The objective of the study was to investigate the impact of photobiomodulation (PBM) on the paretic upper limb in post-stroke patients with spastic hemiparesis and to understand the potential of PBM as a long-term non-invasive therapy for reducing the side effects caused by spasticity in the hemiparetic upper limb after a stroke. This is a double-blind randomized clinical trial constituted of 27 participants, being Control group (CG = 12 healthy individuals) and PBM group (PBMG = 15 post-stroke individuals). In the CG, the baseline blood lactate (BL) was evaluated, followed by the evaluation of the IC torque of the biceps and triceps muscles, with the isokinetic dynamometer associated with surface electromyography (EMG) and, subsequently, a new measurement of BL. The PBMG received 10 sessions of treatment with PBM (780 nm, Power: 100 mV, Power Density: 3.18 W/cm², Energy: 4 J, Fluency: 127.4 J/cm², Time: 40 s per point and 1.280 s total, Spot: 0.0314 cm², 32 Points: 16 points (brachial biceps) and 16 points (brachial triceps) applied with contact at 90°, Total Energy: 64 J), which in the pre-treatment evaluation measured BL, the visual analogue scale (VAS) of pain; torque and EMG of the same muscles in the IC, subsequently, a new measurement of VAS and BL, and measurement of range of motion (ROM) during the reaching movement. At the conclusion of the ten sessions, all participants underwent a reassessment, wherein all tests originally administered during the initial evaluation were repeated. Subsequently, the data were analyzed using the Shapiro–Wilk normality test. For related data, the paired t-test was used for normal distributions and the Wilcoxon test for non-normal data. For unrelated data, the t test was used for normal distributions and the Mann–Whitney test for non-normal data. Muscle torque was higher for the CG, with a significant difference (CGxPBMG = p < 0.0001). There was no significant difference between the EMG values of the CG in relation to the Pre-PBM phase and with the Post-PBM phase of the PBMG (p > 0.05). On the other hand, there was a 38% reduction in pain reported by hemiparetic patients (p = 0.0127) and a decrease in BL in the PBMG. Post-PBM ROM increased by 46.1% in the elbow extension of the paretic limb. In conclusion, Photobiomodulation (PBM) demonstrated significant improvements in muscle performance, reducing fatigue and pain levels, and enhancing range of motion in post-stroke patients with spastic hemiparesis. These findings support the potential integration of PBM into rehabilitation protocols, but further research and clinical trials are needed to validate and expand upon these promising outcomes.

该研究的目的是调查光生物调节（PBM）对中风后痉挛性偏瘫患者上肢的影响，并了解 PBM 作为一种长期非侵入性治疗方法以减少所引起的副作用的潜力。中风后偏瘫上肢痉挛。这是一项双盲随机临床试验，由 27 名参与者组成，即对照组（CG = 12 名健康个体）和 PBM 组（PBMG = 15 名中风后个体）。在 CG 中，评估基线血乳酸 (BL)，然后使用与表面肌电图 (EMG) 相关的等速测力计评估二头肌和三头肌的 IC 扭矩，随后对 BL 进行新的测量。 PBMG 接受 10 次 PBM 治疗（780 nm，功率：100 mV，功率密度：3.18 W/cm ²，能量：4 J，流畅度：127.4 J/cm ²，时间：每点 40 s，总计 1.280 s ，点：0.0314 cm ²，32 点：16 点（肱二头肌）和 16 点（肱三头肌），以 90° 接触施加，总能量：64 J），在治疗前评估中测量 BL（视觉模拟）疼痛等级（VAS）； IC 中相同肌肉的扭矩和 EMG，随后进行 VAS 和 BL 的新测量，以及伸手运动期间的运动范围 (ROM) 测量。在十次会议结束时，所有参与者都接受了重新评估，其中重复了最初评估期间进行的所有测试。随后，使用夏皮罗-威尔克正态性检验对数据进行分析。对于相关数据，配对t检验用于正态分布，Wilcoxon检验用于非正态分布。对于不相关的数据，正态分布使用 t 检验，非正态分布使用 Mann-Whitney 检验。 CG 的肌肉扭矩较高，具有显着差异 (CGxPBMG =  p  < 0.0001)。与 PBMG 的 Pre-PBM 阶段和 Post-PBM 阶段相比，CG 的 EMG 值之间没有显着差异 ( p  > 0.05)。另一方面，偏瘫患者报告的疼痛减少了 38% ( p  = 0.0127)，并且 PBMG 的 BL 减少。 PBM 后瘫痪肢体的肘部伸展活动度增加了 46.1%。总之，光生物调节 (PBM) 证明可以显着改善中风后痉挛性偏瘫患者的肌肉性能，减少疲劳和疼痛水平，并增强运动范围。这些发现支持将 PBM 整合到康复方案中的可能性，但需要进一步的研究和临床试验来验证和扩展这些有希望的结果。