Handle size as a task constraint in spoon-use movement in patients with Parkinson's disease

To examine the effect of spoon-handle size on kinematic performance in people with Parkinson's disease.

A counterbalanced repeated-measures design.

A motor control laboratory in a university setting.

Eighteen individuals with Parkinson's disease and 18 age-matched controls. EXPERIMENTAL CONDITIONS: Each participant was instructed to scoop water (simulated soup) using spoons with three different-sized handles.

Kinematic variables (movement time, peak velocity and number of movement units) of arm movement, size of hand aperture and number of fingers to grasp the spoon.

The movement of the participants with Parkinson's disease was faster (shorter movement time) and smoother (fewer movement units) when they used spoons with a small- or medium-sized handle than when using a spoon with a large-sized handle. In contrast, the healthy controls showed no significant differences in movement kinematics between handle sizes. Moreover, the participants with Parkinson's disease had a significantly smaller hand aperture and used more fingers to hold the spoons than the controls did.

These results suggest that, for people with Parkinson's disease, a small-to-medium-sized handle is more suitable than a large-sized built-up handle.