Influence of Circadian Rhythms on the Temporal Features of Motor Imagery for Older Adult Inpatients
Résumé
Objective
To examine the circadian modulation on motor imagery quality for older adult inpatients to determine the best time of day to use motor imagery in rehabilitation activities.
Design
Time series posttest only.
Setting
Inpatient rehabilitation center.
Participants
Participants included older adult inpatients (N=34) who were hospitalized for diverse geriatric or neurogeriatric reasons. They were able to sit without assistance, manipulate objects, and walk 10m in <30 seconds without technical help or with a walking stick.
Intervention
None.
Main Outcome Measures
The executed and imagined durations of writing and walking movements were recorded 7 times a day (9:15 am–4:45 pm), at times compatible with the hours of rehabilitation activities. Motor imagery quality was evaluated by computing the isochrony index (ie, absolute difference between the average duration of executed and imagined actions) for each trial and each inpatient. The cosinor method was used to analyze the time series for circadian rhythmicity.
Results
Imagined movements duration and isochrony index exhibited circadian modulations, whereas no such rhythmic changes appeared for executed movements. Motor imagery quality was better late in the morning, at approximately 10:18 am and 12:10 pm for writing and walking, respectively.
Conclusions
Cognitive and sensorimotor aspects of motor behaviors differed among the older adults. The temporal features of motor imagery showed a clear circadian variation. From a practical perspective, this study offers information on an effective schedule for motor imagery in rehabilitation activities with older adult inpatients.