Fig. 2

Three tasks in the experiment. a Tapping task: large button task—button diameter of 9.0 mm, small button task—3.0 mm. b Moving task: ad–abduction task—orientation between a and c, flexion–extension task—b and d. c Circling task: clockwise task—direction a–b–c– d, counter-clockwise task: a–d–c–b