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BACKGROUND AND OBJECTIVE: The biomarkers of hand function may differ based on level of motor impairment after stroke. The objective of this study was to determine the relationship between resting state functional connectivity (RsFC) and unimanual contralesional hand function after stroke and whether brain-behavior relationships differ based on level of grasp function. METHODS: Sixty-two individuals with chronic, left-hemisphere stroke were separated into three functional levels based on Box and Blocks Test performance with the contralesional hand: Low (moved 0 blocks), Moderate (moved >0% but <90% of blocks relative to the ipsilesional hand), and High (moved ≥90% of blocks relative to the ipsilesional hand). RESULTS: RsFC in the ipsilesional and interhemispheric motor networks was reduced in the Low group compared to the Moderate and High groups. While interhemispheric RsFC correlated with hand function (grip strength and Stroke Impact Scale Hand) across the sample, contralesional RsFC correlated with hand function in the Low group and no measures of connectivity correlated with hand function in the Moderate and High groups. Linear regression modeling found that contralesional RsFC significantly predicted hand function in the Low group, while no measure correlated with hand function in the High group. Corticospinal tract integrity was the only predictor of hand function for the Moderate group and in an analysis across the entire sample. CONCLUSIONS: Differences in brain-hand function relationships based on level of motor impairment may have implications for predictive models of treatment response and the development of intervention protocols aimed at improving hand function after stroke.
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Positive social comparative feedback is hypothesized to generate a dopamine response in the brain, similar to reward, by enhancing expectancies to support motor skill learning. However, no studies have utilized neuroimaging to examine this hypothesized dopaminergic mechanism. Therefore, the aim of this preliminary study was to investigate the effect of positive social comparative feedback on dopaminergic neural pathways measured by resting state connectivity. Thirty individuals practiced an implicit, motor sequence learning task and were assigned to groups that differed in feedback type. One group received feedback about their actual response time to complete the task (RT ONLY), while the other group received feedback about their response time with positive social comparison (RT + POS). Magnetic resonance imaging was acquired at the beginning and end of repetitive motor practice with feedback to measure practice-dependent changes in resting state brain connectivity. While both groups showed improvements in task performance and increases in performance expectancies, ventral tegmental area and the left nucleus accumbens (mesolimbic dopamine pathway) resting state connectivity increased in the RT + POS group but not in the RT ONLY group. Instead, the RT ONLY group showed increased connectivity between ventral tegmental area and primary motor cortex. Positive social comparative feedback during practice of a motor sequence task may induce a dopaminergic response in the brain along the mesolimbic pathway. However, given that absence of effects on expectancies and motor learning, more robust and individualized approaches may be needed to provide beneficial psychological and behavioral effects.
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Imagen por Resonancia Magnética , Vías Nerviosas , Núcleo Accumbens , Área Tegmental Ventral , Humanos , Masculino , Femenino , Adulto Joven , Adulto , Área Tegmental Ventral/fisiología , Área Tegmental Ventral/diagnóstico por imagen , Vías Nerviosas/fisiología , Núcleo Accumbens/fisiología , Núcleo Accumbens/diagnóstico por imagen , Dopamina/metabolismo , Dopamina/fisiología , Retroalimentación Psicológica/fisiología , Corteza Motora/fisiología , Corteza Motora/diagnóstico por imagen , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Destreza Motora/fisiología , Práctica PsicológicaRESUMEN
BACKGROUND: Physical therapists (PTs) report job satisfaction when delivering autonomous, high-quality care, but they also experience work-related stress, burnout, and emotional exhaustion. Retaining experienced and skilled clinicians is important. However, a subset of PTs are choosing to voluntarily leave clinical practice (i.e., experience attrition). PT attrition may negatively impact patient care, increase organizational costs, and negatively impact the profession. PURPOSE: This study examined the nature of the experiences of PTs voluntarily leaving clinical practice in order to understand factors contributing to PT attrition. METHOD: A pragmatic qualitative approach with individual, semi-structured interviews conducted with PTs who left clinical practice was used. Interviews were transcribed verbatim and analyzed using deductive thematic analyses. DISCUSSION: Nineteen US-based PTs who left clinical practice were interviewed. Participants were predominately female (n=15), Doctors of Physical Therapy (n=10), with a median of 6 years working in clinical practice as a PT. Analyses revealed five key themes contributing to leaving clinical practice subdivided into Herzberg's Theory: 1) lack of career advancement opportunities; 2) rising productivity requirements reducing the quality of patient care; 3) financial concerns due to imbalance between cost of PT education and compensation; 4) physical demands either contributing to attrition or seen as a benefit of the profession; and 5) emotional burden contributing to attrition or emotional connection seen as professional value. CONCLUSIONS: Understanding the factors contributing to PT attrition is important to guide future strategies to address these factors. Further research may identify opportunities to address these concerns in entry-level education, workplace environments, and professional continuing education.
