Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
SATOSHI MURAKI Last modified date:2019.06.10

Professor / Physiological Anthropology / Department of Human Science / Faculty of Design


Papers
1. Ping Yeap Loh, Wen Liang Yeoh, Hiroki Nakashima, Satoshi Muraki, Deformation of the median nerve at different finger postures and wrist angles, PeerJ, 10.7717/peerj.5406, 2018, 8, 2018.08, Background. The objective of this study was to evaluate the changes of the median nerve cross-sectional area (MNCSA) and diameters of the median nerve at different finger postures and wrist angles. Methods. Twenty-five healthy male participants were recruited in this study. The median nerve at wrist crease was examined at six finger postures, and repeated with the wrist in 30° flexion, neutral (0°), and 30° extension. The six finger postures are relaxed, straight finger, hook, full fist, tabletop, and straight fist. Results. The main effects of both finger postures and wrist angles are significant (p < 0:05) on changes of the MNCSA. Different finger tendon gliding postures cause a change in the MNCSA. Furthermore, wrist flexion and extension cause higher deformation of the MNCSA at different finger postures. Discussion. The median nerve parameters such as MNCSA and diameter were altered by a change in wrist angle and finger posture. The results may help to understand the direct biomechanical stresses on the median nerve by different wrist-finger activities..
2. Tadashi Uno, Ping Yeap Loh, Satoshi Muraki, The Influence of Information Acquisition Strategies on Foot Proprioception and Obstacle Avoidance Pattern in People with Low Vision, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume II Safety and Health, Slips, Trips and Falls, 10.1007/978-3-319-96089-0_86, 786-790, 2019.01, The purpose of this study was to understand the influence of various information acquisition strategies on foot proprioception and obstacle avoidance in people with low vision. Ten adult males (41.0 ± 7.1 years) with pigmentary retinal degeneration were recruited for this study. Participants acquired obstacle information (obstacle height: 4 cm and 15 cm) through three different strategies, namely, front (A), downward (B), and tactile (C). Subsequently, the participants performed two different tasks; Task 1: After identification of the obstacles, the participants reproduced the obstacle height by lifting their foot while standing still (10 times). Task 2: Following the acquisition of the obstacle information through conditions B and C, participants performed obstacle step-over from a standing position. In task 1, condition B showed significantly higher toe-rise and coefficient of variance in toe-rise (p < 0.05) than in conditions A and C, which both displayed similar toe-rise. Likewise, in task 2, the highest points of the leading and trailing feet while stepping over the obstacle were significantly higher (p < 0.05) in condition B than in condition C. Additionally, the coefficient of effort in condition B was significantly larger (p < 0.05) than that of condition C. These results suggest that differences in information acquisition strategies have an impact on the foot trajectory during obstacle step-over. Out of the three methods used in this study, information acquisition through the tactile sense may be the best obstacle avoidance feedback method for people with low vision..
3. Jeewon Choi, Ping Yeap Loh, Satoshi Muraki, Simulation study on the effects of adaptive time for assist considering release of isometric force during elbow flexion, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume III Musculoskeletal Disorders, 10.1007/978-3-319-96083-8_46, 347-350, 2019.01, The increasing trend of development of assistive technology allows for the use of assistive robots such as power assist devices to be prevalent in various social domains. Such power assist devices usually provide incidental power to their users, requiring human-machine force interaction. If the power assist device requires users to release their muscular force without considering adaptive time, users might be confused to control the level of their manual performance in response to the external force. This study investigated adaptive time with varying release rates of isometric force during one-arm elbow flexion, focusing on muscle activity and force control. Eight participants conducted graphical force-tracking tasks designed to simulate power-assist condition. Electromyography signals and the tension forces of the biceps brachii and triceps brachii were measured. The results implied that sufficient adaptive time for muscular force release induced better performance level with a smaller difference between the target force and the actual force. However, higher subjective exertion was also accompanied during the longer time for muscular force release. This study suggests that in designing power assist devices, the duration for muscular force release and consequent characteristics should be considered to maintain the precise level of force control..
