24 lines (19 with data), 704 Bytes

AnyFolder Jnts = {
  
  AnyUniversalJoint MCP = 
  { Axis1 = y;
    Axis2 = z;
    AnyRefNode &GroundNode = ..GlobalRef.Metacarpal;
    AnyRefNode &ProximalNode = ..Segs.Proximal_Phalanx.MCP_JT_Node;
  };// MCP joint
  
  AnyRevoluteJoint PIP = {
    Axis = z;
    AnyRefNode &ProximalNode = ..Segs.Proximal_Phalanx.PIP_JT_Node;
    AnyRefNode &MiddleNode = ..Segs.Middle_Phalanx.PIP_JT_Node;
  }; // PIP joint
  
  AnyRevoluteJoint DIP = {
    Axis = z;
    AnyRefNode &MiddleNode = ..Segs.Middle_Phalanx.DIP_JT_Node;
    AnyRefNode &DistalNode = ..Segs.Distal_Phalanx.DIP_JT_Node;
  }; // DIP joint
  
}; // Jnts folder

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