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Agotamiento Profesional , Estrés Laboral , Fisioterapeutas , Humanos , Femenino , Investigación Cualitativa , Satisfacción en el TrabajoRESUMEN
Study objective: Cardiac rehabilitation (CR) programs are effective at reducing cardiovascular disease risk factors, yet programs in the United States (US) have poor participation and completion. The current study evaluates characteristics related to completion and drop-out for CR participants. Design: A cross-sectional study design compared participants who completed the program (finishers) and those did not finish (non-finishers). Variables were compared to determine differences between the dichotomous groups included demographic data, initial six-minute walk test, Zung Depression Index, and Quality of Life Measure (QLM). Logistical regression using variables with differences between groups determined impact on program completion. Setting: Phase two outpatient hospital based cardiac rehabilitation program. Participants: Ninety-seven participants were part of the sample; 61 completed the program, and 36 dropped out. Main outcome measure: Completion of CR. Results: Ninety-seven participants are included; 61 (63 %) were finishers and 36 (37 %) were non-finishers. Finishers were older, had a higher proportion of females and Medicare insurance recipients, had lower depression scores, and reported higher quality of life. Results of the final logistic regression revealed finishers were more likely to have Medicare (odds ratio (OR) = 5.215, confidence interval (CI) 1.897-14.338), be female (OR = 4.597, 95 % CI 1.532-13.795) and have higher QLM Family Sub scores (OR = 1.129, 95 % CI 1.023-1.246). The model correctly classified 71.9 % of cases. Conclusion: The analysis highlights Medicare insurance and family support are associated with program completion. Interventions to increase family and social support, and to provide financial assistance for those with financial burden through lack of insurance or high co-pays may increase cardiac rehabilitation completion rates.
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Motor action selection engages a network of frontal and parietal brain regions. After stroke, individuals activate a similar network, however, activation is higher, especially in the contralesional hemisphere. The current study examined the effect of practice on action selection performance and brain activation after stroke. Sixteen individuals with chronic stroke (Upper Extremity Fugl-Meyer motor score range: 18-61) moved a joystick with the more-impaired hand in two conditions: Select (externally cued choice; move right or left based on an abstract rule) and Execute (simple response; move same direction every trial). On Day 1, reaction time (RT) was longer in Select compared to Execute, which corresponded to increased activation primarily in regions in the contralesional action selection network including dorsal premotor, supplementary motor, anterior cingulate and parietal cortices. After 4 days of practice, behavioural performance improved (decreased RT), and only contralesional parietal cortex significantly increased during Select. Higher brain activation on Day 1 in the bilateral action selection network, dorsolateral prefrontal cortex and contralesional sensory cortex predicted better performance on Day 4. Overall, practice led to improved action selection performance and reduced brain activation. Systematic changes in practice conditions may allow the targeting of specific components of the motor network during rehabilitation after stroke.
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Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Mapeo Encefálico , Humanos , Imagen por Resonancia Magnética , Lóbulo Parietal , Tiempo de Reacción/fisiologíaRESUMEN
Measuring gait parameters (e.g. speed, cadence, step duration) accurately is invaluable for evaluation during treatment of older adults who struggle with disability onset, disease progression, balance, and injurious falls. Traditionally stopwatches or timing gates are used to measure gait speed in clinical settings, and these are limited to measuring gait speed. Other wearable and non-wearable technologies offer the ability to measure additional gait parameters though patients are known to walk differently with the devices and even tend to slow down before engaging with a non-wearable such as a floor mat. Floor vibrations are a promising option to measuring gait parameters while not being intrusive and not requiring line-of-sight to the patient for measurements. This paper presents methodology for extracting gait parameters using vibrations with comparisons to APDM Wearable Technologies Mobility Lab sensors and stopwatch measurements. Performance is examined across 97 participants for self-selected speed forward, full speed forward, and backwards walks at three different testing sites for a total of 1039 walks. Gait speed vibrations measurements demonstrated excellent reliability with APDM Mobility Lab (ICC: 0.98; 99% CI: 0.01±0.01 m/s) and stopwatch (ICC: 0.97; 99% CI: -0.01±0.01 m/s) measurements. Similar excellent results are reported for cadence, gait cycle duration, step duration, and stride length parameters.
