Pelvis Stuart Williams D.O. Chairman & Associate Professor Osteopathic Manipulative Medicine

Objectives 04/08/2013 10:00 -11:00 PPC/OMM pelvis Williams Recall the structural anatomy of the pelvis Describe the functional anatomy of the pelvis Explain the difference between iliosacral and sacroilial motion Recognize common somatic dysfunctions of the pelvis and how to incorporate these into a differential diagnosis. Explain the biomechanics of the pelvis including the axes of motion Recall the lateralizing tests for pelvic somatic dysfunction. Understand the use of anterior & posterior landmarks to diagnose pelvic somatic dysfunctions Name potential diagnoses of pelvic somatic dysfunctions. Understand the difference between physiologic and non-physiologic somatic dysfunction Recall anatomy of Pelvis

Reading Foundations of Osteopathic Medicine, 3rd Ed: “Pelvis and Sacrum” P 575-601

The Pelvis Functionally consists of three bones: - the innominates ilium ischium pubis - the sacrum, And three joints - the sacroiliac joints (two of them) - the pubis symphysis  moves on a transverse axis

Features in Trauma

Most common way to get a pubic shear is because the innominates are so rotated that it pulls the pub w it, but you CAN get isolated pubic shears (usually from trauma)

Inferior Lateral Angle Sacrum Base of Sacrum Sacral Promontory Superior Articular Processes ALA Hiatus- failure of closure of the 5th sacral vertebral lamina Ganglion Impar- where right and left sympathetic chains join is on the anterior surface of the coccyx Median Sacral Crest Apex of Sacrum Sacral Foramina Sacral Hiatus Inferior Lateral Angle

Osteology/Articulations Sacrum articulates with The 5th lumbar superiorly The coccyx inferiorly Two pelvic( innominate bones )through the “L” shaped sacroiliac articulation

Lumbarization Sacralization S1 S2 S3 S4 S5 Occurs in small percentage of people (grey p. 326) Partial Lumbarization – pseudoarthrodial area created. (circle) batwing deformity Complete Lumbarization – one fewer sacral vertebrae (dots) The dorsal wall to the Sacral Canal may be variably deficient d/t imperfect development Orientation of Zygapophysial Lumbosacral joints display wide variation (20 to 90 degrees) Commonly Have low back pain  increased ferguson’s angle S3 Sacralization S4 S5

Sacroiliac Joint The SI joint functions to redirect force from the lower extremities to the rest of the body. Movement in the SI joints is small, but measurable in both rotation (~1.8°) and translation (~1mm). No muscles are directly responsible for this motion. Force is accommodated by the irregular surface of the joint and LARGE posterior ligaments. This has treatment implications, we have to use the legs as levers. 45 degree angle from the AP axis has diagnostic and treatment implications

Pubic Symphysis Motion at each pubic ramus is a PHYSIOLOGIC rotation about a transverse axis. Synarthrosis- intrapubic disc that is covered with hyaline. Fibrocartilagenous joint. When walking, look at iliosacral motion (the ilium on the sacrum) When seated look at sacroiliac motion (the sacrum on the ilium)

Sacroiliac Joints Vertebral disc are thicker in lower lumbar to support weight Know that piriformis attaches to the greater trochanter Know that the iliopsoas attaches to the lesser trochanter  strongest flexor muscle in the body

Toward Greater Trochanter Toward ASIS Sacroiliac Joint The articular surfaces of the upper and lower poles are not the same size This leads to different qualities of motion during diagnosis (don’t compare upper pole motion to lower pole motion) The plane of the upper and lower poles are approximately 90 degrees to one another- look at the prior slide to see how this is effective at “locking the joint” The SI joint is concave on the sacrum. Final fusion not until mid 20s Therefore, the SI joints may not be bilaterally symmetrical d/t developmental differences among individuals Toward Greater Trochanter These joints are not present at birth- they develop functionally They are not totally symmetric

Lumbosacral Junction Ferguson’s Angle as measured from the horizontal should be about 35 degrees. 35º Used on lateral X-ray film to determine hyper-lordosis of lumbar spine. What would happen if the sacral base were anterior or posterior, or highly flexible? Why is this important? Imagine trying to hold that force on a ninety-degree angle. If greater angle  more lordosis If lesser angle  flattened lordosis

