• 대한통합의학회지
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• 제7권2호
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• pp.133-139
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• 2019

Purpose : This study aims to investigate the rating of perceived exertion (RPE) and muscle activity of the inspiratory primary and accessory muscle during breathing exercise with different air hole diameters of the inspiratory muscle trainer (IMT). Methods : The Borg's scale and surface electromyography (EMG) was used to collect data of the RPE and muscle activity of the inspiratory primary the external intercostal (EI) and diaphragm (DIA) and accessory muscles anterior scalene (AS), sternocleidomastoid (SCM), pectoralis major (PM), and upper trapezius (UT) muscles during breathing exercise with different air hole diameters (6 mm, 4 mm, and 2 mm) of the IMT in healthy young male subjects. Results : The RPE and muscle activities of the AS, SCM, and UT are increased significantly in accordance to the decreasing diameter of air hole of air tip in IMT. However, there are no differences in the muscle activities of the PM, EI, and DIA based on differences of diameters of air hole of air tip in IMT. Conclusion : The smaller the diametr of IMT air-hole, RPE and muscle activities of AS, SCM and UT were increased. Therefore, further study would be necessary to investigate the proper intensity and relaxation posture for the exercise protocol to strengthen the inspiratory primary muscles.

• 생명과학회지
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• 제21권1호
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• pp.9-14
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• 2011

심박수(heart rate) 및 산소 소비량(oxygen consumption) 등의 생리학적 변수는 운동자각도(RPE)와 밀접한 관련이 있으며, RPE의 남녀차이에 의한 예측 운동강도의 정확성은 아직 밝혀지지 않고 있고, 본 연구는 남녀 대학생의 심장 혈관 및 신진대사의 반응을 평가하고 남녀의 차이를 밝히는 데 있다. 남자대학생($25.1{\pm}1.56$ yr)과 여자대학생($25.0{\pm}4.12$ yr) 각각 10명이 본 연구에 자발적으로 참여를 하였고, 본 연구를 위하여 설정된RPE는 Borg의 15 범주에서 결정을 하였으며, 점증적 운동부하(graded exercise testing)는 Bruce Treadmill Protocol을 이용하였다. 남녀의 평균 slope (p=0.501)와 RPE의 plotting rates와 최대산소섭취율(% $VO_2$max)은 유의한 차이가 나타나지 않았다. 각자의 상대적 최대산소섭취량은 남학생의 경우52.36${\pm}$7.35 ml/kg/min, 여학생은 41.44${\pm}$6.71 ml/kg/min로 나타나 두 그룹간에 유의하게 큰 차이가 있었으며, 절대적 최대산소섭취량은 남학생은 4.05${\pm}$0.36 l/min, 여학생은 2.53${\pm}$0.39 l/min로 나타나 두 그룹간에 큰 차이가 나타냈다. 남학생과 여학생간의 slope, y-intercept, SEE는 통계적으로 유의한 차이는 없었다. 본 연구에서 운동강도에 따른 남학생과 여학생의 RPE 의 차이는 유의하게 나타나지 않았다. 이상의 결과로 보아 RPE는 운동중 산소섭취량에 대한 운동강도의 예측에 남녀별 차이가 없어 유효한 예측인자라고 사료된다.

• 대한산업공학회지
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• 제7권2호
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• pp.3-17
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• 1981

Isometric muscle strength has become important as it is realized that a large variation in the human exists and is affected by many personal and environmental factors. Experiments have been performed for estimating the individual capabilities of the quadriceps femoris muscle in man. The surface EMG has been recorded on the belly of the rectus femoris muscle during voluntary isometric continuous exertion at 25%, 50%, 75%, and 100% MVC. As a muscle force (% MVC) increases, the rectified mean EMG amplitude increases in a non-linear form. The rectified mean EMG amplitude also increases in a non-linear with respect to fatigue progression. As the muscle force (% MVC) increases, an endurance time of isometric exertion decreases linearly. Analysis shows that rectified mean EMG amplitude is a consistent and sensitive measure of motor unit recruitments and can be useful in estimating an individual capability of a local muscle. Further, the result satisfies the sufficient condition that type S motor units are recruited first, while large motor units are recruited progressively as the fatigue develops.