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BACKGROUND: Despite increased awareness of factors related to athletic performance and injury prevention, youth and adolescent baseball players continue to report injuries at alarming rates. Upper extremity muscle strength is an integral part of physical assessment and injury prevention in baseball players, however minimal data exists in youth populations. Changes in anthropometric measures, inherent in physically developing athletes, have been shown to impact strength measures, however normalization methodology is rarely reported. PURPOSE: The purposes of this study were to 1) compare the measurement properties of five potential methods for normalizing isometric shoulder strength in a cohort of 9-12 year old male baseball players and 2) examine the relationship between normalized isometric shoulder strength and ball velocity in a cohort of 9-12 year old male baseball players. STUDY DESIGN: Prospective cohort study (n=159). METHODS: Baseline and follow up height, weight and bilateral ulnar length measurements were assessed followed by isometric strength in both the dominant and non-dominant shoulders. Strength measures included scapular plane abduction (scaption), external rotation (ER) at 0°, ER and internal rotation (IR) at 90°. Ball velocity was assessed as a measure of throwing performance. Intraclass correlation coefficients (ICC2,1), standard errors of measurement (SEM) and minimal detectable change (MDC95) were calculated for all strength measures. Repeated measures ANOVA were conducted comparing changes in normalized strength using five separate anthropometric measures: weight, height, body mass index, ulnar length and % of non-dominant shoulder strength. Linear regression models were used to examine the relationships between normalized isometric shoulder strength and ball velocity. Statistical significance was set a priori at α=0.05. RESULTS: Shoulder strength normalized using ulnar length was the only method that demonstrated excellent reliability (ICC2,1 0.98-0.99) and detected significant changes between strength in each of the four measures tested (SEM 0.39-0.69 Nm). Modest but significant correlations were observed between scaption and ball velocity (r2 = 0.27, p < 0.001) and ER at 0° and ball velocity (r2 = 0.23, p < 0.001). CONCLUSION: Ulnar length was the most stable and reliable normalization method for assessing isometric shoulder strength in youth baseball players. In addition, normalized scaption strength was the most significant predictor of ball velocity, followed by ER at 0° strength in this population. LEVEL OF EVIDENCE: Level 2b (etiology).
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Introduction: Positive social comparative feedback indicates to the learner that they are performing better than others. While this type feedback supports motor skill learning in some tasks, the effect of social comparative feedback on implicit motor sequence learning remains unknown. The aim of this study was to determine the effect of positive social comparative feedback on the learning of and expectancies for a motor sequence task. Methods: Forty-eight individuals practiced a joystick-based sequence task and were divided into three feedback groups: CONTROL (no performance feedback), RT ONLY (response time only feedback), and RT+POS (response time plus positive social comparison). Participants attended sessions on two consecutive days: Day 1 for repetitive motor practice/skill acquisition and Day 2 for retention testing. Performance related expectancies, like perceived competence, were measured before and after motor practice on Day 1 and at retention on Day 2. Results: While all groups improved with practice, the CONTROL group showed better overall performance/learning (faster response times) compared with the RT ONLY group. Despite similar response times, the RT+POS showed higher peak velocities than the RT ONLY group. Overall, the RT+POS and CONTROL demonstrated increases in perceived competence while the RT ONLY group did not. Discussion: The results of this study suggest that feedback content is an important consideration during motor practice sessions since feedback without context (RT ONLY) may be detrimental to motor sequence learning. The results also suggest that, if providing performance related feedback during practice of a skill that relies on implicit sequence learning processes, comparative context may be necessary for enhancing expectancies and supporting.
