Effect of laser treatment on postural control parameters in patients with chronic nonspecific low back pain: a randomized placebo-controlled trial

The management of nonspecific lumbar pain (NSLP) using laser irradiation remains controversial. A systematic review of recently published studies indicates that the effects of laser therapy are commonly assessed using only imperfect methods in terms of measurement error. The main objective of this study was to assess static postural stability using an objective tool in patients with chronic NSLP after laser irradiation at different doses and wavelengths. In total, 68 patients were included in the laser sessions and were randomly assigned into four groups: high-intensity laser therapy at 1064 nm and 60 J/cm2 for 10 min (HILT), sham (HILT placebo), low-level laser therapy at 785 nm and 8 J/cm2 for 8 min (LLLT), and sham (LLLT placebo). In addition, all patients were supplemented with physical exercises (standard stabilization training). To assess postural stability, a double-plate stabilometric platform was used. All measurements were performed pre- and post-laser sessions (three weeks) and at follow-up time points (one and three months). Laser procedures led to more balanced posture stability in patients, although these positive changes were significant mainly for short-term observation (after 4-week therapy). In the follow-up analysis, the parameters were gradually impaired. Kruskal-Wallis analysis of variance (ANOVA) for independent variables did not show any difference between the studied groups. Low- and high-intensity laser therapy does not lead to a significant improvement in postural sway in patients with NSLP compared with standard stabilization training based on short- and long-term observations.

采用激光照射治疗非特异性腰痛（nonspecific lumbar pain, NSLP）的相关方案至今仍存在争议。针对近期发表研究开展的系统综述显示，当前激光疗法的疗效评估通常仅采用存在测量误差缺陷的不完善方法。本研究的核心目标为借助客观评估工具，对不同剂量与波长的激光照射后慢性非特异性腰痛患者的静态姿势稳定性展开评估。本研究共纳入68名接受激光治疗的患者，并将其随机分为四组：波长1064nm、剂量60J/cm²、照射时长10分钟的高强度激光疗法（high-intensity laser therapy, HILT）组、安慰剂对照高强度激光假照射（HILT安慰剂）组、波长785nm、剂量8J/cm²、照射时长8分钟的低强度激光疗法（low-level laser therapy, LLLT）组，以及安慰剂对照低强度激光假照射（LLLT安慰剂）组。此外，所有患者均辅以标准稳定训练。为评估姿势稳定性，本研究采用双板姿势稳定测定平台。所有测量均在激光治疗前、治疗后（三周疗程结束时）以及随访节点（治疗后1个月、3个月）开展。激光干预可改善患者的姿势稳定性，不过该正向改善仅在短期随访（治疗后4周）中具有统计学显著性。而在长期随访分析中，相关姿势稳定性参数则逐渐出现恶化。针对独立样本的克鲁斯卡尔-沃利斯方差分析（analysis of variance, ANOVA）结果显示，各组间未出现显著差异。综合短期与长期随访结果来看，与标准稳定训练相比，低、高强度激光疗法均未对非特异性腰痛患者的姿势摆动幅度产生显著改善效果。