Hi, Thanks for writing in. The hand and wrist is supplied by radial and ulnar nerves which originate from nerves in the neck. There are possibilities of the nerves supplying your hand getting pinched some where in their path causing pain and distress. If you never had a fracture then there is no significant injury to bones. However the injury to nerves cannot be ruled out without proper clinical examination. Also when doing a twisting action, there is complex movement at the wrist joint and that can cause pain because of ligaments getting stretched. It is best you see a neurologist and then check with your physiotherapist. Seeing a neurologist is more important because the tip of your thumb remains numb even after 4 weeks. A test like electromyography and nerve muscle conduction might be required after clinical assessment.