Group Pilates to reduce chronic low back pain in Primary Health Care users

INTERVENTION: This is a single‐blind, two‐arm, parallel‐group randomized controlled trial. A total of 100 participants will be recruited and randomly allocated in a 1:1 ratio to either the intervention group (50 participants) or the control group (50 participants). Randomization will be performed using a computer‐generated block randomization sequence after completion of the baseline assessment. The study will be single‐blinded, in which the outcome assessors will remain blinded to participants' group allocation, whereas the participants and the researcher responsible for the intervention will be aware of the assigned group. The intervention group will participate in a supervised group‐based classical Mat Pilates program consisting of 24 face‐to‐face sessions conducted twice a week for 12 weeks by a trained Physical Education professional, following a standardized protocol with progressive exercises based on the principles of the classical Mat Pilates method. The control group will receive an educational booklet containing home‐based exercises for the management of chronic nonspecific low back pain, accompanied by standardized initial instructions for performing the exercises at home during the same 12‐week period, without continuous supervision. All participants will undergo outcome assessments before and after the intervention using the instruments specified in the study protocol. CONDITION: C05.651.538 Chronic low back pain ; Musculoskeletal Pain PRIMARY OUTCOME: To evaluate the reduction in low back pain intensity using the Numeric Pain Rating Scale. Scores obtained before the intervention and after 12 weeks will be compared, observing the change in pain intensity between both assessment time points. SECONDARY OUTCOME: To evaluate functional disability using the Oswestry Disability Index. Scores obtained before the intervention and after 12 weeks will be compared, observing the change in functional disability between both assessment time points. To evaluate functional performance using the 30‐second Sit‐to‐Stand Test. The number of repetitions performed before the intervention and after 12 weeks will be compared, observing the change in functional performance between both assessment time points. To evaluate global perceived improvement using the Global Perceived Effect Scale. The score obtained by participants after 12 weeks of intervention will be observed, indicating their perceived overall change compared with the beginning of the study. To evaluate patient‐specific functional ability using the Patient‐Specific Functional Scale. Scores obtained before the intervention and after 12 weeks will be compared, observing the change in patient‐specific functional ability between both assessment time points. To evaluate quality of life using the World Health Organization Quality of Life Instrument – Brief Version. Scores obtained before the intervention and after 12 weeks will be compared, observing the change in quality of life between both assessment time points. INCLUSION CRITERIA: Men and women; aged 45 to 65 years; registered at a Primary Health Care Unit; chronic nonspecific low back pain lasting more than three months; low back pain as the primary complaint at screening; clinical conditions allowing participation in group physical activities; no medical contraindication to physical exercise; willingness to participate by signing the Informed Consent Form