A Standardized Protocol Combining McKenzie Mechanical Therapy and Neurodynamic Techniques for Cervical Radiculopathy

Summary

This protocol describes a standardized clinical intervention for cervical radiculopathy using McKenzie Mechanical Therapy (MMT) and Neurodynamic Treatment (NDT), with cervical range of motion, pain intensity (Visual Analog Scale, VAS), and functional disability (Neck Disability Index, NDI) as primary outcomes.

Abstract

Cervical radiculopathy is a common clinical condition associated with nerve root compression, pain, sensory symptoms, and functional limitation. This protocol describes a standardized clinical intervention that combines McKenzie Mechanical Therapy (MMT) with Neurodynamic Treatment (NDT) for patients with cervical radiculopathy. The approach stratifies treatment according to symptom irritability and provides a structured workflow for patient selection, clinical assessment, intervention delivery, intensity adjustment, and outcome evaluation. Cervical range of motion, pain intensity measured using the Visual Analog Scale, and functional disability assessed using the Neck Disability Index are used as primary outcomes. In a 2-week pilot clinical trial, 33 eligible patients were randomly assigned to either an MMT group or a combined MMT-NDT group. All participants completed the intervention without treatment-related adverse events, indicating good feasibility and safety. Both groups showed clinical improvement, while the combined MMT-NDT approach produced greater improvements in cervical motion, pain reduction, and functional recovery. These findings suggest that integrating NDT with MMT may provide a reproducible and clinically useful rehabilitation strategy for cervical radiculopathy.

Introduction

Neck pain has become increasingly prevalent among individuals with prolonged use of electronic devices, and cervical radiculopathy (CR) represents a common clinical subtype associated with nerve root compression and inflammation at or near the intervertebral foramen¹.

Management strategies include both surgical and conservative approaches, with up to 75% of patients achieving symptom relief through non-surgical treatment². Common conservative interventions include immobilization, anti-inflammatory medication, physical therapy, cervical traction, and epidural steroid injections. Among these, physical therapy is widely adopted due to its accessibility and targeted effects³.

McKenzie Mechanical Therapy (MMT) is a classification-based approach that guides treatment according to mechanical loading responses and symptom behavior². By using repeated movements and specific postures, MMT aims to restore musculoskeletal balance and reduce mechanically induced nerve root irritation. While this mechanically driven intervention successfully addresses structural tension and compression in CR, its clinical impact remains limited against non-mechanical, biochemical inflammatory pain.

Neurodynamic Techniques (NDT) have emerged as an approach that targets the mechanical and physiological functions of peripheral nerves. By improving neural mobility and reducing mechanosensitivity, NDT may address both neuropathic and chemically mediated pain⁴. Recent clinical evidence suggests that neurodynamic interventions may provide superior outcomes compared with conventional physical therapy in patients with nerve-related pain^5,6,7.

Given the complementary mechanisms of MMT and NDT, their combined application may offer additional benefits. However, evidence regarding their synergistic effects remains limited⁸. The objective of this protocol is to provide a reproducible, standardized clinical intervention combining MMT and NDT for patients diagnosed with CR, and to evaluate the resulting short-term changes in objective cervical range of motion (ROM), pain intensity via the Visual Analog Scale (VAS), and neck-related functional disability using the Neck Disability Index (NDI).

Protocol

The First Affiliated Hospital of Sun Yat-sen University served as the primary study site, where participant recruitment and interventions were performed. This protocol was approved by the Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University (Approval No. [2019]407-1). Written informed consent was obtained from all participants prior to enrollment. This study was not prospectively registered in a clinical trial registry.

NOTE: Between April 2022 and October 2023, a total of 33 patients diagnosed with cervical radiculopathy were recruited from the Department of Rehabilitation at the First Affiliated Hospital of Sun Yat-sen University (Figure 1). Participants were randomly assigned to either the MMT group (n = 16) or the combined MMT-NDT group (n = 17). All interventions were delivered by licensed physical therapists from the same department.

