This randomized clinical trial will evaluate whether adding Functional Magnetic Stimulation (FMS) to manual therapy (neurodynamic mobilization) improves clinical outcomes in adults with lumbar radiculopathy caused by lumbar disc herniation. Forty participants will be randomly assigned to two groups: an intervention group receiving manual therapy combined with FMS and a control group receiving manual therapy alone. All participants will complete a three-week physiotherapy program consisting of ten treatment sessions. Outcomes will be assessed at baseline and at the end of the three-week intervention period. Primary outcomes include pain intensity (Numeric Pain Rating Scale, NPRS), functional disability (Roland-Morris Disability Questionnaire, RMDQ), straight leg raise (SLR) range of motion measured with goniometry, and neuropathic symptom characteristics (S-LANSS, Greek). The study aims to determine whether the addition of FMS produces superior clinical improvements compared with manual therapy alone.

Background: Lumbar disc herniation with radiculopathy is a common musculoskeletal and neurological condition caused by compression or irritation of the lumbar nerve roots, often leading to radiating leg pain, paresthesia, and movement limitation. Neural (neurodynamic) mobilization is a manual physiotherapy technique aiming to restore the mechanical and physiological interface between neural tissues and their surrounding structures, thereby improving nerve mobility and reducing mechanosensitivity. Functional Magnetic Stimulation (FMS) is a non-invasive modality that induces deep neuromuscular activation through rapidly changing magnetic fields, potentially enhancing circulation, muscle recruitment, and neural responsiveness. Although FMS has shown promise in both neurological and musculoskeletal disorders, its combined use with neural mobilization in patients with lumbar radiculopathy has not yet been evaluated in a controlled clinical environment.

Aim: This randomized controlled trial aims to investigate the effectiveness of combining manual therapy with Functional Magnetic Stimulation in adults with chronic lumbar radiculopathy due to lumbar disc herniation. The primary objective is to determine whether the combined intervention provides greater reductions in pain, improved functional capacity, and better neuropathic symptom profiles compared with manual therapy alone.

Method: Forty adults aged 18-64 years with clinically and MRI-confirmed lumbar radiculopathy will be randomly assigned to two groups. The intervention group will participate in a three-week physiotherapy program consisting of manual therapy techniques and Functional Magnetic Stimulation applied 3-4 times per week (10 sessions total). The control group will receive the same manual therapy protocol without FMS. Outcomes will be assessed at baseline and at the end of the three-week intervention period. Primary outcome measures include pain intensity (Numeric Pain Rating Scale, NPRS), functional disability (Roland-Morris Disability Questionnaire, RMDQ), straight leg raise (SLR) angle measured with a goniometer, and neuropathic pain features (S-LANSS, Greek). A mixed-model repeated-measures ANOVA will be used for statistical analysis, with significance set at p < .05.

Expected Results: It is anticipated that individuals receiving the combined manual therapy and FMS intervention will demonstrate greater improvements in pain intensity, functional capacity, and neuropathic symptom characteristics compared with those receiving manual therapy alone.

Participants will be eligible for enrollment if they meet all of the following conditions:

• Adults aged 18 to 64 years with a diagnosis of unilateral lumbar disc herniation with radiculopathy (LDHR), established by a spine specialist and confirmed by lumbar MRI demonstrating disc pathology at L4/L5 or L5/S1 impinging on the corresponding nerve root.
• Presence of sciatica-dominant symptoms (radiating pain following the sciatic nerve distribution), accompanied by a positive Straight Leg Raise response consistent with nerve root irritation.
• Symptom duration of at least 12 weeks, indicating a chronic and stable clinical presentation without major fluctuations.
• Referral for physiotherapy management as part of conservative care.
• Ability to comprehend study procedures and provide written informed consent prior to participation.

Exclusion Criteria:

• Candidates will be excluded if any of the following conditions are present:
• Clinical "red flag" indicators such as cauda equina syndrome, suspected spinal infection, or oncologic disease.
• Bilateral radicular involvement or symptoms inconsistent with a single-level LDHR.
• Previous lumbar spine surgery or an upcoming surgical intervention scheduled during the study period.
• Receipt of invasive pain-management procedures (e.g., epidural steroid injections) within the last six weeks.
• Coexisting severe neurologic, metabolic, or inflammatory rheumatologic diseases unrelated to the lumbar radiculopathy.
• Contraindications to magnetic stimulation, including pacemakers, spinal or peripheral neurostimulators, cochlear implants, or clinically significant metallic implants in the stimulation field.
• Pregnancy or breastfeeding.

Single (Outcomes Assessor) A masked assessor will conduct the measurements