4. Satoshi Muraki, Keisuke Hayashi, Nursalbiah Nasir, Ping Yeap Loh, Motor control with assistive force during isometric elbow flexion, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume III Musculoskeletal Disorders, 10.1007/978-3-319-96083-8_24, 191-194, 2019.01, In the modern society, an assistive/powered suit has been developed to enhance the limb and trunk movements by mechanical force. The effective output of assistive products needs cooperation between the users, that is, human beings and the machine. The present study investigated the motor control of external forces that assist with physical exertion. Sixteen adult male participants performed isometric elbow flexion under two conditions of submaximal workload (20% and 40% of the maximal voluntary contraction) and four levels (0%, 33%, 67%, and 100%) of assistive force. The electromyographic (EMG) activity of the agonist and antagonist muscles (biceps and triceps, respectively) and rating of perceived exertion decreased with increased levels of assistive force under both workload conditions. At the lower level of assistance (33%), the EMG amplitude of the biceps was near the expected amplitude, which denotes that the participants made good use of the assistive force. However, at the higher level of assistance (100%), it was far from the expected values at both workload levels. These results suggest that the effectiveness of assistive force changes according to the level of workload and assistive force, and that various human physiological regulations and motor control would be required during cooperative work with assistive force..
5. Shin Takesue, Ping Yeap Loh, Satoshi Muraki, Shinsuke Hamanaka, Atsushi Yamada, Kouichi Ikegami, Kenki Wada, Hiroshi Furutachi, Individual differences in contact pressure on the dorsal surface of the foot during gait, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume VII Ergonomics in Design, Design for All, Activity Theories for Work Analysis and Design, Affective Design, 10.1007/978-3-319-96071-5_22, 216-219, 2019.01, The main objective of this study was to examine how contact pressure on the dorsal surface of the foot changes with varying shapes. Ten healthy young men (22.1 ± 0.6 years) with independent walking ability were recruited in this study. We measured the anthropometric characteristics of the foot. Shoe size for the experiment was individually decided based on the obtained anthropometric data. Subsequently, FlexiForce® sensors were attached to the dorsal side of the first metatarsophalangeal joint (P1), intermediate cuneiform (P2), and pternion (P3) to measure the contact pressure during walking. In addition, foot switch sensors were used to determine the gait cycle. At P2, some participants with a higher foot height showed a lower increase in contact pressure during the loading response or pre-swing phases than did participants with a lower foot height. The observed distribution of the contact pressure on the dorsal foot might be caused by the change in the shape of the shoes and the foot joint movement during walking..
6. Ping Yeap Loh, Wen Liang Yeoh, Satoshi Muraki, Impacts of typing on different keyboard slopes on the deformation ratio of the median nerve, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume III Musculoskeletal Disorders, 10.1007/978-3-319-96083-8_33, 250-254, 2019.01, Carpal tunnel syndrome is a symptomatic compression neuropathy of the median nerve as it travels through the wrist. Several factors such as wrist angle and finger posture cause a change of the intra-carpal tunnel pressure. Carpal tunnel syndrome is one of the most commonly reported work-related musculoskeletal disorders. Computer users are at higher risk of upper extremity musculoskeletal symptoms and work-related musculoskeletal disorders, since time spent on the computer is associated with a higher incidence of musculoskeletal disorders. Objective: to investigate the impact of typing at two keyboard slopes (0° and +20°) on the median nerve deformation ratio. Fifteen healthy young men (24.8 ± 2.3 years) were recruited to type using both 0° and +20° inclined keyboards. The participants performed four 30-min blocks of computer typing at 0° and +20° keyboard inclinations. The left wrist median nerve was examined with an ultrasound machine after each 30-min typing block. Two-way repeated analysis of variance was performed to examine any differences in the deformation ratio of the median nerve cross-sectional area. The four time blocks and two keyboard slope conditions (0° and +20° inclination) were used as factors. Continuous typing activity causes a significant increase in the median nerve cross-sectional area deformation ratio (p < 0.05). Ultrasonography examination of the median nerve following computer typing can be used to generate absolute measurements and deformation ratios. These measurements help provide a better understanding of the impact of typing tasks on the median nerve..