1. Experimental setup

1. Utilize a standard random number table, managed by an independent statistician, to generate the random allocation sequence for all 33 participants.
2. Prepare thirty-three identical cards labeled either 'MMT' or 'MMT-NDT' in strict accordance with the pre-generated random allocation sequence, and seal each card individually in a sequentially numbered, opaque envelope to ensure allocation concealment.
3. Store the sealed envelopes in a locked cabinet managed by an independent study coordinator. Retrieve and open the envelopes in strict numerical order only after the participant has signed the informed consent form and completed all baseline assessments.
4. Ensure that all physical therapists administering the intervention are trained in cervical spine anatomy and proficient in both MMT and NDT used in this study.
5. Administer the intervention 5 times per week for 2 consecutive weeks, with each session lasting 30–40 min. Adjust the treatment approach based on the patient's symptoms, pain, and irritability, as well as the therapist's assessment.

2. Recruitment of patients

1. Screen patients presenting with clinical features of cervical radiculopathy (CR)—including upper limb pain or numbness along the affected nerve root—by performing the Spurling test, cervical distraction test, upper limb tension test (median nerve bias), and measuring ipsilateral cervical rotation.
   1. Confirm participant eligibility based on the presence of at least three positive findings out of the following four clinical criteria: the Spurling test, cervical distraction test, ipsilateral cervical rotation less than 60°, and the upper limb tension test⁹.
   2. Perform the Spurling test by seating the patient in an upright position and stabilizing the shoulder region. Passively guide the cervical spine into extension, lateral flexion, and rotation toward the symptomatic side, then apply a gentle downward axial compression through the apex of the patient’s head.
      NOTE: Consider the test positive if this maneuver reproduces the patient’s typical radicular symptoms in the ipsilateral upper limb.
   3. Perform the cervical distraction test by positioning the patient in either a seated or supine posture and grasping the occiput and mandible to stabilize the head. Subsequently, apply a slow, gentle traction force along the longitudinal axis of the cervical spine.
      NOTE: Consider the test positive if traction reduces or relieves the patient’s radicular symptoms.
   4. Assess ipsilateral cervical rotation by instructing the patient to actively rotate the head toward the symptomatic side while maintaining an upright posture. Quantify the maximal rotation angle using a standard goniometer or inclinometer to determine if the range of motion is less than 60°.
      NOTE: Record the test as positive if cervical rotation toward the symptomatic side is less than 60° or reproduces familiar symptoms.
   5. Perform the upper limb tension test with median nerve bias by positioning the patient supine; manually depress the shoulder girdle, abduct the arm to 90°, extend the wrist and fingers, supinate the forearm, gradually extend the elbow to provoke symptoms, and instruct the patient to actively side-bend the neck contralaterally.
      NOTE: Consider the test positive if the maneuver reproduces the patient’s typical symptoms, which are modified by cervical side bending.
2. Verify that imaging findings (X-ray or MRI) are consistent with the clinical presentation. Exclude patients with conditions unrelated to the cervical spine that could account for upper limb symptoms, including thoracic outlet syndrome, adhesive capsulitis, biceps tendinopathy, lateral epicondylitis, and carpal tunnel syndrome.
3. Exclude patients with tumors involving the head or neck, spinal or upper limb fractures, spinal instability, or spinal cord injury. Exclude patients with a history of cervical spine surgery or severe cervical osteoporosis. Screen for cognitive impairment and exclude patients unable to comply with the protocol.
4. Exclude patients with systemic pathological or metabolic conditions, such as early-stage diabetes mellitus or ankylosing spondylitis. Finally, exclude patients with severe cardiopulmonary disease who are unable to tolerate the intervention⁹.

