( Bones ( ( ( come together ) ( to ( form ( ( joints , ) ( ( most ( of which ) ) ( are ( in ( constant motion ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Bones)) (VP (VBP come) (ADVP (RB together)) (S (VP (TO to) (VP (VB form) (NP (NP (NNS joints)) (, ,) (SBAR (WHNP (JJS most) (WHPP (IN of) (WHNP (WDT which)))) (S (VP (VBP are) (PP (IN in) (NP (JJ constant) (NN motion))))))))))) (. .)))
Bones come together to form joints, most of which are in constant motion.
(ROOT (S (NP (NNS Joints)) (VP (VBP are) (NP (NP (DT the) (NN location)) (SBAR (WHADVP (WRB where)) (S (NP (NNS bones)) (VP (VBP come) (ADVP (RB together))))))) (. .)))
Joints are the location where bones come together.