"I'm concerned about liability issues" - what kind of liability are you asking about: moral, or legal?

IMO, morally you should give the best advice you can (or, failing that, none): which will sometimes be 'see a doctor', and sometimes something else.

Given the question it would be a bit of a joke to be asking the community for legal advice, wouldn't it.

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More recently, https://bicycles.stackexchange.com/q/9969/1097 seemed to me too close to being a question which wanted a serious medical answer.