I noticed that mass centre of middle finger (midfinger) is exactly in the same place as mass centre of matercarpal bone ( metacarpal3) and middle finger cannot moved properly. For index finger, mass centre of (Iphalanx1 )and matercarpal bone (metacarpal2) are in different places.
I enclose picture with mass centre for index finger and middle finger:
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Is it bug in wrist model or my misunderstanding? How should I model joint for middle finger?