A cup half full: exploring the kinematic consequences of variations in the drinking task protocol

Kinematic assessment of the drinking task offers objective metrics of upper limb recovery following neurological injury. The rehabilitation research community's increased interest has led to consensus standardization efforts. These efforts inherently depend on fidelity of the activity protocol underlying drinking task kinematics. This study's objective is to investigate whether differences in the drinking task protocol, as observed in prior literature, impact common kinematic metrics.

Incomplete block design with repeated-measures.

Six neurotypical participants.

Seating position, cup start position, and target definition for cup return were varied. Mixed effects linear models analysed the impact of protocol variants on validated kinematic metrics used in stroke rehabilitation research.

All considered factors have a significant impact on at least 1 kinematic metric. Seating position impacts movement time (p  =  0.035) and trunk displacement (p = 0.017), cup starting position impacts trunk displacement (p = 0.001), and target definition impacts movement time (p = 0.036). Of note, none of the factors significantly altered the number of movement units.

Further refinement and adherence to a standardized protocol for the drinking task activity may reduce between-study effects and promote the successful uptake of upper limb kinematic assessment in the rehabilitation research community.