Pelvic Structure and Function: Support, Stability, and Reproduction

The bony pelvis (ilium, ischium, pubis, sacrum, coccyx) forms a basin‑shaped ring with critical mechanical and physiological roles.

Primary Functions

1. Visceral support: Cradles bladder, rectum, and reproductive organs (uterus/prostate, vagina/seminal vesicles).
2. Load transfer: Transmits axial skeleton weight to femoral heads (via sacroiliac joints and hip joints) during stance/gait.
3. Muscle attachment: Origin/insertion for core (abdominals, pelvic floor), hip (gluteals, rotators, adductors), and thigh muscles.
4. Protection: Bony ring shields pelvic viscera from external trauma.
5. Childbirth (female): Birth canal dimensions (inlet, midplane, outlet) determined by pelvic morphology (gynecoid, android, anthropoid, platypelloid).
6. Postural stability: Pelvic orientation (tilt, rotation) governs lumbar lordosis and spinal alignment.

Sexual Dimorphism

Clinical Relevance

• Pelvic floor dysfunction (incontinence, prolapse) → pelvic floor PT.
• SI joint pain → ligamentous strain, pregnancy, trauma.
• Fractures → high‑energy trauma; assess urethral/rectal/neurovascular injury.
• Obstetric planning: pelvimetry (clinical/imaging) if indicated.

The pelvis is the keystone of the axial‑appendicular interface—integrating locomotion, continence, and reproduction.