How to Score the Peak Oxygen Consumption Obtained Through Cardiopulmonary Exercise Test in Individuals after Stroke?

OBJECTIVES: To compare five distinct methods to score the peak of oxygen consumption (VO2peak) obtained through the cardiopulmonary exercise testing (CPET) in individuals after stroke. MATERIALS AND METHODS: The VO2peak was obtained through the CPET with five methods: method-1: the highest value of the test; method-2: the highest value of the last 30 seconds at peak exercise; method-3: the mean of the last 30 seconds at peak exercise; method-4: the mean of the last 20 seconds at peak exercise; method-5: the highest value averaged of the 3 last blocks of 10 seconds at peak exercise. The coefficient of variance (CV) and the mean differences with 95% confidence interval (CI) between the scoring methods were calculated. A post-hoc test (Tukey HSD) was performed to calculate the adjusted 95%CI. RESULTS: Fifty-nine individuals were included (54±12 years, 56±60 months after stroke). The CV of the methods 1-to-5 were, respectively: 27.91%, 25.77%, 23.38%, 23.83%, and 23.33%. There was no difference between method-1 and method-2 (95%CI: -1.10 to 4.69) and between methods 3 to 5: method-3 and method-4 (95%CI: -2.97 to 2.82); method-3 and method-5 (95%CI: -3.57 to 2.22); method-4 and method-5 (95%CI: -3.49 to 2.30). However, method-1 and -2 provided VO2peak values different from that of methods 3-to-5. CONCLUSIONS: The scoring method of obtaining the VO2peak has an influence on its magnitude. Since methods 3-to-5 showed lower CV and provided similar values, they should be used to calculate the VO2peak obtained through the CPET in individuals after stroke.

Assessment of V̇o2peak and Exercise Capacity After Stroke: A Validity Study of the Human Activity Profile Questionnaire.

OBJECTIVE: To investigate the concurrent validity of the Human Activity Profile (HAP) in individuals after stroke to provide the peak oxygen uptake (V̇o2peak) and the construct validity of the HAP to assess exercise capacity, and to provide equations based on the HAP outcomes to estimate the distance covered in the Incremental Shuttle Walking Test (ISWT). DESIGN: Cross-sectional study. SETTING: University laboratory. PARTICIPANTS: Individuals (N=57) aged 54±11 years who have experienced stroke. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Agreement between the V̇o2peak provided by the HAP (lifestyle energy consumption [LEC] outcome, in mL/kg-1/min-1) and the criterion standard measure of the V̇o2peak (mL/kg-1/min-1), obtained through the symptom-limited Cardiopulmonary Exercise Test (CPET). Correlation between the HAP outcomes (LEC, maximum activity score [MAS], and adjusted activity score [AAS]) and the construct measure: the distance covered (in meters) in the ISWT. An equation to estimate the distance covered in the ISWT was determined. RESULTS: High magnitude agreement was found between the V̇o2peak, in mL/kg-1/min-1, obtained by the symptom-limited CPET and the value of V̇o2peak, in mL/kg-1/min-1, provided by the HAP (LEC) (intraclass correlation coefficient, 0.75; P<.001). Low to moderate magnitude correlations were found between the distance covered in the ISWT and the HAP (LEC/MAS/AAS) (0.34≤ρ≤0.58). The equation to estimate the distance covered in the ISWT explained 31% of the variability of the ISWT (ISWTestimated, -361.91+(9.646xAAS)). CONCLUSION: The HAP questionnaire is a clinically applicable way to provide a valid value of V̇o2peak (in mL/kg-1/min-1) and to assess the exercise capacity of individuals after stroke. Furthermore, an equation to estimate the distance covered in the submaximal field exercise test (ISWT) based on the result of the AAS (in points) was provided.

Five-repetition sit-to-Stand test among patients post-stroke and healthy-matched controls: the use of different chair types and number of trials.

