Does the Type of Electrotherapy Impact the Effectiveness of Complex Physiotherapy Administered to Individuals with Neck Pain?

Background: The widespread prevalence of neck pain (NP) is a serious healthcare and social problem, and the question of which components of physiotherapy are most effective is still valid. Objectives: The objective of this study was to assess the effect of the type of electrotherapy applied on the outcomes of complex physiotherapy administered to individuals with NP. Methods: In line with the study protocol, 100 individuals with NP were enrolled and randomly divided into four groups. All groups received kinesiotherapy and phototherapy. Additionally, each group also received electrotherapy treatment, which was a differentiating factor. Participants were assessed at baseline, post-intervention, and after six months. The examination involved evaluation of pain using VAS and measurement of the cervical range of motion (ROM). Overall, seven parameters were assessed during each examination. Results: Pain intensity decreased in all individuals across the three study periods. A large effect size and changes exceeding the Minimal Clinically Important Difference (MCID) were observed only in the electrotherapy groups. The improvement in cervical spine ROM was comparable in the HF and LF TENS groups in the short- and long-term perspectives; however, a greater number of effects (p < 0.05) was observed in the HF TENS group. TC resulted only in large and moderate short-term effects reflected by improvements in cervical spine ROM. In the PLACEBO group, moderate long-term effects were observed. Conclusions: Low-frequency currents appear to improve the analgesic effectiveness of complex physiotherapy implemented in individuals with NP. TC may provide better short-term effects compared to long-term effects reflected by improvements in cervical spinal ROM. The effects in the PLACEBO group may suggest that phototherapy and kinesiotherapy are more effective due to the continuation of exercise and the education in ergonomics of work.