For whatever it’s worth, my father is a very good drummer and when playing from an overhand grip his wrist movement is a totally linear dart-thrower movement, coupled with some forearm rotation and a subtle action of the fingers which assists in controlling the rebound.
Edit: I’m also willing to bet that the action of throwing a dart smoothly is the motion that the researchers decided to call the dart-thrower motion, which is linear.
I thought the DTM traced a shallow ellipse?
No, dart-thrower is radial extension to ulnar flexion. Something like 10:30 to 4:30 on the clock face.
The path is defined by the antagonist group extensor carpi radialis brevis + longus and flexor carpi ulnaris.
The muscles of the wrist have secondary function in forearm rotation, so some subtle rotation may occur during this motion path, but the wrist motion is essentially linear.
The wrist paths which are curved (DBX movements) come from coordinated use of the two antagonist groups of the wrist, being the group mentioned above and the reverse dart thrower group, extensor carpi ulnaris and flexor carpi radialis.
Sorry, yes I realized i was conflating DTM and Reverse DTM here.
I was thinking specifically of the feeling of drum rolls and double stroke on maracas. I can’t check it right because my wrists on break, but im thinking it’s reverse dart thrower with some rotation.