Pei-Fang Tang

Analysis and Comparison of the Psychometric Properties of Three Balance Measures for Stroke Patients

Background and Purpose— This study compared the psychometric properties of 3 clinical balance measures, the Berg Balance Scale (BBS), the Balance subscale of the Fugl-Meyer test (FM-B), and the Postural Assessment Scale for Stroke Patients (PASS), in stroke patients with a broad range of neurological and functional impairment from the acute stage up to 180 days after onset. Methods— One hundred twenty-three stroke patients were followed up prospectively with the 3 balance measures 14, 30, 90, and 180 days after stroke onset (DAS). Reliability (interrater reliability and internal consistency) and validity (concurrent validity, convergent validity, and predictive validity) of each measure were examined. A comparison of the responsiveness of each of the 3 measures was made on the basis of the entire group of patients and 3 separate groups classified by degree of neurological severity. Results— The FM-B and BBS showed a significant floor or ceiling effect at some DAS points, whereas the PASS did not show these effects. The BBS, FM-B, and PASS all had good reliability and validity for patients at different recovery stages after stroke. The results of effect size demonstrated fair to good responsiveness of all 3 measures within the first 90 DAS but, as expected, only a low level of responsiveness at 90 to 180 DAS. The PASS was more responsive to changes in severe stroke patients at the earliest period after stroke onset, 14 to 30 DAS. Conclusions— All 3 measures tested showed very acceptable levels of reliability, validity, and responsiveness for both clinicians and researchers. The PASS showed slightly better psychometric characteristics than the other 2 measures.

How Active Are People With Stroke? Use of Accelerometers to Assess Physical Activity

Background and Purpose— Accelerometers are a unique tool used to objectively measure free-living physical activity, but their reliability for people with stroke has not been established. The primary aim was to assess the day-to-day reliability of these instruments for the paretic and nonparetic hips. The secondary aims were to measure the amount of physical activity with accelerometers that people with stroke undertake in the community and its relationship with walking capacity (6-minute walk test distance). Methods— Forty people with stroke wore one Actical accelerometer on each hip for 3 consecutive days at home and during the 6-minute walk test in the laboratory. The accelerometer measured physical activity using total activity counts per day and energy expenditure (kcal/d). Results— Excellent intraclass correlation coefficients (ICCs) for the activity counts (paretic hip ICC[1,3]=0.95, nonparetic hip ICC[1,3]=0.94) and for the energy expenditure (paretic hip ICC[1,3]=0.95, nonparetic hip ICC[1,3]=0.95) were found across the 3 consecutive days at home. Excellent ICCs were also found between the paretic versus the nonparetic hips for the activity counts (ICC[1,3]=0.98) and for the energy expenditure (ICC[1,3]=0.96). Free-living physical activity was very low and 58% of the participants did not meet recommended physical activity levels. Only moderate correlations (r=0.6 to 0.73, P<0.001) were found between the 6-minute walk test distance in the laboratory and 3-day physical activity recording at home. Conclusions— The accelerometer was found to be a reliable objective instrument. The use of accelerometers quantified the low level of free-living physical activity of people with stroke.

Control of reactive balance adjustments in perturbed human walking: roles of proximal and distal postural muscle activity

Abstract Studies on the proactive control of gait have shown that proximal (hip/trunk) muscles are the primary contributors to balance control, while studies on reactive balance control during perturbed gait, examining only activity in distal (leg/thigh) muscles, have shown that these muscles are important in compensating for a gait disturbance. This study tested the hypothesis that proximal muscles are also primary contributors to reactive balance control during perturbed gait. Thirty-three young adults participated in a study in which an anterior slip was simulated at heel strike by the forward displacement of a force plate on which they walked. Surface electromyographic data were recorded from bilateral leg, thigh, hip and trunk muscles. Kinematic data were collected on joint angle changes in response to the perturbation. The results did not support the hypothesis that the proximal muscles contribute significantly to balance control during perturbed gait. The proximal muscles did not demonstrate more consistent activation, earlier onset latency, longer burst duration or larger burst magnitude than distal muscles. Moreover, although proximal postural activity was often present in the first slip trial, it tended to adapt away in later trials. By contrast, the typical postural responses exhibited by young adults consisted of an early (90–140 ms), high-magnitude (4–9 times muscle activity during normal walking) and relatively long duration (70–200 ms) activation of bilateral anterior leg muscles as well as the anterior and posterior thigh muscles. Thus, postural activity from bilateral leg and thigh muscles and the coordination between the two lower extremities were the key to reactive balance control and were sufficient for regaining balance within one gait cycle. The adaptive attenuation of proximal postural activity over repeated trials suggests that the nervous system overcompensates for a novel balance threat in the first slip trial and fine-tunes its responses with experience.

