Data Sheet 4_Comparative effectiveness of lower body positive pressure and traditional treadmill training on adults with mild balance impairment.pdf

BackgroundTreadmill training and body-weight supported treadmill training are effective for improving gait and balance in various populations. Lower-body positive pressure (PP) treadmill training uses positive air pressure to support body weight, potentially offering advantages over traditional treadmill training by reducing joint impact and allowing longer sessions. However, no studies have directly compared PP treadmill training with traditional treadmill training in adults with mild balance impairment.
MethodIn this three-armed parallel design randomised controlled trial, 72 adults were randomly assigned to: i) PP treadmill training with 20% bodyweight support (PP-BWS), ii) PP treadmill training without bodyweight support (PP-noBWS), and iii) traditional treadmill training without bodyweight support (TT). Participants in all three groups completed 25 min of treadmill training, three times per week, for 8 weeks. Outcomes included the Berg Balance Scale (BBS), Timed Up and Go (TUG), Functional Reach Test (FRT), and postural sway and gait measured with smartphone accelerometry and force plates. Outcomes were collected at baseline, at the end of the 2nd, 4th, 6th, and 8th week, and follow-up data were collected in the 10th week. Data were analysed using linear mixed-effects models, with multiple-imputation sensitivity analyses.
ResultsAll interventions resulted in significant within-group improvements in balance and mobility measured with the BBS, TUG and FRT. For balance measures, the primary analysis revealed a group by time interaction (p = 0.003) for the BBS, favouring traditional treadmill training and PP-noBWS at week 10, but no between-group differences for the FRT. TUG measures of functional mobility showed a significant group by time interaction (p = 0.028), initially favouring novel PP-BWS, but there were no between-group differences after week 4. This aligned with smartphone accelerometry outcomes, which showed no between-group differences for comfortable walking speed and gait symmetry. Between-group differences in standing postural sway did not consistently favour one group. Due to a large dropout rate at follow-up, a sensitivity analysis was completed; this confirmed the significant within-group effects on balance and mobility at week 10, but between-group differences in balance were no longer statistically significant.
ConclusionAll treadmill interventions led to significant within-group improvements in balance and mobility over the 10-week period. The initial analysis suggested treadmill interventions without body weight support, traditional treadmill training and PP-noBWS, demonstrated larger improvements in balance at week 10, but between-group differences were not sustained after accounting for dropout rates in the sensitivity analysis. This may suggest that the altered gait mechanics and reduced sensory input during PP treadmill training with bodyweight support may limit the improvements in balance that accompany treadmill training.

研究背景
跑步机训练与体重支撑式跑步机训练可有效改善多类人群的步态与平衡能力。下半身正压（Positive Pressure, PP）跑步机训练通过正压空气支撑体重，相比传统跑步机训练具有潜在优势：可降低关节冲击力，支持更长时长的训练。但目前尚无研究针对轻度平衡障碍成人群体，直接比较下半身正压跑步机训练与传统跑步机训练的效果。

研究方法
本研究为三臂平行设计随机对照试验，共纳入72名成年受试者，随机分为三组：① 采用20%体重支撑的下半身正压跑步机训练组（PP-BWS），② 无体重支撑的下半身正压跑步机训练组（PP-noBWS），③ 无体重支撑的传统跑步机训练组（TT）。三组受试者均完成每周3次、每次25分钟的跑步机训练，持续8周。结局指标包括伯格平衡量表（Berg Balance Scale, BBS）、计时起立行走测试（Timed Up and Go, TUG）、功能性前伸测试（Functional Reach Test, FRT），以及通过智能手机加速度计与测力板采集的姿势晃动与步态数据。分别于基线、第2、4、6、8周末采集结局指标，并于第10周采集随访数据。数据分析采用线性混合效应模型，并通过多重插补法完成敏感性分析。

研究结果
所有干预组的组内平衡与移动能力（通过BBS、TUG、FRT评估）均出现显著改善。针对平衡指标的主要分析显示，BBS评分存在显著的组间×时间交互效应（p=0.003），第10周时传统跑步机训练组与PP-noBWS组表现更优，但FRT评分未出现组间差异。TUG评估的功能性移动能力指标存在显著的组间×时间交互效应（p=0.028），早期PP-BWS组表现更优，但第4周后未观察到组间差异。这一结果与智能手机加速度计的检测结果一致：舒适步行速度与步态对称性未出现组间差异。站立姿势晃动的组间差异未呈现出明确的组间优势倾向。由于随访阶段脱落率较高，研究补充完成了敏感性分析：结果确认第10周时各组组内平衡与移动能力仍存在显著改善，但平衡指标的组间差异不再具有统计学意义。

研究结论
所有跑步机训练干预方案在10周周期内均使受试者的组内平衡与移动能力获得显著改善。初始分析显示，无体重支撑的跑步机训练方案（传统跑步机训练与PP-noBWS组）在第10周时平衡能力提升幅度更大，但经敏感性分析校正脱落率后，该组间差异不再持续存在。这提示，带体重支撑的下半身正压跑步机训练过程中，步态力学改变与感觉输入减少，可能会限制跑步机训练伴随的平衡能力提升效果。