Mum had 1 fitted whilst living alone. She had 1 on the wrist, however: when she draped the Tea-towels over her arm on the way to hanging them on the line, she would set off the alarm
. Also the phone was on a table, instead of on the floor which is where she finished up after a fall. So was unable to reach the phone to call for help as the wrist alarm was by the bed!
Have a lookC at AgeUK, there is a charge and would your parents be able to have 1 without paying anything? I don't understand the charging systems between the various companies.
My Mum had a mobile but didn't really understand it and of course, it would probably be put somewhere that again, she couldn't access it!
Social services may be able to give advice too. I know that some have a 'dedicated person' who the contact centre will get in touch with so someone who is able, with a car and living close by might be wise.
Let us know how you get on.