The influence of the intervention time on the motor learning process induced through movement representation techniques: a randomized controlled pilot trial

Abstract

Objective: The main aim was to assess motor learning process comparing action observation (AO), motor imagery (MI), and double time of MI (2MI) at post- and at 1-week post-intervention through Purdue-Pegboard test. The secondary objectives were to assess if improvements enhanced the ability to imagine and the perceived fatigue.
 Methods: 20 healthy subjects were randomly assigned to AO group, MI group, 2MI group or placebo observation group.
 Results: Results in right hand test showed that AO group obtained improvements at post- and at 1-week post-intervention, both with a large effect size (p = .049, d = -1.28 and p = .049, d = -1.4). In left hand test MI group obtained better results than placebo group (p = .016, d = 2.21). In both hand test MI presented differences at the post- and at 1-week post-intervention (p = .006, d = -2.28 and p = .009, d = -1.89). No within- and between-group differences were found in sequence test. With respect to the perceived fatigue, both MI and 2MI showed greater levels of fatigue (p = .003, and p = .045). Finally, no within- and between-group differences were found in the ability to imagine (p > .05).
 Conclusions: Both movement representation techniques enhanced motor learning, although the results must be considered with caution due to the small sample size. MI seems to cause more fatigue than AO. However, increasing imagery time did not results in greater level of fatigue. The improvements did not lead to an increase in the ability to imagine.