Recording-2025-07-21T13:27:45.170Z

Articulations of the Pelvic Girdle & Hip

• Pubic Symphysis  • Type = symphysis (fibro-cartilaginous disc).  • Formed by L & R innominate bones anteriorly.  • Motion: minimal translatory glide; can become slightly mal-aligned in sport.
• “Shot-gun/shot-clock” athletic trainer technique → patient performs resisted hip adduction to ‘click’ joint back; audible pop likened to a shotgun.
• Acetabulofemoral (Hip) Joint  • Type = multi-axial synovial (ball-and-socket).  • Articulation = femoral head ✕ acetabulum.  • Primary link between trunk & lower limb → transmits body weight to femur.  • Inherently very stable: deep socket + thick capsule + multiple ligaments.
• Dislocation uncommon; typically high-energy (e.g., “dashboard injury” where tibia → femur → posterior dislocation).

Palpable Bony Landmarks

• Proximal Femur – only structure reliably palpable = greater trochanter.
• Pelvis (anterior → posterior)  • ASIS (anterior superior iliac spine)  • AIIS (inferior to ASIS)  • Iliac crest (runs ASIS→PSIS)  • PSIS (often marked by ‘dimples’).  • PIIS (inferior to PSIS)  • Ischial tuberosity (“sit bone”; hamstring origin).  • SI joint (junction of sacrum & ilium just medial to PSIS).

Musculature

Regional Grouping

• Iliac / Anterior region • Medial (Adductor) region • Posterior region → superficial vs deep.

Anterior / Iliac Muscles

• Pectineus (also listed medial).  • O: anterior pubis (1 inch above crest).  • I: pectineal line to linea aspera.  • A: hip flexion + adduction + ER.  • N: femoral n.
• Iliopsoas = psoas major, psoas minor, iliacus.  • Iliacus – O: inner iliac fossa → I: lesser trochanter. (Hip flexion; femoral n.)  • Psoas major – O: T12–L5 bodies & TPs → lesser trochanter. (Hip flexion + lumbar flexion + ER; anterior rami L1-L3 plus femoral branches).  • Psoas minor – O: T12–L1 → pectineal line; does NOT cross hip → lumbar flexion only.
• Sartorius (“hacky-sack muscle”).  • O: ASIS → I: pes anserinus (anteromedial tibia).  • A: hip flexion + knee flexion + hip ER + hip abduction (+ ant pelvic tilt).  • N: femoral n.

Medial (Adductor) Muscles – mnemonic “Great Major League Baseball Pitcher”

• Gracilis (G) – O: pubic ramus → I: pes anserinus; hip adduction & IR; weak knee flex; obturator n.
• Adductor Magnus (M) – broad origin pubis & ischium → whole linea aspera to adductor tubercle; hip adduction + ER + assist hip extension; ant fibers obturator n., post fibers sciatic n.
• Adductor Longus (L) – O: pubis below crest → mid-linea aspera; adduction + ER; obturator n.
• Adductor Brevis (B) – O: inf pubic ramus → lower pectineal line & upper linea aspera; adduction + ER; obturator n.
• Pectineus (P) – (already above).

Posterior Muscles – Superficial

• Gluteus Maximus  • O: posterior ilium crest (¼), sacrum, coccyx, TL fascia.  • I: gluteal tuberosity & ITB.  • A: powerful hip extension, posterior pelvic tilt, ER.  • N: inferior gluteal n.
• Tensor Fascia Latae (TFL; “Starbucks muscle”).  • O: ant iliac crest & ASIS area.  • I: IT-band → Gerdy’s tubercle (anterolateral tibial condyle).  • A: hip abduction & IR.  • N: superior gluteal n.

Posterior Muscles – Deep Layer

• Gluteus Medius – O: lateral ilium below crest → post-middle greater trochanter; hip abd + ext; superior gluteal n.
• Gluteus Minimus – O: ilium below medius → ant greater trochanter; hip abd + IR; superior gluteal n.
• PGOGOQ (deep ER set)  • Piriformis (P) – O: anterior sacrum → sup greater trochanter; ER; S1-S2.  • Gemellus Superior (G) – O: ischial spine → GT; ER; sacral plexus.  • Obturator Internus (O) – O: obturator foramen margin → GT; ER; sacral plexus.  • Gemellus Inferior (G) – O: ischial tuberosity → GT; ER.  • Obturator Externus (O) – O: ext obturator foramen → GT; ER; obturator n.  • Quadratus Femoris (Q) – O: ischial tuberosity → intertrochanteric crest; ER; sacral plexus.

Functional / Clinical Concepts

• Tight external rotators & glute max limit hip internal rotation → affects activities like soccer curve-kick.
• Dislocation position (posterior): hip flexed, adducted, internally rotated; ligaments (iliofemoral ± ischiofemoral) torn; e.g., Tua Tagovailoa injury.
• IT-Band is fascial, not contractile – foam-rolling mainly compresses; treatment should focus on TFL & glute weakness.

Ligaments & Labrum

• Superior Pubic Ligament & Inferior (Arcuate) Pubic Ligament – span above/below pubic symphysis; stabilize.
• Inguinal Ligament (Poupart) – ASIS → pubic tubercle; roof of femoral triangle; landmark for hernia & vessel passage.
• Iliofemoral (“Y-ligament of Bigelow”) – AIIS → intertrochanteric line; strongest ligament in body; limits hyper-extension.
• Pubofemoral – obturator crest/pubis → intertrochanteric line; limits abduction, extension, ER.
• Ischiofemoral – posterior acetabulum → posterior intertrochanteric line; limits internal rotation.
• Ligamentum Teres (round ligament) – acetabular notch → fovea capitis; conduit for blood to femoral head, prevents inferior displacement.
• Acetabular Labrum – fibro-cartilage ring deepens socket ↑ stability.

Bursa

• Major clinical bursa = trochanteric bursa (over greater trochanter). Others rarely symptomatic.

Neurovascular Supply

Arteries

• Common Iliac → splits into Internal & External Iliac arteries.
• Internal Iliac → superior gluteal a., inferior gluteal a., obturator a. (supplies pelvic & gluteal structures).
• External Iliac → passes under inguinal ligament → becomes Femoral a. (principal lower-limb supply).  • Femoral a. enters femoral triangle, travels through adductor canal, exits at adductor hiatus → popliteal a.