Lumbar Spine and Pelvis — Palpation Landmarks

Palpation Landmarks

L4 Spinous Process — The Most Important Landmark for Lumbar Palpation

• How to find it: Have the client standing or prone. Place both hands on the client's waist with your fingers pointing toward the midline and your thumbs on the back. Your thumbs naturally rest at the level of the iliac crests. A line drawn between the highest points of the two iliac crests — the supracristal line (also called Tuffier's line) — crosses the spine at the L4 spinous process or the L4–L5 interspace.
• What it feels like: A broad, blunt bony knob in the midline. Lumbar spinous processes are wider and thicker than thoracic spinous processes. They project almost directly posteriorly (unlike thoracic SPs, which angle inferiorly), so the tip of each process is at the same vertebral level as the body in front of it.
• Client position: Prone (preferred for static palpation) or standing (preferred for dynamic assessment). Slight flexion of the lumbar spine (bolster under the abdomen in prone) opens the interspinous spaces and makes the processes easier to distinguish.
• Confirmation: Once you locate L4, count upward: L3, L2, L1 (the last rib attaches at T12, so if you palpate the 12th rib and trace it medially to its vertebra, that is T12 — L1 is one level below). Count downward: L5 is one level below L4, and the sacral base (S1) is the first wide, flat structure below L5.
• Common errors: The supracristal line can pass through L4 or the L4–L5 interspace — there is natural variation. In obese clients, the iliac crests may be harder to locate accurately, which shifts the reference point. In lordotic clients, L4 and L5 spinous processes may be deeply recessed and harder to palpate. Press firmly through the erector spinae.
• Clinical significance: Starting point for counting all lumbar levels. L4-L5 is one of the two most common disc herniation levels. See Assessment Reference Points for Schober's test landmarks.

L5 Spinous Process

• How to find it: From L4 (identified via the supracristal line), drop one interspace inferiorly. L5 is the last freely movable spinous process before the sacrum.
• What it feels like: Similar to L4 — a broad, blunt midline bony prominence. L5 may feel slightly smaller or more recessed than L4 because the lordotic curve deepens at the lumbosacral junction.
• Client position: Prone with a bolster under the abdomen to reduce lordosis.
• Confirmation: L5 sits at approximately the level of the PSIS bilaterally. If you draw a line between the two PSIS dimples and cross the midline, you should be near L5 or the L5–S1 interspace.
• Common errors: In deep lordosis, L5 can be recessed enough that it is difficult to distinguish from the sacral base. Press firmly. If you feel a broad, smooth, immovable surface instead of a discrete bony point, you have gone too far inferiorly and are on the sacrum.
• Clinical significance: Most common disc herniation level (L5 nerve root = lateral leg/dorsal foot pattern). Highest spinal shear forces explain why spondylolisthesis most commonly occurs here. See Clinical Notes.

Sacral Base (S1 Level)

• How to find it: From L5, continue inferiorly in the midline. The first broad, flat, immovable surface you encounter is the sacrum. The sacral base is the superior end of the sacrum at the S1 level. It sits between the two PSIS landmarks — if you place a thumb on each PSIS and drop your index fingers medially, they converge on the sacral base.
• What it feels like: A broad, flat bone that is noticeably wider than the lumbar spinous processes above. You cannot distinguish individual sacral segments by palpation in most people — the sacrum feels like a single, continuous bony plate.
• Client position: Prone.
• Confirmation: The sacral base does not move with lumbar flexion (the lumbar spine moves above it). If you fix one finger on the sacral base and ask the client to flex the lumbar spine (push up into a small cobra position), the lumbar SPs move but the sacrum stays still.
• Common errors: Confusing the sacral base with L5. The sacral base is wider and flat — L5 is a discrete, protruding bony point. If you are unsure, rock your fingertip side to side: on a spinous process, you feel a narrow ridge; on the sacral base, you feel a broad surface.
• Clinical significance: Superior boundary for sacral/SI joint assessment. Increased sacral base angle increases lordosis, loading posterior facet joints. S1 nerve root compression produces posterior leg/lateral foot pain, plantarflexion weakness, and diminished Achilles reflex.

