1. Investigación

We present a neurophysiological hypothesis for the role of motor imagery (MI) and action observation (AO) training in the motor learning process. The e ects of movement representation in the brain and those of the cortical–subcortical networks related to planning, executing, adjusting, and automating real movements share a similar neurophysiological activity. Coupled with the influence of certain variables related to the movement representation process, this neurophysiological activity is a key component of the present hypothesis. These variables can be classified into four domains: physical, cognitive–evaluative, motivational–emotional, and direct-modulation. The neurophysiological activity underlying the creation and consolidation of mnemonic representations of motor gestures as a prerequisite to motor learning might di er between AO and MI. Together with variations in cognitive loads, these di erences might explain the di ering results in motor learning. The mirror neuron system appears to function more e ciently through AO training than MI, and AO is less demanding in terms of cognitive load than MI. AO might be less susceptible to the influence of variables related to movement representation.

The present work is the first study that assess long run change after motor learning. The study’s main objective was to evaluate the short to medium-term impact of motor imagery (MI) and action observation (AO) on motor learning of a sequence of thumb-opposition tasks of increasing complexity. We randomly assigned 45 participants to an AO, MI, or placebo observation (PO) group. A sequence of 12 thumb-opposition tasks was taught for 3 consecutive days (4 per day). The primary outcome was accuracy. The secondary outcomes were required time and perfect positioning. The outcomes were assessed immediately after the intervention and at 1 week, 1 month and 4 months postintervention. Regarding the primary outcome, AO group had significantly higher accuracy than the MI or PO group until at least 4 months (p < 0.01, d > 0.80). However, in the bimanual positions, AO was not superior to MI at 1 week postintervention. Regarding secondary outcomes, AO group required less time than the MI group to remember and perform the left-hand and both-hand gestures, with a large effect size (p < 0.01, d > 0.80). In terms of percentage of perfect positions, AO group achieved significantly better results than the MI group until at least 4 months after the intervention in the unimanual gestures (p < 0.01, d > 0.80) and up to 1 month postintervention in the bimanual gestures (p = 0.012, d = 1.29). AO training resulted in greater and longer term motor learning than MI and placebo intervention. If the goal is to learn some motor skills for whatever reason (e.g., following surgery or immobilization.), AO training should be considered clinically.

Objective. The main objective of this trial was to assess whether action observation (AO) training and motor imagery (MI) produced changes in the cervical joint position sense (CJPS) both at the end of the intervention and 10 min postintervention compared with a placebo intervention in patients with nonspecific chronic neck pain (NSCNP). Methods. A single-blind placebo clinical trial was designed. A total of 30 patients with NSCNP were randomly assigned to the AO group, MI group or placebo observation (PO) group. CJPS in flexion, extension and rotation movements in both planes were the main variables. Results. The results obtained in the vertical plane showed that the AO group obtained greater impr ovements than the PO group in the CJPS in terms of cervical extension movement both at the end of the intervention and 10 min postintervention (p = .001, d = 1.81 and p = .004, d = 1.74, respectively), and also in cervical flexion movement, although only at 10 min after the intervention (p = .035, d = 0.72). In addition, the AO group obtained greater improvements than the MI group in the CJPS only at the end of the intervention in cervical extension movement (p = .041, d = 1.17). Regarding the left rotation cervical movement, both the MI and AO groups were superior to the PO group in both planes at the end of the intervention (p < .05, d > 0.80). Conclusions. Although both AO and MI could be a useful strategy for CJPS improvement, the AO group showed the strongest results. The therapeutic potential of the application of mental practice in a clinical context in the early stages of rehabilitation of NSCNP should be considered.

The aim of the present study was to explore the pain modulation effects of motor imagery(MI) and action observation (AO) of specific neck therapeutic exercises both locally, in the cervicalregion, and remotely. A single-blind, placebo clinical trial was designed. A total of 30 patients withchronic neck pain (CNP) were randomly assigned to an AO group, MI group, or placebo observation(PO) group. Pain pressure thresholds (PPTs) of C2/C3, trapezius muscles, and epicondyle werethe main outcome variables. Secondary outcomes included heart rate measurement. Statistically significant differences were observed in PPTs of the cervical region in the AO and MI groups betweenthe preintervention and first postintervention assessment. Significant differences were found inthe AO group in the epicondyle between the preintervention, first and second post-intervention assessments. Regarding heart rate response, differences were found in the AO and MI groups betweenthe preintervention and average intervention measurements. AO and MI induce immediate painmodulation in the cervical region and AO also induces remote hypoalgesia. OA appears to lead togreater pain modulation as well as a greater heart rate response, however, both should be clinicallyconsidered in patients with CNP.