3. Outcome Assessment

1. Measure Cervical ROM
   1. Position the patient in a seated upright posture with the thoracic spine supported and both feet flat on the ground. Instruct the patient to keep the shoulders relaxed and avoid compensatory trunk movements.
      NOTE: Use standard reference values for cervical ROM when interpreting patient measurements. Normal cervical ROM is approximately 45–50° for flexion, 60–70° for extension, 40–45° for lateral flexion, and 70–90° for rotation. Interpret any reduction in ROM relative to these reference ranges when assessing movement limitation and classifying symptom irritability.
   2. Use a cervical goniometer or inclinometer to measure active cervical movements in six directions: flexion, extension, left lateral flexion, right lateral flexion, left rotation, and right rotation. Instruct the patient to actively move the head to the maximal pain-free range in each direction. Avoid forcing the movement beyond the patient’s tolerance.
      NOTE: Stabilize the thorax manually if necessary to minimize compensatory motion during testing.
   3. Record each movement twice and use the average value for analysis. If a difference greater than 5 ° is observed between trials, perform a third measurement and record the mean of the closest two values.
   4. Ensure that the same assessor performs all measurements at baseline and after the 2-week intervention to reduce inter-rater variability.
2. Assess Pain Intensity Using the VAS
   1. Seat the patient in a quiet environment and allow at least 5 min of rest before assessment to minimize the influence of recent activity. Ensure that the patient is in a neutral sitting position without external support affecting the cervical spine.
   2. Provide the patient with a 10-cm horizontal VAS, with “0” indicating no pain and “10” indicating the worst imaginable pain. Instruct the patient using standardized wording: “Please indicate the average level of neck and arm pain you have experienced over the past 24 h.” Avoid leading or suggestive language during instruction.
      NOTE: Ensure the patient independently marks the scale without assistance. Do not provide feedback or interpretation during the process.
   3. Measure the distance (in cm) from the left endpoint (0) to the patient’s mark using a ruler and record the value to one decimal place. Repeat the assessment once. If the difference between the two measurements exceeds 1.0 cm, perform a third measurement and record the mean of the two closest values.
   4. Conduct all assessments at the same time of day before treatment to minimize diurnal variation. Ensure that the same assessor performs all measurements at baseline and after the 2-week intervention.
3. Evaluate Functional Status Using the NDI
   1. Seat the patient in a quiet environment and allow sufficient time to complete the questionnaire without interruption. Ensure that the patient is in a comfortable position and not experiencing acute symptom exacerbation during assessment.
   2. Provide the patient with the standardized NDI questionnaire, consisting of 10 items covering pain intensity and daily functional activities (e.g., personal care, lifting, reading, work, driving, sleeping, and recreation).
   3. Instruct the patient using standardized wording: “Please select one statement in each section that best describes your current condition.” Avoid providing guidance that may influence the patient’s responses. Ensure that the patient completes the questionnaire independently. Clarify only the meaning of the questions if necessary, without suggesting specific answers.
   4. Check the completed questionnaire immediately to confirm that all items have been answered. If any item is missing, ask the patient to complete it before scoring. Assign a score of 0–5 to each item and calculate the total score (0–50), with higher scores indicating greater disability. Convert the score to a percentage if required.
   5. Perform the assessment at baseline and after the 2-week intervention under consistent conditions. Ensure that the same assessor administers the questionnaire at both time points.
4. Classify Symptom Irritability: Assess pain intensity using a 10-cm VAS and measure active cervical ROM. Identify the most restricted movement and estimate the percentage reduction relative to normal values. Assign 0–2 points for VAS (0–3 = 0, 4–6 = 1, 7–10 = 2) and 0–2 points for ROM limitation (<25% = 0, 25–50% = 1, >50% or unable = 2).
5. Calculate the total score (0–4) and classify irritability as low (0–1), moderate (2–3), or high (4).
6. Conduct all outcome assessments by one independent therapist not involved in the intervention delivery, to ensure the accuracy of the results.