Ligaments

Ligamentous Attachments of the Sacrum Suspended between the innominates by three true ligaments: Anterior Sacroiliac Interosseous Sacroiliac Posterior Sacroiliac And three accessory ligaments: Sacrotuberous Goes between the ILA and the ischial tuberosity Sacrospinous Iliolumbar (L4 and 5, connects to lateral thigh too) Sacrotuberous: PSIS, coccyx and lower part of sacrum to Ischial Tuberosity

Ligaments Iliolumbar ligaments prevent L5 from sliding anterior. It also blends with the anterior sacroiliac to INTEGRATE SI joint mechanics. This allows smooth symmetry of motion. Interosseous ligaments blend the non-articular surfaces of the SI joint. In a weight bearing position the sacral base would move anteriorly if it wasn’t restrained. Iliolumbar is sensitive to pain in conditions that cause sacral instability Sacrotuberous and Sacrospinous ligaments restrain anterior motion of the sacrum by resisting posterior rocking of the apex.

Ligaments Interosseous: not shown Can get sclerotomal pain from these ligaments

Ligaments- Part II Sacrotuberous and Sacrospinous ligaments restrain anterior motion of the sacrum by resisting posterior rocking of the apex The sacroiliac and the iliolumbar ligaments prevent the sacral base from rocking anteriorly. Posterior, Lateral and Axial Rotation are prevented by a combination of the anterior, posterior and interosseous ligaments.

Out of all the ligaments here the iliofemoral ligament (ligament of bigalow?) is the strongest

Iliopsoas Functional Anatomy Concentric contraction results in hip flexion & ext rotation. Function of this muscle is to eccentrically & dynamically stabilize hip extension & internal rotation in bipedal ambulation. Dysfunction can lead to innominant rotations & gluteus inhibition. Thomas test checks for this

Muscular Attachments of the Sacrum Muscles: Gluteus Maximus Longissimus Thoracis Iliocostalis Lumborum Multifidus Ligaments: Sacroiliac Post. Sacrococcygeus mulitfidus Gluteus Maximus Erector spinea

Sacrum Anterior Aspect Muscles: Iliacus Piriformis Coccygeus Ligaments: Sacrospinous Sacrotuberous Ant. Sacrococcygeus Anterior Sacroiliac The piriformis attached to the lateral anterior sacrum, goes through the sciatic notch and attached to the greater trochanter. The sciatic nerve passes inferior to the piriformis (although) there is great variation in this. External rotation If a tight piriformis, a pt will not be able to internally rotate well bc will be stuck in external rotation

A-P View P-A View Psoas Iliacus Quadratus Lumborum Iliopsoas passes from the upper lumbar vertebrae, over the pelvic rim, and to the lesser trochanter like a “violin string” Quadratus Lumborum arises from aponeurotic fibers of the iliolumbar ligament, origin from the last rib and inserts on the TP’s of L1-L4, and the posterior third of the iliac crest (maybe the iliolumbar ligament Psoas Iliacus Quadratus Lumborum

Piriformis Gemellus Superior Obturator Internus Gemellus Inferior Obturator Externus Quadratus Femoris Gluteus Maximus Gluteus Medius Tensor Fascia Lata Semitendinosus Semimembranosus Biceps Femoris External hip roators Iliotibial band mm Hamstrings Anterior AIIS attachments: quadriceps: rectus femoris, vastus lateralis, medius and intermedius (ASIS sartorius mm)

Pelvic Floor Levator Ani Muscles: Puborectalis Pubococcygeus Iliococcygeus Coccygeus These muscles constitute the pelvic diaphragm. They do have rhythmic contractions like the respiratory diaphragm, but when relaxed they will contract with the diaphragm. In disease states of the pelvis, respiratory mechanics are an important consideration. Remember in thorax  want to maintain a – pressure gradient, in abdomen  maintain a + pressure gradient

Autonomic Innervation: Pelvic Viscera (T10-L2) Sympathetic Parasympathetic (S2-S4) Be aware the sympathetic innervation of the lower legs is from T11-L2.

Nervous System Close relationships between the nerves and the sacrum. Pain can be secondary to m/s involvement or visceral or BOTH!