Background: In 2018, the American Physical Therapy Association (APTA) published a clinical guideline for adults with neurological conditions, which included recommendations for the Five-Repetition Sit-to-Stand test (5STSt). According to the APTA, a standard-height chair should be used, but there is no recommendation regarding seat depth. In addition, the APTA recommended the use of one trial of the test, based on expert opinion.Objectives: (1) Compare the 5STSt scores of patients post-stroke and healthy-matched controls using two types of chairs (one standardized and one adjusted to the individual's anthropometric characteristics); and (2) Verify whether different numbers of trial affect the 5STSt scores.Methods: Eighteen patients post-stroke and 18 healthy-matched controls performed three trials of the 5STSt for each type of chair. ANOVA was used for analysis (α = 0.05).Results: No significant interaction between groups and chairs was found. Patients post-stroke showed worsened performances in 5STSt when using both chairs compared to the healthy controls (p = .001). In both groups, the 5STSt scores were lower when using a standardized chair than an adjusted chair (p < .003) and different numbers of trials provided similar 5STSt scores (0.44 ≤ p ≤ 0.98).Conclusion: The 5STSt scores were affected by the physical characteristics of the chair, and an adjusted chair should be used. The APTA recommendation for one trial of the 5STSt is supported by the present results.

Reliability and validity of the incremental shuttle walking test in individuals after stroke.

BACKGROUND: There are limitations to perform the cardiopulmonary exercise test (CPET) and the six-minute walking test (6MWT) in clinical settings. The incremental shuttle walking test (ISWT) might be an alternative assessment of exercise capacity and an estimation of cardiopulmonary fitness after stroke. OBJECTIVES: To investigate the test-retest and inter-rater reliabilities, the standard error of measurement (SEM) and the minimal detectable change (MDC) of the ISWT, its construct validity to assess exercise capacity and its concurrent validity to estimate cardiopulmonary fitness after stroke. METHODS: Prospective diagnostic accuracy study. Fifty-one individuals (54 ± 11 years) at the chronic phase (65 ± 73 months after stroke) were included. The distance walked, in meters, during the 12-stage-ISWT and the 6MWT and the peak oxygen uptake (VO2peak, ml.kg-1.min-1) in the CPET (gold standard) were assessed. RESULTS: Significant and high to very high magnitude test-retest and inter-rater reliabilities (0.88≤ICC≤0.93) of the ISWT was found. The SEM for both reliabilities was small (-23.35 m≤ SEM≤41.47 m). The MDC for test-retest and inter-rater reliabilities were 114.63 m and 64.53 m, respectively. For construct validity, a significant and high magnitude correlation between the ISWT and the 6MWT was found (ICC = 0.82). For the concurrent validity, a significant, but low magnitude correlation was found between the ISWT and the VO2peak (rho = 0.42). CONCLUSIONS: The ISWT demonstrated adequate reliabilities and construct validity for exercise capacity assessment. However, the concurrent validity of the ISWT as an estimation of cardiopulmonary fitness still requires further research.

Effects of detraining on cardiorespiratory fitness of individuals with chronic stroke.

BACKGROUND: Aerobic training can improve cardiorespiratory fitness in individuals after stroke. However, the effects of short-term and long-term detraining are not well known. OBJECTIVE: To determine the effects of short-term (1-month) and long-term (6-month) detraining on cardiorespiratory fitness (VO2peak) of individuals after stroke, who participated in aerobic training. METHODS: A cohort study was developed. Twenty adults (57 ± 11 years old) with stroke were included. After completing an outpatient aerobic training, participants were divided into gain group (VO2peak increase >1.3 ml.kg-1.min-1 from before to immediately after the training) or non-gain group (VO2peak change ≤1.3 ml.kg-1.min-1). Cardiorespiratory fitness (VO2peak), obtained by the cardiopulmonary exercise test was assessed one and 6 months after the end of the training (short- and long-term detraining, respectively), or collected retrospectively from patient chart (before and after the training). RESULTS: There was found a significant interaction effect (time*group) for VO2peak (F= 6.108;p < 0,001). Higher values in the VO2peak observed in the gain group with the aerobic training (F = 25.86; p< .001) were significantly reduced with short-term detraining, reaching values similar to that observed before the training and to that of the non-gain group (F = 14.81;p= .001). Both groups had similar VO2peak values within long-term detraining (F = 2.70;p= .12), with no significant differences from the values observed before the training and after short-term detraining (0.11 ≤ p≤ 1.00). CONCLUSIONS: Detraining on cardiorespiratory fitness of individuals after chronic stroke occurred within only 1 month. Therefore, it is important to maintain aerobic training throughout life.

