The i-LIMB Hand is controlled through the use of myoelectric signals, which uses the muscle signals in the patient's residual arm to move the i-LIMB Hand around. Electrodes are placed at two pre-determined muscle sites. The electrodes pick up the muscle signals when the patient contracts his/her muscles. These signals are then sent to a microprocessor which causes the device to move. The i-LIMB Hand has up to four different muscle triggers. The user is able to assign a grip to move the device to a certain position. These muscle triggers include:
1.`hold open’; This option uses the open signal for a certain amount of time.
2.`double impulse’; This option uses two quick open signals once the hand is opened completely.
3.`triple impulse’ This option uses three quick open signals once the hand is opened completely.
4.`co-contraction’ This allows the device to contract the open and close muscles at the same time.