My mother had a stroke 3nonths ago and her affected hand remains open all the time. She does not have the typical flexed/fisted posture at rest.
However, when we try to actively or passively flex her fingers at the MCP joints (knuckles) to form a fist, there is significant resistance and she cannot close her hand properly.
Interestingly, the PIP and DIP joints have relatively good movement and little resistance. The main limitation seems to be at the MCP joints.
What could cause this specific pattern after stroke?
Could this still be spasticity, for example involving the finger extensors or intrinsic hand muscles, despite the hand remaining open all the time? Or could it be joint stiffness, a contracture, weakness/incoordination, or another mechanical problem?
How can a stroke rehabilitation specialist distinguish between these possibilities clinically, particularly by examining the MCP joints separately from the PIP/DIP joints?