Does grip strength predict lower limb global strength in subjects with stroke? / Força de preensão relaciona-se com força de membros inferiores pós-acidente vascular encefálico? / Fuerza de asimiento y fuerza de miembros inferiores después del accidente cerebrovascular

Abstract Introduction: Grip strength is an important clinical measure and has been used for several purposes in different populations, including those to predict the global strength of lower limbs (LL) and upper limbs. However, little is known about the association between grip strength and lower limb (LL) global strength in subjects with stroke. Objective: To investigate the relationship between grip strength and LL global strength in stroke with subjects at both subacute and chronic phases. Method: Measures of grip strength (handgrip dynamometer) and LL global strength (hand-held dynamometer) were obtained in 20 subjects in the subacute phase of the stroke and 18 in the chronic phase. Pearson correlation coefficient was used to investigate the correlation between grip strength and LL global strength (α = 0.05). Results: Subjects in the subacute phase showed a moderate statistically significant correlation between paretic grip strength and global strength of the non-paretic LL (r = 0.50; p < 0.05), but no correlation with the paretic LL was found (p = 0.25). The non-paretic grip strength showed no statistically significant correlation with global strength of the paretic LL (p = 0.93) and of the non-paretic LL (p = 0.64). In chronic subjects, no statistically significant correlation (0.50 ≤ p ≤ 0.97) was observed. Conclusion: Grip strength does not seem to be an adequate indicator to predict LL global strength of subjects with stroke. This conclusion is different from that obtained for other populations.

Resumo Introdução: A força de preensão palmar (FPP) é uma importante medida clínica e vem sendo utilizada com diversos propósitos em diferentes populações, dentre eles para predizer a força global de membros inferiores (MMII) e superiores. Entretanto, pouco se sabe sobre a associação da FPP e força global de MMII pós-Acidente Vascular Encefálico (AVE). Objetivo: Investigar a relação entre FPP e força global de MMII em indivíduos pós-AVE, nas fases subaguda e crônica. Método: Foram incluídos 38 indivíduos pós-AVE (20 subagudos/18 crônicos). A FPP foi avaliada pelo dinamômetro de preensão palmar e a força global de MMII pelo dinamômetro portátil. Coeficiente de correlação de Pearson foi calculado para investigar a correlação entre FPP e força global de MMII (α = 0,05). Resultados: Para os indivíduos da fase subaguda do AVE, foi observada correlação estatisticamente significativa entre FPP do lado parético e força global de MI do lado não-parético (r = 0,50; p < 0,05). Para o MI parético não houve correlação significativa (p = 0,25). Para FPP do lado não-parético, não foi observada correlação estatisticamente significativa com a força global de MMII tanto para o lado parético (p = 0,93) quanto para o não-parético (p=0,64). Nos indivíduos crônicos, não foi observada nenhuma correlação estatisticamente significativa (0,50 ≤ p ≤ 0,97). Conclusão: A FPP parece não ser uma medida adequada para informar sobre a força global de MMII pós-AVE, diferentemente do observado em outras populações.

Resumen Introducción: La fuerza de prensión de la mano (FPM) es una medida clínica importante y se viene usando con diversos propósitos en diferentes poblaciones, entre ellos para predecir la fuerza global de miembros inferiores (MI) y superiores. Sin embargo, poco se sabe acerca de la asociación entre la FPM y la fuerza global de los MI después del accidente cerebrovascular (ACV). Objetivo: Investigar la relación entre la FPM y la fuerza global de MI en sujetos después del ACV, en las fases subaguda y crónica. Método: Se obtuvieron medidas de la FPM con el dinamómetro hidráulico, de la fuerza global de MI con el dinamómetro digital, de 20 sujetos subagudos y 18 sujetos crónicos después del ACV. El coeficiente de correlación de Pearson se calculó para investigar la correlación entre la FPM y la fuerza global de MI (α = 0,05). Resultados: Para los sujetos de la fase subaguda del ACV, se observó una correlación estadísticamente significativa entre FPM del lado parético y fuerza global de MI del lado no parético (r = 0,50; p < 0,05). Para el MI parético no hubo correlación significativa (p = 0,25). Para FPM del lado no parético, no se observó correlación estadísticamente significativa con la fuerza global de MI tanto para el lado parético (p = 0,93) como para el no parético (p = 0,64). Entre los sujetos crónicos, no se observó ninguna correlación estadísticamente significativa (0,50 ≤ p ≤ 0,97). Conclusiones: La FPM no parece ser una medida adecuada para informar sobre la fuerza global de MI en sujetos después del ACV, a diferencia de lo observado con otras poblaciones.

