Jukka Surakka

Effects of aerobic and strength exercise on motor fatigue in men and women with multiple sclerosis: a randomized controlled trial

Objective: To investigate the effects of aerobic and strength exercise on motor fatigue of knee flexor and extensor muscles in subjects with multiple sclerosis (MS). Design: A randomized controlled trial. Setting: At Masku Neurological Rehabilitation Centre, Masku, and the Social Insurance Institution, Research Department, Turku, Finland. Subjects: Ninety-five MS patients with mild to moderate disability were randomized into exercise group (n = 47) and a control group (n = 48). Intervention: Participants in the exercise group attended in a supervised exercise period of three weeks, which was followed by a home exercise programme lasting for 23 weeks. Patients in the control group continued with their normal living. Outcome measures: Motor fatigue of knee flexor and extensor muscles was measured during a static 30-s maximal sustained muscle contraction. The decline in force (Nm) during the 30 s was recorded, and a fatigue index (FI) was calculated. Subjective fatigue was measured by using the Fatigue Severity Scale (FSS). The Ambulatory Fatigue Index (AFI) was calculated on the basis of a 500-m walking test. Assessment took place at baseline, at the third week (not for the control group) and at the 26th week. All outcome variables were analysed, men and women together, and some interesting contrasts were analysed by gender. Results: Associations were observed with changes in extension FI and Expanded Disability Status Scale (EDSS) score and mean extension torque (Nm), but not with changes in FI and aerobic or strength exercise activity, mean AFI, mean FSS or in mean knee flexion torque. AFI was decreased in all subject groups (p = 0.007). Motor fatigue was reduced in knee flexion (p = 0.0014) and extension (ns) among female but not in male exercisers after six months of exercise. The exercise activity of women was 25% higher than that of the men. Conclusions: Six months of exercise reduced motor fatigue in women, but not in men.

Assessment of muscle strength and motor fatigue with a knee dynamometer in subjects with multiple sclerosis: a new fatigue index

Objective: To measure muscle strength and motor fatigue with a knee dynamometer and to assess the intra-rater reliability of measurements for maximal isometric extensor and flexor torques and the reliability of a new fatigue index (FI) in patients with mild to moderate multiple sclerosis (MS). Design: Repeated assessments with one-week intervals. Setting: The Masku Neurological Rehabilitation Centre, Masku, and the Social Insurance Institution, Research Department, Turku, Finland. Subjects: Twenty-eight MS patients. Outcome measures: Maximal isometric torque during 5 s and fatigue of knee flexors and extensors during isometric contractions of 30 s were assessed. A new FI was established and compared with the two previously used indices (FI1 and FI2). All three indices are based on the calculated area under the force versus time curve (AUFC), with FI1 using the 30-s recording time in its entirety and F2 omitting the initial 5 s in the calculation. In the new fatigue index (FI3), the time point of maximum (TPM) torque achieved by the subject is used as the starting point in the calculation. The patients subjective fatigue was measured by Fatigue Severity Scale (FSS). Results: The intraclass correlation coefficient (ICC) was 0.97 in maximal isometric torque measurements. FI3 showed good intra-rater reliability (ICC 0.68-0.86). None of the fatigue indices correlated with FSS. Conclusions: Maximal isometric torque and motor fatigue of knee flexor and extensor muscles can be reliably measured using a knee dynamometer in MS patients. The new FI proved to be a reliable model for MS patients.

Nordic walking decreased circulating chemerin and leptin concentrations in middle-aged men with impaired glucose regulation

Abstract Background. Dysfunction of adipose tissue is one of the major factors leading to insulin resistance. Altered adipokine concentration is an early sign of adipose tissue dysfunction. The aim of this study was to assess the impact of exercise intervention on adipokine profile, glycemic control, and risk factors of the metabolic syndrome (MeS) in men with impaired glucose regulation (IGR). Methods. Overweight and obese men with IGR (n =144) aged 40–65 years were studied at baseline and at 12 weeks in a randomized controlled multicenter intervention study. BMI varied from 25.1 to 34.9. The subjects were randomized into one of three groups: 1) a control group (C; n =47), 2) a Nordic walking group (NW; n =48), or 3) a resistance training group (RT; n =49). Results. Leptin concentrations decreased in the NW group compared to both other groups. Both types of exercise intervention significantly decreased serum chemerin concentrations compared to the C group. In the NW group also body fat percentage, fatty liver index (FLI), and total and LDL cholesterol concentrations decreased compared to the RT group. Conclusions. Nordic walking intervention seems to decrease chemerin and leptin levels, and subjects in this intervention group achieved the most beneficial effects on components of MeS.

Evidence on physiotherapeutic interventions for adults with cerebral palsy is sparse. A systematic review

Objectives: To identify evidence evaluating the effectiveness of physiotherapy in adolescents (>16 years of age) and adults with cerebral palsy. Data sources: Systematic literature search from the earliest available time until March 2009. Additional studies were identified through reference and citation tracking. Review methods: Two reviewers independently agreed on eligibility, methodological quality and quality of evidence assessment. Standard methods were used for quality assessments. Results: Included were 13 studies, two of which were randomized controlled trials. No article met the criteria for high methodological quality. Evidence of moderate quality was found on gait after strength training. Evidence of low quality was found on balance after strength training and workstation interventions. Low-quality evidence was also found on functionality after strength training in four studies evaluating gross motor capacity. There was very low-quality evidence on increased muscle strength and in outcome measures used to evaluate range of motion. Conclusion: Evidence for the effect of physiotherapy on adolescents and adults with cerebral palsy is sparse, and therefore there is an urgent need for well-designed physiotherapeutic trials for these people.