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BACKGROUND: Structural integrity of the ipsilesional corticospinal tract (CST) is important for upper limb motor recovery after stroke. However, additional neuromechanisms associated with motor function poststroke are less well understood, especially regarding the lower limb. OBJECTIVE: To investigate the neural basis of upper/lower limb motor deficits poststroke by correlating measures of motor function with diffusion tensor imaging-derived indices of white matter integrity (fractional anisotropy (FA), mean diffusivity (MD)) in primary and secondary motor tracts/structures. METHODS: Forty-three individuals with chronic stroke (time poststroke, 64.4 ± 58.8 months) underwent a comprehensive motor assessment and MRI scanning. Correlation and multiple regression analyses were performed to examine relationships between FA/MD in a priori motor tracts/structures and motor function. RESULTS: FA in the ipsilesional CST and red nucleus (RN) was positively correlated with motor function of both the affected upper and lower limb (r = 0.36-0.55, p ≤ 0.01), while only ipsilesional RN FA was associated with gait speed (r = 0.50). Ipsilesional CST FA explained 37.3% of the variance in grip strength (p < 0.001) and 31.5% of the variance in Arm Motricity Index (p = 0.004). Measures of MD were not predictors of motor performance. CONCLUSIONS: Microstructural integrity of the ipsilesional CST is associated with both upper and lower limb motor function poststroke, but appears less important for gait speed. Integrity of the ipsilesional RN was also associated with motor performance, suggesting increased contributions from secondary motor areas may play a role in supporting chronic motor function and could become a target for interventions.
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Tractos Piramidales , Accidente Cerebrovascular , Estudios Transversales , Imagen de Difusión Tensora , Humanos , Extremidad Inferior/diagnóstico por imagen , Imagen por Resonancia Magnética , Tractos Piramidales/diagnóstico por imagen , Núcleo Rojo/diagnóstico por imagen , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
OBJECTIVE: Strength training is frequently utilized by physical therapists; however, there has been discussion about whether physical therapists utilize strength training adequately. The purpose of this study was to describe and compare the strength training attitudes, behaviors, and knowledge of physical therapists and physical therapy students and to determine how participant characteristics influenced knowledge scores. METHODS: An anonymous survey was created in 3 rounds. For round 1, researchers used textbooks to create items assessing demographics, attitudes, behaviors, and knowledge regarding strength training. Rounds 2 and 3 consisted of feedback from 7 content experts until 80% consensus was reached; items were added, removed, or edited based on feedback. The final survey was distributed through social media, list servs, and email targeting physical therapists and students based in the United States. Response frequencies for all items were reported. Overall knowledge scores were calculated by summing correct responses for each item, with a maximum score of 13; scores <70% were considered low. Binomial logistic regression determined which characteristics (demographics, attitudes, or behaviors) influenced whether participants adequately utilized strength training principles (scored ≥70% on knowledge items). RESULTS: There were 777 physical therapist and 648 student participants. Nearly 90% of therapists and students reported frequently prescribing strength training. Over 48% of therapists felt their professional education did not prepare them to apply strength training (compared with 24% of students), and 68% believed that strength training is inadequately applied in physical therapy (compared with 40% of students). Sixty-two percent of therapists and 55% of students scored ≥70% for knowledge items. Additional strength training education and regular participation in strength training increased the odds of scoring ≥70% on knowledge items. CONCLUSION: Physical therapists and physical therapy students frequently prescribe strength training despite similarly low knowledge scores. To increase knowledge, greater emphasis on strength training in professional education, continuing education, participation in strength training, or all 3 is warranted. IMPACT: Strength training is an important intervention used in physical therapy and must be used appropriately to improve the health of patients. According to these findings, strength training education may not currently be optimal, as demonstrated by low knowledge scores by both therapists and students. Further work is needed to determine how knowledge of strength training relates to patient outcomes and also how best to implement strength training in physical therapy education and practice.
