Sacral Mechanics PDF

Sacral Mechanics ROBIN R. DYER, D.O. JANUARY 10, 2024 Objectives Review the anatomy of the sacrum Review the axes of rotation within the pelvis Know the landmarks and the ‘Key Questions’ essential for diagnosing sacral dysfunctions Know the ligaments involved in flexed and extended unilateral dysfun...

Sacral Mechanics ROBIN R. DYER, D.O. JANUARY 10, 2024 Objectives Review the anatomy of the sacrum Review the axes of rotation within the pelvis Know the landmarks and the ‘Key Questions’ essential for diagnosing sacral dysfunctions Know the ligaments involved in flexed and extended unilateral dysfunctions and sacral torsions Know the findings indicative of: Left Sacrum Flexed (LSF) and Right Sacrum Extended (RSE) Left on Left Sacral Torsion (L/LST) and Left on Right Sacral Torsion (L/RST) Bilateral Sacrum Flexed and Bilateral Sacrum Extended. Autonomic nerve supply to pelvic organs SNS T12 - L4 Sacral sympathetic trunks PNS pelvic splanchnic (S2-4) sacral plexus supply left colon & pelvic viscera viscerosomatic symptoms in sacrum Lymphatic and venous flow Generally, follows arterial supply Lymphatic channels under sympathetic control Sciatic Nerve Muscular branch of sacral plexus (L4-S3) Close association with piriformis muscle Passes through greater sciatic notch (85%) just inferior to the muscle Piriformis hypertonicity can cause sciatica - pain referred to posterior thigh Organ Support Pelvic diaphragm obturator internus, pirformis, coccygeus, levator ani Urogenital diaphragm deep perineal & sphincter urethrae muscle/fascia Clinical Application Low back pain Pelvic pain Sciatica Constipation Dysmenorrhea Prostatitis Pregnancy / Labor LBP $100 BILLION/year (2016) 2nd MC reason to see Dr MC cause of Workers’ Comp disability Anatomical structures: Sacrum Lumbar Spine Fused vertebral elements Functionally part of vertebral axis Ilia Part of the innominate bone Functionally part of the lower extremity SI joint L-shaped articulation Arthrodial joint sacral side - hyaline cartilage ilial side - fibrocartilage Ligaments True Ligaments know anterior sacroiliac Stretched with FLEXION of sacrum and increased lordosis interosseous sacroiliac posterior sacroiliac Stretched with EXTENSION of sacrum and decreased lordosis Ligaments Accessory Ligaments Iliolumbar (L4-5 to iliac crest) *Sacrotuberous *Sacrospinous * Restrain anterior movement (FLEXION) of the sacrum Muscles Abdominal muscles, erector spinae, quadratus lumborum - provide stability Multifidi have expansions to the posterior sacroiliac and iliolumbar ligaments Hip extensors influence sacral motion via attachment to sacrotuberous AND sacrospinous ligaments Iliopsoas often involved in lumbopelvic dysfunction Piriformis - only muscle with direct attachment to sacrum Somatic Dysfunction of the Sacrum Motion loss within the normal range of motion Associated with TART Due to abnormal forces experienced during walking, running, lifting, etc. Direct trauma to legs or back May be compensatory (short leg, sprained ankle, knee pain…) Axis of rotation Superior transverse axis (STA) craniosacral flexion/extension & respiration (according to Mitchell, D.O.) Middle transverse axis (MTA) Spinal (postural) flexion/extension Inferior transverse axis (ITA) lower extremity & Innominate motion Left and Right oblique axis (LOA & ROA) walking & combined spinal motion RO A LO A ST A MT A IT A SACRAL AXES Osteopathic Terminology for Sacrum Flexion / Nutation - Anterior movement of the sacral base around a transverse axis in relation to the ilia Extension / Counter-Nutation - Posterior movement of the sacral base around a transverse axis in relation to the ilia Motion tests for Sacral Diagnosis L5 rotation (compensated = opposite sacral rotation) Seated Flexion Test (sacro-ilial motion …sacrum) Backward Bending Test (Sphinx or BBT… test the ability of sacrum to flex) Lumbar spring (sacral extension prevents lumbar spring or flexibility) Seated Flexion Test Operator monitors bilateral PSIS with thumbs as seated patient bends forward. The PSIS that ‘rides up’ is the dysfunctional side (positive side). This tests for sacroiliac dysfunction Sacral motion relative to Lumbar motion Compensatory Backward bending test (Sphinx test) Backward Bending Test (Sphinx) Test the ability of the sacrum to flex (nutate) with backward bending (extension) of the lumbar spine If the sacrum will not flex (held extended) , it is a ‘positive’ test (+) Lumbar Spring Test Sacral extension (counter-nutation) prevents lumbar spring or flexibility Stiffness or lack of spring is a ‘positive’ test (+) Iliac crest Sacral base L5 Greater trochan. Ischial tuberosity PSIS ILA Sacral Dysfunctions