The ability to walk is just as important for the elderly as it is for young people. In fact, in the elderly, decreased mobility limits function in daily life and can lead to more serious situations (e.g., becoming bedridden) . The elderly population has increased over the last decade, and many researchers have studied the mobility of the elderly. However, the focus of most studies has been to facilitate recovery of bedridden individuals and prevent the elderly from becoming bedridden, and particularly to prevent fall-induced fractures, which often cause the elderly to become bedridden. However, about 70-80% of the elderly population do not require care, and it is necessary to conduct research on the maintenance of activities of daily living to make it possible for the elderly to work or volunteer. From this perspective, mobility is an important physical factor. Mobility is dependent on muscle activity and it has long been known that aging reduces muscle mass. Therefore, it is feasible to assume that reduced muscle mass leads to decreased ability to walk, and we have proven that there is a close correlation between the two. When presenting the idea of strength training to the elderly, it is appropriate to focus on the maintenance and improvement of mobility, not on the training itself. The results of our research can be summarized as follows:
Muscle mass decreases with age, with the legs being affected to a greater degree than the arms. Moreover, muscle atrophy is dependent on weakening of muscle fibers, especially fast-twitch (Type II) fibers. Reduced lower limb muscle mass increases the risk of falling and can decrease walking ability to a degree that can affect daily living activities.
In order to improve reduced muscle mass in aging, it is important to use an exercise program that is designed to strengthen fast-twitch fibers, which can be followed even by the elderly. Since walking therapy mostly mobilizes slow twitch fibers, it is not effective in preventing and improving muscle atrophy. It is important to have an exercise program that is designed to mobilize fast-twitch fibers.

The purpose of this study was to investigate the hypothesis that the reduction in walking ability is due to muscle atrophy in the lower limb muscles with aging using equational structure modeling as well as investigate the influence of muscle on walking ability. The subjects consisted of 127 persons (57 males and 70 females) aged 20-84 year, who were grouped into 6 age brackets of 20-39, 40-49, 50-59, 60-69, 70-74, and 75 or older. Using MRI, muscle cross-sectional area was measured on psoas major and thigh muscle (divided into extensor and flexor) . For walking patterns, each subject walked along a 7-m walking passage at normal speed for VTR-recording of the motion. The resulting pictures were used to analyze stride length, trunk inclination and walking speeds. Walking speeds showed a statistically significant decrease in value from the 50's age group in males and the 60's age group in females when compared with the 20-39 age bracket (p<0.05) . In males, a significant co-relationship was observed only between the muscle cross-sectional area of thigh extensor and walking speed (p<0.01) while in females, a significant co-relationship was found between the muscle cross-sectional area of psoas major (p<0.001) /thigh muscle extensor (p<0.01) and walking speed. These results indicate that the muscle atrophy with aging in psoas major and thigh muscle extensor is a factor responsible for the decrease in walking speed. Meanwhile, a difference in sex was observed between the muscle cross-sectional area of psoas major and walking speed. It was considered that the muscle atrophy rate of the female's psoas major being higher than the male's influenced this. Furthermore, it was suggested possibility that the decline of walking ability is due to decreased muscle mass of the lower limbs with aging.

In order to clarify the effect of exercise on the walking performance and the muscle volume in lower limbs, elderly athletes long continuing to be trained and untrained elderly were compared with regard to their muscle cross-sectional area (CSA) of m. psoas major, thigh muscle and crus muscle and their walking ability. The subjects used consisted of thirty-six 80's-aged male and 70's-aged female elderly athletes and twenty-four elders having no regular exercise (control male group : CM, control female group : CF) . The elderly athletes were further divided into two groups in accordance with their results of Japan Fitness Test (high performance male group : HPM, low performance male group : LPM, high performance female group : HPF, low performance female group : LPF) . The walking performance was evaluated by analyzing their walking speed, stride-length and step rate during walking along a 15 m-strip of passage at normal and fast paces using videotaping. The muscle CSA was determined at m. psoas major, thigh muscle (extensors and flexors) and crus muscle (m. tibialis anterior and m. triceps surae) using MRI. As for the walking speed and stride-length at the normal pace, only HPM and HPF showed significantly higher values than CM and CF (male : p<0.05, female : p<0.01) . Meanwhile at the faster pace, HPF and LPF showed significantly higher values than CF in female (HPF : p<0.01, LPF : p<0.05) and in the case of males, only HPM have a higher value only of the walking speed than CM (p<0.05) . The CSA of m. psoas major in HPM and HPF significantly higher than that in CM and CF (all p<0.05), while in CSAs of knee extensor muscles and m. triceps surae, the statistical differences were not consistent among male and female groups. The results suggested that greater muscle mass of m. psoas major could influence higher walking speed in elderly people, and might be affected by regular exercise training.

Background: When a sudden outbreak of an infectious disease occurs, emergency medical services (EMS) response could be negatively affected. The poor prognosis of acute stroke may be largely attributed to delays in treatment. This study aimed to identify the impact of the sudden outbreak of coronavirus disease 2019 (COVID-19) on EMS response for patients with acute stroke. Methods: This comparative cross-sectional study was conducted in 25 safety centers in Seoul, Korea. We enrolled patients with acute stroke who were transferred to the emergency department by EMS. The study period was from February–April 2020 and the same period in 2019. Patients were divided into two groups, pre-COVID-19 period and early-COVID-19 period, and previously collected patient data were analyzed. We performed comparative analyses of EMS response and clinical outcomes between the groups. Results: Of 465 patients, 231 (49.7%) had an acute stroke during the study period. There was no significant difference between clinical characteristics of patients with acute stroke before and after the COVID-19 outbreak. EMS response times increased significantly during the early COVID-19 outbreak. The intensive care unit admission rate and mortality rate increased during the early COVID-19 outbreak. Conclusion In the initial phase after the sudden COVID-19 outbreak, EMS response times for acute stroke were delayed and the clinical outcomes of patients with acute stroke deteriorated.

PURPOSE: The goal of this study was to characterize the difficulty index of the items in the skills test components of the class I and II Korean emergency medical technician licensing examination (KEMTLE), which requires examinees to select items randomly. METHODS: The results of 1,309 class I KEMTLE examinations and 1,801 class II KEMTLE examinations in 2013 were subjected to analysis. Items from the basic and advanced skills test sections of the KEMTLE were compared to determine whether some were significantly more difficult than others. RESULTS: In the class I KEMTLE, all 4 of the items on the basic skills test showed significant variation in difficulty index (P<0.01), as well as 4 of the 5 items on the advanced skills test (P<0.05). In the class II KEMTLE, 4 of the 5 items on the basic skills test showed significantly different difficulty index (P<0.01), as well as all 3 of the advanced skills test items (P<0.01). CONCLUSION: In the skills test components of the class I and II KEMTLE, the procedure in which examinees randomly select questions should be revised to require examinees to respond to a set of fixed items in order to improve the reliability of the national licensing examination.
Emergencies* ; Emergency Medical Technicians* ; Humans ; Licensure*