Training of this concept should include:

Practice grasp and release using various size/shaped objects.

Allowing some fingers to wrap under/around objects.

• Start seated at a table with objects directly in front of the user. Practice simple unilateral grasp and release tasks first, with relatively large objects i.e cones, cups, balls.
• Focus on bringing the i-Digits towards the objects, avoiding any compensatory movements of the elbow, shoulder, back etc. The user may need to adjust their wrist and the thumb position to grasp certain objects effectively without compensating.
• Practice approaching the object from different angles i.e. from the side, from above.
• Practice moving the objects away from the body, to different heights and positions in space, without sending any unexpected signals i.e. reaching to a cabinet or reaching down to the floor.
• Introduce smaller objects as the users' technique develops.

When practicing activities such as carrying heavier objects, pay attention to where the weight is loaded on the i-Digits prosthesis. The weight should be carried between the base of the fingers and the palm of the hand. When lifting heavier objects remember to relax the muscles.

Auto-grasp feature enables the digits to reclose around an object if a quick / accidental open signal is given when the object is being held. This can be turned on/off within global settings of Biosim App.

It is helpful to be aware of accidental signals during initial training by monitoring the myo-graph signals to see when it occurs and encouraging user to fully relax their muscles while holding objects.

The open/closing action occurs in many varying activities of daily life. It is important for the user to have a firm understanding of correct grasp and release, and consistent and predictable control from their muscles.

An appropriate training drill would require the thumb to be repositioned between picking up each object. Examples of objects for varying thumb positions are as follows;

• Lateral - flat objects such as a playing card or plate.
• Cylindrical - handled objects such as a toothbrush or broom.
• Palmar Opposition - larger objects requiring gross grasp such as cup or bottle.
• Pinch / Tripod - smaller objects requiring precision such as toy building blocks or sweets.

For pinch grip the thumb should be aligned with the index finger.

For tripod grip the thumb should be aligned between the index and middle fingers.

Achieving the correct position of the thumb for the required task is applicable throughout the majority of day to day activities.

Becoming familiar with moving the thumb in the early training stages establishes a useful skill.

Vari-Grip can be switched off or the delay for it to start can be adjusted in the Biosim App.

Speed boost can be adjusted in Biosim and My i-Limb App.

Proportional control should be trained at an early stage.

The user can even develop this control during myo-training, before the prosthesis is fitted, by practicing gentle and strong signal strength and receiving visual feedback from the myo-graph or the virtual hand. Refer to myo-testing in resources section for further information on myo-testing and training.

Training Proportional Control

With the prosthesis fitted, training of slow and gentle motion can be conducted using soft objects which can compress. The user should avoid compressing or crushing the object.

Useful objects to practice with are stress balls, plastic/paper cups.

Explore moving the object around in space (up high, down low, stretched forward) avoiding accidental crushing of the object during motion.

Training Vari-Grip

The user can initially feel the additional force of Vari-Grip by holding the i-Digits prosthesis around their opposite forearm. The additional grip can be felt as it increases on each finger in turn, the user may also be able to hear the noise of each finger tightening.

Objects to practice repetitive drills with include; releasing tightly stacked training cones and opening bottles / jars / packets. Ensure sufficient force is applied to the grip to prevent the object slipping or turning.

The use of slow, gentle motion and strong secure grip during daily activities is extremely useful.

Slow gentle grip is useful to avoid crushing soft objects, such as during food preparation or shaking/holding hands with someone.

Activities which benefit from the additional force of Vari-Grip include;

• Opening packets / containers
• Tying shoelaces
• Dressing

• Practice applying the right amount of resistance to a finger to stop its motion.
• Practice initially with stalling the index finger open. This would be a useful position for typing, pressing buttons or pointing.

Other practical use of stalling fingers includes;

• Stalling the index, middle, ring, and small fingers to achieve the position for donning/doffing a shirt sleeve or jacket.
• Stall thumb to achieve lateral grip.

During day to day activities, stalling fingers can be quick and easy way to position the i-Digits prosthesis to complete a task.