scholarly journals Complexity-based analysis of the correlation between stride interval variability and muscle reaction at different walking speeds

2021 ◽  
Vol 69 ◽  
pp. 102956
Author(s):  
Hamidreza Namazi
1999 ◽  
Author(s):  
Pamela R. Tenney ◽  
Michelle L. Spurlock ◽  
Susan J. Shapiro

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 412
Author(s):  
Han-Ping Huang ◽  
Chang Francis Hsu ◽  
Yi-Chih Mao ◽  
Long Hsu ◽  
Sien Chi

Gait stability has been measured by using many entropy-based methods. However, the relation between the entropy values and gait stability is worth further investigation. A research reported that average entropy (AE), a measure of disorder, could measure the static standing postural stability better than multiscale entropy and entropy of entropy (EoE), two measures of complexity. This study tested the validity of AE in gait stability measurement from the viewpoint of the disorder. For comparison, another five disorders, the EoE, and two traditional metrics methods were, respectively, used to measure the degrees of disorder and complexity of 10 step interval (SPI) and 79 stride interval (SI) time series, individually. As a result, every one of the 10 participants exhibited a relatively high AE value of the SPI when walking with eyes closed and a relatively low AE value when walking with eyes open. Most of the AE values of the SI of the 53 diseased subjects were greater than those of the 26 healthy subjects. A maximal overall accuracy of AE in differentiating the healthy from the diseased was 91.1%. Similar features also exists on those 5 disorder measurements but do not exist on the EoE values. Nevertheless, the EoE versus AE plot of the SI also exhibits an inverted U relation, consistent with the hypothesis for physiologic signals.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 674
Author(s):  
Keisuke Itotani ◽  
Kanta Kawahata ◽  
Wakana Takashima ◽  
Wakana Mita ◽  
Hitomi Minematsu ◽  
...  

Physical performance is mainly assessed in terms of gait speed, chair rise capacity, and balance skills, and assessments are often carried out on the lower limbs. Such physical performance is largely influenced by the strength of the quadriceps and hamstrings muscles. Flexibility of the hamstrings is important because quadriceps muscle activity influences the hip flexion angle. Therefore, hamstring flexibility is essential to improve physical performance. In this study, Myofascial Release (MFR) was applied to the hamstrings to evaluate its effects. MFR on the hamstrings was performed on 17 young adults. Physical function and physical performance were measured before, immediately after, and 5 days after the MFR intervention: finger floor distance (FFD), range of motion (ROM) of the straight leg raising test (SLR), standing long jump (SLJ), squat jump (SJ), functional reach test (FRT), comfortable walking speeds (C-walking speed), and maximum walking speeds (M-walking speed). The results of the analysis show a significant increase in FFD (−2.6 ± 8.9 vs. 0.4 ± 9.4 vs. 2.4 ± 8.9, p < 0.01), SLJ (185.6 ± 44.5 vs. 185.0 ± 41.8 vs. 196.6 ± 40.1, p < 0.01), and M-walking speed (2.9 ± 0.6 vs. 3.0 ± 0.6 vs. 3.3 ± 0.6, p < 0.01). This study has shown that MFR for hamstrings not only improves flexibility but also increases M-walking speed and physical performance of the SLJ. As MFR is safe and does not involve joint movement, it may be useful for maintaining and improving performance and flexibility during inactivity and for stretching before exercise.


2021 ◽  
Vol 115 ◽  
pp. 110181
Author(s):  
Shernice A. Thomas ◽  
Daisey Vega ◽  
Christopher J. Arellano

Author(s):  
Takao Kakizaki ◽  
Jiro Urii ◽  
Mitsuru Endo

The 3D mass evacuation simulation of an airplane accident is experimentally verified. Evacuee motion has been experimentally investigated by building a test field that emulates the interior of an actual regional airliner with a capacity of approximately 100 passengers. The experiment results indicate that the evacuation time tends to be affected by the number of passengers and the evacuee guidance at the emergency exit. The results also indicate that any evacuation delay in exiting by individual passengers only slightly affects the total evacuation time because of evacuee congestion in the aisles. Moreover, the importance of evacuation guidance notification was investigated based on the evacuation-order variance. Finally, the experimental results were compared to the corresponding simulation results. Simulations using appropriate evacuee walking speeds can provide valid evacuation times, which are the most important factor in designing evacuation drills. Consequently, these results should be applied to existing 3D simulations using precise KDH models for more accurate mass evacuation/rescue simulations.


1997 ◽  
Vol 2 (3) ◽  
pp. 238-242 ◽  
Author(s):  
Judith G Regensteiner

Claudication is an important cause of impaired exercise capacity, which limits a patient's ability to walk and thus to meet the personal, social and occupational demands of daily life. Given that improvement of the walking impairment is the primary goal of treating claudication, exercise performance and functional status of patients with claudication should be measured before and after any intervention. Assessment of functional status in both the laboratory and community settings is important so that the various treatments can be judged as to relative efficacy. Studies have shown that exercise training programs have a clinically important impact on functional capacity in persons with claudication. A meta-analysis showed that pain-free walking time increased 180% and maximal walking time increased 120% in claudicants who participated in an exercise program. Substantial improvements have been found in walking speeds and distances (65% and 44%, respectively), caloric expenditure (31%) and physical functioning (67%).


2016 ◽  
Vol 44 (6) ◽  
pp. 1036-1055 ◽  
Author(s):  
Andrew M Fraser ◽  
Mikhail V Chester ◽  
David Eisenman ◽  
David M Hondula ◽  
Stephanie S Pincetl ◽  
...  

Access to air conditioned space is critical for protecting urban populations from the adverse effects of heat exposure. Yet there remains fairly limited knowledge of the penetration of private (home air conditioning) and distribution of public (cooling centers and commercial space) cooled space across cities. Furthermore, the deployment of government-sponsored cooling centers is likely to be inadequately informed with respect to the location of existing cooling resources (residential air conditioning and air conditioned public space), raising questions of the equitability of access to heat refuges. We explore the distribution of private and public cooling resources and access inequities at the household level in two major US urban areas: Los Angeles County, California and Maricopa County, Arizona (whose county seat is Phoenix). We evaluate the presence of in-home air conditioning and develop a walking-based accessibility measure to air conditioned public space using a combined cumulative opportunities-gravity approach. We find significant variations in the distribution of residential air conditioning across both regions which are largely attributable to building age and inter/intra-regional climate differences. There are also regional disparities in walkable access to public cooled space. At average walking speeds, we find that official cooling centers are only accessible to a small fraction of households (3% in Los Angeles, 2% in Maricopa) while a significantly higher number of households (80% in Los Angeles, 39% in Maricopa) have access to at least one other type of public cooling resource such as a library or commercial establishment. Aggregated to a neighborhood level, we find that there are areas within each region where access to cooled space (either public or private) is limited which may increase heat-related health risks.


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