Lumbar radiculopathy is a common condition caused by irritation or compression of a lumbar nerve root, often resulting in radiating leg pain, numbness, weakness, and functional limitation. Conservative physiotherapy is commonly used as first-line treatment, but outcomes vary among patients.

This randomized controlled trial will compare Mirror Image Spine Correction Exercises with standardized conservative physiotherapy in adults with lumbar radiculopathy. Participants will be randomly assigned to one of two treatment groups for 12 weeks.

The primary outcome is lumbar nerve root microstructural integrity measured using Diffusion Tensor Imaging (DTI), including Fractional Anisotropy and other diffusion parameters. Secondary outcomes include pain intensity, disability, spinal alignment, and adverse events.

The purpose of this study is to determine whether a targeted posture-correction exercise approach provides greater improvement than conventional physiotherapy.

Lumbar radiculopathy is a neuromusculoskeletal disorder commonly caused by lumbar disc herniation or foraminal stenosis leading to nerve root irritation or compression. Symptoms commonly include radiating leg pain, paresthesia, weakness, altered reflexes, and reduced physical function.

Conservative physiotherapy is recommended as first-line management and may include education, graded exercise, mobility restoration, strengthening, neural mobilization, and symptom management. However, treatment response is heterogeneous, and many patients continue to experience persistent symptoms.

Most previous rehabilitation studies have relied primarily on patient-reported outcomes such as pain and disability. These measures are clinically important but may not fully reflect biological recovery of the affected nerve root.

Diffusion Tensor Imaging (DTI) is an advanced magnetic resonance imaging technique that can quantify neural tissue microstructure. Parameters such as Fractional Anisotropy (FA), Mean Diffusivity (MD), Axial Diffusivity (AD), and Radial Diffusivity (RD) may provide objective markers of nerve recovery.

Mirror Image Spine Correction Exercises are individualized posture-based exercises designed to move the trunk or pelvis opposite to identified alignment deviations. This approach may improve biomechanics, reduce abnormal loading, and decrease neural irritation.

This study is a prospective randomized, parallel-group, superiority trial. Eligible adults with unilateral lumbar radiculopathy will be randomly allocated in a 1:1 ratio to:

Mirror Image Spine Correction Exercise group Standardized Conservative Physiotherapy group Both groups will receive supervised treatment sessions three times per week for 12 weeks.

Primary Outcome:

Change in lumbar nerve root microstructural integrity measured by DTI at baseline and week 12.

Secondary Outcomes:

Pain intensity Disability (Oswestry Disability Index) Spinal alignment Safety outcomes and adverse events The study aims to determine whether Mirror Image Spine Correction Exercises produce superior clinical and imaging outcomes compared with conservative physiotherapy.

Inclusion Criteria:

• Adults aged 18 years or older. Clinical diagnosis of unilateral lumbar radiculopathy. Presence of at least two of the following: dermatomal radiating leg pain, neurological deficit, positive neural tension test.

MRI-confirmed lumbar nerve root compression or irritation consistent with symptoms.

Pain intensity of 3/10 or greater. Able to undergo MRI and Diffusion Tensor Imaging (DTI). Able to understand study procedures and provide written informed consent.

Exclusion Criteria:

• Previous lumbar spine surgery. Bilateral radiculopathy or unclear diagnosis. Tumor, infection, fracture, inflammatory spinal disease, or cauda equina syndrome.

Severe progressive neurological deficit requiring urgent treatment. Contraindications to MRI (pacemaker, incompatible implants, severe claustrophobia).

Recent lumbar injections or surgery. Other neurological or musculoskeletal disorders affecting outcomes. Pregnancy if MRI contraindicated by local policy. Cognitive impairment or inability to follow instructions.

De-identified individual participant data may be shared upon reasonable request after publication, subject to ethics approval, institutional policy, and participant confidentiality protections.

De-identified individual participant data and supporting documents will be available beginning 6 months after publication of the primary study results and will remain available for at least 5 years thereafter, subject to institutional data retention policies.

Qualified researchers with a methodologically sound proposal may request access to de-identified individual participant data, study protocol, statistical analysis plan, informed consent materials, and analytic code. Requests will be reviewed by the study investigators and institution to ensure scientific merit, participant confidentiality, and compliance with ethical approvals. Data will be shared through secure controlled-access electronic transfer following approval of a data use agreement where required.

Outcome assessors and imaging analysts will be blinded to group allocation where feasible. Participants and treating physiotherapists cannot be blinded due to the nature of exercise interventions.