Efficacy of a new video observational training method (intensive visual simulation) for motor recovery in the upper limb in subacute stroke: a feasibility and proof-of-concept study.

OBJECTIVE: To demonstrate the feasibility and efficacy  of a new video-observation training method (intensive visual simulation) to improve upper limb function. DESIGN: Small sample, randomized, evaluator-blind, monocentric study. PATIENTS: Seventeen early subacute ischaemic stroke patients with complete hemiplegia were  randomly assigned to the therapeutic group (n = 8) or control group (CG, n = 9). METHODS: Thirty sessions of intensive visual simulation combined with corrected visual feedback (therapeutic group) or uncorrected visual feedback (control group) were performed over 6 weeks on top of a standard rehabilitation programme. MAIN OUTCOME MEASURE: 400-point hand assessment test (400p-HA). SECONDARY OUTCOME MEASURES: Box and Blocks (B&B), Purdue Pegboard test, Minnesota. RESULTS: The 400p-HA test improved significantly from T0 to 6 months for both groups, with a significant difference between groups at 3 months (MW-UT p = 0.046) and 4 months (MW-UT p = 0.046) in favour of the therapeutic group. One-phase exponential modelling of 400p-HA showed a greater plateau for the therapeutic group (F test p = 0.0021). There was also faster recovery of the ability to perform the B&B tests for the therapeutic group (log-rank test p = 0.03). CONCLUSION: This study demonstrated the feasibility and potential efficacy of an intensive visual simulation training programme to improve upper limb  function in subacute stroke patients. A larger study is needed to confirm these results.

Walking Economy and Preferred Speed in Old and Very Old Men.

PURPOSE: With aging, the decline in preferred walking speed (PWS), influenced by the increased energy cost of walking (CoW), is a key predictor of morbidity. However, the determinants associated with PWS and CoW remain poorly understood, especially after 80 years old. The aim of the study was to characterize the amplitude and mechanisms of age-related decline in CoW and PWS in old (OM) and very old (VOM) men. METHODS: Thirty-nine young men (YM, 22.1 ± 3.4 years), 34 OM (71.7 ± 4.1 years) and 23 VOM (85.8 ± 2.7 years) performed aerobic, neuromuscular, and gait assessments. Net CoW was measured on a treadmill. Physical activity (PA) was evaluated by questionnaire and accelerometry. RESULTS: Net CoW was 32% (p < 0.001), 19% (p < 0.01), 26% (p < 0.001) higher in VOM compared to OM for 1.11, 1.67 m.s-1 and PWS. Net CoW was also 27% (p < 0.001), 26% (p < 0.01), and 29% (p < 0.001) higher in OM compared to YM at these speeds. Linear regression stratified by age showed that net CoW at PWS was associated to step frequency (r = 0.79; p < 0.001) for OM and to both CV of stride mean time (r = 0.48; p < 0.05) and maximal strength of knee extensors (r = -0.54; p < 0.05) for VOM. The same analysis revealed that PWS was correlated with net CoW (r = -0.56; p < 0.05) and PA (r = 0.47; p < 0.05) in VOM. CONCLUSIONS: The progressive increase in net CoW with age was associated with gait and neuromuscular impairments, particularly after the age of 80. This increase in net CoW was related to a decrease in PWS in VOM, suggesting an adaptation of PWS to compensate for the increase in energy demand. Maintaining a high level of PA may potentially delay the age-related decline in PWS despite an age-related increase in net CoW.

Effects of carbon versus plastic ankle foot orthoses on gait outcomes and energy cost in patients with chronic stroke.

