H-Reflex-Guided Direction-Sensitive Exercise Versus Standard Extension Exercise for Functional Recovery in Patients With Lumbar Disc Prolapse

This study will be conducted as a two-arm, parallel-group randomized controlled trial to compare H-reflex-guided direction-sensitive exercise with standard extension exercise in patients with lumbar disc prolapse. The study will recruit adults with clinically diagnosed lumbar disc prolapse and associated low-back and/or radiating leg pain who meet the predefined eligibility criteria. Participants will be randomly allocated in a 1:1 ratio to the experimental or control group. The trial will follow a prespecified protocol describing participant recruitment, randomization, treatment delivery, outcome assessment, adherence monitoring, and safety procedures, consistent with recommendations for transparent randomized-trial protocols.

The experimental group will receive H-reflex-guided direction-sensitive exercise. Before treatment, the participant's clinical response to different lumbar movement directions will be assessed together with soleus H-reflex responses. The exercise direction will then be selected according to the direction associated with the most favorable clinical and neurophysiological response. The program may include repeated directional movements, symptom-guided progression, postural correction, functional movement training, and home exercises. Exercise direction, intensity, repetitions, and progression will be individualized and documented for each participant.

The control group will receive a standardized extension-exercise program based on a predefined clinical protocol. Both groups will receive treatment for the same duration and number of sessions and will be provided with standardized advice regarding posture, activity modification, and safe home exercise. Treatment will be delivered by a trained physiotherapist, and adherence will be recorded through attendance logs and home-exercise diaries. Any clinically important worsening of pain, neurological symptoms, or functional status will be documented and managed according to the safety protocol.

Assessments will be completed at baseline, after 8 weeks of treatment, and at the predefined follow-up visit. The primary outcome will be the change in the Oswestry Disability Index score from baseline to 8 weeks. Secondary outcomes will include soleus H-reflex amplitude, H-reflex latency, the H/H ratio, H-reflex recovery following OSP, low-back pain and leg pain measured using the Numeric Pain Rating Scale, straight-leg-raising performance, lumbar range of motion, functional performance, and the Global Rating of Change. Outcomes will be measured using standardized procedures at each assessment time point, and the assessor will be blinded to treatment allocation whenever feasible.

The soleus H-reflex will be assessed using standardized electrophysiological procedures by a trained examiner. H-reflex amplitude, latency, and related recovery measures will be recorded under consistent testing conditions, including standardized participant positioning and stimulation procedures. Clinical outcomes will include patient-reported pain and disability, physical examination findings, lumbar mobility, and a predefined functional-performance test. The exact definition and procedure for "H-reflex recovery in OSP" must be specified in the final protocol before ethical approval and participant recruitment.

The analysis will compare changes between groups over time, with particular emphasis on the group-by-time interaction. The primary analysis will follow the intention-to-treat principle whenever possible. Treatment effects will be reported using between-group mean differences or adjusted mean differences with 95% confidence intervals, together with appropriate standardized effect estimates. Missing data, protocol deviations, adverse events, and treatment adherence will be reported transparently. This approach will allow the study to determine whether an individualized neurophysiological exercise strategy provides additional clinical and functional benefits over standard extension exercise

• H-Reflex-Guided Direction-Sensitive Exercise (Other): H-Reflex-Guided Direction-Sensitive Exercise (H-RGDSE) is an individualized physiotherapy intervention in which the participant's lumbar posture and movement direction are selected according to changes in the soleus H-reflex. The H-reflex is recorded using surface electromyography while the participant is tested in lying, sitting, standing, and different lumbar movement positions. Increased H-reflex amplitude is interpreted as a favorable response suggesting reduced neural compression, whereas a reduced response indicates a position or direction that should be avoided. Intervention Procedure Baseline assessment: Record pain intensity, neurological findings, range of motion, functional limitations, and baseline soleus H-reflex amplitude on the symptomatic and asymptomatic sides. H-reflex testing: Measure the soleus H-reflex during unloading and loading positions, including supine or prone lying, sitting, standing, lumbar flexion, extension, side bending, rotation, and relevant combine
• Standard Lumbar Extension Exercise (Other): Standard Lumbar Extension Exercise is a standardized physiotherapy program intended to improve lumbar extension mobility, promote upright spinal posture, and strengthen the lumbar extensor muscles. The same exercise sequence is provided to all control-group participants, without using H-reflex findings to select the treatment direction. Exercise Components Prone lying: Lie face down with the legs relaxed and the pelvis supported comfortably. Prone-on-elbows extension: Slowly raise the upper trunk onto the elbows while keeping the pelvis and hips in contact with the mat. Prone press-ups: Place the hands beside the shoulders and gently press the upper body upward while keeping the pelvis relaxed. Standing lumbar extension: Stand with the feet apart and hands supporting the lower back, then gently lean backward while keeping the knees straight. Progressive strengthening: Add controlled trunk-extension, hip-extension, and functional upright-posture exercises as tolerated.

Primary outcomes

• Change in Oswestry Disability Index (ODI) Score [Baseline and immediately after the intervention.]: Functional disability related to low back pain will be assessed using the Oswestry Disability Index. The ODI consists of 10 items, each scored from 0 to 5. Item scores will be summed and converted to a percentage using the formula: ODI (%) = total score ÷ maximum applicable score × 100 The final score ranges from 0% to 100%, with higher scores indicating greater functional disability. If all 10 items are completed, the maximum possible score is 50. Unit of Measure: Percentage (%)

Secondary outcomes

• Change in H-Reflex Amplitude Millivolts (mV) [Baseline and immediately after the intervention.]: H-reflex amplitude will be measured using surface electromyography after electrical stimulation of the tested peripheral nerve. Amplitude will be calculated as the peak-to-peak voltage difference between the largest negative and positive deflections of the H-reflex waveform. unit of measurements: Millivolts (mV)
• Change in H-Reflex Latency Milliseconds (ms) [Baseline and immediately after the intervention.]: H-reflex latency will be measured from the onset of the electrical stimulus to the first deflection of the H-reflex waveform from the baseline. Multiple traces may be recorded and averaged to improve measurement reliability. Unit of Measure: Milliseconds (ms)

Sex: All, ages: 30 Years to 50 Years

Inclusion Criteria:

\- Adults aged 30-50 years.

Clinical diagnosis of lumbar disc prolapse or lumbar disc herniation.

Presence of low-back pain with unilateral or bilateral radiating leg pain consistent with lumbar radiculopathy.

Symptoms persisting for at least 4 weeks.

Pain intensity of at least 3/10 on the Numeric Pain Rating Scale.

Evidence of neurological involvement, such as dermatomal pain, paresthesia, sensory changes, or a positive straight-leg-raising or slump test.

Ability to understand and follow verbal and written instructions.

Ability to attend the scheduled physiotherapy sessions and outcome assessments.

Exclusion Criteria:

* Previous lumbar spine surgery.

Spinal fracture, tumor, infection, or inflammatory spinal disease.

Cauda equina syndrome or progressive/severe neurological deficit.

Severe or worsening muscle weakness.

Bilateral symptoms suggesting serious neurological involvement.

Hip, sacroiliac, or lower-limb pathology that may affect the outcomes.

Other neurological disorders that could influence H-reflex measurements.

Serious cardiovascular, metabolic, or systemic disease that contraindicates exercise.

Pregnancy.

Current participation in another physiotherapy or exercise program for the same condition.