• 한국안전학회지
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• 제16권1호
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• pp.79-83
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• 2001

Posture of the upper limbs in field works is known to be an important risk factor associated with CTD(Cumulative Trauma Disorders). In particular, uncomfortable posture and highly repetitive works in shipbuilding industry(for instance, sand blasting, grinding and blast painting, etc) made workers exposed to a great risk of injuries. The purpose of this paper is to analyze recruitment pattern of the muscles according to posture(joint angle displacement) during grinding. In this study, EMG signals of pectoralis major, latissimus dorsi, and posterior deltoid muscle were measured and analyzed from FlexComp EMG solution. And subjective ratings of perceived exertion were made using Borg's CR-10 rating scale.

• 한국전문물리치료학회지
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• 제1권1호
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• pp.25-34
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• 1994

This study investigated the hypothesis that purposeful activity is an intrinsic motivator. Affecting exertion during the performance of purposeful and nonpurposeful activity was studied in 30 elementary school students. The subjects acted as their own controls in the performance of other exercise. The three experimental exercises were jumping rope, defined as a nonpurposeful activity, and jumping rope with reinforcement, defined as purposeful activity I, and jumping rope with double reinforcement (food), defined as purposeful activity II. Duration and cessation of exercise were entirely controlled by the subject. The number of jumps were measured immediately after cessation of exercise and duration of exercise in seconds by observer. The results were as follows : 1. There was a significant difference in the required time of performance between purposeful and nonpurposeful jumping (p< .05). 2. There was a significant difference in the number of jumps between nonpurposeful and nonpurposeful jumping after reinforcement. (p< .05). Implications for practice and further research are discussed.

• 한국안전학회지
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• 제18권4호
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• pp.143-147
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• 2003

The present investigation examined hammering performance, physiological response, preceived exertion, and user preference with regard to hammering in vertical (wall) and horizontal (bench) orientations, and with regard to using two different hammers. Ten male subjects participated in the experiment. The results support previous findings that horizontally oriented hammering is faster than vertically oriented hammering. In addition, the results suggest that hammer differences can affect hammering performance and perceived exertion; although, the exact contributions of specific design characteristics could not be quantitatively determined. However, participants subjectively identified handle design, weight, and mass distribution as critical factors.

• Asia Marketing Journal
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• 제22권1호
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• pp.27-39
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• 2020

Building on the growing literature on how physical bodily expressions influence psychological processes, the authors propose that exerting physical strength decreases risk perceptions and increases preference for risky options by increasing perceptions of control or agency. The present research is based on the belief of "no pain, no gain", that when an individual exerts physical strength and effort, he believes he can be the agent in bringing about the desired outcome. Because of this automatic association between exerting physical strength and the sense of being in control of the outcome, the authors hypothesize that even in situations where the outcome is determined by chance and luck, individuals exerting effort feel they have more control and thus choose riskier, but more desirable, options. Furthermore, this research clarifies the distinction between physical exertion of strength, high- and low-power poses, and psychological power.

• 대한인간공학회지
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• 제31권5호
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• pp.687-694
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• 2012