Sacral Sulcus

• How to find it: From the PSIS, slide your finger medially and slightly inferiorly. The sacral sulcus is the groove running along either side of the sacral midline, between the median sacral crest (fused spinous tubercles) and the lateral sacral crest. It is essentially the "gutter" between the midline ridge and the posterior SI joint.
• What it feels like: A shallow longitudinal depression approximately 1–2 cm lateral to the midline sacral tubercles. It may feel soft and slightly tender compared to the hard midline tubercles.
• Client position: Prone.
• Confirmation: The sulcus is continuous — you can trace it from the sacral base to the lower sacrum. It is bilaterally symmetrical. Asymmetry (one sulcus deeper or more tender than the other) is a clinical finding suggesting SI joint dysfunction or sacral torsion.
• Common errors: Pressing too far laterally and ending up on the posterior iliac crest rather than the sacral sulcus. The sulcus is within 2 cm of the sacral midline.
• Clinical significance: Depth asymmetry suggests SI joint dysfunction or sacral torsion. Multifidus fills the sulcus — tone asymmetry indicates segmental instability. Common MFR treatment site for SI joint and deep lumbar stabilizers.

Coccyx

• How to find it: Follow the sacral midline inferiorly. The sacrum narrows as you descend. The coccyx is the small, mobile bony tip inferior to the sacrum. It is palpable through the soft tissue of the gluteal cleft, approximately midway between the sacral apex and the anus.
• What it feels like: A small, triangular bony point, roughly 2–3 cm long. It may be slightly mobile — you can gently press it anteriorly and feel a small amount of give at the sacrococcygeal joint.
• Client position: Prone. The coccyx is best palpated through the skin externally. Internal palpation (per rectum) is outside MT scope of practice.
• Confirmation: The coccyx is in the midline and is the most inferior bony structure of the axial skeleton. It does not move with hip or lumbar movement.
• Common errors: Pressing too firmly — the coccyx is sensitive in most people and can be painful in clients with coccydynia (tailbone pain). Always warn the client before palpating this area and use light pressure initially.
• Clinical significance: Tenderness is the primary finding in coccydynia (common after falls or prolonged sitting). Pelvic floor hypertonicity can produce coccygeal pain. Always explain and obtain consent before palpating this area.

Anterior Superior Iliac Spine (ASIS)

• How to find it: Place your hands on the client's waist with thumbs posteriorly on the iliac crests. Slide your fingers anteriorly along the iliac crest. Follow the crest as it curves forward and downward. The ASIS is the most anterior projection of the iliac crest — your fingertips naturally land on it as you reach the front end of the crest. It is a distinct bony point at the front of the hip.
• What it feels like: A rounded, prominent bony point at the anterior end of the iliac crest. It is approximately the size of a fingertip and often visible in lean individuals as the bony "bump" at the front of the hip below the belt line.
• Client position: Standing (for postural assessment) or supine (for measurement). The ASIS is palpable in any position.
• Confirmation: The inguinal ligament runs from the ASIS to the pubic tubercle — you can sometimes trace this taut band from the ASIS inferomedially. Alternatively, the ASIS does not move when the client contracts the quadriceps or flexes the hip (it is part of the pelvis, not the femur). The sartorius originates from the ASIS — resisted hip flexion with knee flexion and external rotation tenses the sartorius tendon at the ASIS.
• Common errors: In overweight clients, the ASIS may be buried under soft tissue. Press firmly — it is always there. Occasionally students confuse the ASIS with the iliac tubercle (a widening of the crest approximately 5 cm posterior to the ASIS on the outer lip of the crest). The ASIS is the actual anterior endpoint of the crest.
• Clinical significance: Starting point for true leg length and Q-angle measurements (see Assessment Reference Points). Key landmark for pelvic tilt assessment (ASIS vs. PSIS height). Avulsion fractures can occur in adolescent athletes before growth plate fusion.