Pupillary function in early multiple sclerosis

Autonomic pupillary function was assessed with pupillometry in 95 mildly or moderately disabled patients with multiple sclerosis (MS) and 81 healthy subjects. The parasympathetic pupillary function was measured as initial diameter (mm), time to minimum diameter (seconds), reflex amplitude (mm), relative reflex amplitude (%), and maximal constriction velocity (mm/seconds). To reflect the sympathetic pupillary function maximal redilatation velocity (mm/seconds), and time of 75% of redilatation (seconds) were measured. Of MS patients 85–99% were within the reference values of healthy subjects. In MS patients the effect of age was observed in the initial diameter, reflex amplitude, and time of 75% redilatation. There were no such age related effects in healthy subjects. In age adjusted analysis the initial diameter and time of 75% redilatation differed significantly from healthy controls. Autonomic pupillary functions were not associated with fatigue, visual defect, or bladder disturbance, as measured by Fatigue Severity Scale, Kurtzke’s Functional System Scales, Expanded Disability Status Scale, or the Multiple Sclerosis Functional Composite. Our results suggest that both parasympathetic and sympathetic pupillary functions are disturbed already early in the course of MS. However, the disturbance is not severe at this stage of the disease. The dysfunction is age-dependent and thus possibly related to the dimished remyelination capacity of the central nervous system.

Unfavorable influence of structured exercise program on total leisure‐time physical activity

In randomized controlled trials (RCTs), with customized structured physical exercise activity (SPEA) interventions, the dose of leisure‐time physical activity (LTPA) should exceed the LTPA dose of the nonexercising control (C) group. This increase is required to substantiate health improvements achievable by exercise. We aimed to compare the dose of SPEA, LTPA, and total LTPA (SPEA + LTPA) between a randomized Nordic walking (NW) group, a power‐type resistance training (RT) group, and a C group during a 12‐week exercise intervention in obese middle‐aged men (n = 144) with impaired glucose regulation. The dose of physical activity was measured with diaries using metabolic equivalents. No significant difference (P > 0.107) between the groups was found in volume of total LTPA. The volume of LTPA was, however, significantly higher (P < 0.050) in the C group than in the NW group, but not compared with the RT group. These results indicate that structured exercise does not automatically increase the total LTPA level, possibly, as a result of compensation of LTPA with structured exercise or spontaneous activation of the C group. Thus, the dose of total LTPA and the possible changes in spontaneous LTPA should be taken into account when implementing a RCT design with exercise intervention.

Unfavorable influence of structured exercise program on total leisure- time physical activity

In randomized controlled trials (RCTs), with customized structured physical exercise activity (SPEA) interventions, the dose of leisure‐time physical activity (LTPA) should exceed the LTPA dose of the nonexercising control (C) group. This increase is required to substantiate health improvements achievable by exercise. We aimed to compare the dose of SPEA, LTPA, and total LTPA (SPEA + LTPA) between a randomized Nordic walking (NW) group, a power‐type resistance training (RT) group, and a C group during a 12‐week exercise intervention in obese middle‐aged men (n = 144) with impaired glucose regulation. The dose of physical activity was measured with diaries using metabolic equivalents. No significant difference (P > 0.107) between the groups was found in volume of total LTPA. The volume of LTPA was, however, significantly higher (P < 0.050) in the C group than in the NW group, but not compared with the RT group. These results indicate that structured exercise does not automatically increase the total LTPA level, possibly, as a result of compensation of LTPA with structured exercise or spontaneous activation of the C group. Thus, the dose of total LTPA and the possible changes in spontaneous LTPA should be taken into account when implementing a RCT design with exercise intervention.

Effect of Power-Type Strength Training on Lumbar Extension and Flexion Velocity

The aim of our study was to investigate the effects of 22 weeks of power-type strength training on isometric peak torque (Nm), dynamic peak torque (Nm), and angular peak velocity (deg/s) of lumbar spine flexion and extension. Subjects (n=125) were sedentary, middle-aged volunteers, of whom 25 women and 28 men were classified in the highly trained group and 35 women and 37 men in the low trained group (=moderately trained, low trained, and nontraining control groups). Isometric peak torque, dynamic peak torque, and angular peak velocity of the lumbar spine in flexion and extension were measured before and after the intervention by using an isoresistive dynamometer. The effects of power-type strength training were mainly manifested in the progress of velocity. With a training frequency of at least twice a week, significant increases were observed in peak flexion and extension velocities in both genders, whereas no such changes were found in isometric or dynamic torque. A training frequency of at least twice a week is apparently needed for improved velocity in lumbar spine extension and flexion in middle-aged, sedentary men and women.