an-instrumented-pull-test-to-characterize-postural-responses

An Instrumented Pull Test to Characterize Postural Responses

Impairment of postural reflexes, termed postural instability, is a common and disabling deficit in Parkinson's disease. To assess postural reflexes, ...

The University of Melbourne

Postural reflexes are impaired in conditions such as Parkinson's disease, leading to difficulty walking and falls. In clinical practice, postural responses are assessed using the "pull test," where an examiner tugs the prewarned standing patient backward at the shoulders and grades the response. However, validity of the pull test is debated, with issues including scaling and variability in administration and interpretation. It is unclear whether to assess the first trial or only subsequent repeated trials. The ecological relevance of a forewarned backward challenge is also debated. We therefore developed an instrumented version of the pull test to characterize responses and clarify how the test should be performed and interpreted. In 33 healthy participants, "pulls" were manually administered and pull force measured. Trunk and step responses were assessed with motion tracking. We probed for the StartReact phenomenon (where preprepared responses are released early by a startling stimulus) by delivering concurrent normal or "startling" auditory stimuli. We found that the first pull triggers a different response, including a larger step size suggesting more destabilization. This is consistent with "first trial effects," reported by platform translation studies, where movement execution appears confounded by startle reflex-like activity. Thus, first pull test trials have clinical relevance and should not be discarded as practice. Supportive of ecological relevance, responses to repeated pulls exhibited StartReact, as previously reported with a variety of other postural challenges, including those delivered with unexpected timing and direction. Examiner pull force significantly affected the postural response, particularly the size of stepping. NEW & NOTEWORTHY We characterized postural responses elicited by the clinical "pull test" using instrumentation. The first pull triggers a different response, including a larger step size suggesting more destabilization. Thus, first trials likely have important clinical and ecological relevance and should not be discarded as practice. Responses to repeated pulls can be accelerated with a startling stimulus, as reported with a variety of other challenges. Examiner pull force was a significant factor influencing the postural response.

Neurophysiological analysis of the clinical pull test.

Ability to walk in the community is important for independence and participation in life roles, but is difficult for many people following stroke. The purpose of this study was to determine the proportion of people with stroke with the physical capacity to be independent community ambulators at discharge from a publicly funded inpatient rehabilitation setting.

One-Quarter of People Leave Inpatient Stroke Rehabilitation with Physical Capacity for Community Ambulation.

Among older people receiving inpatient rehabilitation, does additional supervised physical activity lead to faster self-selected gait speed at discharge? Does additional supervised physical activity lead to better mobility, function and quality of life at discharge and 6 months following discharge?

Jennifer McGinley

Department of Physiotherapy

The University of Melbourne

An Instrumented Pull Test to Characterize Postural Responses

Jennifer McGinley

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Physiotherapy

The University of Melbourne

An Instrumented Pull Test to Characterize Postural Responses

Department of Physiotherapy