Pitfalls of external movement

I include some injury statistics here from NIH: The new online course "Martial Origins of Tai Chi" (Classical Tai Chi at Teachable.com)

discusses how virulent "pitfalls of external" the injuries in external martial arts are. Participants Ike Schultz and yours truly both studied Karate, Tae Kwon Do to Black Belt level and saw first hand how external movement in Kata, sparring exercises, etc. would cause injury because of "snapping" movements and "stopping" or it is called "pulling" the punch or kick whereas Classical Tai Chi moves slowly but teaches to punch or kick "all the way through" with no gaps, stops or snaps in the energy. The NIH reports on how many injuries in martial arts like Karate as well as their most likely commonality:
"The hand/wrist was the most common area injured (53%), followed by the shoulder/upper arm (27%) and the forearm/elbow (19%). Joint sprains/muscle strains were the most frequent injuries reported overall (47%), followed by abrasions/bruises (26%). ... Injuries may result in chronic upper extremity symptoms."