Concurrent training after photobiomodulation in patients with knee osteoarthritis

Purpose: Purpose: To evaluate the aerobic conditioning, pain intensity, muscle strength, and functionality in patients with knee osteoarthritis after photobiomodulation associated with concurrent training. Methods: Triple-Blind Randomized Controlled Clinical Trial. Participants and Ethics: 30 patient women clinically diagnosed by orthopedists and rheumatologists, presenting with unilateral or bilateral knee OA according to the clinical criteria of the American College of Rheumatology and all participants will sign an informed consent form with instructions, approved by the ethics and research committee of the Federal University of São Paulo - Unifesp (number protocol 1.610.677) and approved by the Brazilian Registry of Clinical Trials - ReBEC), under the opinion RBR-7WDRNF. Photobiomodulation: The PBM device used was a cluster containing 5 810 nm infrared diodes (GaAlAs), with each diode having a power of 200mW, energy of 9J, energy per area of the cluster of 45J, totaling 450J per limb. The irradiation time was 45 seconds per area, with a total time of 450 seconds per limb, in continuous mode. PBM will be applied before concurrent training. The bilateral application was placed in 6 areas of the belly of the quadriceps femoris muscle and in 4 areas of the belly of the hamstring muscles. These sites were chosen to irradiate most of the muscle bellies. Concurrent training: After the application of the active or placebo PBM, all participants underwent a treatment protocol for 10 weeks, during 3 times a week, totaling 30 sessions, lasting approximately 60 minutes per session. All exercises were an individualized load progression in two phases: Aerobic training and Anaerobic training. Pre- and post-treatment evaluations: All patients were evaluated at the beginning (pre-treatment), at the 5th week of treatment (half) and 10 weeks (post-treatment) by the same researcher who did not know which group the patients belong to. The non-instrumental evaluations will be the following: World Health Organization Quality of Life (WHOQOL-brief), Knee injury and Osteoarthritis Outcome Score (KOOS) and Numerical Pain Scale (NPS).The instrumental evaluations were: Pain pressure threshold, Muscle Strength (Isokinetic Dynamometry), Maximum oxygen volume (VO2max), Timed up and Go test (TUG), 6-minute walk test (WT-6) and Sit-to-Stand test (STS). Primary outcome: The primary outcome was the KOOS-ADL score between the beginning and end of treatment.Secondary outcomes: The secondary outcomes are changes in the NRS, VO2max, and muscle strength variables between the beginning and end of treatment. Sample Size: Given that this is a pragmatic study, the variable considered for the sample design was the KOOS-activities of daily living score. We considered that the minimum relative difference, to be considered linically significant between pre- and postoperative evaluations, should be 26%, with a standard deviation of 6%. In order to have a power higher than 0.80 and a significance level of 0.05, the minimum sample size, considering a loss rate of 20%, should be 22 individuals per group. Analysis of results: In order to evaluate the measurements made in the Placebo and PBM groups, the Student's t-test will be used for the unrelated samples, such as: Age, Weight, Height, and BMI. In order to study the behavior of the Placebo and PBM groups over the time evaluated regarding the remaining variables of interest (primary and secondary outcomes), the ANOVA variance analysis model with repeated measurements and the Bonferroni multiple comparison method will be used, considering a confidence interval of 95%. We will use the 'R' statistical program.The Cohen's d test will be used to evaluate the magnitudes of intra- and intergroup effects. Results: KOOS: It was not possible to find difference between groups. In d cohen test we could observe an effects 0.77 in symptons aspect to PBM group. WHOQOL: For intra groups analysis there wasn’t significant difference betweem groups except for psychological domain (p<0.01) for PBMG. For inter group analysis we could find p<0.001 for PBMG. Pain: For worst activity pain it was possible to find p<0.06 for PBMG and when the statiscal data were evaluated in both group it was possible to find improvement of pain. For the d Cohen test it was possible to find 0.78 for PBMG. STS, TUG and WT6: It was possible to find significant difference for STS, TUG e WT6 for PBMG group (p<0.001; p<0.001 e p<0.002 respectively). For effect size (d Cohen) we found the values (2, 1.84 and 1.63 respectively). Muscle Strength: We could observe that both group improved the muscle strength as for isometric as isotonic tests but there was no difference between them. The effect size (d Cohen Test) shown for isometric strength 0.74 (absolute) and 0.88 (relative) addressed to PBMG. Maximum oxygen volume (VO2max): We could observe that both group improved the maximum oxygen volume but there was no difference between them. For intra-group analysis we could observe that both group improved the VO2max with p<0.05. For effect size (d Cohen Test) we find 0.73 for PBMG. Conclusions: The concurrent training associated to PBM and only the concurrent training showed improvement in all aspects related to pain, functional capacity and aerobic evaluation. Both training may bring benefits for patients with knee osteoarthritis. Looking deeply in results, there was no difference between them but there was possible to observe that just PBM group improved the VO2max, muscle strength and pain when evaluated during the treatment.