The effect of wrist posture on extrinsic finger muscle activity during single joint movements

Abstract

Wrist posture impacts the muscle lengths and moment arms of the extrinsic finger muscles that cross the wrist. As a result, the electromyographic (EMG) activity associated with digit movement at different wrist postures must also change. We sought to quantify the posture-dependence of extrinsic finger muscle activity using bipolar fine-wire electrodes inserted into the extrinsic finger muscles of able-bodied subjects during unrestricted wrist and finger movements across the entire range of motion. EMG activity of all the recorded finger muscles were significantly different (p < 0.05, ANOVA) when performing the same digit movement in five different wrist postures. Depending on the wrist posture, EMG activity changed by up to 70% in individual finger muscles for the same movement, with the highest levels of activity observed in finger extensors when the wrist was extended. Similarly, finger flexors were most active when the wrist was flexed. For the finger flexors, EMG variations with wrist posture were most prominent for index finger muscles, while the EMG activity of all finger extensor muscles were modulated in a similar way across all digits. In addition to comprehensively quantifying the effect of wrist posture on extrinsic finger EMG activity in able-bodied subjects, these results may contribute to designing control algorithms for myoelectric prosthetic hands in the future.

Gesture Recognition Using Surface Electromyography and Deep Learning for Prostheses Hand: State-of-the-Art, Challenges, and Future

“…Intact subjects performed real movements of the hand, while amputees could only attempt imaginary movements without visual and sensory feedback, so that when they perform the same movements at a specific arm position, the residual muscles of amputated arm might produce sEMG patterns different from those of intact arm (Geng et al, 2012 ; Vidovic et al, 2016 ). When wearing a prosthesis, the amputee's elbow, shoulder, and other parts of the body would appear different degrees of compensation movement, which could affect the sEMG signal of the hand (Geng et al, 2012 ; Hussaini et al, 2017 ; Beringer et al, 2020 ).…”

Exploring forearm muscle coordination and training applications of various grip positions during maximal isometric finger dead-hangs in rock climbers

“…Therefore, SLOPER can attain greater muscle activity, although the load necessary to reach this activity level is higher than for the other grip positions. On the other hand, differences in the gripping position itself could have caused changes in the contributory role of each of the joints involved, especially the interphalangeal and wrist joints ( Charissou et al, 2017 ; Caumes et al, 2019a ; Beringer et al, 2020 ). Therefore, changes in the activity of the muscle groups involved are presented below.…”

Finger Movement Recognition via High-Density Electromyography of Intrinsic and Extrinsic Hand Muscles

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