7. Seiji Saito, Satoshi Muraki, Characteristics of Surface EMG During Gait with and Without Power Assistance, 20th Congress of the International Ergonomics Association, IEA 2018 Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018) - Volume II Safety and Health, Slips, Trips and Falls, 10.1007/978-3-319-96089-0_80, 739-743, 2019.01, Technology that assists and extends various functions of human beings will soon be available not only to medical and welfare but also to healthy individuals. This study aimed to characterize surface electromyography (EMG) signals in response to walking assistive equipment. Ten healthy male students walked on an 8-m uphill road (5.8% incline) using an assist walker (RT.2, RT.WORKS Co., Ltd) under assist and non-assist conditions. The EMG signals were recorded from four muscles (the rectus femoris [RF], biceps femoris, tibialis anterior, and lateral gastrocnemius). During loading response and terminal stance, the percent maximum voluntary isometric contraction (%MVC) peak value for RF was achieved more quickly in the assist condition than in the non-assist condition. However, during loading response and mid-swing, the %MVC peak value of RF was significantly lower in the assist condition than in the non-assist condition. These results indicate that humans alter muscle exertion patterns in specific muscles to adapt to walking assistance; such a change in the muscle exertion pattern may be adapted for smoother walking..
8. Ping Yeap Loh, Hiroki Nakashima, SATOSHI MURAKI, Effects of grip force on median nerve deformation at different wrist angles, PEERJ, 10.7717/peerj.2510, 4, 2016.09.
9. Jinghong Xiong, SATOSHI MURAKI, Thumb performance of elderly users on smartphone touchscreen, SPRINGERPLUS, 10.1186/s40064-016-2877-y, 5, 2016.07.
10. Irma Nur Afiah, HIroki Nakashima, Ping Yeap Loh, SATOSHI MURAKI, An exploratory investigation of changes in gait parameters with age in elderly Japanese women, SPRINGERPLUS, 10.1186/s40064-016-2739-7, 5, 2016.07.
11. Jinghong Xiong, SATOSHI MURAKI, Effects of age, thumb length and screen size on thumb movement coverage on smartphone touchscreens, International Journal of Industrial Ergonomics , doi:10.1016/j.ergon.2015.11.004, 53, 140-148, 2016.05, The present study investigated the effects of touch button size on touchscreen operability and compared these effects between young adult and elderly participants. A total of 21 young adults (aged 22.3 ± 1.5 years) and 20 elderly adults (aged 68.1 ± 4.9 years) were recruited and asked to press square number buttons (from 0 to 9) on an experimental touchscreen with their right index finger. The buttons' size changed during the experiment with six conditions (6, 8, 10, 12, 14 and 16 mm). It was found that a decrease of the button size to 10 mm or below tended to increase the operation time and error rate, whereas it decreased the subjective overall operability of the touchscreen. Such effects were greater in the elderly adults than in the young adults. In addition, the reaction positions on the buttons were found to be close to the right side of them, which led the fingertip to approach the right outline of the buttons. These findings suggest that the use of small touch buttons should be minimised on touchscreens, especially for elderly users..
12. Lu'lu' Purwaningrum, Kyotaro Funatsu, Jinghong Xiong, Cucuk Nur Rosyidi, SATOSHI MURAKI, Effect of Furniture Weight on Carrying, Lifting, and Turning of Chairs and Desks among Elementary School Children, PLOS ONE, 10.1371/journal.pone.0128843, 10, 6, 2015.06.
13. Loh Ping Yeap, Hiroski Nakashima, SATOSHI MURAKI, Median nerve behavior at different wrist positions among older males, PEERJ, 10.7717/peerj.928, 3, 2015.04, The effect of wrist flexion-extension on the median nerve appearance, namely the cross-sectional area (MNCSA) and the longitudinal (D1) and vertical (D2) diameters, was investigated among older adults (N = 34). Ultrasound examination was conducted to examine the median nerve at different wrist angles (neutral; and 15°, 30°, and 45° extension and flexion), in both the dominant and nondominant hand. Median nerve behavior were significantly associated with wrist angle changes. The MNCSA at wrist flexion and extension were significantly smaller (P < .001) compared with the neutral position in both the dominant and nondominant hand. The D1 and D2 were significantly reduced at flexion (P < .001) and extension (P < .001), respectively, in both the dominant and nondominant hand. Our results suggest that a larger flexion-extension angle causes higher compression stress on the median nerve, leading to increased deformation of the MNCSA, D1, and D2 among older adults..