A Single Trial May Be Used for Measuring Muscle Strength With Dynamometers in Individuals With Stroke: A Cross-Sectional Study.

BACKGROUND: The mean of 3 trials is commonly employed to report measures of muscle strength after a stroke. However, consistent and reliable results have been found for single trial dynamometric measures of grip, pinch, and trunk strength in individuals with stroke. Nevertheless, no studies were found that investigated whether only a single trial could be used for the assessment of the strength of both the upper and lower limb muscles. OBJECTIVE: To determine the best scoring method (one vs the means of 2 or 3 trials) to measure the strength of the upper and lower limb muscles in individuals with sub-acute and chronic stroke. DESIGN: Cross-sectional observational study. SETTING: Research laboratory, participants' homes, and community-based settings. PARTICIPANTS: Fifty-five individuals at the sub-acute (mean age: 61 ± 13 years; 3.7 ± 0.7 months poststroke) and 59 at the chronic poststroke phases (mean age: 57 ± 130 years; 90 ± 71 months poststroke). MAIN OUTCOME MEASUREMENTS: Bilateral maximum isometric strength measures of the shoulder, elbow, and wrist flexors/extensors; shoulder abductors; hip, knee, and ankle flexors/extensors; and hip abductors were obtained with a hand-held dynamometer. METHODS: After familiarization, 3 trials of maximal isometric strength were obtained for all evaluated muscle groups. One-way analysis of variance was used to compare the results obtained with the first vs the means of 2 and 3 trials for all the assessed muscle groups. RESULTS: The values provided by the different scoring methods were similar for all evaluated muscle groups in individuals with sub-acute (.68 ≤ P ≤ .99) and chronic (.69 ≤ P ≤ .99) stroke. CONCLUSIONS: A single trial, after familiarization, may be used for measuring the strength of the upper and lower limb muscles with hand-held dynamometers in individuals with sub-acute and chronic stroke. This increases the clinical applicability of hand-held dynamometers for strength measurement, as it reduces the assessment burden placed on the participants and therapists. LEVEL OF EVIDENCE: III.

Trunk flexor and extensor muscle performance in chronic stroke patients: a case-control study.

BACKGROUND: Although chronic stroke patients commonly show impairment of trunk muscle performance, this disability has only been analyzed in terms of peak torque. Therefore, other measures are needed for a more adequate description. OBJECTIVE: This study aimed to compare concentric muscle performance of trunk flexor/extensor muscles between chronic stroke patients and matched-healthy subjects. METHODS: 18 chronic stroke patients and 18 healthy subjects were matched according to their age, sex, body mass index and level of physical activity. After familiarization, trunk flexor/extensor concentric muscle strength was measured using an isokinetic dynamometer (Biodex Medical Systems Inc, Shirley, NY, USA) with 3 repetitions at a velocity of 60°/s and 5 repetitions at a velocity of 120°/s. Trunk muscular performance was characterized by peak torque, torque at 90°, total work, and total work normalized by trunk mass. Student's t-test was used for independent samples (α=0.05) for group comparisons. RESULTS: All trunk muscle performance variables values investigated were significantly lower in chronic stroke patients when compared to matched-healthy subjects (p≤0.001). The obtained ratios of chronic stroke patients scores to that of the matched-healthy subjects at velocities of 60°/s and 120°/s were, respectively: flexor peak torque (60% & 53%)/extensor (54% & 53%); flexor torque at 90° (56.20% & 36.58%)/extensor (57.92% & 30.65%); flexor total muscular work (51.27% & 38.03%)/extensor (47.97% & 39.52%); and flexor total muscular work normalized by trunk mass (55.57% & 40%)/extensor (51.40% & 42%). CONCLUSIONS: Chronic stroke patients showed decreased trunk muscle performance when compared to matched-healthy subjects in all variables investigated.