Lower limb muscles Flashcards
Coccygeus
O: ischial spine
I: coccyx
A: Support pelvic viscera; aids in continence
N: S3,S4
Piriformis
O: Pelvic surface of sacrum between 2nd, 3rd and 4th anterior sacral foramina; pelvic surface of sacrotuberous ligament; gluteal surface of ilium
I: Superior border of greater trochanter of femur
A: Lateral rotation of extended thigh; abduction of flexed thigh
N: L5,S1,S2
Internal obturator
O: Inner surface of obturator membrane; margin of obturator foramen
I: medial surface of greater trochanter
A: Lateral rotation of the hip; extension
N: L5, S1, S2
Deep transverse perineii
O: ischial ramus and tuberosity
I: perineal body
A: fixation of the perineal body and pelvic support
N: Pudendal nerve
Superficial transverse perineii
O: ischial ramus and tuberosity
I: perineal body
A: provides support to pelvic floor and perineal body
N: Pudendal nerve
Ischiocavernosus
O: ischial tuberosities and ischial pubic ramus
I: penis on men; corpora cavernosa and crura of the clitoris
A: compression of the clitoris or penis; maintains erection
N: pudendal n.
Bulbospongiosus
O: perineal body and fascia of the bulb of the vestibule (women); central tendinous point and the midline raphe on the bulb of the penis (men)
I: perineal membrane (both); corpus cavernosum (females); dorsal surface of corpus spongiosum and the deep penile fascia (males)
A: compress the vestibular bulb and constricts the vaginal orifice (females); compress the bulb of the penis and compress the spongy urethra (males)
N: pudendal n.
External anal sphincter
O: perineal body
I: anococcygeal body
A: constricts the anal canal
N: pudendal
Gluteus medius
O: external surface of the ilium between the anterior and posterior gluteal lines
I: Lateral surface of greater trochanter
A: Hip abduction and stabilization of pelvis;
anterior part = flexion and IR
posterior pat = extension and ER
N: Superior gluteal (L4,5, S1)
Gluteus maximus
O: fascia of the gluteus medius; external surface of ilium behind post. gluteal line; fascia of erector spinae; dorsal surface of sacrum; lateral margin of coccyx; sacrotuberal ligament
I:
Upper fibers: posterior part of the ilitiotibial tract and the fasciae latae muscles
Lower fibers: the gluteal tuberosity of the proximal femur
A: extension of the femur when flexed; lateral stabilization of the hip and knee joints; external rotation of the femur
N: inferior gluteal n. (L5-S2)
Tensor fascia latae
O: anterior superior iliac spine and the anterior part of the iliac crest
I: iliotibial tract
A: tenses the fascia lata; abduction, flexion and internal rotation at the hip joint
N: superior gluteal n. (L5, S1)
Gluteus minimus
O: external surface of the ilium between the anterior and inferior gluteal lines
I: Greater trochanter of the femur
A: abduction of the hip and stabilization of the pelvis;
Anterior part: flexion and internal rotation
Posterior part: extension and external rotation
N: Superior gluteal n. (L5, S1)
Obturator internus
O: inner surface of the obturator membrane and the margin of the obturator foramen
I: medial surface of the greater trochanter above the trochanteric fossa
A: lateral rotation
N: L5-S2
Piriformis
O: pelvic surface of sacrum
I: superior border of the greater trochanter of the femur
A: external rotation; abduction and extension of the hip joint; stabilization of the hip
N: L5-S2
Quadratus femoris
O: lateral border of the ischial tuberosity
I: quadrate line below the intertrochanteric crest of the femur
A: external rotation and adduction of the hip joint
N: L4-S1