Self-determined Speed Research Articles

Reference Values of Spatial and Temporal Gait Parameters in a Contemporary Sample of Spanish Preschool Children: A Cross-Sectional Study.

The aim of this study was to analyze the influence of age and sex on kinematic gait parameters in preschool children, and derive reference values for this population. A total of 383 preschool children (age 3–5 years; 207 girls, 176 boys) participated in this study. We used the OptoGait system to assess the kinematics of gait at a comfortable and self-determined speed. No significant differences between the sexes were found for the main gait parameters. Among the participants, there was a significant increase in double support, reductions in absolute cadence and the coefficient of variation (CV) of cadence, an increase in absolute step length (SL), and an increase in the walk ratio (WR) from 3 to 5 years of age. However, the normalized SL and normalized WR displayed a significant reduction in both sexes. Partial correlation indicated a significant association of age with SL and normalized SL, and WR. Additionally, WR showed a significant correlation with the CV of cadence. To summarize, no relevant differences in gait performance were found according to sex; however, age was found to influence gait maturation. The normative values established for Spanish preschool children can be used to monitor healthy gait development.

Crawl technique observation sheet for beginning swimmers: an evaluation proposal for swimming teachers

Abstract Aims: This study aimed to present a technical evaluation proposal for the crawl stroke that can be used with large groups of swimmers, based on an observation sheet. Methods: Fifteen healthy university students aged between 18 and 30 years were chosen to participate in the study. The subjects were recorded swimming at a distance of 50 meters using the crawl technique at a comfortable and self-determined speed. The recordings simulated docent observation capacity. Five swimming teachers were selected to evaluate the proposed checklist and the subjects’ technique. An observation sheet was created based on references present in literature containing ten items that are considered fundamental for swimming movements. The study was divided into (i) checklist validation, (ii) intra-evaluator consistency, and (iii) inter-evaluator consistency. Results: The proposed checklist fulfilled the validity criteria, with intra-evaluator consistency varying between reasonable and substantial, with k varying between 0.36 and 0.73 respectively, while inter-evaluator consistency was deemed reasonable (k = 0.24). Conclusion: According to the results that were obtained, the suggested list is valid and adequate for what it proposes to do.

Treadmill vs. Cycle Ergometry Graded Exercise Test Responses in Multiple Sclerosis Patients

INTRODUCTION: Cardiorespiratory fitness is measured by peak oxygen consumption (VO2max) and is one of the strongest predictors of all-cause and cardiovascular disease mortality. In a healthy adult population, VO2max values obtained on a treadmill are approximately 10-15% higher than those yielded by cycle ergometry. VO2max testing in those with multiple sclerosis (MS) is typically performed on a cycle ergometer, as loss of walking mobility or balance issues may limit treadmill walking. Therefore, potential mode-specific differences in VO2max may result in the inability to accurately assess MS patients’ risk and lead to inaccurate exercise prescriptions in this cohort. PURPOSE: To compare hemodynamic, ventilatory, and cardiorespiratory responses between graded exercise tests performed on both a treadmill and cycle ergometer in individuals with relapsing-remitting MS. METHODS: Twenty persons with MS (42±11 years, 11±10 years since Dx, 26.9±6.5 kg[BULLET OPERATOR]m-2) completed two VO2max tests approximately 1 week apart, with random order of testing. Treadmill tests consisted of a constant, self-determined speed with an increase in grade of 2% every two minutes. Cycle ergometry tests increased wattage by 15 watts per minute. A repeated measures ANOVA was used to investigate differences in testing response to both treadmill and cycle ergometry. RESULTS: Treadmill testing resulted in VO2max values that were 11% higher and respiratory exchange ratio (RER) values that were 8% lower than those obtained via cycle ergometry. See Table 1. DISCUSSION: Relapsing-remitting MS patients exhibit a mode-related difference in VO2max similar to healthy adults. Therefore, exercise prescriptions or study designs cannot directly calculate submaximal workloads for one mode based on maximal data obtained from the other. Additionally, while HRpeak values are within normal limits, they’re bordering chronotropic incompetence.Table 1: Mean ± SD. *p<0.05 between Treadmill and Cycle Ergometer

