Throughout winter, more than at any other time year, grip is the issue that concerns us trail runners. Get it right and you can fly across wetlands, through the darkest bogs in the worst weather and up and down the steepest, slippiest hills, safe in the knowledge that your feet will go where you expect them to. Get it wrong, and you'll be reduced to a walk. And we're not Trail Walking magazine! That's why we've taken a look at these eight shoes. As ever, every terrain will have different requirements. Great grip in a Cambridge park is a different beast to the deep lugs you need for Pen y Fan in South Wales. Keep your preferred terrain in mind when reading this review by Paul Larkins and you won't go wrong.