OBJECTIVE: To compare the walking performances of hemiplegic subjects with chronic stroke under 3 conditions: with a new standard carbon fibre ankle foot orthosis (C-AFO), with a personal custom-made plastic AFO (P-AFO), and without any orthosis (No-AFO). DESIGN: Randomized, controlled crossover design. PATIENTS: Fifteen chronic patients with stroke (3 women  and 12 men, 59 [10] years, 13 [15] years since injury). METHODS: Patients performed 3 randomized sessions (with C-AFO, P-AFO, no-AFO), consisting of a 6-min walk test (6MWT) with VO2 measurement and a clinical gait analysis. Energy cost (Cw), walking speed, spatio-temporal, kinetic, and kinematic variables were measured. RESULTS: No significant differences were found between the C-AFO and P-AFO conditions. Distance and walking speed in the 6MWT increased by 12% and 10% (p < 0.001) and stride width decreased by -8.7% and -13% (p < 0.0001) with P-AFO and C-AFO compared with the No-AFO condition. Cw decreased by 15% (p < 0.002), stride length increased by 10% (p < 0.01), step length on affected leg increased by 8% (p < 0.01), step length on contralateral leg by 13% (p < 0.01), and swing time on the contralateral leg increased by 6% (p < 0.01) with both AFO compared with the No-AFO condition. CONCLUSION: The use of an off-the-shelf composite AFO (after a short habituation period) in patients with chronic stroke immediately improved energy cost and gait outcomes to the same extent as their usual custom-made AFO.

Factors Associated with Fatigue in COVID-19 ICU Survivors.

PURPOSE: Approximately 30% of people infected with COVID-19 require hospitalization, and 20% of them are admitted to an intensive care unit (ICU). Most of these patients experience symptoms of fatigue weeks post-ICU, so understanding the factors associated with fatigue in this population is crucial. METHODS: Fifty-nine patients (38-78 yr) hospitalized in ICU for COVID-19 infection for 32 (6-80) d, including 23 (3-57) d of mechanical ventilation, visited the laboratory on two separate occasions. The first visit occurred 52 ± 15 d after discharge and was dedicated to questionnaires, blood sampling, and cardiopulmonary exercise testing, whereas measurements of the knee extensors neuromuscular function and performance fatigability were performed in the second visit 7 ± 2 d later. RESULTS: Using the FACIT-F questionnaire, 56% of patients were classified as fatigued. Fatigued patients had worse lung function score than non-fatigued (i.e., 2.9 ± 0.8 L vs 3.6 ± 0.8 L; 2.4 ± 0.7 L vs 3.0 ± 0.7 L for forced vital capacity and forced expiratory volume in 1 s, respectively), and forced vital capacity was identified as a predictor of being fatigued. Maximal voluntary activation was lower in fatigued patients than non-fatigued patients (82% ± 14% vs 91% ± 3%) and was the only neuromuscular variable that discriminated between fatigued and non-fatigued patients. Patient-reported outcomes also showed differences between fatigued and non-fatigued patients for sleep, physical activity, depression, and quality of life ( P < 0.05). CONCLUSIONS: COVID-19 survivors showed altered respiratory function 4 to 8 wk after discharge, which was further deteriorated in fatigued patients. Fatigue was also associated with lower voluntary activation and patient-reported impairments (i.e., sleep satisfaction, quality of life, or depressive state). The present study reinforces the importance of exercise intervention and rehabilitation to counteract cardiorespiratory and neuromuscular impairments of COVID-19 patients admitted in ICU, especially individuals experiencing fatigue.

Cardiorespiratory Fitness and Neuromuscular Function of Mechanically Ventilated ICU COVID-19 Patients.

OBJECTIVES: The aim of the current study was to investigate the level of cardiorespiratory fitness and neuromuscular function of ICU survivors after COVID-19 and to examine whether these outcomes are related to ICU stay/mechanical ventilation duration. DESIGN: Prospective nonrandomized study. SETTING: Patients hospitalized in ICU for COVID-19 infection. PATIENTS: Sixty patients hospitalized in ICU (mean duration: 31.9 ± 18.2 d) were recruited 4-8 weeks post discharge from ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients visited the laboratory on two separate occasions. The first visit was dedicated to quality of life questionnaire, cardiopulmonary exercise testing, whereas measurements of the knee extensors neuromuscular function were performed in the second visit. Maximal oxygen uptake (V o2 max) was 18.3 ± 4.5 mL·min -1 ·kg -1 , representing 49% ± 12% of predicted value, and was significantly correlated with ICU stay/mechanical ventilation (MV) duration ( R = -0.337 to -0.446; p < 0.01 to 0.001), as were maximal voluntary contraction and electrically evoked peak twitch. V o2 max (either predicted or in mL· min -1 ·kg -1 ) was also significantly correlated with key indices of pulmonary function such as predicted forced vital capacity or predicted forced expiratory volume in 1 second ( R = 0.430-0.465; p ≤ 0.001) and neuromuscular function. Both cardiorespiratory fitness and neuromuscular function were correlated with self-reported physical functioning and general health status. CONCLUSIONS: V o2 max was on average only slightly above the 18 mL·min -1 ·kg -1 , that is, the cut-off value known to induce difficulty in performing daily tasks. Overall, although low physical capacities at admission in ICU COVID-19 patients cannot be ruled out to explain the association between V o2 max or neuromuscular function and ICU stay/MV duration, altered cardiorespiratory fitness and neuromuscular function observed in the present study may not be specific to COVID-19 disease but seem applicable to all ICU/MV patients of similar duration.

