Repeatability of phasic muscle activity: Performance of surface and intramuscular wire electrodes in gait analysis

Introduction:Single force-displacement characteristics of mechanical key switches have been shown to affect performance, fatigue and discomfort during keyboard use. This study compared the effects of mechanical key switches with differing force-displacement characteristics on forearm muscle activity, typing performance, Fitts Study task performance, subjective fatigue and user preference. Methods: Using a within subjects intervention study of crossover design, 64 subjects completed modified Fitts and typing tasks on five different mechanical key switches to mimic dual word processing and gaming keyboard use. Bilateral muscle activity was recorded using surface electromyography (EMG); typing and Fitts task performance measures were tracked. Results: The key switch with a linear force displacement curve had higher net strokes and lower net typing speed than two key switches with tactile feedback (p<0.05). The key switch with the longest tactile travel, operating travel and highest bottom force required slightly higher peak muscle activity compared to 2 other key switches with lower values (p<0.05). Key switches with shorter tactile and operating travel and lower bottom forces were preferred over other key switches.Conclusions: Among mechanical key switches, a linear force displacement curve had the worst outcomes; key switches with shorter tactile (1.2mm) and operating travel (2.0mm) and a lower bottom force (35-40g) had best outcomes overall.

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Muscle Activity and Gait Analysis of Assistive Device for Rehabilitation Gait Abnormalities Patient

Journal of Physics Conference Series ◽

10.1088/1742-6596/2107/1/012063 ◽

2021 ◽

Vol 2107 (1) ◽

pp. 012063

Author(s):

Ruzy Haryati Hambali ◽

Suriati Akmal ◽

Nurul Hamizan Komaruddin

Keyword(s):

Gait Analysis ◽

Muscle Contraction ◽

Root Mean Square ◽

Muscle Activity ◽

Surface Electromyography ◽

Assistive Device ◽

Mean Square ◽

Gait Abnormality ◽

Muscle Disorder ◽

Gait Abnormalities

Abstract Gait abnormality is a muscle disorder that disabling the patient to walk properly. This is caused by several factors including genetic influence, accident history, health issue, and others. Some suffered from this illness could be cured but some cases only could be helped by rehabilitation. This work is an original initiative in developing an assistive device as part of patient’s recovery and rehabilitation in helping the patient to regain muscle, as well assisting patient in performing their activities. However, the effectiveness on the device’s performance to serve its purpose has not yet been confirmed. Therefore, an electrical tool known as surface Electromyography (EMG) is being used to obtain the information required. This research is analysing the patient’s nerves system with and without the assistive device and demonstrate the effectiveness of the assistive device in reducing the muscle contraction, as well to increase the time-to-fatigue of the muscle. The findings of this research showed that the reduction in percent of average Root Mean Square (RMS) value of patient’s contraction muscle when using the device has increase the time-to-fatigue of the muscle. In conclusion, this assistive device assists the patient, minimise the muscle fatigue, and ease the patient in their daily chores.

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Myoelectric Activity Differences in Three Learning Sessions

Journal of Psychophysiology ◽

10.1027//0269-8803.16.2.92 ◽

2002 ◽

Vol 16 (2) ◽

pp. 92-96

Author(s):

Tiina Ritvanen ◽

Reijo Koskelo ◽

Osmo H„nninen

Keyword(s):

High School Students ◽

Muscle Activity ◽

Muscle Tension ◽

Emg Activity ◽

Traditional Learning ◽

Myoelectric Activity ◽

School Students ◽

Language Laboratory ◽

Upper Trapezius ◽

Muscle Groups

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.

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