Iliosacral Dysfunctions — Opposite vs Same
ICOM Year 4 · Pelvic Dysfunction Overview · Google Classroom
= ROTATION
IN = ASIS moves IN (medial)
Long → Short = Posterior
The pelvis functions as an osteoarticular ring comprising the two innominates and the sacrum. Its primary role is force attenuation — managing descending forces (body weight) and ascending forces (ground reaction force and concussion).
Efficient force transmission depends on three interdependent mechanisms:
- Form closure — optimal bone geometry, joint congruence, and ligamentous integrity
- Force closure — dynamic compression via muscles and fascia (gluteus maximus, biceps femoris, thoracolumbar fascia)
- Neural control — appropriate motor, autonomic, emotional, and psychological regulation
The sacroiliac joint (SIJ) is part synovial, part syndesmosis. It is fundamental to force attenuation, elasticity during ambulation, and pelvic expansion during childbirth.
📚 ICOM Pelvic Dysfunction Overview, Year 4 Google ClassroomIliosacral dysfunction = the innominate moving on the sacrum. This is distinct from sacroiliac dysfunction (sacrum moving on the innominates).
Physiological lesions: Anterior rotation, Posterior rotation, Outflare, Inflare
Non-physiological lesions: Superior sheer (upslip), Inferior sheer (downslip), Pubic sheer, Pubic compression
📚 ICOM Pelvic Dysfunction OverviewRotations (ASIS and PSIS move in OPPOSITE directions)
| Dysfunction | PSIS | ASIS | SIFT | Leg Length | Mechanism |
|---|---|---|---|---|---|
| Anterior Rotation | Superior ↑ | Inferior ↓ | Positive ipsilateral | Long leg | Hip flexor tightness; prolonged sitting; hip extension |
| Posterior Rotation | Inferior ↓ | Superior ↑ | Positive ipsilateral | Short leg | Hamstring tightness; fall onto ischial tuberosity; hip flexion |
Flares (innominate rotates in transverse plane)
| Dysfunction | PSIS | ASIS | Leg Length | Description |
|---|---|---|---|---|
| Outflare | Medial | Lateral | Variable / neutral | Innominate rotates outward in transverse plane. ASIS flares OUT (lateral). |
| Inflare | Lateral | Medial | Variable / neutral | Innominate rotates inward in transverse plane. ASIS moves IN (medial). |
Innominate Sheers (ASIS and PSIS move in SAME direction)
| Dysfunction | PSIS | ASIS | SIFT | Leg Length | Mechanism |
|---|---|---|---|---|---|
| Superior Sheer (Upslip) | Superior ↑ | Superior ↑ | Positive ipsilateral | Short leg | Vertical jolt onto extended leg; fall onto ischial tuberosity; jumping |
| Inferior Sheer (Downslip) | Inferior ↓ | Inferior ↓ | Positive ipsilateral | Long leg | Traction injury; hanging from one leg; forceful hip distraction |
Pubic Dysfunction
| Dysfunction | ASIS/PSIS | SIFT | Clinical Features |
|---|---|---|---|
| Pubic Sheer | Asymmetric | Positive | Pubic ramus tender; inguinal ligament tender; groin tension; asymmetric pubic rami |
| Pubic Compression | Level | Positive or negative | Bilateral pubic rami tender; symphysis pubis tender; pain with adduction |
Standing: Observe iliac crests, PSIS levels, ASIS levels, SIFT (Standing Iliac Flexion Test / Stork test) — identifies which side is restricted.
Seated: Seated flexion test — patient seated, observe PSIS movement during forward flexion; positive = restricted side moves first/further.
Prone (after reseat): PSIS levels, sacral sulci depth, ILA (inferior lateral angle) levels, spring test for sacral mobility.
Supine: ASIS levels, pubic rami tenderness, ASIS compression (squish) and gapping, passive SI mobility, Weber-Barstow manoeuvre for true vs apparent leg length discrepancy, Supine-to-Sit test.
Supine-to-Sit Interpretation:
- METs (Muscle Energy Techniques): First-line for rotations, flares, and sheers — patient contracts against resistance to restore neutral position
- Shotgun technique: For pubic dysfunction — bilateral hip compression/distraction
- HVLAT: Anterior/posterior rotations; leg tug technique for upslip (superior sheer)
Patient Advice:
- Avoid crossed legs and prolonged unilateral standing
- Stairs: "Good to heaven, bad to hell" — lead with good leg going up, bad leg going down
- Pillow between knees when sleeping on side
- Hydrotherapy and ice for acute pain
- Core stability exercises (transversus abdominis, multifidus)
- SI belt if hypermobility or pregnancy-related instability
- Lifting while flexing with rotation (shovelling, golf swing)
- Prolonged unilateral stance (carrying child on one hip)
- Fall directly onto ischial tuberosity → posterior rotation or upslip
- Vertical jolt onto extended leg (jumping, missing a step) → superior sheer
- Hormonal ligamentous laxity (pregnancy, post-partum)
- Habitual asymmetry (habitual leg crossing, asymmetric sleep position)
From ICOM Pelvis Clinical Setting — absolute and relative contraindications:
- Fracture or dislocation of lumbars, pelvis, or lower extremity (LEX)
- Sacroiliitis / seronegative arthropathy / ankylosing spondylitis
- Infection, acute abdomen, pyrexia, local heat, raised PR (pulse rate)
- Tumours — osteosarcoma, fibroids, prostate cancer, pelvic malignancy
- Paget disease, osteoporosis (relative — modify technique)
- Pelvic DVT (deep vein thrombosis)
- Intermittent claudication / AAA (abdominal aortic aneurysm)
- UMN signs or cauda equina syndrome — immediate medical referral
- Bilateral leg weakness, numbness, or tingling (cauda equina)
- Bladder or bowel dysfunction — saddle anaesthesia (cauda equina emergency)
- Unexplained weight loss, night sweats, fever with pelvic pain (malignancy / infection)
- Severe unremitting pain not relieved by rest or position change
- History of cancer with new pelvic pain
- Acute trauma with suspected fracture or dislocation
- Signs of AAA — pulsatile abdominal mass, severe back/flank pain
- Progressive neurological deficit — refer immediately
- ICOM Pelvic Dysfunction Overview, Year 4 Google Classroom
- ICOM Pelvis Clinical Setting, Year 4 Google Classroom
- ICOM Lumbar Spine Dysfunction notes, Year 4
- ICOM Manipulation Notes Summary, Year 4
- Vleeming A et al. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J Anat. 2012;221(6):537–567.
- Greenman PE. Principles of Manual Medicine. 3rd ed. Lippincott Williams & Wilkins; 2003.
- DiGiovanna EL, Schiowitz S, Dowling DJ. An Osteopathic Approach to Diagnosis and Treatment. 3rd ed. Lippincott; 2005.
- Lee D. The Pelvic Girdle. 4th ed. Churchill Livingstone; 2011.