Key questions to ask: Side of the deep sacral sulcus? Is L5 compensated? (rotated opposite the sacrum) Side of the posterior & caudad ILA? (Unilateral or Torsion?) Findings of your motion test? (backward bending test or seated forward bending test or lumbar spring test) Flexed or Extended dysfunction? Unilateral Sacral Dysfunctions Flexed sacrum Associated symptoms LBP SI pain pain with sitting difficulty bending forward difficulty getting up and down from chair Involved soft tissue iliolumbar ligaments anterior sacroiliac ligaments Left Sacrum Flexed LSF Left sacral sulcus deep L5 rotated left (compensated) Left ILA posterior/caudad BBT gives improved findings (-) Lumbar spring (-) Seated forward bending test (+) left Left side held flexed about MTA X Glides anterior MTA ILA glides caudad and posterior LEFT SACRUM FLEXED Tx for Left Sacrum Flexed Extended sacrum Associated symptoms LBP difficulty bending backward “leaned over to pick something up and couldn’t get back up” Involved soft tissue iliolumbar ligaments posterior sacroiliac ligaments Right Sacrum Extended RSE Left sacral sulcus deep L5 rotated left Left ILA posterior/caudad BBT gives more pronounced findings (+) Lumbar spring (+) Seated forward bending test (+) right Right side held extended about MTA X Glides posterior MTA RIGHT SACRUM EXTENDED Tx for Right Sacrum Extended Sacral torsions Sacral torsions Associated symptoms SI pain LBP sciatic pain pelvic pain/bowel complaints Involved soft tissues piriformis muscle tension on sacrotuberous and sacrospinous ligaments tension on pelvic floor muscles Sacral Torsions Common Named __ /__ ST (ie. L/RST) First letter tells you the direction the sacrum is rotated Second letter tells you which oblique axis the rotation is occurring around FOM 3 p. 590 “Board question” Forward torsions (L/L & R/R) L5 neutral mechanics e.g. SB left; Rotate right (shown in figure) Backward torsions (L/R & R/L) L5 non-neutral mechanics e.g. SB right; Rotate right Left on left sacral torsion L/LST Right sacral sulcus deep (sacrum rotated left) L5 sidebent left / rotated right (compensated) Left ILA posterior/caudad Backward bending test shows improvement (-) Lumbar spring test (-) Seated forward bending test (+) right Right piriformis causes the L-oblique axis Left rotation about the left oblique axis “Forward” torsion with sacral base held flexed on the right X LO A Glides anterior L / L SACRAL TORSION Tx for L/LST (Flexed torsion) Left on right sacral torsion L/RST Right sacral sulcus deep (rotated left) L5 sidebent and rotated right (compensated) Left ILA posterior/caudad Backward bending test - more pronounced findings (+) Lumbar spring test (+) Seated forward bending test (+) left Left piriformis causes the R-oblique axis Left rotation about the right oblique axis “Backward” torsion with sacral base held extended on left X ROA Glides posterior L / R SACRAL TORSION Tx for L/RST (Extended Torsion) Tx for L/RST (Extended Torsion) Bilateral Sacral Flexion Both sacral sulci are deep Minimal motion of sacrum with inhalation Backward bending test and spring test should be negative Seated flexion test may appear to be negative as both sides are dysfunctional Tx for Bilateral Sacral Flexion Lie the patient prone Abduct both legs approximately 15 degrees. You may fine tune the amount of abduction if needed. Place the heel of your hand on the bilateral ILAs and apply an anterior and cephalad force. Encourage this motion during inhalation and resist with exhalation through 5 deep breaths. Recheck Sacral extension (counter nutation) accompanies inhalation. Sacral flexion (nutation) accompanies exhalation. Bilateral Sacral Extension Both sacral sulci are shallow Minimal motion of sacrum with exhalation Backward bending test and spring test should be postive Seated flexion test may appear to be negative as both sides are dysfunctional Tx for Bilateral Sacral Extension Lie the patient prone Abduct both legs approximately 15 degrees. You may fine tune the amount of abduction if needed. Place the heel of your hand on the base of the sacrum and apply an anterior and caudad force. Encourage this motion during exhalation and resist with inhalation through 5 deep breaths Recheck Sacral extension (counter nutation) accompanies inhalation. Sacral flexion (nutation) accompanies exhalation. Treatment Sequence in the Pelvis (LIPLSIP) Lower extremities Innominates Pubes Lumbars Sacrum Ilia Psoas / iliopsoas Osteobyte ALWAYS rely on what you know!! Example: Left Shallow sacral sulcus Right anterior and cephalad ILA Positive BBT Diagnosis?? Example: Right Shallow sacral sulcus Right cephalad and anterior ILA Positive BBT Diagnosis?? …see you in lab