Force control predicts fine motor dexterity in high-functioning stroke survivors.

BACKGROUND AND PURPOSE: High-functioning stroke survivors with mild to moderate motor impairments show greater functional autonomy in activities of daily living, and often return to work or prior activities. Increased functional independence necessitates dexterous use of hands to execute tasks such as typing, using a phone, and driving. Despite the absence of any pronounced motor impairments, high-functioning individuals with stroke report challenges in performing skilled manual tasks. Two prominent motor deficits that limit functional performance after stroke are decline in strength and force control. Here, we quantify the deficits in fine motor dexterity in high-functioning stroke survivors and determine the relative contribution of strength and force control to fine motor dexterity. METHODS: Fifteen high-functioning participants with stroke (upper-limb Fugl-Meyer score ≥43/66) and 15 controls performed following tasks with the paretic and non-dominant hands respectively: i) Nine-hole peg pest, ii) maximum voluntary contraction and iii) dynamic force tracking with isometric finger flexion. RESULTS: High-functioning stroke participants required greater time to complete the pegboard task, showed reduced finger strength, and increased force variability relative to the controls. Importantly, the time to complete pegboard task in high-functioning stroke participants was explained by finger force variability, not strength. DISCUSSION AND CONCLUSIONS: High-functioning stroke survivors show persistent deficits in fine motor dexterity, finger strength, and force control. The ability to modulate forces (control) contributes to fine motor dexterity in high-functioning stroke survivors. Interventions to improve fine motor dexterity in these individuals should include the assessment and training of force control.

Validity and reliability analysis of Cooper's 12-minute run and the multistage shuttle run in healthy adults.

Field tests are a practical method to assess aerobic fitness, but they demonstrate greater error variability than laboratory tests. The principal goals of this study were to identify potential sources of systematic error in 2 commonly used field tests (Cooper's 12-minute run [12MR] and the multistage shuttle run [MSR]) and estimate the reliability of the 2 tests from these data. In addition, criterion-related validity evidence for field tests was evaluated via Bland-Altman plots. To assess trends across test protocol and test trials, 60 subjects (mean age = 21.8 ± 3.6 years) completed 6 test trials, including 3 trials of each field test. Of these 60 individuals, 21 volunteers completed an incremental treadmill run and expired gas analysis (TR) that was used to establish criterion-related validity evidence for the 2 field tests. G-study analysis of the field test data returned a high reliability coefficient (ϕ = 0.96), with the largest amount of systematic error variance (4.3%) attributable to an interaction between subjects and test occasions. The MSR predicted Vo2max scores lower than those measured in the laboratory setting (p < 0.01), whereas 12MR and TR scores were not different (p > 0.05). However, Bland-Altman plots showed the 12MR to underestimate Vo2max scores at lower Vo2max values and overestimate Vo2max scores at higher values, a trend not observed in the MSR data. These data suggest high overall reliability for Vo2max field tests in young, healthy individuals. Nevertheless, test administrators must use caution when attempting to use field test data to predict criterion Vo2max scores. The MSR appears to be a more useful tool than the 12MR because of a consistent mean bias across fitness levels.

A lower-extremities kinematic comparison of deep-water running styles and treadmill running.

The purpose of this investigation was to identify a deep-water running (DWR) style that most closely approximates terrestrial running, particularly relative to the lower extremities. Twenty intercollegiate distance runners (women, N = 12; men, N = 8) were videotaped from the right sagittal view while running on a treadmill (TR) and in deep water at 55-60% of their TR VO(2)max using 2 DWR styles: cross-country (CC) and high-knee (HK). Variables of interest were horizontal (X) and vertical (Y) displacement of the knee and ankle, stride rate (SR), VO(2), heart rate (HR), and rating of perceived exertion (RPE). Multivariate omnibus tests revealed statistically significant differences for RPE (p < 0.001). The post hoc pairwise comparisons revealed significant differences between TR and both DWR styles (p < 0.001). The kinematic variables multivariate omnibus tests were found to be statistically significant (p < 0.001 to p < 0.019). The post hoc pairwise comparisons revealed significant differences in SR (p < 0.001) between TR (1.25 +/- 0.08 Hz) and both DWR styles and also between the CC (0.81 +/- 0.08 Hz) and HK (1.14 +/- 0.10 Hz) styles of DWR. The CC style of DWR was found to be similar to TR with respect to linear ankle displacement, whereas the HK style was significantly different from TR in all comparisons made for ankle and knee displacement. The CC style of DWR is recommended as an adjunct to distance running training if the goal is to mimic the specificity of the ankle linear horizontal displacement of land-based running, but the SR will be slower at a comparable percentage of VO(2)max.

Health behaviors, body composition, and coronary heart disease risk in women with multiple sclerosis.