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Competencia Clínica , Conocimientos, Actitudes y Práctica en Salud , Empleos en Salud/educación , Fisioterapeutas/educación , Entrenamiento de Fuerza/métodos , Adulto , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
Background and Purpose: Walking has the potential to improve endurance and community participation after stroke. Obtaining ≥6000 daily steps can decrease subsequent stroke risk. Early identification of those prone to low daily steps could facilitate interventions that lead to increased walking and improved health. The purpose of this study was to (1) determine which factors at 2 months poststroke can predict daily step counts at 1 year and (2) determine what step count at 2 months corresponds to obtaining ≥6000 daily steps at 1-year poststroke. Methods: This was a secondary analysis of data from the Locomotor Experience Applied Post Stroke trial, which enrolled participants with walking speeds <0.80 m/second at 2 months poststroke. Daily steps were assessed at 2 months and 1-year poststroke. Linear regression was used to predict daily step counts at 1 year based on factors including age, sex, race and/or ethnicity, stroke severity, walking speed, endurance, fitness, motor function, balance, and balance confidence. A receiver operating characteristic curve determined which step count corresponded to reaching ≥6000 steps at 1 year. Results: Data from 206 participants, mean age=63 (13) years, 43% female, mean baseline daily step count=2922 (2749) steps, were analyzed. The final model to predict daily steps at 1 year poststroke contained daily steps at 2 months and balance (Berg Balance Scale score); these factors explained 38% of the variability in daily steps at 1 year (P≤0.001). Participants obtaining ≥1632 daily steps at 2 months were 1.86 (95% CI, 1.522.27) times more likely to reach ≥6000 daily steps at 1-year poststroke. Conclusions: Daily steps and balance at 2 months poststroke were the strongest predictors of future daily steps. Improving daily physical activity and targeting balance early after stroke may be necessary to increase physical activity at 1-year poststroke.
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Ejercicio Físico/fisiología , Motivación/fisiología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Caminata/fisiología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/psicología , Velocidad al Caminar/fisiologíaRESUMEN
Action selection (AS), or selection of an action from a set of alternatives, is an important movement preparation process that engages a frontal-parietal network. The addition of AS demands to arm training after stroke could be used to engage this motor planning process and the neural network that supports it. The purpose of this case series is to describe the feasibility and outcomes associated with task-oriented arm training aimed at engaging the AS behavioral process and the related neural network in three individuals with chronic stroke. Three participants with mild to moderate motor deficits completed 13 to 15 sessions of task-oriented arm training that included AS cues for each movement repetition; cues dictated movement direction, height, or distance. Before and after training, individuals completed an AS brain-behavior probe during functional MRI. AS behavioral performance improved after training (increased accuracy, decreased reaction time) in all participants while brain activation in the AS network (dorsal premotor, parietal, dorsolateral prefrontal cortices) decreased in two participants. Gains in motor function were also found in all three participants, especially on patient-reported measures of perceived difficulty and confidence to complete upper extremity functional tasks. It was feasible to target the AS behavioral process and the related neural network through the addition of AS demands to functional, task-oriented arm training in three individuals with mild to moderate motor dysfunction poststroke.
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Encéfalo/fisiopatología , Movimiento , Desempeño Psicomotor/fisiología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Anciano , Brazo/fisiopatología , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Vías Nerviosas/fisiopatología , Lóbulo Parietal/fisiopatología , Corteza Prefrontal/fisiopatologíaRESUMEN
Background Survivors of stroke face movement disability and increased cardiovascular disease and stroke risk. Treatment includes rehabilitation focused on functional movement with less emphasis on aerobic capacity. After rehabilitation, survivors of stroke must self-manage activity with limited appropriate community programs. Lack of structured activity contributes to sedentary behavior. The objective of this systematic review and meta-analysis is to review aerobic programs for stroke survivors similar in activity and dosage to cardiac rehabilitation programs to determine their efficacy for improving aerobic and walking capacity. Methods and Results Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to review 5 databases. Group interventions for survivors of stroke with a primary aerobic component and dosage from 18 to 36 visits over 8 to 18 weeks (matching cardiac rehabilitation requirements in the United States) were included. The 6-minute walk test, maximal oxygen consumption (VO2) peak, and walking speed were included as measures of aerobic capacity. Summary effect sizes and outcome measure mean differences were calculated for preintervention to postintervention, and summary effect sizes were calculated for preintervention to follow-up. Activity type and initial 6-minute walk test moderator analyses were performed. Nineteen studies with 23 eligible groups were selected. Survivors of stroke improved their composite aerobic capacity with an effect size of 0.38 (95% CI, 0.27-0.49). Studies including 6-minute walk test demonstrated a pooled difference in means of 53.3 m (95% CI, 36.8-69.8 m). Follow-up data were inconclusive. Conclusions Survivors of stroke benefit from aerobic programs with similar dosing to cardiac rehabilitation in the United States. The potential integration into existing programs could expand the community exercise options.
