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Calkins, Cori

University of British Columbia

Motor imagery training (MIT) is the mental rehearsal of a motor task with no overt movement. Improvements in force steadiness (FS) are related to adaptations in neural excitability, and in older adults FS is related to functional performance. Age-related decline in functional ability is greater in females compared to males. Purpose: To determine if one session of MIT influences corticospinal excitability and improves FS of isometric elbow flexion contractions in young and older female adults. Hypotheses: MIT would increase corticospinal excitability and improve isometric elbow flexion FS, and the enhancement would be greater in older females compared to young females Methods: Young (19-35 years old) and older (65-90 years old) participants were randomly assigned to a MIT group or control group that were tested in a similar block fashion. Participants performed isometric elbow flexion contractions at 10% maximal voluntary contraction prior to and following MIT (training group) or no training (control group; viewed documentary for similar time). Elbow flexion contractions were performed in blocks 1,3 and 5. M¬IT or documentary viewing was performed in blocks 2 and 4. Motor evoked potentials (MEP) elicited by transcranial magnetic stimulation were collected within the last five seconds of each submaximal contraction. Results: 13 older (n=7 MIT) and 22 young participants (n=11 MIT) completed the study. The MIT group had a higher CV of force than the control group in block one (p=0.02), and FS improved in the older group with MIT in block three (p=0.008). There were no significant findings for MEPs (p>0.05). For visual (p=0.05) and global (p=0.04) motor imagery ratings from the MIT blocks, young had higher motor imagery ratings than older females. There was a significant negative relationship in older females between global (r=-0.715, r²=0.5, p=0.035) and visual (r=-0.773, r²=0.60, p=0.021) motor imagery ratings from block 2 and CV of force in block 3, suggesting a higher global and visual motor imagery score was associated with increased ability to produce steady contraction in older females. Conclusion: Older females have the ability to undertake MIT and improves FS.

Text

2024-01-02

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87036

Health and Exercise Sciences

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/