Sacrum Pelvis Hip Muscles Flashcards
Gluteal Region Muscles:
Gluteus Maximus:
O: posterior gluteal line of the ilium and portion of the bone superior & posterior to it (iliac crest), posterior surface of the lower part of the sacrum, side of the coccyx, aponeurosis of the erector spinae, sacrotuberous ligament, and gluteal aponeurosis
I: larger proximal portion and superficial fibers of the distal portion of the muscle into the iliotibial tract of the tensor fascia lata
I: smaller distal portion deep fibers into the gluteal tuberosity of the femur
A: extends & laterally rotates the hip joint, helps to stabilize knee in extension via its insertion into the IT band
lower fibers: assists in adduction of hip
upper fibers: assists in abduction of hip
N: inferior gluteal nerve (L5, S1, S2)
Muscle Testing: Gluteus Maximus:
Patient: prone, knee flexed to 90 degrees
Fixation: posteriorly: the back muscles, laterally: the lateral abdominal muscles, anteriorly: the opposite hip flexors
Test: hip extension with knee flexed
Pressure: against lower part of posterior thigh
Gluteal Region Muscles
Gluteus Medius:
O: external surface of the ilium between the iliac crest & the posterior gluteal line dorsally and the anterior gluteal line ventrally & the gluteal aponeurosis
I: oblique ridge on the lateral surface of the greater trochanter of the femur
A: abduction of hip joint
the anterior fibers medially rotate and may assist in flexion of the hip joint
the posterior fibers laterally rotate and may assist in extension of hip joint
N: superior gluteal nerve (L4, L5, S1)
Muscle Testing: Gluteus Medius:
Patient: side-lying, bottom leg flexed at hip & knee, pelvis is rotated slightly forward
Fixation: examiner stabilizes the pelvis
Test: abduction of the hip with slight extension and slight external rotation. Knee is maintained in extension
Pressure: against the leg, near ankle
Gluteal Region Muscles:
Gluteus Minimus:
O: external surface of the ilium between the anterior & inferior gluteal lines & th margin of the greater sciatic notch
I: anterior border of the greater trochanter of the femur & hip joint capsule
A: abducts, medially rotates and may assist in flexion of the hip joint
N: superior gluteal nerve (L4, L5, S1)
Muscle Testing: Gluteus Minimus:
Patient: side-lying
Fixation: examiner stabilizes the pelvis
Test: abduction of the hip in neutral (no extension or external rotation)
Pressure: against the leg
Gluteal Region Muscles - External Rotators:
Piriformis:
O: pelvic surface of the sacrum close to S1-S4 sacral foramina, margin of the greater sciatic foramen and the pelvic surface of the sacrotuberous ligament
I: superior border of the greater trochanter of the femur
A: lateral rotation of hip, abduction of hip when the thigh is flexed
N: sacral plexus- nerve to the piriformis (L5, S1, S2)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Gluteal Region Muscles - External Rotators
Superior Gemellus:
O: external surface of the spine of the ischium
I: with the tendon of the obturator internus into the medial surface of the greater trochanter of the femur
A: lateral rotation of hip, abduction of thigh when hip is flexed
N: sacral plexus-nerve to obturator internus (L5, S1, S2)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Gluteal Region Muscles - External Rotators
Obturator Internus:
O: internal or pelvic surface of the obturator membrane and margin of the obturator foramen, pelvic surface of the ischium posterior and proximal to the obturator foramen
I: medial surface of the greater trochanter of the femur, proximal to the trochanteric fossa
A: lateral rotation of hip joint, abduction of thigh when hip is flexed
N: nerve to obturator internus, sacral plexus (L5, S1, S2)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Gluteal Region Muscles - External Rotators
Inferior Gemellus:
O: proximal part of the tuberosity of the ischium
I: with the tendon of the obturator internus into the medial surface of the greater trochanter of the femur
A: lateral rotation of hip; abduction of thigh when the hip is flexed
N: sacral plexus- nerve to quadratus femoris(L4, L5, S1, S2)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Gluteal Region Muscles - External Rotators
Obturator Externus:
O: rami of the pubis and ischium and the external surface of the obturator membrane
I: trochanteric fossa of femur
A: lateral rotation of the hip joint, weak adduction of thigh
N: obturator nerve (L3, L4)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Gluteal Region Muscles - External Rotators
Quadratus Femoris:
O: proximal part of the lateral border of the tuberosity of the ischium
I: proximal part of the quadrate line (see next slide), extending distally from the intertrochanteric crest
A: lateral rotation of hip joint, adduction of thigh (weak action)
N: sacral plexus-nerve to quadratus femoris (L4, L5, S1, S2)
Muscle Testing: Lateral or External Rotators:
Patient: sitting, knees bent
Fixation: weight of trunk stabilizes
Test: lateral rotation of the thigh at the hip
Pressure: examiner applies counter pressure at lower leg on the medial side
Pelvic Floor Muscles
Ischiocavernosus Muscle
Bulbospongiosus (bulbocavernosus) Muscle
Transverse perineal Muscles
Levator Ani Muscles
Male Pelvic Muscles:
- Cremaster (connected to internal oblique muscle)
surrounds each testicle
contracts to raise or lower the testicles (raising them brings them closer to the body and warms them up, lowering them does the opposite)
- Dartos
surrounds the penis, foreskin and scrotum
contracts to wrinkle the scrotal skin to reduce heat loss, relaxes them does the opposite.