Landmarks

Landmarks of the Pelvis Patient Standing Iliac crest level PSIS Greater trochanters Patient Supine ASIS Pubic symphysis Pubic tubercles Medial malleoli Patient Prone PSIS Sacral sulcus Sacral base Inferior lateral angle Sacortuberous lig. Ischial tuberosity Iliac crest Piriformis muscle Iliolumbar ligament

Sacral base Inferior Lateral angle

Sacral Axes Multiple axes of motion: Transverse (3) Vertical A/P Superior S1 (TP) Middle S2 (TP) Inferior S3 (TP) Vertical A/P Oblique (2) Left Right Flexion occurs when the Sacral Base moves anterior, Extension when it occurs moves posterior on middle transverse axis. Superior Transverse axis: at level of second sacral segment, posterior to the SI joint in the SP area. (“respiratory axis”) Middle Transverse axis: at anterior convexity of the upper & lower limbs of SI joint. (sacral flexion & extension) Inferior Transverse axis: at posterior-inferior portion of the inferior limb of the SI joint. (anterior & posterior innominate rotation)

SACRAL ANATOMIC AXIS Transverse axis Superior: the cranial primary respiratory mechanism creates motion around this axis Middle: sacral base anterior and posterior (FB/BB) occur around this axis Inferior: the innominates rotate around this axis Reference Foundations p.1136-1137 Know this

SACRAL PHYSIOLOGIC AXIS Oblique: both left and right oblique axes are named for the superior pole Sagittal: includes both mid-sagittal and an infinite number of parasagittal axes Horizontal: functional axis of sacral flexion/extension occur around this axis (analogous to the middle transverse axis above)

SACRAL MECHANICS Physiologic diagnoses of the sacrum occur in neutral and non-neutral mechanics:

Neutral Mechanics a.k.a. Left rotation on a Left Oblique Axis Forward Torsion In neutral mechanics, the sacrum rotates in the same direction as the oblique axis (left rotation on a left oblique axis). (all three are equivalent terms!!)

Non-neutral Mechanics a.k.a. Right rotation on a Left Oblique Axis Backward Torsion In non-neutral mechanics, the sacrum rotates in the opposite direction of the oblique axis (right rotation on a left oblique axis). (all three are equivalent terms!!)

Walking Cycle and the Pelvis Double support Double support Single limb support Single limb support (opposite side) Know this slide well Know your pressure is more on the lateral aspect of your foot Heel strike Flat foot Mid-stance Heel off Toe off Mid swing Heel strike

Pelvic Mechanics During the Walking Cycle Walking induces (reversible) neutral oblique axis mechanics in the sacrum with every step e.g., right rotation on right oblique axis, then left on left oblique axis. It induces side bending of the lumbar spine towards the side of the weight bearing leg. It also causes posterior rotation of the weight bearing ilium and anterior rotation of the non-weight bearing ilium. Second point- this means that rotation will be AWAY from the side of the weight bearing cycle. We would expect this in order to preserve physiologic axis.

Gait Cycle To move the right foot - the body must shift to the left. A N SLRR motion occurs in the L spine A left oblique axis occurs at sacrum. Sacrum rotates left on oblique axis. Right quadriceps tighten and the right innominate rotates anteriorly. Right hamstrings contract. Hamstrings pull right innominate into a relative posterior position. Pubic sympyhsis provides a transverse axis. Heel strikes the ground. Left leg thrusts body forward. Center of gravity shifts forward & to the right. Gait Cycle

Walking Cycle

Anterior Anatomical Landmarks

Posterior Anatomical Landmarks

Movement of the Innominates Innominates rotate around the inferior transverse axis of the sacrum Located at inferior limb of sacroiliac joint This is iliosacral motion, not sacroiliac motion S: pubic symphysis H: acetabulum X: inferior transverse axis

Possible Somatic Dysfunctions of Innominates Anterior Innominate Rotation( Innominate Anterior) Posterior Innominate Rotation(Innominate Posterior) Upslipped Innominate (Superior Innominate Shear) Non-physiologic SD, traumatic etiology Not involved in inferior transverse axis mechanics Downslipped Innominate (Inferior Innominate Shear) Non-physiologic SD, Rare Innominate Inflare/ Innominate Outflare Innominates rotate around respective vertical axes Non physiologic means there isn’t an axis there

Once you have lateralized the patient to one side, all other findings are named in relation to what is found on the restricted side Mark your diagnostic worksheet accordingly

Lateralization of the Pelvis Seated Flexion ASIS Compression Don’t forget to reset the pelvis! Standing Flexion Thumbs under PSIS! Palms cupping ASISs, force vector is posteromedial

Supine Diagnosis Put thumbs horizontally under the ASIS’s Are they level? Is the lateralized side inferior or superior relative to the non-lateralized side? correct incorrect

Supine Diagnosis visualize & palpate: do they agree?

