How often during the day do you wear a counterforce brace for tennis elbow? and how many weeks should you wear it for?

Wrist splint: I find that a wrist splint actually works better than a counterforce brace for tennis elbow. The exception is when playing sports such as golf or tennis. A wrist splint works by reducing wrist extension and thus, tension on the common extensor tendon. Try wearing it for most of the day for 10-14 days for acute tennis elbow and then when doing exacerbating activities.