4. Intervention Procedures

1. Apply Treatment Based on Irritability
   1. High Irritability (Score = 4): Apply low-load, symptom-relieving techniques. Perform cervical retraction within a pain-free range (10 repetitions). Position the cervical spine in slight flexion or neutral for static opening. Perform low-amplitude neural sliding of the median nerve within tolerance (10 repetitions). Avoid end-range movements, overpressure, and neural tension techniques.
   2. Moderate Irritability (Score = 2–3): Apply directional preference-guided MMT combined with controlled NDT. Perform cervical retraction and progress to retraction with extension if centralization occurs (10–15 repetitions). Apply gentle overpressure at end range if tolerated. Perform neural sliding techniques with moderate excursion (10–15 repetitions).
   3. Low Irritability (Score = 0–1): Progress to higher-load and combined interventions. Perform retraction with extension and add lateral flexion or rotation as indicated (10–15 repetitions). Apply end-range overpressure to improve mobility. Perform neural tension techniques combined with cervical movement (10 repetitions).
2. MMT
   1. Assess symptom centralization by guiding the patient through repeated cervical movements in different directions. Identify the direction of movement that reduces distal symptoms and promotes centralization toward the midline. Select this direction as the primary treatment direction.
   2. Instruct the patient to sit or stand upright with the head in a neutral position. Guide the patient to retract the head posteriorly to the maximal range without flexion or extension. Maintain the end position for 2 s and return to the starting position. Instruct the patient to keep the eyes facing forward and avoid compensatory head tilting.
      NOTE: Apply overpressure at the end range by placing one hand on the chin and gently pushing posteriorly to increase the range of motion, if tolerated.
   3. Instruct the patient to retract the head fully, then slowly extend the cervical spine to the maximal range. Hold the end position for 2 s before returning to neutral. Apply gentle upward overpressure at the end range to increase extension, if tolerated.
   4. Instruct the patient to retract the head and then perform lateral flexion toward the affected side. Hold the end position for 2 s. Apply gentle overpressure at the end range to increase lateral flexion. Avoid cervical rotation during the movement.
   5. Instruct the patient to retract and extend the cervical spine, then perform small-amplitude rotations to both sides (4–5 repetitions) at the end range. Apply gentle rotational overpressure at the end range if tolerated.
   6. Instruct the patient to actively flex the cervical spine by bringing the chin toward the chest.
      Apply overpressure by placing both hands behind the head and gently increasing flexion at the end range for 1 s.
   7. Position the patient in supine with the head and upper thoracic region supported near the edge of the treatment table. Support the occiput with one hand and the mandible with the other hand. Apply a gentle, sustained traction force along the longitudinal axis of the cervical spine for 5–6 min. Monitor patient symptoms continuously.
      NOTE: Apply therapist-assisted traction when symptoms persist despite active exercises, or when cervical extension remains limited and is associated with neural compression signs.
   8. Maintain a low level of traction force and instruct the patient to perform cervical retraction followed by extension. Gradually reduce traction force at the end range without fully releasing it.
      Add small-amplitude cervical rotations (4–5 repetitions) while maintaining traction to increase extension range.
      ​NOTE: Introduce combined traction and movement when traction alone reduces symptoms but does not sufficiently improve range of motion or centralization.
3. NDT (MMT-NDT group only)
   1. Position the patient in supine and place a pillow under the cervical spine to achieve a comfortable flexion angle. Guide the cervical spine into lateral flexion and rotation toward the unaffected side. Maintain the position for 1 min while monitoring symptom response.
   2. Instruct the patient to maintain relaxed breathing and avoid shoulder elevation during movement. Median Nerve Sliding: Position the upper limb in 30–60° abduction with forearm supination and palm facing upward. Instruct the patient to alternate between elbow flexion with wrist and finger flexion and elbow extension with wrist and finger extension.
   3. Ulnar Nerve Sliding: Position the shoulder in external rotation and elbow flexion. Instruct the patient to alternate between wrist extension toward the shoulder and wrist flexion with elbow extension.
   4. Radial Nerve Sliding: Position the upper limb in slight abduction with internal rotation and wrist flexion. Instruct the patient to alternate between wrist flexion and extension within a comfortable range.
4. Perform Neural Tension Techniques
   1. Median Nerve Tension: Depress the shoulder girdle manually. Position the arm in abduction with elbow extension, forearm supination, and wrist/finger extension. Gradually increase abduction while instructing the patient to laterally flex the cervical spine to the contralateral side.
   2. Radial Nerve Tension: Depress the shoulder girdle. Position the arm in internal rotation with wrist and finger flexion and ulnar deviation. Increase shoulder abduction while maintaining cervical contralateral lateral flexion.
   3. Ulnar Nerve Tension: Depress the shoulder girdle. Position the shoulder in abduction and external rotation with maximal elbow flexion, forearm supination, and wrist extension. Instruct the patient to laterally flex the cervical spine to the contralateral side at end range.
5. Apply Dynamic Opening Technique
   1. Combine cervical positioning from the static opening technique with neural sliding or tension techniques. Adjust the combination based on symptom response. Apply static opening techniques during the acute stage. Progress to neural sliding techniques as pain decreases. Introduce neural tension techniques during the chronic stage.
   2. Administer NDT during each treatment session in the MMT-NDT group, within the same 30–40 min session duration.

