Abstract
BACKGROUND: Chronic nonspecific neck pain (CNSNP) is a prevalent and complex condition. Although many studies have evaluated the effectiveness of transcutaneous electrical nerve stimulation (TENS), interferential current (IFC), therapeutic exercise (TE), and manual therapy (MT) individually, this study aimed to determine whether adding IFC and/or TENS to a Multimodal Therapeutic Intervention Program (MTIP) would produce better outcomes than the MTIP alone concerning functional capacity, pain intensity, pain catastrophising, kinesiophobia and overall perceived effect in individuals with CNSNP. METHODS: Seventy-five individuals with CNSNP were randomly assigned to one of three groups: MTIP, MTIP + IFC, or MTIP + TENS. Interventions were conducted over 8 weeks. Outcomes were assessed at baseline, post-intervention, and at a 1-month follow-up. The primary outcome was the Neck Disability Index (NDI). Secondary outcomes included the Numeric Pain Rating Scale (NPRS) at rest and during movement, the Pain-Related Catastrophizing Thoughts Scale (PRCTS), the Tampa Scale for Kinesiophobia (TSK), the Copenhagen Neck Functional Disability Scale (CNFDS), the WHO Disability Assessment Schedule (WHODAS 2.0), and the Global Perceived Effect Scale (GPES). RESULTS: No significant differences were observed between groups for the primary outcome. For secondary outcomes, the MTIP group showed improved results for NPRS-m and CNFDS. Additionally, MTIP was superior to MTIP + IFC for NPRS-r post-intervention, while MTIP + TENS outperformed both groups at follow-up. No significant differences were found for GPES, and none of the differences reached clinical significance. CONCLUSIONS: The addition of IFC and/or TENS to an MTIP did not enhance clinical outcomes in individuals with CNSNP. SIGNIFICANCE: The results of this study assist clinicians in making informed decisions regarding the selection of therapeutic resources for managing chronic nonspecific neck pain. They also support researchers in refining and conducting new studies focused on improving the implementation of multimodal intervention protocols. Additionally, these findings help individuals with chronic nonspecific neck pain better understand which interventions may be most appropriate to include in their rehabilitation process. TRIAL REGISTRATION: NCT05400486.