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- Alametsä, Jarmo, et al.
(author)
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Age-related circulatory responses to whole body cooling: observations by ballistocardiographic EMFi sensors
- 2014
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In: Proceedings of Ambience 14&10i3m : Scientific Conference for Smart and Functional Textiles, Well-Being, Thermal Comfort in Clothing, Design, Thermal Manikins and Modellin, 7-9 September 2014, Tampere, Finland - Scientific Conference for Smart and Functional Textiles, Well-Being, Thermal Comfort in Clothing, Design, Thermal Manikins and Modellin, 7-9 September 2014, Tampere, Finland. - 2342-4540. - 9789521532696 ; 1
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Conference paper (peer-reviewed)abstract
- The purpose was to study age related changes in circulatory system via Ballistocardiography (BCG) by utilizing Electromechanical Film (EMFi) sensors by gradually changing the ambient temperature from a thermoneutral area to cold direction. ECG and BCG were recorded from a young person (23 years) and from an older person (78 years), both males. During the tests, brachium blood pressure (BP) and pulse signals were recorded from neck and ankle (with EMFi sensor strips). Thermal camera images were taken in order to find out temperature changes in whole body and limbs. Temporal durations and amplitudes of seat BCG:s components (systolic and diastolic) as well as from pulse signals from neck and ankle were calculated. Aortic pulse wave velocity (PWV) was obtained by utilizing the time between ECG’s R wave and maximum value of the ankle pulse signal. In both persons, the ankle pulse amplitude decreased when propagating to cold direction and increased in young person when returning to warmer ambient temperature. With young and old BCG:s systolic and diastolic temporal complexes remained stable, but systolic amplitudes increased in the older person (AHI 1.02 – 2.87, AIJ 0.7 – 2.66) as well as diastolic amplitudes (old; AKL 0.47 – 2.37). In the older person, PWV increased when moving to colder side. BP increased with a young person (from 95/64 to 132/75 mmHg), and with older person (from 125/68 to 176/101 mmHg) having a prominent rise in diastolic values during the cooling. The neck pulse wave amplitude AOP rise was modest with the younger person and had variation with the older person. Older person had also more intensive shivering compared to younger one. With the older person, the limbs stayed cold in thermal images when returning from cold to thermoneutral area. The present preliminary observations indicated clear age-related differences in the circulatory response to a mild whole-body thermal challenge.
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| 2. |
- Gao, Chuansi, et al.
(author)
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Using a walkway with adjustable inclination to measure and assess slip and fall risks
- 2014
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In: Proceedings of CIB W099 International Conference Achieving Sustainable Construction Health and Safety. - 9789176230053 ; , s. 118-124
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Conference paper (peer-reviewed)abstract
- Fall is the most common cause of serious work related accidents. Falls and related injuries not only cause suffering for individuals, but also means a high economic burden to industries and society. The objective of the study was to use a walkway with in-built force plate, adjustable inclination and surface to assess how risks of slips and falls vary due to inclination and friction of the walkway surface. A walkway was designed with adjustable slopes between 0 to 30 degrees. Subject walking tests were performed on dry and wet steel sheet surfaces in two walking directions (uphill and downhill) at three inclination angles (0, 5 and 10 degrees). 3D ground reaction forces while walking were recorded using the force plate. Required coefficient of friction (RCOF) was derived to determine slip and fall risks. The main finding of this study is that the RCOF during heel strike when walking downwards on the steel plate surface increases linearly as the inclination increases. The results contribute to the understanding of slipping and falling mechanisms and the prevention of slipping and falling accidents. When ramps or sloped surfaces are used in workplaces, slip resistance between footwear and the sloped surfaces should be improved.
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| 3. |
- Halder, Amitava, et al.
(author)
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Effects of Cooling on Ankle Muscle Strength, Electromyography, and Gait Ground Reaction Forces
- 2014
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In: Journal of Sports Medicine. - : Hindawi Limited. - 2314-6176 .- 2356-7651. ; 2014
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Journal article (peer-reviewed)abstract
- The effects of cooling on neuromuscular function and performance during gait are not fully examined. The purpose of this study was to investigate the effects of local cooling for 20 min in cold water at 10 C in a climate chamber also at 10 C on maximal isometric force and electromyographic (EMG) activity of the lower leg muscles. Gait ground reaction forces (GRFs) were also assessed. Sixteen healthy university students participated in the within subject design experimental study. Isometric forces of the tibialis anterior (TA) and the gastrocnemius medialis (GM) were measured using a handheld dynamometer and the EMG was recorded using surface electrodes. Ground reaction forces during gait and the required coefficient of friction (RCOF) were recorded using a force plate. There was a significantly reduced isometric maximum force in the TA muscle (
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| 4. |
- Halder, Amitava, et al.
(author)
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Muscle Cooling and Performance: A Review
- 2014
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In: European Journal of Sports Medicine. - 1792-4979. ; 2:1, s. 39-48
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Research review (peer-reviewed)abstract
- Objectives: Skeletal muscle performance is determined by muscle temperature. This paperpresents a review of the research literature to contribute to a better understanding of thephysiological mechanisms of muscle fatigue and performance in cold exposure and in repetitiveor sustained physical exertion in terms of isometric maximal force production,electromyographic activities, and gait ground reaction forces.Materials and Methods: The PubMed and MEDLINE databases were searched for relevantarticles in English. The titles and abstracts of all identified studies were initially screened bythe first author to determine whether they could be included. Relevant articles were consideredfor full text analysis. The reference lists of the relevant studies were also checked.Results: The review showed that different cooling methods have been used in the researchsettings. Current applications are reported of cold exposure to assess muscle strength throughmaximum voluntary contraction and functional activities, manual work of the upper limbs,gait and balance, fall risks, and mobility of the lower limbs. The review also showed thatneuromuscular functions are impaired at 0° to 25°C of cold water immersion for 10 to 40 minwhere loss of strength and fatigue occurred in the limb muscles. Although some of the findingsin previous studies about isometric force production in cooled muscles and joints arecontroversial, this review found that impeded strength is relatively well-established.Conclusions: Cooling in cold water at certain temperatures can influence our maximum muscleperformance but may not impact daily activities.
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