Effects of dual tasking on the postural performance of people with and without multiple sclerosis: a pilot study

Abstract

People with multiple sclerosis (MS) exhibit both cognitive and postural impairments. This study examined the effects of MS and of dual tasking on postural performance, and explored associations among dual-task postural performance, cognitive capacity, fear of falling, and fatigue. Thirteen subjects with MS (Expanded Disability Status Scale: 0-4.5) and 13 matched subjects without MS performed three tasks of standing postural control, with and without dual tasking amid an auditory Stroop task: (1) step initiation, (2) forward leaning to the limits of stability, and (3) postural responses to rotations of the support surface. Two-factor general linear models were used to evaluate differences between the groups (with or without MS) and two conditions (single or dual tasking) for each postural task. During step initiation, dual tasking significantly delayed the onset of the anticipatory postural adjustment (APA) more for the subjects with MS than for those without MS, and step lengths increased for the subjects with MS but decreased for those without MS. No other significant group-by-condition interactions were evident on the recorded variables of stepping, leaning, postural responses, or Stroop-response accuracies and latencies. The scores for the subjects with MS on the Modified Fatigue Impact Scale significantly associated with the change between single-task to dual-task conditions in APA onset and foot-lift onset during step initiation as well as in lean position variability and lean onset times during forward leaning. The results suggest dual-task effects were more evident during step initiation and are associated with levels of fatigue for subjects with MS.

Gait termination in individuals with multiple sclerosis

“…Indeed, GTST norm was nearly 25% higher in the cognitively distracting condition compared to baseline within the MS group. Previous literature has demonstrated increased impairment under cognitively distracting conditions on various gait tasks in persons with MS [20,34,35]. For instance, cognitive distractions have shown to delay anticipatory postural adjustments on a step initiation task in individuals with MS [35] as well as increase postural sway in persons with MS [36].…”

Feedforward postural control in individuals with multiple sclerosis during load release

“…At the same time research on anticipatory postural adjustments in individuals with MS is insufficient. While anticipatory activity was studied in MS in relation to gait [15,16], it is important to investigate feedforward postural control in standing. To this end, a first study investigating anticipatory EMGs and COP displacements in MS using rapid arm flexion and extension movements [17] showed that individuals with MS demonstrate poor postural preparation as compared to healthy controls.…”

Dual task training as a therapeutic strategy in neurologic physical therapy: a literature review

“…Its presence creates disadvantages and may lead to the risk of bodily injury when one of them requires close postural control or screening of environmental risks. [4][5][6] Several studies have demonstrated the presence of dual task interference in individuals with a neurological disease or injury, such as Parkinson's, Alzheimer's, Huntington's Disease, multiple sclerosis, traumatic brain injury (TBI), or stroke (CVA). [5][6][7][8][9][10] It can be expressed in the gait as a decrease in the speed, in the length of the stride, and in the cadence and as an increase in the time of double support.…”

“…[4][5][6] Several studies have demonstrated the presence of dual task interference in individuals with a neurological disease or injury, such as Parkinson's, Alzheimer's, Huntington's Disease, multiple sclerosis, traumatic brain injury (TBI), or stroke (CVA). [5][6][7][8][9][10] It can be expressed in the gait as a decrease in the speed, in the length of the stride, and in the cadence and as an increase in the time of double support. 5,11,12 The interference can also occur in the form of a worse performance of the upper limb, a decrease in the number of words spoken, and an increase in body oscillation, among other things.…”

“…[5][6][7][8][9][10] It can be expressed in the gait as a decrease in the speed, in the length of the stride, and in the cadence and as an increase in the time of double support. 5,11,12 The interference can also occur in the form of a worse performance of the upper limb, a decrease in the number of words spoken, and an increase in body oscillation, among other things. [13][14][15] Three theoretical models were developed in order to explain the dual task interference.…”