Objective: This study aims to survey the prevalence of musculoskeletal disorders(MSD) among Korean hospital workers and to analyze the relationship of MSD symptoms and workload perceived by workers. Background: Despite of high exposure to the MSD risk factors and high MSD symptom prevalence among health care workers, there were not enough studies of MSD prevalence among the hospital workers. Method: This study designed a survey based on Nordic questionnaire to obtain MSD symptoms and the degree of four perceived workloads: work repetition, urgency, physical exertion and satisfaction. In this survey, 1,846 workers in a hospital participated. The prevalence of MSD was analyzed for each body part, and MSD cases, which were predetermined in this study, were identified. The relationship between the MSD cases and each perceived workload was analyzed using chi-square test. Results: The pain in the shoulder was the most prevalent among the workers as 52%, and the low back(37%) and leg discomfort(36%) followed. The MSD cases, in which degree of pain was more than severe, were also the most prevalent in the shoulder(13%). Female workers had higher rate of MSD cases than the males. Among the four workload variables, the physical exertion was the statistically related to MSD cases for all the body parts. In addition, the others also had significant relation to MSD cases except one or two body parts. Conclusion: This study found that Korean hospital workers had MSD symptoms mainly in the shoulder, low back and legs in order, and the perceived workload surveyed in this study was highly correlated with MSD symptoms. Application: This study provides another evidence that subjective physical exertion perceived by workers is an important factor to explain MSD cases as same as the objective one.

• The Journal of Korean Physical Therapy
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• 제32권2호
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• pp.132-136
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• 2020

Purpose: The talk test (TT) is an alternative, self-reported method for prescribing and guiding exercise training in both healthy adults and patients with cardiovascular and pulmonary diseases. This study examined whether the TT is a valid tool for evaluating the exercise intensity during two different types of aerobic activity on a treadmill or stationary bicycle in a healthy population. Methods: A total of ten subjects (six males and four females) who had no medical history related to musculoskeletal, cardiovascular, and pulmonary disorders were enrolled in this study. They were evaluated using the TT, which consisted of three-level of difficulties demanding cardiac loads while performing aerobic activities on a treadmill and bicycle ergometer across two consecutive days in a counterbalanced manner. During the activities, the psychophysiological response markers were collected in terms of the heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents. Results: Statistical analyses revealed a significant difference in the between-subject variance regarding the TT level effect (p<0.05). On the other hand, no significant findings were detected on the between-group variance(p>0.05) and the TT level×group interaction (p>0.05). The independent t-test indicated no significant differences in heart rate, oxygen saturation, rating of perceived exertion, and metabolic equivalents at any levels of the TT in the two groups. The TT showed a strong correlation with the rating of perceived exertion. Conclusion: This study showed that the TT is a valid and alternative tool for evaluating the aerobic exercise intensity in a healthy population. In addition, differences in the psychophysiological response markers between two aerobic activities, treadmill and bicycle ergometer, were detected in the same exercise intensity scaled with the TT. The TT can be used to evaluate and prescribe the exercise intensity of aerobic activity in cardiovascular and pulmonary physical therapy.

• Physical Therapy Rehabilitation Science
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• 제3권2호
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• pp.86-92
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• 2014

Objective: Whole body vibration (WBV) and plyometrics are common training techniques which increase strength, blood flow, and lower body force and power. The effects these techniques have on sedentary population is unknown. It is our aim to assess the effectiveness of WBV and plyometrics on sedentary population. Design: Experimental study. Methods: Twenty-seven sedentary subjects were assigned to either the control group, jumping only group, or jumping with vibration group. Jump height (myotest or vertec), velocity, force, blood lactates, and rating of perceived exertion (RPE). Subjects were measured on the initial, seventh, and eighteenth visits. Control group attended measurements only. Jumping only and jumping with vibration groups performed jumping from a vibrating platform to a surface 7 1/2 inches higher for 3 bouts of 20 seconds. Each subject in jumping only and jumping with vibration groups attended three times per week for six weeks. Vibration was set at 40 Hz and 2-4 mm of displacement. Results: There was no significant change among groups in force, velocity, vertec height, and myotest height. However there was a significant increase in vertec height from initial to final measure (p<0.05) for jumping with vibration group. RPE was significantly higher between control group and jumping with vibration group after intervention (p<0.05). Conclusions: WBV with vibration increased jump height. Jumping with vibration group experienced increased exertion than for controls. WBV with plyometrics had no effect on force, velocity, blood lactates, or calculated jump height. Further studies controlling for initial measure of blood lactates and using an external focus may be necessary to elicit velocity, force and jump height changes.