Background

Multiple sclerosis (MS) is a debilitating, neurodegenerative disorder causing considerable gait and balance dysfunction. Reactive balance (i.e., quick movements in response to a loss of balance) is particularly important for fall risk and is impaired in people with MS compared to neurotypical peers. Therefore, improving reactive balance among those with MS is critical. However, for maximum ecological validity, improvements in reactive balance through training would be demonstrable upon first loss-of-balance, rather than an average of several trials as is typically reported. This study evaluated changes in performance on the first stepping trial in people with MS after one day of practice.

Methods

Fourteen people with MS underwent two, consecutive days of support-surface perturbations from stance. On day 1, participants underwent a single backward-stepping trial, followed by 35 practice trails (forward and backward). Approximately 24 h later, participants were again exposed to a single backward stepping perturbation. Protective stepping outcomes were step length, step latency, and margin of stability at first foot contact. The backward step performance on the first trial of days one and two were compared, and difference scores were evaluated for relationships with correlates based on theoretical considerations.

Findings

First-trial margin of stability increased (improved) from day 1 to day 2 (P = .016). Steps were also faster on average by approximately 5 ms on day 2, although this improvement was not significant (P = .062).

Interpretations

Although preliminary, these findings provide evidence that individuals with MS may be able to experience first-trial improvements after a low dose of perturbation training.

中文翻译：

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多发性硬化症患者保护性步骤练习后“首次试验”表现的变化

背景

多发性硬化症 (MS) 是一种使人衰弱的神经退行性疾病，会导致严重的步态和平衡功能障碍。反应性平衡（即对失去平衡作出反应的快速运动）对于跌倒风险尤其重要，并且与神经典型的同龄人相比，MS 患者的反应性平衡受损。因此，改善 MS 患者的反应平衡至关重要。然而，为了获得最大的生态有效性，通过训练对反应性平衡的改善将在第一次失去平衡时得到证明，而不是像通常报告的那样是几次试验的平均值。这项研究评估了多发性硬化症患者在一天的练习后第一次踏步试验的表现变化。

方法

14 名 MS 患者连续两天因站立而受到支撑表面的扰动。第 1 天，参与者进行了一次后退试验，随后进行了 35 次练习（前进和后退）。大约 24 小时后，参与者再次受到单次后退扰动的影响。保护性踏步结果是步长、踏步潜伏期和第一次脚接触时的稳定性边际。比较了第一天和第二天第一次试验的后退表现，并根据理论考虑评估了与相关者的关系的差异分数。

发现

从第 1 天到第 2 天，首次试验的稳定性边际增加（改善）（P  = .016）。第 2 天的平均步数也快了大约 5 毫秒，尽管这种改进并不显着 ( P  = .062)。

解释

尽管是初步的，但这些发现提供了证据，表明 MS 患者在接受低剂量扰动训练后可能能够体验到首次试验的改善。