Fatigue, physical activity, and quality of life in people self-reporting symptoms of chronic venous disease.

OBJECTIVE: The aim of this study was to quantify fatigue and quality of life (QoL) in people self-reporting chronic venous disease (CVD) symptoms or at risk of CVD within a large cohort representative of the French population. The relationship between self-reported physical activity and both fatigue and QoL was also investigated. We hypothesized that a greater fatigue and impaired QoL would exist in participants self-reporting CVD symptoms, with the impairments being attenuated in those with greater level of physical activity. METHODS: Using a web-based, custom and adaptive survey, 3008 participants were asked to self-report the presence of common symptoms and risk factors of CVD. Fatigue, QoL, and physical activity were assessed using the Functional Assessment of Chronic Illness Therapy-Fatigue scale, the Chronic Venous Insufficiency Quality of Life Questionnaire, and the Godin-Shepard Leisure-Time Physical Activity Questionnaire, respectively. RESULTS: Thirty-two percent of participants were categorized as having CVD symptoms, whereas 50% were categorized as at risk of CVD. Fatigue was greater in participants with CVD symptoms than non-CVD participants (P < .001), with the score of participants at risk of CVD being intermediate (P ≤ .001). QoL was more impaired in participants with CVD symptoms compared with participants at risk of CVD (P < .001). In participants with CVD symptoms, there were relationships between fatigue and QoL (P < .001) and between physical activity and fatigue (P < .001). Despite the relationship between physical activity and QoL not reaching significance (P = .067), a lower QoL was found in insufficiently active as compared with active (P < .001) and moderately active (P < .001) participants with CVD symptoms. CONCLUSIONS: Participants self-reporting CVD symptoms suffer from greater fatigue and impaired QoL. In this population, a higher level of physical activity is associated with less fatigue and a tendency toward improved QoL.

Performance Determinants in Trail-Running Races of Different Distances.

PURPOSE: While the physiological determinants of road running have been widely studied, there is a lack of research in trail-running racing performance. The aim of our study was to determine the physiological predictors of trail-running performance in races of different distances in similar terrain and weather conditions. METHODS: Seventy-five trail runners participating in one of the races of the Ultra-Trail du Mont-Blanc were recruited. Previous to the race, each runner was evaluated with (1) an incremental treadmill test to determine maximal oxygen uptake, ventilatory thresholds, cost of running, and substrate utilization; (2) a power-force-velocity profile on a cycle ergometer; (3) maximal voluntary contractions of the knee extensors and plantar flexors; and (4) anthropometric characteristics. Neuromuscular fatigue was evaluated after the races. Twenty-four runners finished a SHORT (<55 km), 16 finished a MEDIUM (101 km), and 14 finished a LONG (>145 km) race. Correlations and multiple linear regressions were used to find the determinants of performance in each race distance. RESULTS: Performance in SHORT was explained by maximal oxygen uptake and lipid utilization at 10 km/h (r2 = .825, P < .001). Performance in MEDIUM was determined by maximal oxygen uptake, maximal isometric strength, and body fat percentage (r2 = .917, P < .001). A linear model could not be applied in LONG, but performance was correlated to peak velocity during the incremental test. CONCLUSIONS: Performance in trail running is mainly predicted by aerobic capacity, while lipid utilization also influences performance in races <60 km and performance in approximately 100 km is influenced by muscle strength and body composition.

Sex Differences in Neuromuscular Fatigue and Changes in Cost of Running after Mountain Trail Races of Various Distances.

