Q Can you explain why I seem to suffer from pins and needles in my left foot when I’m out for run? It can strike at any time, and if I continue running my whole foot goes numb. But as soon as I stop, the problem disappears.

A Pins and needles, or parasthesia, has a variety of causes. The most obvious cause is having your shoes laced too tightly – or wearing a sock liner or even sock that’s too snug – as this can restrict the circulation in your feet. Along similar lines, you might find that you’re one of those people with naturally poor circulation – so extremities such as your feet can suffer.

Parasthesia can also be caused by a ‘trapped’ or restricted nerve in the foot. In turn this might be connected to a minor biomechanical imbalance in the foot, in which case you’ll need it fully assessed by a qualified podiatrist.

There are some first-aid measures you can try before seeing a podiatrist. Make sure that you stretch your calf muscles diligently with your knee both flexed and fully extended while leaning against a wall. Also try standing on the edge of the stairs and raising and lowering your heels slowly to enhance the stretch. You may also find that hamstring stretches help ease the problem.

—Simon Costain, podiatric consultant