1.4 Ensure that operation requires minimal strength, grip and wrist twisting
Using the terminal may require a number of physical operations - pressing buttons or keys, turning knobs or other moving parts, inputting cards or other items and retrieving cards, tickets or other outputs. All these operations should be possible with minimal grip, pushing and pulling strength or twisting of the wrist.
Many, particularly older, users have greatly reduced strength due to degenerative conditions that affect muscle power or restrict movements of the joints in the fingers, hands and wrists. Most operations on a terminal require finger or hand movements. If the controls are too stiff, the slots too narrow or the machine's grip on items too tight, some users may not have the strength to overcome this and will be unable to use the terminal.
Directions and Techniques
Favour pressing, but with modest force
As far as possible, avoid using controls that have to be gripped and turned rather than pressed. Allow for a maximum pressing force of 5lbf.
Don't grip outputs too tightly
Ensure that the machine's grip on outputs such as money, tickets, receipts and returned cards is no more than is necessary to prevent them being pulled out by the wind or other environmental conditions.
Make tearing easy
If tickets are delivered using perforated paper rolls, make sure the perforations are easily broken by a tugging motion.
How you could check for this:
Test with real users
To test for this, you should have a prototype used in a realistic situation by real people, particularly older people.
About user testing