Posterior Superior Iliac Spine (PSIS)

• How to find it: From the iliac crest, slide your fingers posteriorly. The PSIS is the most posterior projection of the iliac crest. In most people, it is visible as a skin dimple — the "dimples of Venus" — located approximately 4–5 cm lateral to the midline at the S2 level.
• What it feels like: A small, rounded bony point. It is less prominent than the ASIS but identifiable by the overlying skin dimple and by palpating from the iliac crest posteriorly until you feel the crest end at a distinct bony point.
• Client position: Standing (for postural assessment) or prone (for SI joint assessment).
• Confirmation: The PSIS dimples are typically visible. To confirm by palpation, ask the client to extend the hip (prone leg raise) — the PSIS on the same side may shift slightly as the innominate moves with hip extension, especially if SI joint motion is present. Compare both sides — symmetry is expected.
• Common errors: Confusing the PSIS with the sacral sulcus or the posterior iliac crest. The PSIS is a discrete point, not a ridge. If you are feeling a broad surface, you are on the sacrum (medially) or the iliac crest (laterally) rather than the PSIS itself.
• Clinical significance: Primary screen for pelvic obliquity (compare heights bilaterally — see Assessment Reference Points). Approximates L5/S2 level for cross-referencing. Tenderness is a common finding in SI joint dysfunction.

Iliac Crest (Full Length — ASIS to PSIS)

• How to find it: Place your hands on the client's hips. The iliac crest is the superior border of the ilium — the curved bony ridge you feel when you "put your hands on your hips." It runs from the ASIS anteriorly to the PSIS posteriorly. It is subcutaneous for most of its length and easily palpable.
• What it feels like: A broad, smooth bony ridge that curves from anterior to posterior. The highest point of the crest is approximately at the L4 level (laterally). The crest has an inner lip (attachment for transversus abdominis and iliacus), an intermediate zone (attachment for internal oblique), and an outer lip (attachment for external oblique, latissimus dorsi, and TFL).
• Client position: Standing or prone. The crest is palpable in any position.
• Confirmation: The crest is continuous and bilateral. Run your thumbs along the full length from ASIS to PSIS — you should be able to trace the entire ridge without losing contact with bone.
• Common errors: In clients with significant soft tissue over the hips, the crest may feel less distinct. Press firmly. Also, the crest dips slightly between the ASIS and the iliac tubercle (about 5 cm posterior to the ASIS) — do not interpret this dip as the end of the crest.
• Clinical significance: Crest height comparison is the simplest pelvic obliquity screen (see Assessment Reference Points). The supracristal line (highest crest points) = L4 level — the most reliable lumbar level identification method. Multiple muscle attachments (see Muscle Attachments table) make crest tenderness a nonspecific finding.

Ischial Tuberosity — "Sit Bones"

• How to find it: The ischial tuberosities are the bony prominences you sit on. With the client prone, locate the gluteal fold (the crease where the buttock meets the posterior thigh). The ischial tuberosity is deep to the gluteus maximus, approximately at the level of the gluteal fold, midway between the midline and the lateral thigh. Press through the gluteal tissue superiorly and laterally from the gluteal fold — the tuberosity is a large, rounded, hard bony mass.
• What it feels like: A large, broad, rounded bony surface — roughly the size of your thumbpad. It is surprisingly large and hard once you are on it. In a seated position, it is immediately subcutaneous (you sit directly on it — the gluteus maximus slides superiorly when you sit, leaving the tuberosity covered only by fat, fascia, and the ischial bursa).
• Client position: Prone with the hip slightly flexed (a bolster under the anterior thigh or having the client bend the knee toward the chest opens the gluteal fold and makes the tuberosity more accessible). In a seated position, the tuberosities are palpable by reaching under the buttock.
• Confirmation: The ischial tuberosity does not move with hip rotation or flexion/extension — it is part of the pelvis. If the structure moves when the client extends the hip, you are on the proximal hamstring tendons (which do originate from the tuberosity but are softer than the bone itself). Press through the tendons to the bone.
• Common errors: Not pressing deeply enough through the gluteal tissue — the tuberosity is deep to the gluteus maximus in prone position. Hip flexion slides the gluteus maximus superiorly and exposes the tuberosity more directly. Also, students sometimes find the sacrotuberous ligament (a thick, cord-like band medial to the tuberosity) and mistake it for bone — the tuberosity is broader and rounder.
• Clinical significance: Hamstring origin (see Muscle Attachments) — tenderness is a primary finding in proximal hamstring tendinopathy and ischial bursitis ("weaver's bottom"). Sacrotuberous ligament tension here can contribute to SI joint pain.

