Neyroud Daria, Armand Stéphane, De Coulon Geraldo, Maffiuletti Nicola A, Kayser Bengt, Place Nicolas
Institute of Sport Sciences, Faculty of Biology Medicine, University of Lausanne, Lausanne, Switzerland; Institute of Movement Sciences and Sports Medicine, University of Geneva, Geneva, Switzerland.
Willy Taillard Laboratory of Kinesiology, Geneva University Hospitals and Geneva University, Switzerland.
Res Dev Disabil. 2017 Feb;61:66-76. doi: 10.1016/j.ridd.2016.12.015. Epub 2017 Jan 5.
Patients with cerebral palsy develop an important muscle weakness which might affect the aetiology and extent of exercise-induced neuromuscular fatigue.
This study evaluated the aetiology and extent of plantar flexor neuromuscular fatigue in patients with cerebral palsy.
Ten patients with cerebral palsy and 10 age- and sex-matched healthy individuals (∼20 years old, 6 females) performed four 30-s maximal isometric plantar flexions interspaced by a resting period of 2-3s to elicit a resting twitch. Maximal voluntary contraction force, voluntary activation level and peak twitch were quantified before and immediately after the fatiguing task.
Before fatigue, patients with cerebral palsy were weaker than healthy individuals (341±134N vs. 858±151N, p<0.05) and presented lower voluntary activation (73±19% vs. 90±9%, p<0.05) and peak twitch (100±28N vs. 199±33N, p<0.05). Maximal voluntary contraction force was not significantly reduced in patients with cerebral palsy following the fatiguing task (-10±23%, p>0.05), whereas it decreased by 30±12% (p<0.05) in healthy individuals.
Plantar flexor muscles of patients with cerebral palsy were weaker than their healthy peers but showed greater fatigue resistance.
Cerebral palsy is a widely defined pathology that is known to result in muscle weakness. The extent and origin of muscle weakness were the topic of several previous investigations; however some discrepant results were reported in the literature regarding how it might affect the development of exercise-induced neuromuscular fatigue. Importantly, most of the studies interested in the assessment of fatigue in patients with cerebral palsy did so with general questionnaires and reported increased levels of fatigue. Yet, exercise-induced neuromuscular fatigue was quantified in just a few studies and it was found that young patients with cerebral palsy might be more fatigue resistant that their peers. Thus, it appears that (i) conflicting results exist regarding objectively-evaluated fatigue in patients with cerebral palsy and (ii) the mechanisms underlying this muscle fatigue - in comparison to those of healthy peers - remain poorly understood. The present study adds important knowledge to the field as it shows that when young adults with cerebral palsy perform sustained maximal isometric plantar flexions, they appear less fatigable than healthy peers. This difference can be ascribed to a better preservation of the neural drive to the muscle. We suggest that the inability to drive their muscles maximally accounts for the lower extent of exercise-induced neuromuscular fatigue in patients with cerebral palsy.
脑瘫患者会出现明显的肌肉无力，这可能会影响运动诱发的神经肌肉疲劳的病因及程度。
本研究评估脑瘫患者跖屈肌神经肌肉疲劳的病因及程度。
10例脑瘫患者和10名年龄及性别匹配的健康个体（约20岁，6名女性）进行4次30秒的最大等长跖屈，每次之间间隔2 - 3秒的休息时间以引出静息抽搐。在疲劳任务前后分别对最大自主收缩力、自主激活水平和峰值抽搐进行量化。
疲劳前，脑瘫患者比健康个体更弱（341±134牛 vs. 858±151牛，p<0.05），自主激活水平更低（73±19% vs. 90±9%，p<0.05），峰值抽搐也更低（100±28牛 vs. 199±33牛，p<0.05）。疲劳任务后，脑瘫患者的最大自主收缩力没有显著降低（-10±23%，p>0.05），而健康个体降低了30±12%（p<0.05）。
脑瘫患者的跖屈肌比健康同龄人更弱，但表现出更强的抗疲劳能力。
脑瘫是一种广泛定义的病理状态，已知会导致肌肉无力。肌肉无力的程度和起源是先前几项研究的主题；然而，关于其如何影响运动诱发的神经肌肉疲劳的发展，文献中报道了一些不一致的结果。重要的是，大多数关注脑瘫患者疲劳评估的研究使用的是一般问卷，并报告疲劳水平增加。然而，仅有少数研究对运动诱发的神经肌肉疲劳进行了量化，发现年轻的脑瘫患者可能比同龄人更具抗疲劳能力。因此，似乎（i）关于脑瘫患者客观评估的疲劳存在相互矛盾的结果，（ii）与健康同龄人相比，这种肌肉疲劳的潜在机制仍知之甚少。本研究为该领域增添了重要知识，因为它表明当患有脑瘫的年轻成年人进行持续的最大等长跖屈时，他们似乎比健康同龄人更不易疲劳。这种差异可归因于对肌肉神经驱动的更好保留。我们认为，无法最大程度地驱动肌肉是脑瘫患者运动诱发的神经肌肉疲劳程度较低的原因。
