Dyad Practice Does Not Enhance Proprioceptive Learning

Skill acquisition is associated with concurrent gains in motor and proprioceptive performance. Dyad practice—two learners alternating between physical and observational practice—can enhance motor learning, but its effects on proprioceptive learning remain unclear. Forty-two healthy participants (18–35 years) were randomized into three groups: dyad practice, physical practice with rest (PP-rest), and physical practice without rest (PP-no rest). Participants practiced a wrist movement task for 20 min using a wrist-robotic device. Outcome measures were a kinematic-based Motor Performance Score reflecting motor performance, and the wrist position sense Just-Noticeable-Difference threshold and Uncertainty as measures of proprioceptive acuity. Dyads had higher Motor Performance Score than both PP groups at the end of training ( p  < .001) and at retention ( p  = .02). Improved Just-Noticeable-Difference thresholds were only observed in the PP-no rest group at retention ( p  = .03). No significant differences in Uncertainty were found. Changes in Motor Performance Score and Just-Noticeable-Difference or Uncertainty were not significantly correlated ( p  > .05). Dyad practice yielded superior gains in motor performance, but no comparable gains in proprioceptive acuity. Possibly, the recruitment of explicit motor learning mechanisms during dyad motor skill practice does not enhance the implicit learning mechanisms underlying proprioceptive learning.