14. Ping Yeap Loh, SATOSHI MURAKI, Effect of Wrist Angle on Median Nerve Appearance at the Proximal Carpal Tunnel, PLOS ONE, 10.1371/journal.pone.0117930, 10, 2, 2015.02.
15. PING YEAP LOH, SATOSHI MURAKI, Effect of different wrist position on median nerve cross-sectional area at proximal carpal tunnel, 149-154, 2014.11.
16. Cucuk Nur Rosyidi, Susy Susmartini, Lu'lu' Purwaningrum, SATOSHI MURAKI, Mismatch Analysis of Elementary School Desk and Chair Key Characteristics in Indonesia, 660, 1057-1064, 2014.10.
17. PING YEAP LOH, SATOSHI MURAKI, Effect of wrist deviation on median nerve cross-sectional area at proximal carpal tunnel level, 43, 3, 180-185, 2014.10.
18. Jinghong Xiong, KIYOTAKA FUKUMOTO, SATOSHI MURAKI, The effects of touch button size on touchscreen operability. Journal of Mechanics Engineering and Automation, 4, 8, 667-672, 2014.08.
19. Su-Young Son, Ilham Bakri, SATOSHI MURAKI, Yutaka Tochihara, Comparison of firefighters and non-firefighters and the test methods used regarding the effects of personal protective equipment on individual mobility, 45, 4, 1019-1027, 2014.07.
20. Jinghong Xiong, SATOSHI MURAKI, An ergonomics study of thumb movements on smartphone touch screen, 2014.05.
21. Masahiro Horiuchi, SATOSHI MURAKI, Yukari Horiuchi, Naofumi Inada, Daijiro Abe, Energy cost of pushing a wheelchair on various gradients in young men, , 44, 3, 442-447, 2014.05.
22. NOTO HIROKO, SATOSHI MURAKI, Effect of rear-wheel operation of a manual wheelchair on user's riding comfort and helper's strain while navigating steps, 19, 1, 17-22, 2014.05.
23. SATOSHI MURAKI, Seiji Saito, Mitsuru Okura, Physical strain and risk during stroller locomotion on cross and combined slopes, 10, 43-45, 2013.12.
24. SATOSHI MURAKI, Kiyotaka Fukumoto, Osamu Fukuda, Prediction of the muscle strength by the muscle thickness and hardness using ultrasound muscle hardness meter, 2, 457, 2013.09.
25. Hiroko Noto, SATOSHI MURAKI, Rear-wheels operation indexes for manual wheelchair helpers navigating step, 189-192, 2013.05.
26. Influence of slope gradients and wheelchair pushing techique on the user's postural change and physiological responses.
27. Effectiveness of the applying the wheelchair pushing techiques while starting and stopping with the step.
28. The effects of stairs dimensions on movements during climbing up and down stairs.
29. Steps and helper's wheelchair pushing tecniques for passing steps that consider both the user's riding comfort and the helper's physical strain.
30. Muraki S, Okabe K, Abe T, Sai A , The preferable keypad layout for ease of pressing small cell phone keys with the thumb, Journal of Human Ergology, 39, 2, 133-142, 2010.12.
31. Inoue M, Fukuda O, Tsubai M, Muraki S, Okumura H, Arai K, Automated discrimination method for measuring the thickness of muscular and subcutaneous fat layers based on tissue elasticity, Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE , 5175-5178, 2009.09.
32. Fukumoto K, Muraki S, Tsubai M, Fukuda O., Calibration of cross-sectional images measured by an ultrasound-based muscle evaluation system, Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE, 428-431, 2009.09, [URL].
33. Mika Kuroiwa, Satoshi Muraki, Kiyotaka Fukumoto, Masayoshi Tsubai, Osamu Fukuda, The relationship between muscle hardness in the trapezius and subjective symptoms of shoulder discomfort in Japanese adults, Proceeding of 17th World Congress on Ergonomics (CD-ROM), 5 pages, 2009.08.
34. Tomoaki Mori, Satoshi Muraki, Kazunobu Oyama, Syohei Sakadume, The effects of barrier-free housing on the physical fitness and incidence of falls among healthy middle-aged and elderly people, Proceeding of 17th World Congress on Ergonomics (CD-ROM), 4 pages, 2009.08.
