**4.7 Height adjustable arm rests**

The armrests are designed to be automatically adjustable up or down using a button input placed on the left arm rest of the wheelchair. The arm rests are actuated by telescoping arms that are placed in the tube of the wheelchair frame such that when they are activated, they protrude upwards, lifting the armrests to a desired height. Spiral lift telescoping arms are used for their ability to withstand the high the load exerted while projected at any height. These consist of threaded vertical profiles that move up or down inside a threaded cylinder bands that form a column. The bands are combined, separated and stored by an assembly with an electrical motor located at the base of the column and this is connected to the control unit while receiving input from the button pad on the arm rest. The desired height is determined by the duration on pressing the up/down button and on releasing the button, the armrest remain at their current height. They move simultaneously at a low constant speed that is safe for the user. When the user is in standing posture, the armrests automatically rise up for the sake of support and stability purposes.
