Low back pain is a significant public health condition and it is associated with a high rate of absenteeism from work, disability, and frequent use of health services . Approximately 39% of the population suffers from low back pain at some stage in their lives [2, 3]. The Brazilian National Survey by Household Sample (PNAD, 2010)  ranked back pain as the second most prevalent health condition after systemic arterial hypertension . This high prevalence explains the vast amounts expended on treatment for patients with this condition. The most recent systematic review on the cost associated with low back pain indicates that the majority of direct costs were spent on physiotherapy (17%), followed by medication (13%) and other primary health care (13%), however these costs account for less than 20% of the total costs of this condition, i.e. most of the costs are related to indirect expenses with absenteeism from work and lower productivity .
Current literature provides several possibilities for the treatment of low back pain that vary according to duration of symptoms and classification of this condition [6, 7]. These treatments range from educational programs  to behavioural cognitive therapy , medication , electrophysical agents , manual therapy [12–14] (e.g. joint mobilisation/manipulation, myofascial release), general exercises  and specific spinal stabilisation exercises , among others . Although clinical practice guidelines recommend the aforementioned treatments for patients with chronic nonspecific low back pain, most randomised controlled trials, from which the guidelines are taken, have shown that these treatments provide only mild to moderate clinical improvement in these patients when used in isolation [7, 12, 16]. These same clinical practice guidelines also state that there is no difference between the various modalities of exercise-based therapy as well as the various manual therapy techniques .
Given the modest clinical improvement and the lack of a leading therapy, new interventions are being tested within the variety of physiotherapy techniques to enhance the effect size of the treatment being used and thus increase patient satisfaction. A new treatment option that is very popular in athletes is the Kinesio Taping and it is being widely used in patients with low back pain. This method was created in Japan by Kenso Kase in the 70's . The technique uses an elastic tape that is extremely thin and much more elastic than conventional bandages and applies it to the patient’s skin. This tape can be stretched to 140% of its original length, producing less mechanical retention and restriction to movement . During assessment, the therapist decides which technique and level of traction to give the bandage, generating more or less tension on the skin. According to its developers, this traction elevates the epidermis increasing the pressure on the mechanoreceptors below the dermis, thus decreasing nociceptive stimuli. The creators of the Kinesio Taping also state that the tape is able to improve blood and lymphatic circulation, reduces pain, realigns joints, and reduces muscle tension [17, 18]. Additionally, the use of Kinesio Taping is likely to change the pattern of recruitment of muscle fibres [18–20]. In the case of the latter, which involves great activation of the paravertebral musculature in response to pain, it is expected that the use of bandages (such as Kinesio Taping) would inhibit this excessive activation, thus increasing range of motion and, subsequently, will improve functionality and would reduce pain intensity [19–21].
There are three systematic reviews on the use of the Kinesio Taping in patients with musculoskeletal conditions [22–24]. All reviews were consistent in concluding that there is no high-quality evidence of the use of Kinesio Taping in patients with musculoskeletal conditions, including patients with chronic low back pain. However, most of the clinical trials used Kinesio Taping in isolation, had small samples, and had high risk of bias. From a pragmatic standpoint, Kinesio Taping is not used by physiotherapists as an isolated form of intervention, but as an additional component in the treatment of patients with low back pain in order to increase and prolong the effect of pain reduction and disability in these patients.
Given that most patients with chronic nonspecific low back pain receive a variety of interventions within the scope of conventional physiotherapy (advice/counselling, manual therapy techniques, general exercise, and specific spinal stabilisation exercises), the present study intends to investigate whether the addition of Kinesio Taping to conventional physiotherapy treatment can provide greater pain relief and functionality than conventional physiotherapy alone in patients with chronic nonspecific low back pain.
The primary objective of this trial protocol will be to investigate the efficacy of the addition of the use of Kinesio Taping in relieving pain and improving disability in patients with chronic nonspecific low back pain treated according to the principles of conventional physiotherapy (based on the clinical practice guidelines) compared to patients treated only with conventional physiotherapy. An assessment will be conducted immediately after the treatment (5 weeks after randomisation) (primary outcomes).
The secondary objectives of this study will be:
To analyse the difference between the group that will receive Kinesio Taping in addition to conventional physiotherapy treatment and the group that will be treated only with conventional physiotherapy in the outcomes pain intensity (pain relief) and disability assessed 3 and 6 months after randomisation (secondary outcomes).
To analyse the difference between the group that will receive Kinesio Taping in addition to conventional physiotherapy treatment and the group that will be treated only with conventional physiotherapy in the outcome global perceived effect assessed 5 weeks, 3 months, and 6 months after randomisation (secondary outcomes).
To analyse the patient’s adherence to and satisfaction with the treatment (secondary outcomes).
The hypothesis of this study is that the patients with chronic nonspecific low back pain who receive conventional physiotherapy treatment in addition to Kinesio Taping will have greater reduction in pain intensity levels, better global perceived effect, and less disability compared to patients who receive only conventional physiotherapy treatment as assessed immediately after the 5 week intervention and that these benefits will be maintained until the reassessments 3 and 6 months after randomisation.