Parkinson's disease versus ageing: different postural responses to soleus muscle vibration

Publication date: Available online 19 July 2018

Source: Gait & Posture

Author(s): Diana Bzdúšková, Peter Valkovič, Zuzana Hirjaková, Jana Kimijanová, František Hlavačka

Abstract

Background

Impairments of postural stability occur with increasing age and in neurodegenerative diseases like the Parkinson's, disease (PD). While changes in balance have been described in many, studies under steady-state conditions, less is known about the dynamic, changes in balance following sudden transition to different sensory, inputs,

Research question

The aim was to clarify different effects of age and Parkinson's disease on dynamic postural responses immediately after lower leg muscle stimulation offset. Sudden removing of active sensory input represents a transient period in balance control.

Methods

Postural responses of 13 young, 13 healthy elderly and 13 PD patients to proprioceptive bilateral vibration of soleus muscles during stance were assessed by a force platform and two accelerometers attached on the upper and the lower trunk. The experimental protocol consisted of 2 conditions of soleus muscle vibration with 1) eyes open and 2) eyes closed randomly repeated four times.

Results

During vibration period before stimulus offset, postural responses were similar in elderly and PD patients. Contrary, immediately after vibration offset significantly larger backward amplitude of centre of foot pressure (CoP) displacement and trunk tilts were observed in PD patients compared to healthy peers. In returning to vertical position, peak-to-peak amplitudes, maximal velocity of CoP and trunk tilts significantly increased in PD patients. Without vision, their postural responses were more enhanced. The differences between young and elderly were found in most parameters in transient period after vibration offset and also during vibration.

Significance

The PD patients showed more unstable transient postural responses to selective sensory stimulation switch off, which may reflect impairment of sensory reweighting in balance control. Understanding how early stages PD patients differ in balance control from neurologically intact peers may help researchers and clinicians to refine their intervention and fall prevention programs.

from #Audiology via ola Kala on Inoreader https://ift.tt/2NuH6OK
via IFTTT