Recovery of peripheral muscle function from fatiguing exercise and daily physical activity level in patients with multiple sclerosis: A case- control study Kelly Ickmans a, b , Fauve Simoens a , Jo Nijs a, b, *, Daphne Kos c, f , Patrick Cras d , Barbara Willekens d , Mira Meeus e, f a Pain in Motion Research Group, Departments of Human Physiology and Physiotherapy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Belgium b Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Belgium c Pain in Motion Research Group, Division of Occupational Therapy, Artesis University College Antwerp, KU Leuven, Belgium d Department of Neurology, Faculty of Medicine, Antwerp University , Belgium e Rehabilitation Sciences and Physiotherapy, Faculty of Medicine, Antwerp University, Belgium f Rehabilitation Sciences and Physiotherapy, Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Belgium A R T I C L E I N F O Article history: Received 30 August 2013 Received in revised form 20 March 2014 Accepted 23 April 2014 Available online 2 May 2014 Keywords: Multiple sclerosis Muscle recovery Physical activity Rehabilitation Physiotherapy A B S T R A C T Objectives: Delayed recovery of muscle function fo`owing exercise has been demonstrated in the lower limbs of patients with multiple sclerosis (MS). However, studies examining this in the upper limbs are currently lacking. This study compared physical activity level (PAL) and recovery of upper limb muscle function following exercise between MS patients and healthy inactive controls. Furthermore, the relationship between PAL and muscle recovery was examined. Methods: PAL of 19 MS patients and 32 controls was measured using an accelerometer for 7 consecutive days. Afterwards, recovery of muscle function was assessed by performing a fatiguing upper limb exercise test with subsequent recovery measures. Results: Muscle recovery of the upper limb muscles was similar in both groups. Average activity counts were significantly lower in MS patients than in the control group. MS patients spent significantly more time being sedentary and less time on activities of moderate intensity compared with the control group. No significant correlation between PAL and recovery of muscle function was found in MS patients. Conclusions: Recovery of upper limb muscle function following exercise is normal in MS patients. MS patients are less physically active than healthy inactive controls. PAL and recovery of upper limb muscle function appear unrelated in MS patients. ã 2014 Elsevier B.V. All rights reserved. 1. Introduction Multiple sclerosis (MS) is a chronic and progressive demyelin- ating disease of the central nervous system (CNS). The disease is characterized by a demyelination process that expresses itself in inflammation and damage of axons in the CNS. This damage results in an important conduction delay and eventually a conduction block of electrical potentials at the level of the lesions [1–5]. MS has a large impact on life, mainly because of the unpredictability in progression and heterogeneous presentation of symptoms. The disease presents with a wide variety of chronic and variable symptoms (including cerebellar-, motor-, sensory-, emotional- or sexual-related symptoms) depending on the affected area in the CNS [1–3,6,7]. Previous studies demonstrated various central and peripheral muscle alterations in MS during and after fatiguing exercise. Examples of these alterations are an incomplete motor unit recruitment [8], slowing of muscle contractile properties [9,10], decreased muscle oxidative capacity [8,11], impaired excitation– contraction response [8–10], impaired calcium kinetic properties [9] , and altered muscle metabolic response to exercise such as a larger decrease in intracellular phosphocreatine and pH [11] . All of these can possibly influence recovery of muscle function post- * Corresponding author at: Vrije Universiteit Brussel, Medical Campus Jette, Building F-Kine, Laarbeeklaan 103, BE-1090 Brussels, Belgium. Tel.: +32 24774489; fax: +32 26292876. E-mail addresses: Jo.Nijs@vub.ac.be, http://www.paininmotion.be (J. Nijs). http://dx.doi.org/10.1016/j.clineuro.2014.04.021 0303-8467/ ã 2014 Elsevier B.V. All rights reserved. Clinical Neurology and Neurosurgery 122 (2014) 97–105 Contents lists available at ScienceDirect Clinical Neurology and Neurosurgery journal homepage: www.else vie r.com/locate /cline uro