The ‘leading’ wrist moves from radial deviation to a neutral position at impact. At this point, the momentum of the golf club is trying to force the ‘leading’ wrist into ulnar deviation. The ECU ...

"The forearm consists of two bones: the radius and the ulnar," explains ... If it's too low, it can require unnecessary wrist flexion and ulnar deviation," which can make ulnar sided wrist pain ...

ECU instability results from disruption or dysfunction of its subsheath, and there is particular risk of injury when the wrist moves from pronation to supination (fixed in flexion and ulnar deviation) ...