein


  Origin – medial aspect of dorsal venous arch of foot, travels within subcutaneous layer of skin on anterior aspect of leg and thigh, Termination – drains into femoral vein at the level below the groin region
• Deep drainage is more important than superficial
• Superficial lymphatics follow veins; deep lymphatics follow arteries
• Superficial lymphatics are particularly important at picking up pathogens and drain into lymph nodes
• Skin


  • Usually thick and coarse (c.f. skin of thigh) particularly in males
• Adipose - hypodermis (formerly known as superficial fascia)


  • Characteristic shape of the buttock largely due to the pad of adipose tissue in the gluteal region
  • Both males and females deposit adipose in the gluteal region
  • Adipose deposition can be highly variable
• Lymph nodes where superficial lymphatics drain

  • Horizontal inguinal group – drain gluteal region, lower abdomen & genital region
  • Vertical inguinal group – drain tissues along course of GSV
  • Popliteal group – drain tissues along course of SSV
• Fascia lata - deep fascia of the gluteal region and thigh


  • Attaches onto bony prominences and ligaments of the pelvis
  • Encloses gluteus maximus and tensor fasciae latae muscles
  • Both muscles insert onto it at iliotibial tract
• A painful or swollen lymph node


  May indicate spread of infection or disease from the region drained by the lymphatics which pass through the lymph node
• Iliotibial tract (ITT)


  • Lateral thickening of the fascia lata
  • Attached to femur via the lateral intermuscular septum (IMS) of the thigh
• With an infected cut on the little toe, the popliteal group of lymph nodes are likely to become inflamed.