Musculoskeletal: Anatomy - Gluteal and posterior thigh regions Flashcards
Describe the gluteal ligaments
Posterior sacroiliac ligament (continuous inferiorly with sacrotuberous ligament)
Posterior sacrococcygeal ligaments
Sacrotuberous ligament
Sacrospinous ligament
How are the greater and lesser sciatic foramina formed and what is the significance of each?
Sacrotuberous ligament extends across sciatic notch, converting it into a foramen that is subdivided by the sacrospinous ligament and ischial spine into the greater and lesser sciatic foramen
Greater sciatic: structures travelling to and from pelvis
Lesser sciatic: structures travelling to and from perineum
Which muscle fills most of the greater sciatic foramen?
Piriformis
Four muscles of the superficial layer of the gluteal region
Gluteus maximus
Gluteus medius
Gluteus minimus
Tensor fascia latae
Five muscles of the deep layer of the gluteal region
Obturator internus
Piriformis
Superior gemellus
Inferior gemellus
Quadratus femoris
Describe the proximal attachment and actions of the superficial gluteal muscles generally
Proximal attachments to posterolateral (external) surface and margins of ala of ilium
Mainly extend, abduct and medially rotate the hip
Describe the distal attachment and actions of the deep gluteal muscles generally
Distal attachments to intertrochanteric crest
Lateral rotators and stabilise femoral head in acetabulum
Six lateral rotators of the thigh
Obturator externus (anterior compartment)
Obturator internus
Piriformis
Superior gemellus
Inferior gemellus
Quadratus femoris
Which three muscles form the triceps coxae?
Superior and inferior gemelli, and obturator internus
Proximal and distal attachments, innervation, and main actions of gluteus maximus
Proximal: ilium posterior to posterior gluteal line, dorsal sacrum and coccyx, sacrotuberous ligament
Distal: gluteal tuberosity, iliotibial tract
Innervation: inferior gluteal n. (L5, S1-2)
Actions: hip extension, assists in lateral rotation
Proximal and distal attachments, innervation, and main actions of gluteus medius
Proximal: ilium between anterior and posterior gluteal lines
Distal: lateral greater trochanter
Innervation: superior gluteal n. (L5, S1)
Actions: hip abduction and medial rotation
Proximal and distal attachments, innervation, and main actions of gluteus minimus
Proximal: ilium between anterior and inferior gluteal lines
Distal: anterior greater trochanter
Innervation: superior gluteal n. (L5, S1)
Actions: hip abduction and medial rotation
Proximal and distal attachments, innervation, and main actions of obturator internus
Proximal: pelvic surface of obturator membrane and surrounding bones
Distal: medial greater trochanter (trochanteric fossa)
Innervation: nerve to obturator internus (L5, S1)
Actions: abduction of flexed thigh and lateral rotation of extended thigh, steadies femoral head in acetabulum
Proximal and distal attachments, innervation, and main actions of superior gemellus
Proximal: ischial spine
Distal: medial greater trochanter (trochanteric fossa)
Innervation: nerve to obturator internus (L5, S1)
Actions: abduction of flexed thigh and lateral rotation of extended thigh, steadies femoral head in acetabulum
Proximal and distal attachments, innervation, and main actions of inferior gemellus
Proximal: ischial tuberosity
Distal: medial greater trochanter (trochanteric fossa)
Innervation: nerve to quadratus femoris (L5, S1)
Actions: abduction of flexed thigh and lateral rotation of extended thigh, steadies femoral head in acetabulum
Proximal and distal attachments, innervation, and main actions of piriformis
Proximal: anterior sacrum and sacrotuberous ligament
Distal: superior greater trochanter
Innervation: anterior rami S1-2
Actions: abduction of flexed thigh and lateral rotation of extended thigh, steadies femoral head in acetabulum
Proximal and distal attachments, innervation, and main actions of quadratus femoris
Proximal: lateral ischial tuberosity
Distal: quadratus tubercle on intertrochanteric crest
Innervation: nerve to quadratus femoris (L5, S1)
Actions: lateral rotation of thigh, steadies femoral head in acetabulum
Proximal and distal attachments, innervation, and main actions of tensor fascia latae
Proximal: ASIS, anterior iliac crest
Distal: iliotibial tract to lateral tibial cond0yle
Innervation: superior gluteal n. (L5, S1)
Actions: hip abduction and medial rotation
Three bursae associated with gluteus maximus
Trochanteric bursa: separates from greater trochanter (largest, present at birth)
Ischial bursa: separates from ischial tuberosity
Gluteofemoral bursa: separates iliotibial tract from vastus lateralis