Upper extremity muscle activation during drinking from a glass in subjects with chronic stroke

[Purpose] The purpose of this study was to compare the muscle activities of upper extremities during a drinking task between the stroke-affected and less-affected sides. [Subjects] Eight stroke patients (8 men; age 45.3 years; stroke duration 21.9 months) participated in this study. [Methods] Electromyography (EMG) was used to measure nine muscle activities of the upper extremity. The drinking task was divided into 5 phases. [Results] Analysis of the EMG data showed that the percentage of maximum voluntary isometric contraction (%MVIC) across all phases of drinking differed between the affected and less-affected sides. Participants used relatively higher levels of %MVIC in the anterior deltoid, flexor muscles, brachioradialis, and infraspinatus on the stoke-affected side. [Conclusion] The difference in muscle activation across all phases of the drinking movement allowed us to determine how upper extremity muscle activation may influence drinking performance on the stroke-affected and less-affected sides.