Pelvic Girdle

PELVIC GIRDLE PHYR144 Fall 2009

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Osteology 4 bones: • Sacrum • Coccyx • 2x hip bones – Ilium – Ischium – Pubis

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Arthrology • Right and left SI Joints • Symphysis pubis • L/S joint

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Functions • Supports upper half of body • Transmits ground forces from ambulation • Origin of powerful hip mm • Protects internal organs

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Defiinitions • Pelvic inlet- from sacral promontory to pubic symphysis • Pelvic outlet- from tip of coccyx to inferior pubic symphysis, • False pelvis- area between iliac crests above inlet • True pelvis- between inlet and outlet, contains intestines, reproductive organs 6

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Sacroiliac joint • Synovial joint w/ irregular surfaces – Can become in inflamed, painful

• No axis of rotation- linear mov’t • Very stable/ little mobility – Keystone shaped

• Transmits weight of upper body to hip bones • Reinforced by very strong ligaments 8

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Joint motion • Nutation (nodding)/ flexion – base of sacrum moves anteriorly/ inferiorly – Increases size of pelvic outlet – Occurs with trunk flexion/ hip extension

• Counternutation/ extension – base of sacrum moves posteriorly/ superiorly – Increases size of pelvic inlet – Occurs with trunk extension / hip flexion 10

Pelvic Girdle motions Saggital Plane • Anterior tilt: – PSIS moves superiorly, ASIS moves anterior and inferior – L/S hyperextends, hips flex

• Posterior tilt: – PSIS moves inferiorly, ASIS moves posteriorly and inferiorly – L/S flexes (loss of lordosis), hips extend 11

Pelvic Girdle motions Frontal Plane • Lateral (side) tilt: – Unsupported side is point of reference – Unsupported side drops during swing (unweighted) phase – Prevents rise of COG – Hip adduction on WB side – Hip abduction on NWB side 12

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Pelvic Girdle motions Transverse Plane • Pelvic rotation: – Unsupported side is point of reference – Pelvis moves in concert with the lower limb – Hip rotation: • Lateral with forward limb mov’t • Medial with backward mov’t (toe off)

– Spine rotation occurs in opposite direction 14

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Muscle control • Anterior tilt: lumbar extensors, hip flexors • Posterior tilt: lumbar extensors, hip flexors • Tilt: hip abductors on WB side, lateral trunk mm – Weakness• Trendelenburg • Compensated Trendelenburg

• http://www.youtube.com/watch?v=0Z6hW 16

LANDMARKS Anterior superior iliac spine (ASIS) • Partner standing • Fingers on side of hips, run thumbs up until you feel inferior aspect of ASIS • Note relative height and prominence

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LANDMARKS Iliac crest • Partner standing • Thumbs on ASIS, move fingers superior, then slide down until you palpate bone • Place index finger on crests • Note relative height and prominence • Alt: have partner in sidely as in page 287, fig 6.28

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LANDMARKS Posterior superior iliac spine (PSIS) • Partner standing or prone • Fingers on side of hips, run thumbs up until you feel inferior aspect of PSIS • Note relative height and prominence in standing

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LANDMARKS Ischial tuberosity • Partner prone • Push superiorly at midpoint of gluteal fold • May have partner extend hip

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LANDMARKS Greater trochanter • Partner prone • From middle of iliac crest slide fingers until you palpate large bony bump • Confirm by having partner rotate hip (passively or actively)

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