Supine Diagnosis - Inflare/Outflare Visualize a line from each ASIS to umbilicus Is lateralized side relatively further (outflare) or closer (inflare) to umbilicus? L R

Supine Diagnosis Place thumbs under medial malleoli Apply slight inferior traction Is the lateralized side inferior or superior relative to the non-lateralized side? Malleoli are mixed landmarks, but can alert the operator to stresses placed on pelvis, leg, and ankle, or to functional/anatomical short leg Can be used to help confirm diagnosis L correct incorrect

Prone Diagnosis Place thumbs horizontally under the PSIS’s Are they level? Is the lateralized side inferior or superior relative to the non-lateralized side? There is a “dimple” under the PSIS: place thumbs horizontally Correct Incorrect

Prone Diagnosis L

Prone Diagnosis Ischiotuberosity L Can also use heels. Will show in lab. This is a time to exhibit professionalism.

Innominate Diagnoses: Left Anterior Rotation Findings Left ASIS relatively inferior Left PSIS relatively superior S: pubic symphysis H: acetabulum X: inferior transverse axis

Innominate Diagnoses: Left Posterior Rotation Findings Left ASIS relatively superior Left PSIS relatively inferior S: pubic symphysis H: acetabulum X: inferior transverse axis

Pubic Symphysis Diagnosis Patient is supine Explain to your patient what you are going to do Ask male patients if they need to adjust Using the heel of your hand, start at the umbilicus and slide inferiorly with gentle pressure until you reach the pubic symphysis

Pubic Symphysis Diagnosis Place your fingers on the superior aspect of the pubic symphysis to diagnose sup./inf. Place your fingers on the anterior aspect of the pubic symphysis to diagnose ant./post. L L

Pubic Symphysis Somatic Dysfunctions Pubic Symphysis Superior/Inferior Shear May often follow innominate SD, or be SD by itself (rare) Can follow innom ant/post rotation, up/down slipped innom. Can follow sacral shear Common in obstetrical patients due to relaxin Pubic Symphysis Anterior/Posterior Shear Relatively rare, usually caused by trauma

Innominate Diagnoses: Left Inferior Pubic Shear Findings Left ASIS relatively inferior Left PSIS relatively superior Usually has an associated L anteriorly rotated innominate. S: pubic symphysis H: acetabulum X: inferior transverse axis

Innominate Diagnoses: Left Superior Pubic Shear Findings Left ASIS relatively superior Left PSIS relatively inferior Usually associated with a posteriorly rotated innominate if physiologic. S: pubic symphysis H: acetabulum X: inferior transverse axis

Innominate Diagnoses: Left Upslipped Innominate Findings Left ASIS relatively superior Left PSIS relatively superior Nonphysiologic. No axis! Symphysis and Ischial tuberosity could also be superior in more severe cases. S: pubic symphysis H: acetabulum X: inferior transverse axis

Innominate Inflare/Outflare Somatic Dysfunction Lateralized ASIS is closer to the umbilicus than the non-lateralized side i.e., with a left inflare, there is a shorter distance between the umbilicus and left ASIS than the right ASIS Outflare: Lateralized ASIS is further away from the umbilicus than the non-lateralized side i.e., with a left outflare, there is a longer distance between the umbilicus and left ASIS than the right ASIS Innominate inflare/outflare somatic dysfunction is not involved in inferior transverse axis mechanics It occurs about a vertical axis

Left Outflare

Innominate Diagnosis Checklist Lateralization of Pelvis (at least 2/3) Standing/Seated Flexion Test ASIS Compression Supine: ASIS (superior/inferior) Inflare/Outflare Pubic Symphysis (superior/inferior, anterior/posterior) Medial Malleoli (superior/inferior) Prone: PSIS (superior/inferior)

Right Anterior Innominate

Right Posterior Innominate

Left Superior Pubic Shear

Right Upslipped