• Safety and Health at Work
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• 제7권2호
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• pp.124-129
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• 2016

Background: Work-related fatigue has a strong impact on performance and safety but so far, no agreed upon method exists to detect and quantify it. It has been suggested that work-related fatigue cannot be quantified with just one test alone, possibly because fatigue is not a uniform construct. The purpose of this study is therefore to measure work-related fatigue with multiple tests and then to determine the underlying factorial structure. Methods: Twenty-eight employees (mean: 36.11; standard deviation 13.17) participated in five common fatigue tests, namely, posturography, heart rate variability, distributed attention, simple reaction time, and subjective fatigue before and after work. To evaluate changes from morning to afternoon, t tests were conducted. For further data analysis, the differences between afternoon and morning scores for each outcome measure and participant (${\Delta}$ scores) were submitted to factor analysis with varimax rotation and each factor with the highest-loading outcome measure was selected. The ${\Delta}$ scores from tests with single and multiple outcome measures were submitted for a further factor analysis with varimax rotation. Results: The statistical analysis of the multiple tests determine a factorial structure with three factors: The first factor is best represented by center of pressure (COP) path length, COP confidence area, and simple reaction time. The second factor is associated with root mean square of successive difference and useful field of view (UFOV). The third factor is represented by the single ${\Delta}$ score of subjective fatigue. Conclusion: Work-related fatigue is a multidimensional phenomenon that should be assessed by multiple tests. Based on data structure and practicability, we recommend carrying out further studies to assess work-related fatigue with manual reaction time and UFOV Subtest 2.

• The Journal of Korean Physical Therapy
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• 제35권4호
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• pp.105-110
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• 2023

Purpose: The purpose of this study was to determine whether the degree of dizziness affects static balance due to the disruption or absence of the senses involved in balance. To this end, the correlation between the Dizziness Handicap Inventory (DHI), which objectively evaluates dizziness, the Fourier Index (FI; Frequency bands of postural oscillation, F1, F2-4, F5-6, F7-8) and the Stability Index (ST), which evaluates static balance ability, were examined. Methods: This study investigated balance and dizziness issues in 30 healthy young adults. Participants underwent multiple tests like the DHI and tetra-ataxiometric posturography (Tetrax) under different conditions (eyes open/closed, standing on a foam-rubber pillow, and with the head in various orientations). Results: We found that F1 exhibited a weak positive correlation with dizziness under normal conditions, as well as when the eyes were closed (r=0.396, p<0.05) and the head was tilted back (r=0.375, p<0.05). Meanwhile, F5-6 showed a moderate positive correlation with dizziness in both head-back (HB: r=0.471, p<0.05) and head-forward postures (r=0.404, p<0.05). Lastly, both F7-8 and ST demonstrated a moderate positive correlation with dizziness when the head was in a forward posture (F7-8: r=0.483; ST: r=0.403, p<0.05). Conclusion: The study results indicate that the severity of dizziness affects sensory systems and balance. It also suggests that head movements, especially forward and backward, further stimulate the vestibular system, intensifying dizziness, and balance problems in affected individuals.

• 대한물리의학회지
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• 제18권4호
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• pp.155-162
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• 2023

PURPOSE: The primary objective of this study was to develop a virtual reality-based vestibular rehabilitation system to enhance balance perception, target rehabilitation specialists, and evaluate its usability. A key goal was establishing a system refinement strategy based on the collected data. METHODS: We conducted a study involving ten adults aged 10 to 29 in Gwangju Metropolitan City to evaluate the usability of a virtual reality-based vestibular rehabilitation system to enhance balance perception. After introducing the product and explaining its use to the participants, balance assessments and training were conducted using computerized dynamic posturography (CDP) (also called the test of balance [TOB]). Subsequently, participants were given a questionnaire to evaluate subjective stability, operability, and satisfaction. Frequency analysis was utilized to determine the frequency of the variable values of the measurement items in the survey for descriptive statistics. RESULTS: We found that the average usability score was 2.587. When broken down by category, stability received an average rating of 2.725, operability scored an average of 2.783, and satisfaction averaged 2.454. These findings suggest that most participants experienced positive sentiments and considerable satisfaction. CONCLUSION: The study successfully developed a virtual reality-based vestibular rehabilitation system, which was an improvement over the previous model and addressed its shortcomings. The results show that users with vestibular impairments are satisfied and more engaged with this system, indicating that additional studies are warranted.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5518-5524
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• 2011