INTRODUCTION: Women have been shown to experience less neuromuscular fatigue than men in knee extensors (KE) and less peripheral fatigue in plantar flexors (PF) after ultratrail running, but it is unknown if these differences exist for shorter trail running races and whether this may impact running economy. The purpose of this study was to characterize sex differences in fatigability over a range of running distances and to examine possible differences in the postrace alteration of the cost of running (Cr). METHODS: Eighteen pairs of men and women were matched by performance after completing different races ranging from 40 to 171 km, divided into SHORT versus LONG races (<60 and >100 km, respectively). Neuromuscular function and Cr were tested before and after each race. Neuromuscular function was evaluated on both KE and PF with voluntary and evoked contractions using electrical nerve (KE and PF) and transcranial magnetic (KE) stimulation. Oxygen uptake, respiratory exchange ratio, and ventilation were measured on a treadmill and used to calculate Cr. RESULTS: Compared with men, women displayed a smaller decrease in maximal strength in KE (-36% vs -27%, respectively, P < 0.01), independent of race distance. In SHORT only, women displayed less peripheral fatigue in PF compared with men (Δ peak twitch: -10% vs -24%, respectively, P < 0.05). Cr increased similarly in men and women. CONCLUSIONS: Women experience less neuromuscular fatigue than men after both "classic" and "extreme" prolonged running exercises but this does not impact the degradation of the energy Cr.

Effect of race distance on performance fatigability in male trail and ultra-trail runners.

The etiology of changes in lower-limb neuromuscular function, especially to the central nervous system, may be affected by exercise duration. Direct evidence is lacking as few studies have directly compared different race distances. This study aimed to investigate the etiology of deficits in neuromuscular function following short versus long trail-running races. Thirty-two male trail runners completed one of five trail-running races as LONG (>100 km) or SHORT (<60 km). Pre- and post-race, maximal voluntary contraction (MVC) torque and evoked responses to electrical nerve stimulation during MVCs and at rest were used to assess voluntary activation and muscle contractile properties of knee-extensor (KE) and plantar-flexor (PF) muscles. Transcranial magnetic stimulation (TMS) was used to assess evoked responses and corticospinal excitability in maximal and submaximal KE contractions. Race distance correlated with KE MVC (ρ = -0.556) and twitch (ρ = -0.521) torque decreases (p ≤ .003). KE twitch torque decreased more in LONG (-28 ± 14%) than SHORT (-14 ± 10%, p = .005); however, KE MVC time × distance interaction was not significant (p = .073). No differences between LONG and SHORT for PF MVC or twitch torque were observed. Maximal voluntary activation decreased similarly in LONG and SHORT in both muscle groups (p ≥ .637). TMS-elicited silent period decreased in LONG (p = .021) but not SHORT (p = .912). Greater muscle contractile property impairment in longer races, not central perturbations, contributed to the correlation between KE MVC loss and race distance. Conversely, PF fatigability was unaffected by race distance.

French Translation and Validation of the Rating-of-Fatigue Scale.

BACKGROUND: The Rating of Fatigue (ROF) scale can measure changes in perceived fatigue in a variety of contexts. OBJECTIVE: The aim of the present study was to translate and subsequently validate the ROF scale in the French language. METHODS: The study was composed of three phases. Phase 1 involved a comprehensive translation, back-translation, and consolidation process in order to produce the French ROF scale. During phase 2, the face validity of the French ROF scale was assessed. A cohort of 60 native French speaking participants responded to a range of Likert scale items which probed the purposes of the ROF scale and what it is intended to measure. During phase 3, the convergent and divergent validity of the ROF scale was assessed during ramped cycling to exhaustion and 10 min of resting recovery. RESULTS: The results from phase 1 demonstrated comparability and interpretability between the original and back-translated ROF scale. In phase 2, participants reported a high face validity, with a score of 3.48 ± 0.70 out of 4 when given the item probing whether the scale "measures fatigue". This score further improved (3.67 ± 0.57, P = 0.01) after participants read the accompanying instructions. Participants were able to distinguish the purposes of the scale for measuring fatigue rather than exertion. In phase 3, strong correlations were found between ROF and heart rate (HR) both during exercise (r = 0.91, P < 0.01) and recovery (r = 0.92, P < 0.01), while discriminant validity between ROF and rating of perceived exertion (RPE) was found during recovery. CONCLUSION: The present study permits the applications of the ROF scale in the French language.