1 Department of Biomechanics and.
2 Department of Pulmonary and Critical Care Medicine and.
Ann Am Thorac Soc. 2017 Jun;14(6):858-866. doi: 10.1513/AnnalsATS.201607-547OC.
Compared with control subjects, patients with chronic obstructive pulmonary disease (COPD) have an increased incidence of falls and demonstrate balance deficits and alterations in mediolateral trunk acceleration while walking. Measures of gait variability have been implicated as indicators of fall risk, fear of falling, and future falls.
To investigate whether alterations in gait variability are found in patients with COPD as compared with healthy control subjects.
Twenty patients with COPD (16 males; mean age, 63.6 ± 9.7 yr; FEV/FVC, 0.52 ± 0.12) and 20 control subjects (9 males; mean age, 62.5 ± 8.2 yr) walked for 3 minutes on a treadmill while their gait was recorded. The amount (SD and coefficient of variation) and structure of variability (sample entropy, a measure of regularity) were quantified for step length, time, and width at three walking speeds (self-selected and ±20% of self-selected speed). Generalized linear mixed models were used to compare dependent variables.
Patients with COPD demonstrated increased mean and SD step time across all speed conditions as compared with control subjects. They also walked with a narrower step width that increased with increasing speed, whereas the healthy control subjects walked with a wider step width that decreased as speed increased. Further, patients with COPD demonstrated less variability in step width, with decreased SD, compared with control subjects at all three speed conditions. No differences in regularity of gait patterns were found between groups.
Patients with COPD walk with increased duration of time between steps, and this timing is more variable than that of control subjects. They also walk with a narrower step width in which the variability of the step widths from step to step is decreased. Changes in these parameters have been related to increased risk of falling in aging research. This provides a mechanism that could explain the increased prevalence of falls in patients with COPD.
与对照受试者相比，慢性阻塞性肺疾病（COPD）患者跌倒发生率增加，并且在行走时表现出平衡缺陷和中侧躯干加速度改变。步态可变性的测量已被认为是跌倒风险、跌倒恐惧和未来跌倒的指标。
研究与健康对照受试者相比，COPD 患者是否存在步态可变性改变。
20 例 COPD 患者（16 名男性；平均年龄 63.6±9.7 岁；FEV/FVC，0.52±0.12）和 20 名对照受试者（9 名男性；平均年龄 62.5±8.2 岁）在跑步机上行走 3 分钟，同时记录他们的步态。在三种步行速度（自身选择速度和自身选择速度的±20%）下，分别对步长、时间和宽度的变异性（SD 和变异系数）和结构（样本熵，一种衡量规则性的指标）进行量化。采用广义线性混合模型比较了因变量。
与对照受试者相比，COPD 患者在所有速度条件下的平均和 SD 步时均增加。他们还以更窄的步宽行走，随着速度的增加而增加，而健康对照受试者则以更宽的步宽行走，随着速度的增加而减小。此外，与对照组相比，COPD 患者在所有三种速度条件下的步宽变异性较小，SD 降低。两组间步态模式的规则性无差异。
COPD 患者行走时步间时间延长，且该时间比对照组更具可变性。他们还以更窄的步宽行走，其中步宽的变异性从一步到下一步减小。这些参数的变化与衰老研究中跌倒风险增加有关。这提供了一种可以解释 COPD 患者跌倒发生率增加的机制。