Gait training strategies to optimize walking ability in people with stroke: A synthesis of the evidence

Stroke is a leading cause of long-term disability. Impairments resulting from stroke lead to persistent difficulties with walking and, subsequently, improved walking ability is one of the highest priorities for people living with a stroke. In addition, walking ability has important health implications in providing protective effects against secondary complications common after a stroke such as heart disease or osteoporosis. This paper systematically reviews common gait training strategies (neurodevelopmental techniques, muscle strengthening, treadmill training and intensive mobility exercises) to improve walking ability. The results (descriptive summaries as well as pooled effect sizes) from randomized controlled trials are presented and implications for optimal gait training strategies are discussed. Novel and emerging gait training strategies are highlighted and research directions proposed to enable the optimal recovery and maintenance of walking ability.

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study.

Study design:This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI).Objectives:To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity.Setting:Urban community setting.Methods:A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI).Results:Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms.Conclusions:Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

Daily physical activity and its contribution to the health-related quality of life of ambulatory individuals with chronic stroke

BackgroundParticipation in daily physical activity (PA) post-stroke has not previously been investigated as a possible explanatory variable of health-related quality of life (HRQL). The aims were 1) to determine the contribution of daily PA to the HRQL of individuals with chronic stroke and 2) to assess the relationship between the functional ability of these individuals to the amount of daily PA.MethodsThe amount of daily PA of forty adults with chronic stroke (mean age 66.5 ± 9.6 years) was monitored using two measures. Accelerometers (Actical) were worn on the hip for three consecutive days in conjunction with a self-report questionnaire [the PA Scale for Individuals with Physical Disabilities (PASIPD)]. The daily physical activity was measured as the mean total accelerometer activity counts/day and the PASIPD scores as the metabolic equivalent (MET) hr/day. HRQL was assessed by the Physical and Mental composite scores of the Medical Outcomes Study Short-Form 36 (SF-36) in addition to the functional ability of the participants. Correlation and regression analyses were performed.ResultsAfter controlling for the severity of the motor impairment, the amount of daily PA, as assessed by the PASIPD and accelerometers, was found to independently contribute to 10-12% of the variance of the Physical Composite Score of the SF-36. No significant relationship was found between PA and the Mental Composite Score of the SF-36.The functional ability of the participants was found to be correlated to the amount of daily PA (r = 0.33 - 0.67, p < 0.01).ConclusionThe results suggest that daily PA is associated with better HRQL (as assessed by the Physical composite score of the SF-36) for people living with stroke. Daily PA should be encouraged to potentially increase HRQL. Accelerometers in conjunction with a self-report questionnaire may provide important measures of PA which can be monitored and modified, and potentially influence HRQL.

Meta-analysis of type and complexity of a secondary task during walking on the prediction of elderly falls

Aim:  Dual‐tasking probes divided attention and causes performance changes that are associated with an increased risk for falls in the elderly. There is no systematic review investigating the effect of task type and complexity on the prediction of elderly falls. This article synthesizes research evidence regarding this issue on the contents of dual‐tasking walking.

