For over a quarter century, I have taught wrist grab breaks
As I've mentioned before, I lead psychiatric intervention teams at events like concerts and street festivals (see Shaolin Trips Ep 1 if you didn't already know this). Part of my job is to present in-services to medical and security responders. It's basic self defense methods for people who don't practice martial arts - simple skills, mostly break-and-run methods - extracted and modified from various programs used in emergency medicine, enforcement and corrections. I almost always begin with methods to break a wrist grab. It's the easiest one, and it demonstrates how by nullifying the thumb, most grabs can be broken. I've dealt with all sorts of assaults in the field but no one has ever grabbed my wrist. Not ever. I really wish someone would because I have dozens of well-practiced counters at my fingertips. But no, it's primarily an academic pursuit. That being said, I still teach these, because it's a good stepping stone in learning more useful practical techniques. There's a pedagogical logic to beginning with wrist grabs. However, in my experience, they just don't happen in the real world.
The leg jam is a totally different issue. If someone jams your leg, they have some fighting knowledge as it's not a natural emotional response to a street fight. With a trained fighter, everything changes.
