Résumé
INTRODUCTION: About 10 million people have low back pain (LBP) disability in Brazil. Several therapies are used to treat this condition, such as kinesiotherapy, manual therapy (MT), and photobiomodulation (PBM). Although the use of these methods in LBP has been investigated, studies evaluating the efficacy of the association between these techniques are still needed. OBJECTIVE: To evaluate the activation of the lumbar region muscles by PBM or MT associated with kinesiotherapy for the treatment of LBP. METHODS: Twenty individuals with chronic LBP were randomlydivided into two groups. The first group (MT) received vertebral mobilization associated with a kinesiotherapy exercise program. The second group (830nm-PBM) received PBM associated with the exercise program, twice a week for 8 weeks. Evaluation of pain perceived was performed by the visual analogic scale (VAS), lumbar disability by the Oswestry questionnaire, muscle strength by strain gauge, and activation through surface electromyography (EMG). Data were collected before and after the treatment. EMG data was analyzed by MatLab®. The ANOVA two-way test was used (degree of significance p≤0.05), and the size of the effect by the Hedge test. RESULTS: Considering pain, the two groups presented a significant result (p<0.05). In muscle activation, only the multifidus was different during the side bridge (p<0.05) when compared intragroup. None of the variables were different when evaluating intergroup. CONCLUSION: Both MT and PBM associated with kinesiotherapy for 8 weeks are effective in reducing pain, and improving motor control and stability of the lumbar spine in patients with chronic LBP.