Lower Extremity

• iliohypogastric nerve

  roots: L1 (contributions from T:12) ; Functions: innervates internal oblique and transverse abdominis
• ilioinguinal nerve

  roots: L1 ; Functions: innervates the internal oblique and transverse abdominis
• genitofemoral nerve

  roots: L1-L2 ; Functions: innervates the cremasteric muscle
• lateral femoral cutaneous nerve

  roots: L2-L3
• obturator nerve

  roots: L2-L4 ; functions: motor supply to medial thigh muscles
• femoral nerve

  roots: L2-L4 ; function: motor supply to anterior thigh muscles
• nerve plexus

  branching network of intersecting(anastomosing) nerves; made up of anterior (ventral rami) spinal nerves
• axons in the posterior rami innervate

  paravertebral muscles, posterior parts of vertebrae and overlying cutaneous areas
• axons in the anterior rami innervate

  the skeletal, muscular, and cutaneous areas of the limbs and the anterior and lateral trunk
• peripheral region

  lateral
• spinal region

  medial
• cervical plexus roots

  C1-C4
• brachial plexus roots

  C5-T1
• lumbar plexus roots

  L1-L4
• sacral plexus roots

  S1-S4
• oblique angle of femur creates

  strain on the femoral neck
• anterior compartment of knee

  hip flexors and knee extensors; innervated: femoral n.; BS: fem a., deep fem. a., lat. circumflex a.
• main vascular supply of the thigh

  medial and lateral circumflex arteries
• femoral triangle contents

  femoral nerve, femoral artery, femoral vein; retroinguinal space: holds down structures passing anterior to the hip joint during flexion, ASIS to pubic tubercle
• medial compartment of the knee

  hip adductors; inn: obturator nerve; BS: deep femoral artery, medial and lateral circumflex arteries, and obturator arteries
• "rider's strain"


  strains of adductor longus; can have ossification of the tendons; due to active adduction
• x-ray

  taking multiple images from different perspectives, different views allow objects of interest in the series to be more complete; fluoroscopy: shows a continuous x-ray image on a monitor (x-ray movie); shorter wavelength and higher energy
• computed tomography (CT)

  spatial resolution
• magnetic resonance imaging

  contrast resolution
• lumbosacral joint

  between L5 and S1; strengthened by iliolumbar ligaments
• sacroiliac joint

  synovial; between sacrum and ilium; strengthened by: sacroiliac ligaments, sacrospinous ligament, sacrotuberous ligament
• pubic symphysis

  cartilaginous; between 2 pubic bones
• nutation

  clockwise; posterior pelvic tilt
• counternutation

  counterclockwise; anterior pelvic tilt
• greater sciatic foramen

  divided by piriformis
• cancellous bone of the hip

  optimal site for bone marrow aspiration
• weak small gluteals

  results in pelvic drop toward the opposite side OR shifted center of gravity towards weakness
• cutaneous innervation

  sensory
• synovial joint

  ball and socket; over 1/2 of the femoral head sits in the acetabulum
• anastomosis

  2 arteries connect
• fractures to the femoral head

  can cut off blood supply to the hip joint; cruciate anastomoses provide alternative routes in case of damage to blood vessels; damage of cruciate anastomoses could leas to avascular necrosis
• avascular necrosis

  caused by: fractures, over-injecting, sepsis; femoral head collapse
• Hilton's Law

  "the joint is supplies by branches from nerves supplying muscles acting on it"
• iliofemoral ligament (y ligament)


  strongest lig. of the hip joint (and the body); runs from AIIS and acetabular rim to the greater trochanter and intertrochanteric line; limits extension and external rotation of the hip
• pubofemoral ligament

  runs from superior pubic ramus and acetabular rim to the neck of the femur; limits extension and abduction of the hip; taut in extension