Effects of Motor Imagery and Action Observation on Electromyographic Activity and Intramuscular Oxygenation in the Hand Gripping Gesture

Universidad Autonoma de Madrid

Status: Completed

Conditions: Asymptomatic Subjects; Painfree Voluntiers; Neuroscience

Treatments: Other: Mental Practise

Study type: Interventional

Funder types: Other

Identifiers

NCT03324217

uamadrid 3

Details and patient eligibility

About

Motor imagery is defined as a dynamic mental process of an action, without its real motor execution. Action observation training consists of watching an action performed by someone else. The primary objective of this study was to evaluate the effects of motor imagery and action observation combined with a hand grip strength program on strength gains in asymptomatic participants. The secondary objective was to assess the influence of motor imagery and action observation training combined with a hand grip strength program on electromyographic activity and intramuscular oxygenation of the forearm muscles.

Full description

Motor imagery is defined as a dynamic mental process of an action, without its real motor execution. Action observation training consists of watching an action performed by someone else. Both motor imagery and action observation have been shown to produce a neurophysiological activation of the brain areas related to the planning and execution of voluntary movement in a manner that resembles how the action is performed in reality.

Several studies have shown that patients can report a significant improvement in strength with motor imagery training. There is also evidence regarding the improvements in motor skills in participants who perform motor imagery training combined with mirror therapy. Motor imagery is recognized as one of the most popular and effective forms of training to improve learning strategies and to increase the capacity to perfect sports movements, as has been observed in rhythmic gymnastics athletes.

In addition to the previously mentioned adaptations, a recent research proved that motor imagery and action observation provoke an activation of the sympathetic-excitatory nervous system. Changes in respiration, heart rate and skin temperature are produced, as well as an increase in electrodermal activity.

Both motor imagery and action observation are interventions that can generate adaptive neuroplastic changes on a cortical level, leading to a decrease in chronic pain. These rehabilitation techniques are used in pain treatment and impaired movement injuries that could be due to a nervous system alteration.

Action observation effectively facilitates motor learning, and is a tool for rehabilitation in neurological and musculoskeletal diseases. Action observation training leads to significant improvements in static balance and helps improve gait in patients with hemiparesis after an ictus.

A recent study showed that the patient's functionality loss is lessened if motor imagery and action observation are applied after an immobilization process, reducing the loss of wrist mobility, strength and muscle mass.

The effectiveness of motor imagery is controversial; several studies have presented unfavorable outcomes from this technique. Some variables, such as the duration of the sessions, the time employed the type of motor task or the number of sessions can influence the outcomes of these studies. Thus, it is necessary to clarify the controversial aspects of motor imagery, which lead us to perform this study.

This study evaluates variables that have not yet shown conclusive results: intramuscular oxygenation and electromyography. Focusing principally on the effectiveness of the treatment and the adaptations that are generated on an intramuscular level leads to a better understanding of what occurs as a result of training with motor imagery and action observation, and also whether these variables influence the effectiveness of the treatment.

Therefore, the primary objective of this study was to evaluate the effects of motor imagery and action observation combined with a hand grip strength program on strength gains in asymptomatic participants. The secondary objective was to assess the influence of motor imagery and action observation training combined with a hand grip strength program on electromyographic activity and intramuscular oxygenation of the forearm muscles.

Enrollment: 60 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• asymptomatic participants;
• men and women aged 18 to 65 years.

Exclusion criteria

• participants who had any knowledge of physical therapy;
• underage participants;
• participants with pain at the time of the study;
• participants with any type of neurological disease.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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60 participants in 3 patient groups

Motor Imagery Group

Experimental group

Description:

The participants in the motor imagery group were given instructions to perform a daily training composed of two sets of activities. The main set consisted of 10 isometric hand grip contractions for 3 seconds each with a tennis ball, leaving a 20-second break between contractions. In the first set, the participant only had to imagine that he was performing that task, placed in the standard position with the tennis ball in the hand. Once the first set was completed, the participant had to take a 2-minute break before starting the second set, in which they had to complete the set both imagining and actively performing the isometric contractions with the tennis ball.

Treatment:

Other: Mental Practise

Action Observation Group

Experimental group

Description:

The participants in the action observation group were given instructions to perform a daily training comprised of two sets of activities. The main set consisted of 10 isometric hand grip contractions for 3 seconds each with a tennis ball, leaving a 20-second break between contractions. In the first set, the participant simply watched a video that showed a forearm performing the task, placed in the standard position and with the tennis ball in the hand. Once that first set was completed, the participant took a 2-minute break before starting the second set, in which they performed the 10 isometric contractions with the tennis ball while they watched the video.

Treatment:

Other: Mental Practise

Control Group

Active Comparator group

Description:

The participants in the control group were given instructions to perform a daily training of a single set. The set consisted of 10 isometric hand grip contractions for 3 seconds each with a tennis ball, leaving a 20-second break between contractions.

Treatment:

Other: Mental Practise