ASSOCIATION OF DEPRESSION AND PAIN INTERFERENCE WITH DISEASE-MANAGEMENT SELF-EFFICACY IN COMMUNITY-DWELLING INDIVIDUALS WITH SPINAL CORD INJURY

OBJECTIVE To determine factors influencing disease-management self-efficacy in individuals with spinal cord injury. DESIGN A cross-sectional study. SUBJECTS/PATIENTS Forty-nine community-dwelling individuals with chronic spinal cord injury (mean age 44 years) participated in the study. METHODS Each subject was evaluated for disease-management self-efficacy (Self-efficacy for Managing Chronic Disease), depression (10-item Center for Epidemiologic Studies Depression Scale), pain interference (Pain Interference Scale), and availability of support (Interpersonal Support Evaluation List short form). Multiple regression analysis was performed to determine the relative contributions of these factors to disease-management self-efficacy. RESULTS The mean disease-management self-efficacy score was 6.5 out of 10 (standard deviation 1.6). Bivariate correlation analysis showed that higher self-efficacy was significantly correlated with longer time since injury (r = 0.367, p = 0.010), better social support (r = 0.434, p = 0.002), lower pain interference (r = -0.589, p <0.001), and less severe depressive symptoms (r=-0.463, p=0.001). In multiple regression analysis, only lower pain interference and less severe depressive symptoms were significantly associated with higher disease-management self-efficacy (F 4,44=10.249, R2=0.482, p<0.001). CONCLUSION Disease-management self-efficacy is suboptimal in many community-living people with spinal cord injury. This research suggests that rehabilitation of patients with spinal cord injury should include self-efficacy-enhancing strategies. Alleviation of depressive symptoms and pain self-management may be important for improving disease-management self-efficacy in this population, but this requires further study.

Tract-Specific and Region of Interest Analysis of Corticospinal Tract Integrity in Subcortical Ischemic Stroke: Reliability and Correlation with Motor Function of Affected Lower Extremity

BACKGROUND AND PURPOSE: TS analysis has been suggested as a useful method to evaluate the fiber integrity of white matter tracts. This study investigated the intrarater and interrater reliability and validity of a TS analysis for the CST and compared the results with those of a ROI-based analysis. MATERIALS AND METHODS: Diffusion spectrum imaging was performed on 7 patients with subcortical ischemic stroke on a 3T MR imaging system. For the TS analysis, seed regions were placed at the cerebral peduncle and the medial portion of the primary motor cortex to reconstruct the tracts of the CST for motor control of the lower extremity. The mean GFA was measured at the PLIC by calculating the weighted sum of the GFAs sampled by the CST tracts at this segment. For the ROI-based analysis, the posterior two-thirds of the PLIC were enclosed on the GFA maps, and the mean GFA in this ROI was calculated. RESULTS: The results showed good-to-excellent intrarater and interrater reliability on the seed region/ROI placement (mean κ values >0.80) and mean GFA values (ICCs >0.90) for both the TS and ROI-based analyses. Both the GFAPLIC-TS and GFAPLIC-ROI values were highly correlated with the motor function of the affected lower extremity (r = 0.76 and 0.80, respectively; P < .05). CONCLUSIONS: We demonstrated good reliability and validity of the TS and ROI-based analyses of the CST corresponding to lower extremity motor control in patients with subcortical ischemic stroke.

Role of the premotor cortex in leg selection and anticipatory postural adjustments associated with a rapid stepping task in patients with stroke

The premotor cortex (PMC) plays an important role in selecting and preparing for movement. This study investigates how stroke-induced PMC lesions affect stepping leg selection and anticipatory postural adjustments (APAs) preparation. Fifteen hemi-paretic patients (eight with PMC lesions (PMC(Lesion)) and seven PMC spared (PMC(Spared))) and eight age- and sex-matched healthy adults participated in the study. The subjects performed rapid forward stepping with the right or left leg under simple and choice reaction time conditions. The percentage of trials in which the subject showed the correct initial vertical ground reaction force pattern before lift-off of the stepping leg indicated the accuracy in selecting the designated stepping leg. The latency of bilateral contractions in the tibialis anterior (TA) and the reaction time (RT) of the stepping leg represented the time needed to prepare for stepping-related APAs and stepping movement, respectively. All three groups demonstrated a similar rate of accuracy of the stepping leg selection under both conditions. However, in both conditions, the PMC(Lesion) group exhibited a longer RT and TA contraction latency of the affected leg than the healthy and PMC(Spared) groups. The PMC(Lesion) group also presented a longer TA contraction latency of the unaffected leg than the healthy group in both conditions. These results suggest that the PMC is involved in APAs associated with leg stepping movement and that a PMC lesion in one hemisphere impairs APAs of both the contralateral and ipsilateral legs during stepping.