Introduction: Currently, clinical practice guidelines recommend exercise as a first-line approach to the treatment of chronic low back pain (LBP). On the other hand, passive techniques such as cupping therapy have gained space in the management of this population, however, important gaps regarding the combination of cupping therapy with active exercises in individuals with nonspecific chronic low back pain are still present in the literature. In this context, this protocol describes a sham-controlled, randomized and blinded study that aims to evaluate the additional effects of cupping therapy in association with McKenzie method exercises on pain and functional outcomes of individuals with nonspecific chronic low back pain. Methods: 108 individuals with nonspecific and localized chronic low back pain in the age group of 18 to 59 years will be recruited and evaluated, regarding the inclusion and exclusion criteria. Subsequently, they will be randomized to one of 2 groups: intervention group, in which they will be submitted to the McKenzie method intervention and later the addition of the dry suction cup; and sham group, in which, after the intervention of the McKenzie method, the application of the sham cup will be added.

The individuals will be classified and treated according to the McKenzie method (MDT) and then they will receive the application of cups in parallel to the vertebrae from L1 to L5, bilaterally. Interventions will be carried out twice a week for eight weeks. Volunteers will be evaluated before treatment (T0), immediately after the first intervention (T1), with 4 weeks of intervention (T4) and with 8 weeks of intervention (T8)

The individuals will be classified and treated according to the McKenzie method and then they will receive the application of cups in parallel to the vertebrae from L1 to L5, bilaterally. Interventions will be carried out twice a week for eight weeks. Volunteers will be evaluated before treatment (T0), immediately after the first intervention (T1), with 4 weeks of intervention (T4) and with 8 weeks of intervention (T8). The primary outcome will be physical function, functionality (Timed Up and Go test), while the secondary outcomes will be pain intensity (Numerical Pain Scale), lumbar range of motion (finger to floor test), patient expectation and patient perception (Global Perceived Effect Scale).

Inclusion Criteria:

• Individuals, male and female, 18 to 59 years, non-obese, with non-specific localized LBP for more than 3 months;
• Report pain intensity between 3 and 8 according to the numerical pain scale;

Exclusion Criteria:

• Have previously performed cupping therapy in some body segment;
• Present neurological, vestibular, visual or auditory deficits that make assessments impossible;
• Being in the gestational period;
• Having severe spinal disease (including fractures, tumour, inflammatory diseases, or tumours);
• Have undergone previous spinal surgery;
• Present with radiating or sacroiliac back pain; another rheumatic disease such as fibromyalgia,or ankylosing spondylitis.

there is not a plan to make individual participant data (IPD) available to other researchers.

All assessments will be carried out by researcher A who will not be involved with the interventions and will remain blind to the identification of groups.

Each participant will remain identified by numbers and not names. Participants will be informed about the aim of the study to assess the additional effect of two different cupping techniques, the classic and the sham, in association with active exercise. In order not to compromise the blinding of the study, all participants will undergo the same assessment before the interventions. Intervention times will be differentiated so that there is no contact between the groups and possible exchanges of information. Data collected during participant assessments will not be revealed to the researchers responsible for the interventions.