OBJECTIVES: To explore coronary heart disease risk in a sample of women with multiple sclerosis (MS) by identifying the presence of established risk factors for coronary heart disease and to determine the relationship between disease severity and level of participation in health-related behaviors. DESIGN: Survey study. SETTING: Five general community settings in Oregon. PARTICIPANTS: Women with physician-diagnosed MS (N=123) recruited from MS chapters, physician referrals, and newspaper announcements. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Modified Yale Physical Activity Survey, Block Food Frequency Questionnaire, blood analysis, skinfolds, and waist and hip circumferences. RESULTS: The majority of women met current physical activity guidelines. The frequencies of unfavorable levels of metabolic variables and obesity were similar to those reported in the general population. Significant associations were observed between mobility and physical activity, total and abdominal fat, and several dietary habits. CONCLUSION: Coronary heart disease risk in this sample was comparable to that of the general population of women without MS. Physical inactivity, body composition, and perhaps nutritional habits decline with decreasing mobility, emphasizing the need for families and health care providers to work together to find solutions that increase health-promoting behaviors in women with more advanced MS.

Effects of an eight-week training program on upper-body power in women cross-country skiers.

A distinguishing feature of elite cross-country skiers is their superlative upper-body power (UBP). Recently, roller board training was shown to be superior for improving UBP in cross-country skiers; however, the newly developed wind machine had not yet been tested. The purpose of this study was to determine if wind machine training was as effective as roller board training at increasing UBP. Forty-four women cross-country skiers, age 23-59 years, were matched on initial UBP, measured in watts (W), and placed into 1 of 2 experimental groups (roller board or wind machine). All women underwent 8 weeks of UBP training. Although both groups improved significantly pre-post (p < 0.05) in UBP, t-tests indicated that there was no significant difference (p > 0.05) between the 2 groups' improvements (roller board, pre 74.5 +/- 30.9, post 95.9 +/- 29.8 W; wind machine, pre 74.5 +/- 33.5, post 99.3 +/- 34.3 W). Thus the wind machine was as effective at enhancing UBP as the roller board.

Effects of exercise on physiological and psychological variables in cancer survivors.

PURPOSE: The primary purpose of this study was to examine the effect of aerobic exercise on physiological and psychological function in patients rehabilitating from cancer treatment. A second purpose was to evaluate the differential effects of low- and moderate-intensity exercise on these variables. METHODS: Eighteen survivors of breast or colon cancer (15 female and 3 male, 40-65 yr of age) served as subjects. The subjects were matched by aerobic capacity and scores on a Quality of Life questionnaire, and then randomly assigned to a control, low- (25-35% heart rate reserve (HRR)), or a moderate- (40-50% HRR) intensity exercise group. The exercise groups performed lower-body aerobic exercise three times a week for 10 wk. After the exercise training, there were no statistically significant differences between the two exercise groups on any of the physiological variables. Therefore, the exercise groups were combined into one group for the final analysis. RESULTS: The results revealed statistically significant increases in aerobic capacity (P < 0.001) and lower-body flexibility (P = 0.027), a significant decrease in body fat (P < 0.001), and a significant increase in quality of life (P < 0.001) and a measure of energy (P = 0.038) in the exercise group when compared with the control group. CONCLUSION: Low- and moderate-intensity aerobic-exercise programs were equally effective in improving physiological and psychological function in this population of cancer survivors. Aerobic exercise appears to be a valuable and well-tolerated component of the cancer-rehabilitation process.

Coronary heart disease risk between active and inactive women with multiple sclerosis.

PURPOSE: Physical activity is strongly recommended as a principal component of coronary heart disease (CHD) risk factor management aimed at favorably lowering abdominal fat accumulation, lowering levels of triglyceride (TG), raising levels of high-density lipoprotein-cholesterol (HDL-C), and improving insulin sensitivity. Although physical activity practices are reported to be low in women with multiple sclerosis (MS), some women with MS remain physically active despite their disability. Thus, the primary aim of the study was to determine whether abdominal fat accumulation and levels of TG, HDL-C, and glucose differ between active and inactive women with MS. METHODS: The study sample consisted of 123 women with MS, aged 23-72 yr. Venous blood was collected for measurement of lipids, lipoprotein-cholesterol, and glucose. Skin-fold thicknesses and girth circumferences were obtained for estimation of total and abdominal body fat. Leisure-time physical activity (LTPA) during the last 12 months was assessed by the physical activity questionnaire used in the Postmenopausal Estrogens/Progestins Intervention (PEPI) Study. Eating habits were assessed by the Block Food Frequency Questionnaire. RESULTS: LTPA was significantly associated with lower waist circumference (P = 0.0001), lower TG levels (P = 0.0005), and lower glucose levels (0.002). After adjusting for several covariates, women participating in low- to moderate-intensity LTPA had significantly lower waist circumferences, TG levels, and glucose levels relative to inactive women. CONCLUSION: Low- to moderate-intensity LTPA was significantly associated with less abdominal fat accumulation, lower levels of TG, and lower levels of glucose in the present sample of women with MS. These findings suggest that exercise levels attainable by women with MS may improve CHD risk and contribute to important health-related benefits.

Carotid vs Radial Pulse Counts.

In brief Carotid pulse counting is widely used to monitor exercise intensity. However, some researchers believe it may underestimate postexercise heart rates by initiating the carotid sinus reflex. This study compared carotid, radial, and ECG pulse rates in 20 asymptomatic adults. The authors concluded that carotid pulse counts can be used safely by many healthy adults, but because at least one subject had low heart rate counts after carotid palpations, they present some guidelines: Exercisers should (1) perform the procedure correctly, (2) periodically compare the carotid and radial pulses, and (3) exercise at the lower range of their target heart rate zone.