Relationships between mediolateral step modulation and clinical balance measures in people with chronic stroke.

BACKGROUND: Many people with chronic stroke (PwCS) exhibit walking balance deficits linked to increased fall risk and decreased balance confidence. One potential contributor to these balance deficits is a decreased ability to modulate mediolateral stepping behavior based on pelvis motion. This behavior, hereby termed mediolateral step modulation, is thought to be an important balance strategy but can be disrupted in PwCS. RESEARCH QUESTION: Are biomechanical metrics of mediolateral step modulation related to common clinical balance measures among PwCS? METHODS: In this cross-sectional study, 93 PwCS walked on a treadmill at their self-selected speed for 3-minutes. We quantified mediolateral step modulation for both paretic and non-paretic steps by calculating partial correlations between mediolateral pelvis displacement at the start of each step and step width (ρSW), mediolateral foot placement relative to the pelvis (ρFP), and final mediolateral location of the pelvis (ρPD) at the end of the step. We also assessed several common clinical balance measures (Functional Gait Assessment [FGA], Activities-specific Balance Confidence scale [ABC], self-reported fear of falling and fall history). We performed Spearman correlations to relate each biomechanical metric of step modulation to FGA and ABC scores. We performed Wilcoxon rank sum tests to compare each biomechanical metric between individuals with and without a fear of falling and a history of falls. RESULTS: Only ρFP for paretic steps was significantly related to all four clinical balance measures; higher paretic ρFP values tended to be observed in participants with higher FGA scores, with higher ABC scores, without a fear of falling and without a history of falls. However, the strength of each of these relationships was only weak to moderate. SIGNIFICANCE: While the present results do not provide insight into causality, they justify future work investigating whether interventions designed to increase ρFP can improve clinical measures of post-stroke balance in parallel.

Progressive resistance exercise as complementary therapy improves quality of life and body composition in anorexia nervosa: A randomized controlled trial.

BACKGROUND: and purpose: Exercise has not typically been used as an adjunct in treatment of anorexia nervosa (AN). This study aimed to examine the effects of progressive resistance exercise (PREx) on perceived quality of life (QoL) and body composition in adolescents with AN. MATERIALS AND METHODS: Forty-four adolescents diagnosed with AN were randomly allocated to either PREx or control groups after hospitalization. The PREx group completed twenty-four PREx sessions over two months including three sets of 8-10 repetitions of eight whole-body exercises at a moderate intensity. QoL and body composition were evaluated at baseline and after two months using Health Questionnaire Short-Form 36 (SF-36) and anthropometric measurements. RESULTS: At completion, forty-one participants (n = 19 PREx, and n = 22 controls) with mean age of 12.78 ± 0.88 years and mean body mass index of 18 ± 2.2 kg/m2 were analyzed. Significant group x time effects were found on SF-36 role physical (RP) scores. Significant improvements with large effect sizes (d > 0.72) were found in RP, and arm circumferences in the PREx group. Spearman association analyses between percent change in anthropometric variables and change in QoL scores showed positive associations with moderate-to-large effect sizes in the PREx group among the following variables: mid-thigh-circumference, physical functioning (PF) and general health (GH); calf-circumference relaxed and body pain; biceps skinfold and GH scores; triceps-skinfold, and role physical (RP) and vitality (VT); supraspinale-skinfold and RP and VT; mid-thigh-skinfold and calf-skinfold and VT. CONCLUSION: PREx after hospitalization enables modest positive changes in QoL associated to anthropometric changes in adolescents with AN without adverse effects on weight recovery.

Physical Fitness-Not Physical Activity Levels-Influence Quality of Life in Anorexia Nervosa.

Background: Incorporating physical activity (PA) has been a challenge for health care professionals working with anorexia nervosa (AN) patients. This has contributed to partial physical fitness (PFit) recovery that persists after weight restoration. Objective: This cross-sectional study aimed to examine the relationships between PA, sedentary behaviors, PFit, and quality of life (QoL) in a group of adolescents after hospitalization. Methods: QoL, PA, and sedentary behaviors were measured using the Health-Questionnaire Short-Form 36 (SF-36) and accelerometers, while PFit was assessed through cardiorespiratory fitness, body composition (anthropometry), and strength (six repetition maximum) tests in a total of 63 patients. Results: Light-PA (LPA), moderate-PA (MPA), moderate-to-vigorous-PA (MVPA), and relative sedentary time (%ST) did not meet the recommendations (p < 0.001). Only 22% of the patients met MVPA criteria, and ~82% exceeded %ST. SF-36 scores were lower than normative values except the physical component scale. Absolute cardiorespiratory fitness was reduced (p < 0.001) in 84% of the patients, and was positively associated to body weight, body mass index (BMI), circumferences, and muscle areas. Additional positive significant relationships were found between QoL, muscular strength, and body composition, and negative associations between vigorous-to-very vigorous PA and BMI, skinfolds, and percent body fat. Regression analyses revealed lower body strength as an explanatory factor for improved QoL (OR 1.03, 95%CI 1.00−1.07). Conclusions: PFit and QoL scores are poor after hospitalization. LPA, MPA, and MVPA do not meet recommendations. PFit management­with emphasis on improving muscular fitness­may be a valuable strategy for QoL improvement in AN after hospitalization.

Effects of Targeted Assistance and Perturbations on the Relationship Between Pelvis Motion and Step Width in People With Chronic Stroke.

During walking in neurologically-intact controls, larger mediolateral pelvis displacements or velocities away from the stance foot are accompanied by wider steps. This relationship contributes to gait stabilization, as modulating step width based on pelvis motion (hereby termed a "mechanically-appropriate" step width) reduces the risk of lateral losses of balance. The relationship between pelvis displacement and step width is often weakened among people with chronic stroke (PwCS) for steps with the paretic leg. Our objective was to investigate the effects of a single exposure to a novel force-field on the modulation of paretic step width. This modulation was quantified as the partial correlation between paretic step width and pelvis displacement at the step's start (step start paretic [Formula: see text]). Following 3-minutes of normal walking, participants were exposed to 5-minutes of either force-field assistance (n = 10; pushing the swing leg toward mechanically-appropriate step widths) or perturbations (n = 10: pushing the swing leg away from mechanically-appropriate step widths). This period of assistance or perturbations was followed by a 1-minute catch period to identify after-effects, a sign of altered sensorimotor control. The effects of assistance were equivocal, without a significant direct effect or after-effect on step start paretic [Formula: see text]. In contrast, perturbations directly reduced step start paretic [Formula: see text] (p = 0.004), but were followed by a positive after-effect (p = 0.02). These results suggest that PwCS can strengthen the link between pelvis motion and paretic step width if exposed to a novel mechanical environment. Future work is needed to determine whether this effect is extended with repeated perturbation exposure.