Effect of visual acuity in older females on energy expenditure during obstacle navigation

ObjectivesTo investigate the effects of good and poor visual acuities in older females on energy expenditure during obstacle navigation under different three conditions. MethodsNineteen older females living in the community were enrolled in the present study. Ten participants had a binocular visual acuity worse than or equal to 0.4 (logarithm of the minimum angle of resolution (logMAR) (poor binocular visual acuity [PBVA]) and the other nine had a binocular visual acuity better than or equal to 0.3 logMAR (good binocular visual acuity [GBVA]). An accelerometer was attached over the L3 spinous process and each participant walked at a self-determined speed, under three different conditions (bare foot, wearing socks, and navigating obstacle while wearing socks) on a GAITRite® mat. Differences in gait velocity and energy expenditure were analyzed using the independent t-test for comparisons between groups. The gait velocity and energy expenditure of the GBVA and PBVA groups, derived under the three test conditions, were analyzed via one-way repeated-measures analysis of variance. ResultsThe gait velocity of the GBVA group was significantly faster than that of the PBVA group under the bare foot, wearing socks, and navigating obstacles while wearing socks. Whereas the energy expenditure of the GBVA group was significantly less than that of the PBVA group under the bare foot, wearing socks, and navigating obstacles while wearing socks. In addition, the gait velocity and energy expenditure of the groups differed significantly among the three experimental conditions. ConclusionsThe present study suggests that visual acuity in the older female influences both gait velocity and energy expenditure during obstacle gait. In addition, elderly subjects with PBVA exhibited inefficient walking patterns compared with those with GBVA, remarkably when foot sensory input was distorted and obstacles were present.

The psychophysiological cost of intense information load in 5-to 14-year-old children and adolescents

The psychophysiological cost of activity was determined in 5- to 14-year-old children and adolescents (n = 612) by correlating the performance of intense information load with the value of autonomic shifts in the course of the test. It was shown that the psychophysiological cost of information load in the state of functional comfort (self-determined speed) decreased 2.2- to 5.4-fold in the period from 5–6 to 13–14 years of age and the psychophysiological cost of intense intellectual activity with the maximum speed under the conditions of a time deficit (the maximum speed) decreased 1.2- to 4-fold. The greatest changes in the psychophysiological cost of intense intellectual activity were observed at the beginning of regular schooling and during puberty. The data indicate the need for a continuous search for new, efficient, and more physiologically adequate ways of control of the process of training and education taking into consideration the psychophysiological cost of intense academic activity in different periods of ontogeny and ensuring a beneficial effect of educational technologies on the health and development of schoolchildren.

Sensory timing cues improve akinesia of grasping movements in Parkinson's disease: A comparison to the effects of subthalamic nucleus stimulation

Five parkinsonian subjects with chronic bilateral stimulation of the subthalamic nucleus and five sex- and age-matched healthy controls grasped, lifted, and held an instrumented object. The grip-lift task was either performed at self-determined speed or in response to an auditory cuing signal. Parkinsonian subjects performed the task with subthalamic nucleus stimulation switched ON and OFF. In Parkinson's disease, stimulation of the subthalamic nucleus and the presentation of auditory timing cues improved akinesia of both the grasp and lift components of the task. The finding that auditory timing cues improve akinesia in the absence of subthalamic nucleus stimulation suggests that the basal ganglia are less involved in the control of movements made in response to environmental cues. However, subthalamic nucleus stimulation caused parkinsonian subjects to apply excessive grip forces, regardless of whether the movement was made under self-determined or externally guided speed conditions. This implies that subthalamic nucleus stimulation produces a generalized upregulation in the gain of all components of a movement without the subtlety of focused control that is required to normalize performance.