Influence of Attentional Control on Protective Arm Responses to Balance Perturbations in Older Adults and People with Peripheral Neuropathy
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Old Age; Debility
- Sponsor
- University of Maryland, Baltimore
- Enrollment
- 25
- Locations
- 1
- Primary Endpoint
- Grasp Accuracy
- Status
- Completed
- Last Updated
- last year
Overview
Brief Summary
The overall objective of this study is to investigate the effect of attention control training on reach-grasp stabilizing responses during fall-induced perturbations. The central hypothesis is that training attention control during reach to grasp balance perturbations will lead to increased grasp accuracies and reduced in-task falls. This research will mark the first explore the effects of training attention control on protective arm responses and fall rate during a balance perturbation paradigm and the first feasibility testing of a fully integrated cognitive and physical rehabilitation paradigm, moving beyond correlative designs and parallel treatments. The overall public health significance of the proposed research is that with improved protective arm responses and grasp accuracies, a larger randomized control study may be designed to mitigate falls among community dwelling older adults.
Participants will be involved in 6 sessions. Session 1 will include the assessment, questionnaires, and training. Session 2 will include just the training. Session 3 will include the assessment and training. Sessions 4-5 will include just the training. Session 6 will include the assessment, questionnaires, and training.
Detailed Description
Participants will be involved in 6 sessions. Session 1 will include the assessment, questionnaires, and training. Session 2 will include just the training. Session 3 will include the assessment and training. Sessions 4-5 will include just the training. Session 6 will include the assessment, questionnaires, and training. Assessment: Using a specialized treadmill that induces balance perturbations (ActiveStep, www.simbex.com), an individualized perceived balance threshold will first be assessed. In brief, participants will stand feet together, arms relaxed at their sides, eyes focused on a red 'X' at eye level and asked only to grasp when participants feel a true need to restore balance. Testing perturbations will proceed 2 levels above this threshold. Next, two lateral perturbation conditions, each with 10 trials (5x right; 5x left) will be randomly applied. Perturbation direction and timing will be unknown and random. Condition 1 has no cognitive task. Condition 2 has participants engaged in a cognitive task 30-120s prior to perturbation with instructions, "as soon as the participant feels a falling sensation, stop the task and grab a single rail to quickly restore balance." To promote high cognitive task engagement, a mental arithmetic task was selected as one of the most effective stressors. Psychophysiological stressors are known to result in greater task engagement than pleasant tasks, thus adding a consistent challenge to task inhibition and in turn, attention switching. To allow characterization of the 'first trial response', the first and second trial will include one of each condition, separated by a 5min rest. The 'first trial response' has less stability compared with subsequent perturbations and is relevant to the study of mechanisms underlying 'real-life' falls. Objective kinematic and electromyographic (EMG) assessment of balance responses to the perturbations will be conducted. Following the balance perturbation assessment, clinical tests of balance, including the four square step test and miniBEST, will be conducted. The investigators will also be using a device to record physiological responses using sensors attached to the fingers (Biopac Systems, Inc.) to record stress at baseline and during the reactive balance responses assessment. Subjects will also complete questionnaires on balance confidence and anxiety. These include: 1. Activity specific balance confidence scale (ABC): Questions are on how confidence subjects feel when performing normal activities of daily living that involves maintaining their dynamic balance. 2. Stait Trait Anxiety Inventory: Measure of trait and state anxiety 3. Subjective Units of Distress Scale (SUDS): Measures anxiety and distress on a scale of 0 no distress and totally relaxed to 100 highest distress/ anxiety ever felt 4. Mini Mental State Examination (MMSE): A validated sensitive test for detecting mild cognitive impairments. It involves documenting the participants responses to cognitive tasks such as c subtractions, memory recall repeating number sequences, naming as many nouns starting with "F" etc. 5. Beck Anxiety Inventory (BAI): Consists of 21 self-reported items (four-point scale) used to assess the intensity of physical and cognitive anxiety symptoms during the past week Training: Participants will each undergo 6 sessions of an attention task combined with balance perturbation and upper limb responses. The investigators define feasibility in terms of whether key components of our approach are met, including valid and reliable pre-perturbation cognitive engagement and reactive arm recovery responses over repeated trials, as well as overall participant satisfaction.
Investigators
Kelly Westlake
PI
University of Maryland, Baltimore
Eligibility Criteria
Inclusion Criteria
- •65 to 88 years of age
- •Community ambulatory with or without a straight cane
Exclusion Criteria
- •Significant musculoskeletal or neurological impairments as indicated by limitations in activities of daily living, ADL (less than 6/6 on Katz Index in ADLs)
- •Clinically identified uncorrected visual loss
- •Complaints of dizziness or known vestibular disorder
- •Upper extremity strength less than 4/5 manual muscle test at the shoulder, elbow, wrist, or grip.
- •Mini Mental State Examination score of less than 25
Outcomes
Primary Outcomes
Grasp Accuracy
Time Frame: Within the first second immediately following the balance perturbation onset
Grasp accuracy refers to the success of the reach to grasp response. This can be a full grasp (grasping with all 5 fingers), overshoot, or undershoot of the handrail
In-task falls incidence
Time Frame: The peak load on the safety harness within the first second of the balance perturbation onset.
A load cell attached to the overhead safety harness will record the percentage of the participants body weight that is being supported by the harness. If the harness is holding up more than 30% of the participants body weight, this is considered a fall, 4.5-30% of the participants body weight is considered a harness-assist, and less than 4.5% of the participants body weight is considered recovery.
Secondary Outcomes
- Electromyography (EMG) of the shoulder muscles(Within the first second following onset of the balance perturbation)
- Physiological responses (electrodermal activity)(5 minutes at baseline and 5 minutes during the balance perturbation tasks)
- Physiological responses (heart rate variability)(5 minutes at baseline and 5 minutes during the balance perturbation tasks)
- Activity specific balance confidence scale(The questions ask about the 4 weeks before the first day of testing)
- Stait Trait Anxiety Inventory(The questions ask about the participants current feelings and their feelings in general over the past year)
- Subjective Units of Distress Scale(In the moment immediately following the balance perturbations)
- Beck Anxiety Inventory(The items in the scale ask about the participants feelings over the previous week)
- Mini Mental State Examination (MMSE)(At baseline)
- Somatosensation(This will be assessed at baseline only)