dont worry about the digging mines been bad for ages now,when im working its fine as i can be carefull but as spade says the b*****d sneaks up on you,just bending down, turning,or any normal day to day jobs can set it off, i was told that a belt could make it worse as it is supporting it therefore making it weak but i suppose its up to the individual,basically its knackered and there is nothing that can be done (sorry)