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Modified Reversed Contralateral Axial Rotation (MRCAR) Position

Original Editor - Saemeh Eldaly Top Contributors - Saemeh Eldaly, Abdelrahman Sameh Abdelkarim Attia and Vidya Acharya

Overview

The Modified Reversed Contralateral Axial Rotation (MRCAR) position represents a significant evolution from earlier manual therapy techniques such as the classic “reverse rotation strain.” While both share conceptual roots, the MRCAR position is biomechanically distinct: it combines controlled lumbar axial rotation, side bending, and flexion across three anatomical planes—transverse, frontal, and sagittal. This compound movement strategy offers a more targeted decompression effect on the lumbar intervertebral foramen (LIVF)[1] [2] [3] [4].

Importantly, this 2025 study by Raffet et al. is the first publication in the English medical literature to define, investigate and introduce the MRCAR position as a structured therapeutic intervention. It is also the first study ever to utilize integrated 3D computed tomography with PET/CT to assess real-time changes in the cross-sectional area (CSA) of the LIVF during specific trunk positioning in patients with lumbar disc prolapse[5].

classic “reverse rotation strain.” in the transverse plane, as described by Winkel (1996), Sabbahi and Ovak-Bittar (2018), Cyriax (1993), and Ombregt (2013).

Modified Reversed Contralateral Axial Rotation position protocol[5]

Modified Reversed Contralateral Axial Rotation (MRCAR) Position
  1. The trunk is laterally flexed and rotated toward the non-painful side, with the pelvis positioned on a hard wedge pillow.
  2. The trunk is then rotated into a semi-prone position in the opposite direction of the pelvic rotation.
  3. Both arms are resting on the bed, both shoulders abducted to 90°, forearms hanging off the end of the bed while both elbows are flexed at 90°.
  4. The lowermost hip and knee are both flexed to approximately 90°.
  5. The uppermost hip is hyperextended while the knee is fully extended.

(Raffet et al., 2025) Indicates that a four-time-per-day application for 20-minutes is effective in maximizing the final decompressing effect at the level of the lumbar intervertebral foramen.

Target Population

This technique is recommended specifically for male patients aged 20–40 years diagnosed with unilateral lumbar disc prolapse and radiculopathy, including:

  • Disc bulge levels: L3/L4, L4/L5, or L5/S1.
  • Bulge type: Second-grade paracentral or foraminal (2–3 mm), classified according to Fardon and Milette[6].
  • Confirmed by T2-weighted axial MRI.
  • No disc extrusion, with disc material confined between parent disc endplates.
  • Pedicle to vertebral body height ratio ≤ 0.5 mm.
  • Symptoms lasting ≥ 3 months:
    • Lower back pain.
    • Unilateral radiculopathy.
    • Positive Straight Leg Raise (SLR) test.
    • Confirmed through neurological assessment: motor, sensory, and reflex testing.

Summary

According to findings from Raffet et al. (2025), MRCAR manipulation position results in a significant improvement in LIVF dimensions at L3/L4, L4/L5 and L5/S1 spaces, therefore there was measurable increase in the SLR degrees of motion within 48 hours. The study also implies a decompressive, in the moment effect on nerve roots that were impinged, potentially with clinical significance for patients who have not had success with conventional conservative care. This manual position represents an appealing future pathway, in non-invasive nerve root decompression for suspected lumbar disc pathology [5].

Mean values of the CSA of the (LIVF) cm at the three 3D-CT scan images different tested
3D-CT scan images of the CSA of the LIVF at L5/S1 level

References

  1. ↑ Sabbahi, M. A., & Ovak-Bittar, F. (2018). Electrodiagnosis-based management of patients with radiculopathy: The concept and application involving a patient with a large lumbosacral disc herniation. Clinical Neurophysiology Practice, 3, 141–147. https://doi.org/10.1016/j.cnp.2018.06.005
  2. ↑ Winkel, D. (1996). Diagnosis and treatment of the spine : nonoperative orthopaedic medicine and manual therapy. CiNii Research. https://cir.nii.ac.jp/crid/1130000797017777280
  3. ↑ Cyriax JH. Cyriax’s Illustrated Manual of Orthopaedic Medicine. 2nd Edition: Butterworth-Heinemann; Oxford. 1993. Chapter 13, 197–299.
  4. ↑ Ombregt, Ludwig. A System of Orthopaedic Medicine-E-Book: A System of Orthopaedic Medicine-E-Book. Elsevier Health Sciences, 2013.
  5. ↑ 5.0 5.1 5.2 Raffet, A., Laslett, M., Lee, R., Khaled, N., Mohamed, G. a. M., Sayed, H. Y., Omar, A. H., Hawana, M. M., Ali, M. M., Elhafez, S. M., ElMeligie, M. M., & Fawaz, H. E. (2025). 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, 20(1). https://doi.org/10.1186/s13018-025-05762-8
  6. ↑ Fardon, David F. MD* and; Milette, Pierre C. MD†. Nomenclature and Classification of Lumbar Disc Pathology: Recommendations of the Combined Task Forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology. Spine 26(5):p E93-E113, March 1, 2001.https://journals.lww.com/spinejournal/citation/2001/03010/nomenclature_and_classification_of_lumbar_disc.6.aspx
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