THE EFFECT OF APPLYING MOTOR IMAGERY WITH ACTION OBSERVATION TO HIP MOTOR CONTROL TRAINING

T.-K. Cheng¹, Y.-F. Shih¹, L.-W. Chou¹

¹National Yang Ming Chiao Tung University, Physical Therapy and Assistive Technology, Taipei, Taiwan

Background: Training of hip motor control can enhance the lower extremity movement performance and prevent sports injuries.Motor imagery combined with action observation (AOMI) has been proved that it can improve motor control ability, and combined with physical training (PT) can lead to better movement performance. To understand the neurophysiological mechanisms behind the training effect, we used the Y-balance test (YBT) to assess the motor control ability and collected the activity of electroencephalography (EEG) and electromyography (EMG) during the YBT.

Purpose: The aim of the study is to compare the effect of AOMI, PT and AOMI-PT training on motor control in healthy people.

Methods: 34 healthy subjects were recruited and randomized into 3 groups (AOMI: 25.91±5.39, n=11; PT: 27.45±6.33, n=11; AOMI-PT: 29.33±5.16, n=12). We tested muscle strength of the hip abductors (Habd), hip adductors, hip extensors (Hext) and lower abdominal muscles, measured lower limb range of motion, and assessed the imagery ability and activity level using the psychometric scales. The subjects performed the YBT as the pre- and post-test, while EMG of hip and trunk muscles and EEG, which Cz channel represented the primary motor cortex (M1) activity of trunk and lower limbs, were collected. The standing clamshell exercise, sliding exercise and Romanian deadlift with AOMI, PT or AOMI-PT strategies were practiced as hip motor control training. YBT scores, EMG amplitude, relative power spectral density (rPSD) of EEG and corticomuscular coherence (CMC) were calculated, and one-way ANOVA was used to compare the immediate changes of the YBT and neurophysiological parameters between 3 groups with the α level at 0.05.

Results: The changes of YBT scores and EMG amplitudes of hip and trunk muscles showed no significant difference between 3 groups. Only the changes of β band rPSD in the anterior reaching of the YBT were significantly different between groups (AOMI: 1.14±4.41, PT: -2.82±2.64, AOMI-PT: -1.32±3.58, p=0.047). The changes of γ band CMC of Habd in the posterolateral reaching (AOMI: 0.0469±0.0767, PT: -0.0284±0.0449, AOMI-PT: -0.0165±0.0579, p=0.015) and β band CMC of Hext in the posteromedial reaching (AOMI: 0.0284±0.0405, PT: -0.0412±0.0826, AOMI-PT: 0.0314±0.0908, p=0.049) were significantly different between groups. In addition, we observed dominant β and γ band CMC between M1 and all muscles during the YBT.

Conclusions: The significant differences inβ band rPSD, β and γ band CMCchanges immediately after training indicated that the modulation of cortex activities and the functional connection between cortex and peripheral muscles were dependent on training strategies. However, these changes would not directly reflect the motor control ability.

Implications: AOMI has been used broadly in motor learning, sports training, and rehabilitation. Our findings showed that there were different neurophysiological mechanisms between different training strategies, and the longer-term training effects need further research to clarify.

Funding acknowledgements: This work was supported by the National Science and Technology Council, Taipei, Taiwan. [MOST 111-2410-H-A49-040]

Keywords:
Motor imagery
Action observation
Hip motor control

Topics:
Musculoskeletal: lower limb
Neurology

Did this work require ethics approval? Yes

Institution: Institutional Review Board of National Yang Ming Chiao Tung University

Committee: National Yang Ming Chiao Tung University

Ethics number: YM110027EF