BackgroundRecent work on mental practice using motor imagery (MI) in the treatment of post-stroke motor impairments. AimTo provide evidence regarding effects of MI on hemiplegic intrinsic hand muscles. ObjectivesExperiment one‟s objective was to identify if kinaesthetic MI (KMI) activated the hemiplegic lumbrical muscles and reduced overall movement time (MT). Experiment two‟s objective was to identify if KMI and visual motor imagery (VMI) had different effects on lumbrical activity and MT. Experiment three‟s objective was to establish if VMI or KMI provoked electromyogram (EMG) activity in the hemiplegic or intact abductor pollicis brevis (APB).
Design/methodologyExperiment one used optoelectronic motion capture in a single factor independent groups design. Dependent variables (DVs) included joint magnitude, velocity and MT. Experiment two employed optoelectronic capture in a between-within design. DVs included interjoint correlation, joint magnitude and MT. Experiment three used a between-within design, measuring EMG in APB and abductor digiti minimi (ADM). DVs were EMG levels in different conditions. ParticipantsExperiment one involved ten adults with hemiplegia. (Mage= 74.4, SDage= 10.3). Five were male.Experiment two involved 15 adults with hemiplegia (Mage= 60.6, SDage= 12.9). Six were male. Experiment three involved ten adults with hemiplegia (Mage= 59.8, SDage= 10.57). Five were male. It also included ten non-hemiplegic adults (Mage= 59.8, SDage= 9.09). Six were male. All were Colombian.
ResultsIn experiment one MT was shorter for KMI (p= .031). Experiment two also showed shorter MT for KMI (p= .022) and significant negative correlation between two finger joints for VMI (p= .01), suggesting improved lumbrical activation. ivExperiment three found lower EMG in the hemiplegic APB following KMI (p= 0.019), compared with rest.ConclusionsKMI is more effective in reducing MT and pathologically raised EMG. VMI may improve interjoint coordination.