One month of treatment through a back exercise program combined with KT or TENS on patients with CLBP showed an improvement in disability, intensity of pain, anxiety, depression, sleep pattern and pain thresholds. However, the combination of exercises with TENS improved more significantly the intensity of pain, disability and kinesiophobia at the end of the 4-week course of treatment.
CLBP is a significant health problem with high prevalence worldwide. It is associated with huge costs for society.31 Clinical practice guidelines show many of the interventions available to treat patients with CLBP, but the vast majority of interventions have a modest effect in reducing pain and disability.32
An intervention that has been widespread in recent years is the use KT.13,33 As recent studies that investigated the effect of a combination of exercise and KT on pain and stability in patients with CLBP34–36, our findings in terms of LBP pain were consistent with these results, which observing a highly significant difference in pain reduction, after four weeks of treatment with KT in conjunction with exercise. Although the mechanism through which KT acts on the conditions of the musculoskeletal system is still unclear, the most accepted hypothesis is that KT applies pressure to the skin or stretches the skin and that this external load can stimulate cutaneous mechanoreceptors (large fibers myelinated) and therefore inhibit pain transmission according to the theory of door control.37,38
In recent years, it has been theorized that this type of bandage can be useful to achieve an analgesic effect on the spine. A recent systematic review analysed this effect in patients with CLBP, finding statistically significant differences regarding the degree of pain between the group to which KT was applied and the group to which a placebo was applied35. In fact, a decrease in pain has been reported after the specific use of KT application (origin to insertion) in different pathologies.39–42 However, regarding the methodological quality of the selected articles, we found serious limitations in terms of the fulfilment of the defined criteria.
Concerning another of the techniques used in our study, some studies show that TENS therapy was effective in pain relief.41 TENS is a common modality for the treatment of musculoskeletal pain.43 According to the door control theory38, TENS can stimulate large diameter afferent fibers, which can reduce the transmission of pain signals through the small nociceptive of afferent fibers, thus inhibiting pain discrimination and perception. In our study, it has been observed how the TENS have produced a significant improvement, in the threshold of pressure pain (in the intragroup analysis, based on pre-post-treatment), in all points examined bilaterally (L5-S1, gluteus medius, anterior sural and tibial triceps).
People with LBP usually show a 6-point improvement in the ODI19. Our estimation of the effect of KT on disability measures on the ODI is 7.5 points, which is a relatively good score compared to the gamma of possible scores on the ODI19, and compared to the initial score of the study participants.
For the TSK questionnaire, a variation of 1.33 points has been observed in patients treated with KT. In the article by Castro-Sánchez et al.44, the measurement of this variable is also reflected, showing a change of 2 points at 4 weeks after applying the treatment.
In both therapies, the presence of short-term placebo analgesic effects in response to the simulated control should support the use of the placebo protocol. The placebo analgesic responses are modulated through expectations regarding the treatment of pain and are regulated through responses to harmful stimuli in the spinal cord and brain, as well as the activation of descending pain by inhibitory pathways45.
The present study has some limitations. Firstly the small sample of patients, which may not be representative of the entire population of individuals with nonspecific CLBP thus affecting external validity. Secondly, we only investigated the short-term results of analgesic currents and a certain type of bandage with KT, and we could not conclude their longer-term effects, which deserve future research through randomized clinical trials. Finally, including a third group that only involves the performance of therapeutic exercise could help to better understand the individual contributions made by electroanalgesia and bandage to said therapy.
In conclusion, individuals with non-specific CLBP experienced a significant improvement in pain intensity and disability after receiving 12 treatment sessions that combined a back exercises program with KT or TENS, being greater in the group treated with TENS application. More future researches are needed to evaluate the effects of KT and electrotherapy over a longer period to observe the long-term effects.