Transcutaneous Electrical Nerve Stimulation Versus Interferential Therapy, Each Combined with Neck Strengthening Exercises, in the Management of Cervical Radiculopathy: A Critical Narrative Review

Abstract

Cervical radiculopathy is a debilitating condition that arises when one or more cervical nerve roots are compressed or chemically irritated, producing radicular pain, sensory disturbance, and motor dysfunction in the corresponding dermatomal and myotomal distributions. Conservative physiotherapy remains the cornerstone of initial management, and electrotherapy — most commonly transcutaneous electrical nerve stimulation (TENS) and interferential therapy (IFT) — is routinely paired with structured therapeutic exercise. Yet despite how widely both modalities are used, the comparative efficacy of TENS combined with neck strengthening exercises against IFT combined with neck strengthening exercises has never been comprehensively characterised in the published literature. This critical narrative review brings together the available mechanistic and clinical evidence on both treatment combinations. TENS works largely through gate-control inhibition at the spinal dorsal horn and through activation of endogenous opioid pathways, offering analgesia that the patient can apply and control directly. IFT, by contrast, delivers medium-frequency alternating currents whose interference generates therapeutically active beat frequencies at greater tissue depth, which may give it an advantage in reaching deeper cervical structures while producing less skin discomfort. When either modality is paired with structured neck strengthening exercises that target the neuromuscular deficits and biomechanical vulnerabilities sustaining nerve root irritation, both appear to produce clinically meaningful gains in pain intensity, functional disability, and cervical range of motion. The evidence available to date does not point to a consistent advantage for one combination over the other. Practical factors — TENS's portability and suitability for self-management against IFT's depth-penetration profile and the treatment fidelity that comes with clinic-based supervision — may reasonably tip clinical decision-making in the absence of a clear superiority signal from trials. What is genuinely needed going forward is a properly powered, direct head-to-head randomised trial using standardised electrotherapy parameters and a comprehensive outcome battery.