사람이 서있는 동안의 안정성 감소는 낙상에 영향을 끼치는 요인 중 하나이다. 따라서 본 논문은 낙상 발생률이 높은 65세 이상의 노인여성을 대상으로 균형기능 검사를 실시하고, 성인여성의 연령대별 비교를 통해 균형능력이 노화에 따라 변화해가는 정형외과 및 신경학적 요인들을 밝혀 낙상을 예방하고자 한다. 연구 대상자는 보조기나 약물복용 없이 독립보행이 가능한 65세 이상의 신체 건강한 노인여성 10명(평균연령: 71.9세)과 성인여성 10명(평균연령: 23.2세)으로 하였다. 균형능력 평가장치(Tetrax)를 이용하여 8가지 자세에 대한 안정성 지수(Stability Index, ST), 푸리에 지수(Fourier index, F), 체중분표(Weight Distribution (%), WD), 체중분포율 지수(Weight Distribution Index, WDI), 동기화 지수(Synchronization Index, SI), 낙상율지수(fall index, FI)를 측정하였다. 그 결과, 안정성 지수(ST)는 노인여성과 성인여성간 PO를 제외한 모든 자세에서 통계적으로 유의한 차이를 나타냈다(p<.01) 푸리에지수는 낮은주파수(low, F1)에서 PO를 제외한 모든 자세에서 노인여성과 성인여성은 유의한 차이를 나타냈다(p<.01). 또한 중간낮은 주파수(middle-low, F2-F4), 중간높은주파수(middle-high, F5-F6), 높은주파수(high, F7-F8) 모두에서 노인여성이 성인여성보다 통계적으로 유의하게 높은 수치를 나타냈다. 모든 자세에서 노인여성의 체중분포율지수가 더 높게 나타났으나, PO와 PC에서만 통계적으로 유의했다. 이는 노화에 따른 생리학적 변화로 체성감각기관, 전정기관, 중추신경계등 전반적인 부분에서 능력이 저하됨에 따라 나타난 것으로 사료된다.

• 한국노년학
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• 제29권4호
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• pp.1261-1275
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• 2009

노화로 인한 근력, 균형 및 보행능력의 감소가 노인의 신체활동 저하를 일으킨다. 가상현실운동은 노인의 기능적 균형과 움직임을 회복하는데 사용되고 있다. 본 연구의 목적은 비디오게임을 이용한 가상현실운동프로그램(VR)이 노인의 근력, 균형 및 보행능력에 미치는 영향을 알아보는 것이다. 48명의 노인을 대상으로 VR군(남자 11명, 여자 14명, 나이 68.4세)과 대조군(남자 10명, 여자 13명, 나이 67.6세)으로 무작위 추출하였다. VR군은 가상현실 운동을 8주 동안 주 2회 실시하였으며 대조군은 특별한 운동을 실시하지 않았다. 가상현실운동프로그램은 준비운동(10분), 가상현실프로그램(40분), 정리운동(10분)으로 구성되었으며 가상현실프로그램은 상하지의 움직임뿐만 아니라 시청각피드백을 제공하는 플레이스테이션 아이토이플레이로 수행되었다. 운동 전·후의 변화를 비교하기 위하여 하지의 근력, 힘판을 이용한 정적균형능력, 기능적 팔 뻗기와 일어나 걸어가기 검사로 구성된 동적균형능력과 10m 보행검사와 6분 보행검사로 이루어진 보행능력을 사전, 사후로 측정하였다. VR군은 하지 근력과 정적균형능력, 동적균형능력, 보행능력에서 모두 유의하게 향상되었다(p<.05). 결론적으로 가상현실운동프로그램이 노인의 근력, 균형 및 보행능력의 개선에 효과가 있는 것으로 나타났다.