35. Muraki S,Tsunawake, Relationship between pedaling rate and physiological responses during passive leg cycling.  , Isokinetics and Exercise Science, 2008.06.
36. Abe D, Muraki S, Yasukochi, Ergonomic effects of load carriage on the upper and lower back on metabolic energy cost of walking. , Applied Ergonomics , 39(3): 392-398 , 2008.05.
37. Abe D, Muraki S, Yasukochi, Ergonomic effects of load carriage on energy cost of gradient walking. , Applied Ergonomics , 39(2): 144-149 , 2008.03.
38. Abe D, Muraki S, Yanagawa K, Fukuoka Y, Niihata S, Changes in EMG characteristics and metabolic energy cost during 90-min prolonged running. , Gait and Posture, 26(4) 607-610 , 2007.10.
39. Saito S, Muraki S, Tochihara Y, Effects of worn-out soles on lower limb stability, shock absorption and energy cost during prolonged walking. , Journal of Physiological Anthropology, 26(5):521-526 , 2007.09.
40. Muraki S, Fornusek C, Raymond J, Davis GM, Muscle oxygenation during prolonged electrical stimulation-evoked cycling in paraplegics. , Applied Physiology, Nutrition, and Metabolism, 32(3):463-472 , 2007.06.
41. Abe D, Muraki S, Yanagawa K, Fukuoka Y, Niihata S., Changes in EMG characteristics and metabolic energy cost during 90-min prolonged running, Gait and Posture , 25 (5):, 2007.05.
42. Muraki S, Saito S, Mihoshi A, Physiological Approach to a Desirable Gradient of Longitudinal Slope for All Users., The Proceeding of the 2nd International Conference for Universal Design in Kyoto 2006,, 2006.10.
43. Abe D, Tokumaru H, Niihata S, Muraki S, Fukuoka Y, Usui S, Yoshida T, Assessment of short-distance breaststroke swimming performance with critical velocity., Journal of Sports Science & Medicine , 5 (2): 340-348, 2006.06.
44. Muraki S, Tsunawake N, Yamasaki M, Difference in cardiac autonomic control between steady-state arm cranking and leg cycling in women., Advances in Exercise and Sports Physiology, 10: 93-100, 2004.12.
45. Muraki S, Tsunawake N, Yamasaki M, Limitation of muscle deoxygenation in the triceps during incremental arm cranking in women, European Journal of Applied Physiology, 10.1007/s00421-003-0962-8, 91, 2-3, 246-252, 91:246-252, 2004.04.
46. Muraki S , Tsunawake N, Yamasaki M, Limitation of muscle deoxygenation in the triceps during
   incremental arm cranking in women., European Journal of Applied Physiology, 10.1007/s00421-003-0962-8, 91, 2-3, 246-252, 2003.01.
47. Muraki S, Ehara Y, Yamasaki, Cardiovascular responses at the onset of passive leg cycle exercise in paraplegics with spinal cord injury, European Journal of Applied Physiology, 81:271-274, 2000.01.
48. Muraki S, Tsunawake N, Tahara Y, Hiramatsu S, Yamasaki M, Multivariate analysis of factors influencing physical work capacity in wheelchair-dependent paraplegics with spinal cord injury, European Journal of Applied Physiology, 81:28-32, 2000.01.
49. Muraki S, Tsunawake N, Hiramatsu S, Yamasaki M, The effect of frequency and mode of sports activity on the psychological status in tetraplegics and paralegics, Spinal Cord, 38: 309-314, 2000.01.
50. Muraki S, Tsunawake N, Ehara Y, Tahara Y, Yamasaki M, Factors affecting physical work capacity in wheelchair-dependent paraplegics with spinal cord injury., Adapted Physical Activity, Nakata H (Ed.), pp.41-47, Shonan Syuppan, 1999.04.
51. Muraki S, Yamasaki M, Ehara Y. Kikuchi K, Seki K, Cardiovascular and respiratory responses to passive leg cycle exercise in people with spinal cord injuries., European Journal of Applied Physiology, 74: 28-32, 1996.09.