Author: Dr. Rowan Huang, PT, DPT, MS, CSCS
Have you ever experienced pain that starts in your lower back and shoots down your leg?
Or perhaps numbness, tingling, or weakness that just won’t go away?
Many people assume the problem is in the leg itself, but in many cases, the real source is a nerve root in the lower back.
Let’s take a closer look.
Why Does a Back Problem Cause Leg Pain?
Imagine your spine as a hallway with several doorways.
These “doorways” are called the lumbar intervertebral foramina—small openings where the spinal nerves exit your spine and travel into your legs.
These nerves carry information for:
- Movement
- Sensation
- Muscle control
When one of these openings becomes narrowed, the nerve can become irritated or compressed, leading to symptoms that extend far beyond the lower back.
What Is Lumbar Radiculopathy?
Lumbar radiculopathy occurs when a lumbar nerve root becomes irritated or compressed.
Common symptoms include:
- Pain radiating down the leg (commonly called sciatica)
- Tingling or “pins and needles”
- Numbness
- Muscle weakness
- Difficulty walking or standing for long periods
The symptoms often follow the path of the affected nerve rather than staying only in the lower back.
Can We Create More Space for the Nerve?
Traditionally, treatment focuses on reducing inflammation, improving mobility, strengthening surrounding muscles, and helping the nervous system become less sensitive.
Interestingly, newer imaging research suggests that certain body positions may temporarily increase the size of the intervertebral foramen, allowing the nerve root more room while also improving nerve mobility.
One combination that showed promising results included:
- Rotating the trunk toward the pain-free side
- Side bending toward the pain-free side
- Adding gentle lumbar flexion
These positions were shown to increase foraminal space in the study participants.
Modified Reversed Contralateral Axial Rotation (MRCAR)
The study introduced a three-dimensional positioning strategy called the Modified Reversed Contralateral Axial Rotation (MRCAR) position.
This technique combines lumbar flexion, side bending, and axial rotation to mechanically increase the available space around the affected nerve root.
Using 3D CT imaging, researchers observed an immediate increase in the lumbar intervertebral foramen area while participants were positioned in MRCAR. After following the protocol for 48 hours, additional improvements in foraminal area and straight leg raise mobility were also reported.
What Did the Research Show?
The study used the following protocol:
- 4 sessions per day
- 20 minutes each session
- Changes in foraminal space and nerve mobility were observed after just 48 hours
Although more research is still needed, these early findings suggest that positioning strategies may become another useful tool alongside traditional rehabilitation.
Clinical Takeaway
Lumbar radiculopathy is rarely caused by a single problem. Successful treatment often requires addressing multiple factors, including:
- Nerve root irritation
- Joint and soft tissue mobility
- Neural mobility
- Core and hip strength
- Movement mechanics
- Daily activity modifications
Most importantly, not every patient responds to the same direction of movement. A position that relieves one person’s symptoms may aggravate another’s. That’s why a thorough evaluation is essential before choosing the most appropriate treatment strategy.
Ready to Take the Next Step?
Understanding how to reduce pressure on an irritated nerve root is only one part of the recovery process. Every case of lumbar radiculopathy is different, and the most effective treatment begins with a thorough evaluation to identify the true source of your symptoms.
At FuncPhysio, our physical therapists combine comprehensive movement assessments, evidence-based manual therapy, and individualized exercise programs to address the underlying cause—not just the symptoms. Whether you’re experiencing back pain, sciatica, numbness, tingling, or leg weakness, we’ll work with you to create a personalized plan that helps you move with confidence again.
Schedule an evaluation with one of our physical therapists today:
👉 Book an Appointment at FuncPhysio
Reference
Raffet A, Laslett M, Lee R, et al. A nerve root decompression position identified by 3D CT scan: the modified reversed contralateral axial rotation position for patients with lumbar disc prolapse. Journal of Orthopaedic Surgery and Research. 2025;20:386. doi:10.1186/s13018-025-05762-8