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Rehabilitación Cardiaca/métodos , Terapia por Ejercicio/métodos , Ejercicio Físico , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/fisiopatología , Tolerancia al Ejercicio , Humanos , Consumo de Oxígeno , Resultado del Tratamiento , Prueba de Paso , Velocidad al CaminarRESUMEN
Objectives: Tight hamstrings contribute to inefficiency of movement and increased risk for injury. Static stretching is the most common intervention for this problem, but the use of alternatives like instrument-assisted soft tissue mobilization (IASTM) and proprioceptive neuromuscular facilitation (PNF) is increasing among clinicians. This study examined two prospective studies with the common aim of demonstrating the effectiveness of IASTM or PNF over static stretching for improving hamstring tightness. Methods: Nondisabled adults were recruited on a university campus. IASTM study: N = 17 (11 males and 6 females). PNF study: N = 23 (7 males and 16 females). Hip flexion range of motion was measured with a passive straight leg raise (for IASTM) or active straight leg raise (for PNF) before and after stretching. Participants performed a self-static stretch on one leg and received the alternative intervention on the contralateral leg. The two studies were analyzed separately for reliability indices and significant differences between interventions. Results: Hip flexion measures showed good reliability in both studies (intraclass correlation coefficient = 0.97) with a minimal detectable change of <4.26. Both studies showed significant interactions between time and intervention (p < 0.05). Follow-up analyses revealed PNF and IASTM interventions resulted in greater increases in hip flexion range than static stretching. Discussion: These findings demonstrate the effectiveness of PNF and IASTM techniques over static stretching for hamstring flexibility. These interventions provide more efficient alternatives for improving flexibility in the clinic, allowing greater progress in a shorter period of time than an equivalent static stretching program. Level of Evidence: 1b.
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Músculos Isquiosurales , Articulación de la Cadera , Movimiento , Ejercicios de Estiramiento Muscular/métodos , Modalidades de Fisioterapia , Propiocepción , Rango del Movimiento Articular , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
BACKGROUND: To investigate the association between cardiorespiratory fitness and risk of cardiovascular disease, cancer, and all-cause mortality in men with musculoskeletal conditions. METHODS: Participants were 12,728 men (mean age 47.0 [9.3] y) with a history of musculoskeletal conditions (including joint pain, low back pain, stiff joints, arthritis, osteoporosis, or gout) and were followed for all-cause mortality to December 31, 2003. Fitness was quantified by maximal treadmill exercise test and was categorized for analysis as low, moderate, and high performance. Cox proportional hazards regression was used to calculate hazard ratios and 95% confidence intervals. RESULTS: Overall, the multivariable-adjusted hazard ratios and 95% confidence intervals for mortality across incremental fitness categories were 1.00 (reference), 0.45 (0.30-0.68) and 0.35 (0.22-0.53), linear trend P < .01 for all-cause, 0.50 (0.23-1.10) and 0.29 (0.12-0.71), linear trend P = .02 for cardiovascular disease, and 0.38 (0.20-0.74) and 0.40 (0.20-0.80), linear trend P = .01 for cancer mortality. CONCLUSION: Among men with musculoskeletal conditions, higher fitness is associated with lower risk of death by cardiovascular disease, cancer, or any cause, independent of other risk factors.
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Capacidad Cardiovascular/fisiología , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Ejercicio Físico/fisiología , Adulto , Fenómenos Fisiológicos Cardiovasculares , Sistema Cardiovascular , Prueba de Esfuerzo , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculoesqueléticas/epidemiología , Aptitud Física/fisiología , Modelos de Riesgos Proporcionales , Factores de Riesgo , Adulto JovenRESUMEN
BACKGROUND: Pairing a bout of high-intensity exercise with motor task practice can enhance motor learning beyond task practice alone, which is thought, in part, to be facilitated by an exercise-related increase in brain-derived neurotrophic factor (BDNF). The purpose of the current study was to examine the effect of different exercise intensities on BDNF levels and motor learning while controlling for exercise-related energy expenditure. METHODS: Forty-eight young, healthy participants were assigned to one of three groups: high-intensity exercise [High], low-intensity exercise [Low], or quiet rest [Rest]. The duration of the exercise bouts were individually adjusted so that each participant expended 200â¯kcals regardless of exercise intensity. BDNF was measured before and after exercise or rest. After exercise or rest, all participants practiced a 3-dimensional motor learning task, which involved reach movements made to sequentially presented targets. Retention was tested after 24-h. BDNF genotype was determined for each participant to explore its effects on BDNF and motor learning. RESULTS: All participants equally improved performance, indicated by a reduction in time to complete the task. However, the kinematic profile used to control the reach movement differed by group. The Rest group travelled the shortest distance between the targets, the High group had higher reach speed (peak velocity), and the Low group had earlier peak velocities. The rise in BDNF post-exercise was not significant, regardless of exercise intensity, and the change in BDNF was not associated with motor learning. The BDNF response to exercise did not differ by genotype. However, performance differed between those with the polymorphism (Met carriers) and those without (Val/Val). Compared to the Val/Val genotype, Met carriers had faster response times throughout task practice, which was supported by higher reach speeds and earlier peak velocities. CONCLUSION: Results indicated that both low and high-intensity exercise can alter the kinematic approach used to complete a reach task, and these changes appear unrelated to a change in BDNF. In addition, the BDNF genotype did not influence BDNF concentration, but it did have an effect on motor performance of a sequential target reach task.
