Finger force changes in the absence of visual feedback in patients with Parkinson’s disease

•Patients with Parkinson’s disease (PD) show an accelerated drop in total force in accurate two-finger force production tasks performed without visual feedback.•Sharing of the total force between the two fingers drifts towards a 50:50 pattern without a difference between the PD patients and control subjects.•The accelerated force drop in PD may reflect adaptive changes to the documented loss of action stability.