Greater Trochanter

• How to find it: With the client standing or side-lying, locate the lateral aspect of the hip. The greater trochanter is the large bony prominence on the lateral proximal femur. Place the heel of your hand on the lateral hip, halfway between the iliac crest and the knee — the trochanter is the hardest point under your hand. It is approximately a hand-width below the iliac crest.
• What it feels like: A broad, flat bony surface facing laterally. It is larger than most students expect — approximately 5 cm tall and 3 cm wide. The upper border is approximately level with the pubic symphysis anteriorly.
• Client position: Side-lying (affected side up) or standing. The trochanter is palpable in any position but easiest to confirm in side-lying.
• Confirmation: Place your fingertip on the trochanter and ask the client to slowly internally and externally rotate the hip (with the knee flexed in side-lying). The trochanter rolls under your finger — it moves anteriorly with internal rotation and posteriorly with external rotation. This rolling motion is the definitive confirmation that you are on the trochanter and not on soft tissue.
• Common errors: Palpating too far anteriorly or posteriorly. The trochanter faces directly laterally. Also, confusing the trochanteric bursa (soft tissue over the trochanter) with the bone — press through the bursa to feel the hard bone underneath. In some clients, the iliotibial band is taut over the trochanter and may produce a "snapping" sensation with hip rotation — this is snapping hip syndrome, not a normal finding but not a palpation error.
• Clinical significance: Tenderness is the hallmark of greater trochanteric pain syndrome (gluteal tendinopathy more often than true bursitis). Tip approximates the center of the femoral head. A trochanter sitting higher than expected may indicate coxa vara or femoral neck fracture.

Pubic Symphysis

• How to find it: The pubic symphysis is in the anterior midline, approximately halfway between the umbilicus and the perineum. With the client supine, locate the midline of the lower abdomen. Move inferiorly from the umbilicus until you feel a firm, bony surface deep to the soft tissue of the lower abdomen. The pubic symphysis is the cartilaginous joint at the midline junction of the two pubic bones.
• What it feels like: A firm, flat bony surface in the midline with a subtle midline ridge or depression where the joint itself lies. The superior border of the pubic bones (the pubic crest) is the most easily palpated feature — a horizontal bony ledge you can hook your fingertips over from above.
• Client position: Supine. Knees may be bent to relax the abdominal muscles.
• Confirmation: The pubic symphysis is in the exact midline and is immobile. The pubic tubercles (the lateral projections of the pubic crest, approximately 2–3 cm lateral to the midline on each side) can be palpated as small bony bumps — the inguinal ligament attaches here.
• Common errors: Not going far enough inferiorly — students often palpate the lower abdominal wall above the pubic bone and do not reach the bone itself. Also, pressing too hard — the pubic symphysis region is sensitive and can be uncomfortable. Always explain what you are palpating and why before touching this area.
• Clinical significance: Osteitis pubis and adductor strains produce tenderness here. This is a sensitive area — explain the clinical reason, obtain verbal consent, follow CMTO Standards of Practice. In many cases, ASIS and PSIS provide sufficient information without direct symphysis palpation.