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Factor Neurotrófico Derivado del Encéfalo/sangre , Ejercicio Físico/fisiología , Aprendizaje/fisiología , Destreza Motora/fisiología , Tiempo de Reacción/fisiología , Adulto , Fenómenos Biomecánicos , Factor Neurotrófico Derivado del Encéfalo/genética , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: Humans use voluntary eye movements to actively gather visual information during many activities of daily living, such as driving, walking, and preparing meals. Most stroke survivors have difficulties performing these functional motor tasks, and we recently demonstrated that stroke survivors who require many saccades (rapid eye movements) to plan reaching movements exhibit poor motor performance. However, the nature of this relationship remains unclear. OBJECTIVE: Here we investigate if saccades interfere with speed and smoothness of reaching movements in stroke survivors, and if excessive saccades are associated with difficulties performing functional tasks. METHODS: We used a robotic device and eye tracking to examine reaching and saccades in stroke survivors and age-matched controls who performed the Trail Making Test, a visuomotor task that uses organized patterns of saccades to plan reaching movements. We also used the Stroke Impact Scale to examine difficulties performing functional tasks. RESULTS: Compared with controls, stroke survivors made many saccades during ongoing reaching movements, and most of these saccades closely preceded transient decreases in reaching speed. We also found that the number of saccades that stroke survivors made during ongoing reaching movements was strongly associated with slower reaching speed, decreased reaching smoothness, and greater difficulty performing functional tasks. CONCLUSIONS: Our findings indicate that poststroke interference between eye and limb movements may contribute to difficulties performing functional tasks. This suggests that interventions aimed at treating impaired organization of eye movements may improve functional recovery after stroke.
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Actividades Cotidianas , Movimientos Oculares/fisiología , Desempeño Psicomotor/fisiología , Recuperación de la Función/fisiología , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rehabilitación Neurológica , Rehabilitación de Accidente Cerebrovascular , Prueba de Secuencia AlfanuméricaRESUMEN
Advances in neuroimaging have enabled the mapping of white matter connections across the entire brain, allowing for a more thorough examination of the extent of white matter disconnection after stroke. To assess how cortical disconnection contributes to motor impairments, we examined the relationship between structural brain connectivity and upper and lower extremity motor function in individuals with chronic stroke. Forty-three participants [mean age: 59.7 (±11.2) years; time poststroke: 64.4 (±58.8) months] underwent clinical motor assessments and MRI scanning. Nonparametric correlation analyses were performed to examine the relationship between structural connectivity amid a subsection of the motor network and upper/lower extremity motor function. Standard multiple linear regression analyses were performed to examine the relationship between cortical necrosis and disconnection of three main cortical areas of motor control [primary motor cortex (M1), premotor cortex (PMC), and supplementary motor area (SMA)] and motor function. Anatomical connectivity between ipsilesional M1/SMA and the (1) cerebral peduncle, (2) thalamus, and (3) red nucleus were significantly correlated with upper and lower extremity motor performance (P ≤ 0.003). M1-M1 interhemispheric connectivity was also significantly correlated with gross manual dexterity of the affected upper extremity (P = 0.001). Regression models with M1 lesion load and M1 disconnection (adjusted for time poststroke) explained a significant amount of variance in upper extremity motor performance (R2 = 0.36-0.46) and gait speed (R2 = 0.46), with M1 disconnection an independent predictor of motor performance. Cortical disconnection, especially of ipsilesional M1, could significantly contribute to variability seen in locomotor and upper extremity motor function and recovery in chronic stroke. Hum Brain Mapp 39:120-132, 2018. © 2017 Wiley Periodicals, Inc.
