抄録
This report describes the relationship of eating utensils (chopsticks and spoon) and type of food (tofu and boiled egg) to the used muscles in eating action which were investigated by electromyogram.
The results were as follows;
1) In EMG patterns of eating action using chopsticks, co-activation of wrist extensor muscles were distinctive up to thumb flexor muscle. This co-movement of wrist extensor and flexor muscles acts on the fine control of pressure of chopsticks tips.
2) In EMG patterns of eating action using chopsticks, action potentials of thumb flexor muscle, wrist flexor and extensor muscles varied according to the process of the action using chopsticks. Thus these co-movements of muscles provide the skilled eating action, when picking up and carrying or when the type of food influences the eating action.
3) In EMG patterns of spooning, action potentials of thumb flexor and wrist extensor varied according to the process of spooning, and these co-movements of muscles provided the action of spooning. However action potentials were not influenced by the type of food.
4) As discussed above, eating action using chopsticks requires fine co-movement of fingers and arm muscles. Especially wrist extensor muscles play on important role in this co-movement.
So that, these facts would explain why hemiplegic patients whose wrist extensor muscles are weaker than the wrist flexor muscles have difficulty in using chopsticks.
