Introduction

Persons with multiple sclerosis (pwMS) accumulate impairments in muscle strength and limitations in physical function as the disease progresses. The same symptoms are seen in the biological process of aging (years of age > 60 years). Nonetheless, no previous studies have examined the combined effects of aging and multiple sclerosis (MS) in regards to lower extremity muscle strength concomitant with physical function (e.g. walking capacity). The aim of this cross-sectional study was to examine potential differences in pwMS vs. healthy controls (HC) across the adult lifespan in these outcomes.

Methods

A total of n = 53 pwMS and n = 48 age-matched HC were enrolled, and divided into groups of young (≤ 44 years), middle-aged (45–59 years), and old (≥ 60 years). Assessment of knee extensor (KE) and plantar flexor (PF) muscle force-velocity characteristics (isometric and dynamic concentric force at contraction velocities of 0–300 deg^.s⁻¹) alongside assessment of timed 25 ft walk tests (T25FWT), two minute walk tests (2MWT), and 9-step stair ascend (9SSA) were carried out.

Results

Overall, substantial impairments in KE and PF isometric (ranging from −18 to −23%) and dynamic muscle strength (ranging from −26 to −38%) alongside limitations in T25FWT, 2MWT, and 9SSA (ranging from −24 to −33%) were observed in pwMS vs. HC (p < 0.05). With advanced age (young → middle-aged → old), more pronounced impairments in PF (but not KE) isometric and dynamic muscle strength, alongside limitations in T25FWT, 2MWT, and 9SSA, were observed in pwMS vs. HC (p < 0.05). In pwMS, associations were observed between physical function and isometric KE + PF muscle strength (r² = 0.21–0.45) as well as dynamic KE + PF muscle strength (r² = 0.36–0.61) (p < 0.05).

Conclusion

Substantial impairments of KE and PF muscle strength occur in pwMS across the adult lifespan accompanied by/associated with limitations in walking and stair climbing capacity, with PF muscle strength being preferentially affected in pwMS vs. HC.

中文翻译：

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成年期多发性硬化症患者的下肢肌肉力量：对步行和爬楼梯能力的影响。

介绍

随着疾病的发展，多发性硬化症（pwMS）的人会累积肌肉力量的损害和身体机能的限制。在衰老的生物学过程中（年龄大于60岁）也可以看到相同的症状。尽管如此，没有以前的研究已经检查了组合的问候老化和多发性硬化（MS），以降低与身体机能（例如行走能力）下肢肌力伴随的效果。这项横断面研究的目的是检查在这些结果中，成人整个生命周期内pwMS与健康对照（HC）的潜在差异。

方法

总共 纳入了n = 53 pwMS和n  = 48个年龄相匹配的HC，并将其分为年轻组（≤44岁），中年组（45-59岁）和中老年（≥60岁）。伸膝（KE）和跖屈（PF）肌肉力-速度特性的评估（在0-300℃下的收缩速度等长和动力同心力^。小号^-1）沿着计时25英尺行走评估测试（T25FWT），两个进行了分钟步行测试（2MWT）和9步楼梯上升（9SSA）。

结果

总体而言，KE和PF等距（从-18到-23％）和动态肌肉力量（从-26到-38％）的重大损伤，以及T25FWT，2MWT和9SSA的局限性（从-24到-33）相对于HC，在pwMS中观察到了％（p  <0.05）。随着年龄的增长（年轻人→中年人→老年人），在pwMS vs. HC中观察到PF（但不是KE）的等长和动态肌肉力量的更明显损害，以及T25FWT，2MWT和9SSA的局限性（p  <0.05 ）。在pwMS中，观察到身体功能与等长KE + PF肌肉强度（r ²  = 0.21-0.45）以及动态KE + PF肌肉强度（r ²  = 0.36-0.61）之间的关联（p  <0.05）。

结论

在整个成年寿命的pwMS中，KE和PF肌肉力量明显受损，伴有/伴随着步行和爬楼梯能力的局限性/相关性，pwMS与HC相比，PF肌肉力量优先受到影响。