Contralateral Neural Tissue Mobilization for Cervical Radiculopathy

Background and Rationale:

Pain phenotyping has emerged as an important clinical framework within physical therapy, enabling classification of pain presentations on the basis of pain mechanisms, clinical features, and patient-reported symptoms. Current pain phenotyping models identify three primary mechanisms: nociceptive, peripheral neuropathic, and nociplastic pain. Peripheral neuropathic pain is estimated to account for approximately one-quarter of patients presenting to outpatient physical therapy. It is characterized by pain arising from a lesion or disease of the somatosensory nervous system, with complex underlying biological mechanisms including neurogenic inflammation, immune dysregulation, demyelination, axonal loss, ion channel changes, and vascular alterations. Clinically, peripheral neuropathic pain commonly presents with pain in dermatomal or cutaneous nerve distributions, a history of nerve injury or mechanical compromise, and symptom provocation during neurodynamic or palpatory testing.

Cervical radiculopathy (CR) is a frequent and well-recognized form of peripheral neuropathic pain. CR most often results from intervertebral disc herniation or spondylosis, typically affecting the C7, C6, and C8 nerve roots. Patients commonly present with neck pain, upper extremity pain, and/or sensory, motor, or reflex deficits. Current evidence suggests that when patient presentation aligns with a peripheral neuropathic phenotype, interventions should be matched accordingly. Neural tissue mobilization (NTM) has demonstrated effectiveness in individuals with chronic neck and arm pain and is believed to exert beneficial effects through improvements in neuromeningeal mobility, blood flow, intraneural and extraneural fluid dynamics, inflammatory modulation, and graded exposure to movement.

However, some patients with CR present with significant allodynia, hyperalgesia, or fear of movement, making direct treatment of the symptomatic extremity challenging. Basic neuroanatomy and preliminary research suggest that contralateral NTM may produce therapeutic effects similar to ipsilateral NTM. Although early work in the lower extremity-including one clinical trial and one case study-has shown that contralateral NTM can reduce pain related to lumbar radiculopathy, this concept has not yet been explored in the upper extremity. Therefore, this exploratory study seeks to examine whether contralateral NTM produces immediate positive effects in patients presenting to physical therapy with CR.

Study Design:

This investigation uses a case-series design with pre- and post-intervention measures. A convenience sample will be recruited from four outpatient physical therapy clinics specializing in musculoskeletal pain. Clinicians participating in the study must have completed at least a 2-day (15-hour) post-professional training course in pain science and assessment of peripheral neuropathic pain, including instruction in NTM.

A total of approximately 40 patients aged 18 years or older will be recruited over a 3-month period. Eligible individuals must demonstrate unilateral arm pain in a dermatomal distribution consistent with CR, with or without neck pain. Exclusion criteria include bilateral upper-extremity pain, non-dermatomal pain, contraindications to NTM on the contralateral limb (e.g., recent surgery, significant tissue injury, allodynia), inability to read English, or unwillingness to consent.

Procedures and Outcome Measures:

After obtaining written informed consent, participants will complete baseline (pre-intervention) measures including:

Demographic questionnaire (non-identifiable data only)

Numeric Pain Rating Scale (NPRS) for upper-extremity pain

Neck Disability Index (NDI)

Fear-Avoidance Beliefs Questionnaire - Physical Activity subscale (FABQ-PA)

Pain drawing, quantified using a standardized grid overlay

Upper Limb Neurodynamic Test 1a (ULNT1a) of the affected limb, including goniometric measurement of elbow extension at symptom onset

Following baseline measures, each participant will receive a single treatment session of contralateral NTM, performed on the limb opposite the symptomatic side. The intervention consists of 8-10 minutes of standardized passive neurodynamic mobilizations in supine with specific variations in cervical positioning, followed by active "slider" and "tensioner" exercises in sitting.

Immediately after the intervention, participants will repeat all outcome measures (NPRS, FABQ-PA, pain drawing, and ULNT1a). After data collection is complete, clinical care will proceed according to the treating clinician's usual practice and will not be influenced by study procedures.

Data Handling and Analysis:

All data packets will be de-identified and coded by clinic and clinician. Data will be transferred to a secure electronic spreadsheet for analysis. Descriptive statistics (means, standard deviations, frequencies, and percentages) will summarize demographic variables and baseline characteristics. Pre- to post-intervention changes will be evaluated using paired t-tests with statistical significance set at p \< 0.05.

Purpose of the Study:

The purpose of this exploratory case series is to determine whether contralateral neural tissue mobilization produces immediate changes in pain intensity, disability, fear-avoidance beliefs, pain distribution, and neurodynamic mechanosensitivity among individuals presenting with clinical features of cervical radiculopathy. Findings may inform future research and contribute to clinical understanding of whether contralateral NTM is a viable treatment option in patients unable to tolerate direct treatment of the symptomatic extremity

• Neck Disability Index (NDI) [Time frame: Pre-intervention to immediately post-intervention (same session).]
• Fear-Avoidance Beliefs Questionnaire - Physical Activity Subscale (FABQ-PA) [Time frame: Pre-intervention to immediately post-intervention (same session).]
• Pain Drawing Area (Body Chart Grid Count) [Time frame: Pre-intervention to immediately post-intervention (same session).]