Effects of motor imagery combined with action observation training on the lateral specificity of muscle strength in healthy subjects

Abstract

Unilateral training of both lateral limbs increases unilateral muscle strength, whereas bilateral training increases bilateral muscle strength, a phenomenon known as lateral specificity in resistance training. Although motor imagery (MI) combined with action observation (AO) (i.e., MI + AO) training increases muscle strength, it is not completely understood whether such training increases the lateral specificity of muscle strength in a way resistance training does. To investigate whether MI + AO induces lateral specificity of muscle strength increase, 18 healthy subjects were divided into groups: MI + AO and the control groups. The control group watched a movie of natural sceneries for ten minutes per day five times a week for three weeks, whereas the MI + AO group imagined bilateral shoulder flexion while watching a movie of athletes performing bilateral shoulder flexion with barbells or dumbbells, with the same time schedule. The MI + AO group alone showed a significant increase in bilateral shoulder strength at three weeks after the intervention compared with the baseline. Unilateral shoulder strength was not significantly altered. These results suggest that MI + AO training increases muscle strength, providing evidence that similar to resistance training, lateral specificity also exists in MI + AO training.

Effectiveness of a Remote Monitoring-Based Home Training System for Preventing Frailty in Older Adults in Japan: A Preliminary Randomized Controlled Trial

“…The first is the potential impact of the imagery effect from watching the videos in the SUKUBARA ® exercise protocol. In a previous study involving young participants, watching videos of high-intensity resistance exercises led to increased muscle strength in the specific muscle groups even without performing the actual exercises [28]. This phenomenon has been attributed to the effects of both motor imagery and action observation (observational learning).…”

The effects of combined action observation and motor imagery on corticospinal excitability and movement outcomes: Two meta-analyses

“…Studies have delivered AOMI interventions over short- (e.g., Bek et al, 2019) and longer-term (e.g., Shimada et al, 2019) periods when investigating their effects on movement outcomes. Meta regression analysis was used in the Movement meta-analysis to assess the relationship between intervention volume (total minutes) and the effects of AOMI on movement outcomes.…”

“…This research has been conducted in sport (e.g., Romano-Smith et al, 2019) and rehabilitation (e.g., Scott et al, 2018) contexts, with neurotypical (e.g., Di Rienzo et al, 2019) and neurodivergent (e.g., Marshall et al, 2020) populations. The existing literature has almost exclusively demonstrated that movement outcomes are improved for different motor skills after AOMI interventions when compared to control conditions (e.g., Marshall et al, 2019; Romano-Smith et al, 2018; Shimada et al, 2019). However, comparisons with AO and MI interventions are equivocal, with some studies showing greater improvements in movement outcomes for AOMI compared to AO (e.g.…”

Enhancing motor imagery practice using synchronous action observation

“…AO + MI instructions have further been used to successfully counteract a pain-induced reduction in cortico-motor excitability (Larsen et al, 2019;see Suso-Martí et al, 2020), while AO + MI treatment has also been recommended for reducing adverse effects on the motor system following immobilisation-induced hypoactivity (Monany et al, 2022). Positive results of AO + MI treatment have additionally been obtained in muscular rehabilitation following hip replacement (Marusic et al, 2018; for related studies on strength training with healthy participants, see Shimada et al, 2019;di Rienzo et al, 2019). Finally, there is evidence of the potential benefits of using AO + MI instructions in brain-computer interface paradigms (e.g.…”