The effect of wrist orthoses on forearm muscle activity
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Development of a Novel Task-oriented Rehabilitation Program using a Bimanual Exoskeleton Robotic Hand
Published on: May 20, 2020
Lena Johansson1, Gunnar Björing, Göran M Hägg
1Department for Work and Health, National Institute for Working Life, Stockholm SE-113 91, Sweden. lena.johansson@arbetslivsinstitutet.se
Abstract:
A general hypothesis is that a wrist orthosis reduces the wrist extensor muscle load. The aim of this study was to investigate the effects of a completely stiff wrist orthosis (SO) and a commercially available wrist orthosis (CO) on flexor and extensor electromyographic (EMG)-activity in a standardised intermittent gripping task and during standardised manual work tasks. Surface EMG from two forearm flexor and two extensor muscles was recorded. The target grip forces were 5%, 20% and 40% of maximal voluntary contraction (MVC). During the grip contraction phase CO had no effect on the EMG-readings. SO resulted in higher EMG activity than when gripping with CO and with no orthosis (NO), especially when gripping with 40% MVC. During the relaxation phase neither CO nor SO had any effect on the extensors. For the flexors the SO gave higher EMG-readings than when gripping with CO and NO, especially at 40% MVC. In conclusion the wrist orthoses tested did not reduce the EMG-activity from the flexors or the extensors during gripping or manual tasks.
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