SACRAL PLEXUS Flashcards
Branches:
To the lower limb that leave the PELVIS through the GREATER SCIATIC FORAMEN
Sciatic (L4, L5, S1, S2 and S3)
Superior Gluteal (GLUTEUS MEDIUS/MINIMUS)
Inferior gluteal (GLUTEUS MAXIMUS)
Nerve to Quadratus femoris
Nerve to Obturator internus
Posterior cutaneous nerve of the thigh
Branches:
To the PELVIS MUSCLES, PELVIC VISCERA, and PERINEUM
Pudendal (S2, S3 and S4) - PERINEUM
Nerve to Piriformis
Pelvic Splanchnic nerves (S2, S3, and S4)
Supplies the skin on the lower medial part of the buttock
Perforating cutaneous nerve
Large nerve of the body
From L4-S3
Supplies NO structures in the gluteal region, skin of the foot and leg, posterior thigh muscles
SCIATIC NERVE
Results to weakened abduction of the thigh by gluteus medius
“wadding” gait, pelvis sags on the side of unsupported limb
(+) Trendelenburg sign
SUPERIOR GLUTEAL NERVE INJURY
Hip joint stability
Stability when a person stands on one leg with the foot of the opposite leg raised above the ground depends 3 factors
GLUTEUS MEDIUS and MINIMUS must be functioning normally
HEAD of the FEMUR must be located normally within the ACETABULUM
NECK of the FEMUR must be intact and must have a normal angle with the SHAFT of the FEMUR
Weakness in the ability to LATERALLY ROTATE and EXTEND THE THIGH AT HIP JOINT
Difficulty extending the thigh at the hip from a flexed position, as in CLIMBING STAIRS OR RISING FROM A CHAIR
Have a GLUTEUS MAXIMUS GAIT, in which patients thrust their torso posteriorly in an attempt to counteract the weakness of the gluteus maximus
INFERIOR GLUTEAL NERVE LESIONS
Susceptible to damage from an IM injection in the lower medial quadrant of the gluteus maximus muscle or it may be compressed as a result of a posterior dislocation of the femur
L5 and S1 roots are commonly compressed - pain radiates into the L5 and S1 derrmatomes of the leg and foot
SCIATIC NERVE LESIONS
Common site for intramuscular injections
Should be made on the SUPEROLATERAL PART OF THE BUTTOCK to avoid hitting nerves and vessels
INTRAGLUTEAL INJECTIONS
PIRIFORMIS MUSCLE irritates and places pressure on the SCIATIC NERVE causing pain in the buttocks and referring pain along the course of SCIATIC NERVE
PIRIFORMIS SYNDROME
Radiates down the back of thigh into the lower back
SCIATICA
May be damaged in the abdomen by an abscess of the PSOAS MAJOR
Weakness in the ability to flex the thigh at the hip
Weakness in the ability to extend the leg at the knee
Diminished PATELLAR TENDON REFLEX
FEMORAL NERVE LESIONS
May be lesioned during a surgical procedure of the leg to remove part of the great saphenous vein or may be lacerated as it pierces the wall of the adductor canal
Pain and Paresthesia in the skin of the medial aspect of the leg and foot
SAPHENOUS NERVE LESIONS
Most commonly lesioned in the pelvis
Patients are unable to adduct the thigh at the hip
Paresthesia in the skin of the medial thigh
OBTURATOR NERVE LESIONS
Lies on the POSTERIOR PELVIC WALL in front of the PIRIFORMIS MUSCLES
Formed by the ANTERIOR RAMI of L4 and L5 and S1-S4
NOTE: contribution from L4 joins L5 to form the LUMBOSACRAL TRUNK
Sacral plexus