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Lateralidad Funcional , Imagen por Resonancia Magnética , Corteza Motora/diagnóstico por imagen , Accidente Cerebrovascular/diagnóstico por imagen , Extremidad Superior/fisiopatología , Velocidad al Caminar , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Imagen de Difusión Tensora , Femenino , Lateralidad Funcional/fisiología , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Necrosis/diagnóstico por imagen , Necrosis/fisiopatología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiopatología , Examen Neurológico , Accidente Cerebrovascular/fisiopatología , Velocidad al Caminar/fisiologíaRESUMEN
Purpose Determine the relationship between balance impairments and the ability to increase walking speed (WS) on demand in individuals with chronic stroke. Methods WS and Berg Balance Scale (BBS) data were collected on 124 individuals with chronic stroke (>6 months). The ability to increase WS on demand (walking speed reserve, WSR) was quantified as the difference between participants' self-selected (SSWS) and maximal (MWS) walking speeds. Correlation, regression and receiver operating characteristic (ROC) analyses were performed to investigate the relationship between balance and the ability to increase WS. Results Of sample, 58.9% were unable to increase WS on demand (WSR < 0.2 m/s). BBS scores were associated with WSR values (rs=0.74, 0.65-0.81) and were predictive of 'able/unable' to increase WS [odds ratio (OR) = 0.75, 0.67-0.84]. The AUC for the ROC curve constructed to assess the accuracy of BBS to discriminate between able/unable to increase WS was 0.85 (0.78-0.92). A BBS cutscore of 47 points was identified [sensitivity: 72.6%, specificity: 90.2%, +likelihood ratio (LR): 7.41, -LR: 0.30]. Conclusions The inability to increase WS on demand is common in individuals with chronic stroke, and balance appears to be a significant contributor to this difficulty. A BBS cutscore of 47 points can identify individuals who may benefit from balance interventions to improve the ability to increase their WS. Implications for Rehabilitation A majority of individuals with chronic stroke may be unable to increase their walking speed beyond their self-selected speed on demand. This may limit functional ambulation, as these individuals are walking "at capacity". Balance impairments contribute to the inability to increase walking speed. A Berg Balance Scale score <47 points can be used to identify individuals with chronic stroke walking "at capacity" due to balance impairments.
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Equilibrio Postural/fisiología , Accidente Cerebrovascular/fisiopatología , Velocidad al Caminar/fisiología , Enfermedad Crónica , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rehabilitación de Accidente CerebrovascularRESUMEN
BACKGROUND: Clinicians and researchers have used bathroom scales, balance performance monitors with feedback, postural scale analysis, and force platforms to evaluate weight bearing asymmetry (WBA). Now video game consoles offer a novel alternative for assessing this construct. By using specialized software, the Nintendo Wii Fit balance board can provide reliable measurements of WBA in healthy, young adults. However, reliability of measurements obtained using only the factory settings to assess WBA in older adults and individuals with stroke has not been established. PURPOSE: To determine whether measurements of WBA obtained using the Nintendo Wii Fit balance board and default settings are reliable in older adults and individuals with stroke. METHODS: Weight bearing asymmetry was assessed using the Nintendo Wii Fit balance board in 2 groups of participants-individuals older than 65 years (n = 41) and individuals with stroke (n = 41). Participants were given a standardized set of instructions and were not provided auditory or visual feedback. Two trials were performed. Intraclass correlation coefficients (ICC), standard error of measure (SEM), and minimal detectable change (MDC) scores were determined for each group. RESULTS: The ICC for the older adults sample was 0.59 (0.35-0.76) with SEM95 = 6.2% and MDC95 = 8.8%. The ICC for the sample including individuals with stroke was 0.60 (0.47-0.70) with SEM95 = 9.6% and MDC95 = 13.6%. DISCUSSION: Although measurements of WBA obtained using the Nintendo Wii Fit balance board, and its default factory settings, demonstrate moderate reliability in older adults and individuals with stroke, the relatively high associated SEM and MDC values substantially reduce the clinical utility of the Nintendo Wii Fit balance board as an assessment tool for WBA. CONCLUSIONS: Weight bearing asymmetry cannot be measured reliably in older adults and individuals with stroke using the Nintendo Wii Fit balance board without the use of specialized software.