Where would we be these days without our smartphones? While they are undoubtedly useful, did you know that using them to excess can actually cause a telltale physical sign? Here’s all you need to know about ‘smartphone finger’ – and what you can do about it if you’ve got itWhere would we be these days without our smartphones? While they are undoubtedly useful, did you know that using them to excess can actually cause a telltale physical sign? Here’s all you need to know about ‘smartphone finger’ – and what you can do about it if you’ve got it