I came across a very annoying problem this night. I have modeled a jacket for M4, grouped it and already made it to a conforming cloth. Most parts of it pose fine along with the model, only the sleeves give me headache because they are kind of "glued" to a spot and will only distort and split instead of moving. I first thought, that I could have missed some parts while grouping but from what I have checked so far, everything looks right there. I attach an image and would be really grateful for any help. (ignore the general pokethrough on the hand, will fix that later)

Check that the cuff of the sleeve is grouped with forearm, and that the joint inclusion zone for the wrist excludes all of the cuff.

If its too long for that and must move with the hand then check that part of the cuff is grouped to the hand , and the joint zone for the wrist includes it with the hand.

One or the other.

Thanks for the answer. I tried it both ways, grouped to the hand and in another try to the forearm with the same result. How can I check the joint inclusion zones? Sorry if that is a dump question, it's the first time I have created something with long sleeves and I have to learn a lot yet.

activate the joint editor (window, joint editor) and select a bodypart, then select in joint editor the bend direction. you will get two lines red and green that can be adjusted to include (green) or exclude(red) . If you used spherical zones then you get two circles.

You have propblem with joint zones, as Markschum wrote.

Solution here:

http://www.philc.net/joint_parameters_2.php