Depending on what I'm wearing there can be a gap along my leg where a tick could crawl up without making much (or any) contact with my running shorts. Ticks generally climb onto their hosts from low grasses and small shrubs that you brush up against while walking (or sit on) so unless you are wearing pants and tucking them in I would think that there is always some risk of a tick getting over your shoes & sock line. This is all just my own opinion though - HYOH!