5. Statistical analysis

1. Present the continuous variables as mean ± standard deviation (M ± SD). Analyze within-group pre/post changes using paired-samples t-tests. Between-group comparisons were conducted using independent-samples t-tests on post-treatment values. Effect sizes were calculated using Cohen’s d, and 95% confidence intervals were reported where appropriate. For multiple ROM outcomes, no formal adjustment for multiplicity was applied. All statistical tests were two-sided, and P < 0.05 was considered statistically significant. Statistical procedures and data visualizations were performed using statistical and graphing software.
2. Missing follow-up data were handled using the last observation carried forward (LOCF) method. Because the study included only two time points and a relatively small sample size, more advanced repeated-measures methods were not used.

Results

Feasibility and Safety: 33 enrolled patients completed the 2-week intervention without any treatment-related adverse events. The overall adherence rate was 100%, with no missed treatment sessions. All therapists implemented the protocol consistently, in accordance with the standardized procedures and symptom- and irritability-based adjustment guidelines, confirming the protocol's clinical applicability and reproducibility.

Baseline Characteristics: No significant differences were observed betw...

Discussion

This study developed a combined therapeutic protocol of MMT plus NDT for patients with CR, refined the detailed operational procedures, and conducted a preliminary clinical trial to evaluate its feasibility. Clinical findings demonstrated that the combined regimen was non-inferior to standalone MMT in improving cervical range of motion, pain intensity, and functional status, with comparable safety profiles. Moreover, the observed outcome trends implied therapeutic potential for the combined intervention. The combination ...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Treatment table (height-adjustable)	Chattanooga (DJO Global, USA)	N/A	Used for patient positioning and manual therapy
Cervical traction unit	Chattanooga (DJO Global, USA)	Triton Traction Unit	Used for therapist-assisted cervical traction
Universal goniometer	Fabrication Enterprises Inc., USA	N/A	Used to measure cervical range of motion
Digital inclinometer	JTECH Medical, USA	Dualer IQ Inclinometer	Used for precise ROM measurement
Visual Analog Scale (VAS) form	Custom printed	N/A	10-cm scale for pain assessment
Neck Disability Index (NDI) questionnaire	Standard instrument	N/A	Validated questionnaire for functional assessment
Treatment pillow	Any clinical brand	N/A	Used to support cervical alignment
Disposable gloves	Ansell, Australia	N/A	Used for hygiene
Alcohol wipes	3M, USA	N/A	Used for skin cleaning
Stopwatch	Casio, Japan	HS-80TW	Used to standardize treatment duration