• Journal of International Academy of Physical Therapy Research
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• v.11 no.3
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• pp.2107-2112
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• 2020

Background: With the increasing elderly population, the need for gait analysis of these elderly individuals is also increasing. Most devices are costly and not portable; however, smartphones using built-in sensors capable of measuring motion and are easily available. Objectives: To examine the reliability and validity of knee joint angles of the elderly using smartphone measurements during walking. Design: Quasi-experimental research. Methods: Sixteen elderly people, aged 65+ and living in Daejeon and Chungbuk, South Korea, participated in the study. Electrogoniometers and smartphones were attached to the thigh and the side and front of the shank of each subject, respectively, using double-sided tape, an arm band, and an elastic band. Each subject completed two sets of at least seven gait cycles (14 steps). Results: Both the smartphones and electrogoniometers exhibited high agreement in terms of their primary and secondary measurements (ICC>.75). The agreement between the smartphones and electrogoniometers was also high in terms of both the primary and secondary measurements (ICC<.60). Conclusion: These results indicate that smartphones can be costly equipment cannot, even though they cannot completely replace existing clinical-grade devices. Their utility is emphasized herein for measuring knee joint angles of the elderly during walking.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2004-2009
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• 2003

The purpose of this study is to define how wrist motion is affected by different postures and supporting devices and to discover functional range of wrist motion for keyboard typing. The range of wrist motion (ROM) needed for fourteen experienced typists to type on a computer keyboard was measured by flexible and biaxial electrogoniometers. The most frequent wrist motion during typing was in extended and ulnarly deviated positions in both wrists. Range of wrist motion was similar in both wrists. The average ROM for keyboard typing with the typists' own posture was about 39 in flexion/extension (FEM) and 29 in radial/ulnar deviation (RUD) in both wrists. The range of wrist motion was significantly reduced to 30 in FEM and 27 in RUD with use of either wrist or forearm supporting devices, which suggests that these devices might help to relieve fatigue, discomfort, or pain during and/or after typing. Results of this study will be of interest to clinicians and helpful to those who are professionally or non-professionally involved in typing.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.241-246
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• 2009

Since inappropriate muscle forces mean that people cannot perform some activities related to roles of the muscle, muscle forces have been considered as an important parameter in clinic. Therefore, many methods have been introduced to estimate muscle forces indirectly. One of the methods is muscle tissue dynamics and it is widely used in commercial softwares including musculoskeletal model, such as SIMM. They, however, need motion data captured from 3-dimensional motion analysis system. In this study, we introduced an algorithm to estimate muscle forces in real-time by using joint angles. The heel-rise movements were performed for a normal with 3-dimensional motion analysis system, EMG measurement system, and electrogoniometers. Joint angles obtained from electrogoniometers and EMG signals were used to estimate muscle forces. Simulation was performed to find muscle forces using motion data which was imported into musculoskeletal software. As the results, muscle lengths and forces from the developed algorithm were similar to those from commercial software in pattern. Results of this study would be helpful to implement a tool to calculate reasonable muscle forces in real-time.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.15-23
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• 2015

PURPOSE: We aims to promote the development of proprioception measurement using smartphones, goniometers, and laser pointers as compared to the conventional use of electrogoniometer measurement. METHODS: Measurements using an electrogoniometer were previously proved to be reliabile and valid. Among E-university students, 20 who had no fracture, operation history, or inflammatory arthritis were examined. These subjects had not performed regular exercise in the past 3 months. Proprioception measurements were performed using four different measurement tools, three times per day, for test-retest analysis. RESULTS: No notable test-retest differences were noted for any of the measurement methods (P>0.05). With regard to the test-retest reliability for each measurement method, we observed that the readings from both the electrogoniometer and smartphone have high reliability (ICC>0.80), whereas the readings from the laser pointer have moderate reliability (ICC>0.60). When assessing the concurrent validity between electrogoniometers with individual measurements, we did not observe any notable difference between the smartphone and electrogoniometer (P>0.05) and these tools in fact showed high correlation (r>0.60, P<0.05) and a moderate reliability (ICC>0.60). Moreover, there was no notable difference in between electrogoniometers and laser pointers (P<0.05). CONCLUSION: CONCLUSION: The findings of this suggested that proprioception can be measured by using smart-phones, and proved that this method has sufficient credibility. Moreover, we noted that the concurrent validity with smartphones was high in comparison with the conventional electrogoniometer, which also indicates the validity and credibility. Based on these findings, we conclude that the measurement of proprioception by using a smartphone can be widely adopted.