[Study Log] Releasing the "Piriformis" without "stepping on the sciatic nerve." Access routes to the deep gluteal region and palpation records

## The danger of the "numb buttocks = piriformis syndrome" mental shortcut

Hello, this is Kocha.

In clinical practice, when encountering a complaint of "numbness from the buttocks to the back of the thigh while sitting," I think many physical therapists immediately suspect Piriformis Syndrome.

I was one of them.

I would jump to conclusions, thinking, "The SLR is negative and it worsens in a seated position, so it must be the piriformis," and then instruct the patient on piriformis stretches or self-release using a tennis ball.

However, when I opened an anatomy book and re-examined this area, I was chilled by the simple fact that "the sciatic nerve runs directly beneath the piriformis."

Applying pressure blindly with a tennis ball is the same as "putting your body weight directly on the nerve."

This time, I am recording the verification of access routes to "safely" release the piriformis, using my own body and my wife's body.

## Anatomical image: The "six pathways" of the sciatic nerve

The piriformis originates from the anterior surface of the sacrum (S2-S4), passes through the greater sciatic foramen, and attaches to the superior border of the greater trochanter; it is the leader of the deep six external rotators.

The greatest risk lies in its positional relationship with the sciatic nerve.

Textbooks state that it passes "under the piriformis (infrapiriform foramen)," but in reality, there are anatomical variations.

According to the Beaton & Anson classification (1938), six patterns have been reported.

1. **Type A (approx. 85%)**: The sciatic nerve passes **below** the piriformis muscle (as described in textbooks).

2. **Type B (approx. 10%)**: The common peroneal nerve **pierces** the piriformis muscle, and the tibial nerve passes below it.

3. **Type C (approx. 3%)**: The common peroneal nerve passes **above** the piriformis muscle, and the tibial nerve passes below it.

4. **Type D–F (rare)**: The sciatic nerve is undivided and pierces the piriformis muscle, etc.

In other words, in **about 15% of people, a portion of the sciatic nerve passes through the piriformis muscle**.

What happens if you aggressively compress the piriformis in these individuals...? Just thinking about it makes me break into a cold sweat.

Reference: Beaton LE, Anson BJ. (1938). The Relation of the Sciatic Nerve and of Its Subdivisions to the Piriformis Muscle. *Anatomical Record*.

## Palpation Tip: Dive in from the line connecting the "greater trochanter" and the "sacrum"

Last night, I practiced palpating the deep gluteal region again.

Because the piriformis is located deep, you need to "move aside" the gluteus maximus.

**Step 1: Confirming landmarks**

Side-lying position is best.

- Confirm the **apex of the greater trochanter** (the bone you feel with your fingertip).

- **Lateral border of the sacrum** (the hard bone next to the gluteal cleft)

The line connecting these two points is the exact **direction of the fibers** of the piriformis muscle.

**Step 2: Part the gluteus maximus**

To reach the piriformis, you must first get past the thick muscle belly of the gluteus maximus.

The key is to **aim for the superior border of the gluteus maximus**.

Since the gluteus maximus originates from the iliac crest, its superior border is relatively thin; it is easier to access the deep layers by sinking your fingers diagonally downward from there.

**Step 3: Look for the "rolling" sensation**

When you sink your fingers posterior and slightly superior to the greater trochanter, there is a point where you can feel a muscle belly that feels like a **"rolling sausage"** on the bone.

Confirmation test here:

- When the hip joint is in a slightly flexed position and internally rotated, the **piriformis is stretched and becomes taut under your fingers**

- When externally rotated, it **relaxes** (because the piriformis is an external rotator)

If you can catch this change in tension with your fingertips, that is the piriformis.

**Step 4: Confirming the zone where you do not step on the nerve**

The sciatic nerve runs along the **inferior border (caudal side)** of the piriformis.

Therefore, the release touch should target the upper half to the center of the piriformis, ensuring no pressure is applied to the lower edge.

Specifically, the image is to apply pinpoint pressure slightly cranial (superior) to the line between the apex of the greater trochanter and the sacrum.

## Practical Release: "Lifting and Sliding" instead of "Pushing"

This is the most important point.

Applying vertical pressure to the piriformis carries the risk of compressing the sciatic nerve located in its deep layer.

What I practice is a horizontal slide.

1. Grasp (pinch) the muscle belly with your fingertips.

2. Find the interface between the gluteus maximus and the piriformis.

3. Slowly shift it laterally in the direction where the fasciae slide against each other.

The image here is not to "crush the muscle," but rather the sensation of "sliding one sheet of paper over another."

This is a fundamental aspect of inter-tissue release, but it is especially critical in the deep gluteal region.

If the patient complains of a "sharp electric shock" during the release, release your hand immediately.

That is a sign of sciatic nerve compression. Either correct the direction or depth of the pressure, or discontinue the approach for that session.

## "Dull pain," not "numbness," is the correct response

When the trigger point of the piriformis is accurately captured, the patient's reaction is "a dull pain that resonates deep inside," not "a tingling numbness."

- **Dull resonance** → Piriformis fascia/trigger point → Continue release

- **Electric shock/sharp numbness** → Sciatic nerve compression → Stop immediately

It is important to explain this difference between "dull" and "sharp" to the patient and manage risks through collaborative effort.

## Summary: Palpate with knowledge of anatomical risks

The piriformis is a muscle often approached with the simplistic idea that "stretching is enough," but the second-thickest nerve in the body runs directly beneath it.

When a patient says their "buttocks are numb" in tomorrow's clinical practice:

- First, visualize the path of the sciatic nerve in 3D

- Safely access it from the upper half of the piriformis

- "Slide" rather than "press"

By keeping these three points in mind, you should be able to perform an effective release while minimizing risks.

Deep palpation is intimidating, but that is precisely why it is worth returning to anatomy.

It is a repetitive and modest review, but I believe this will change tomorrow's clinical practice.