The multicomponent nature of equilibrium in persons with parkinsonism: A regression approach

Abstract

Lower extremity strength and joint range of motion, body sway, and electromyography responses have all been determined to be factors in balance control of healthy older individuals. The purpose of this study was to identify variables which effect balance control (equilibrium scores) of persons with Parkinsonism, and examine their relationships and predictive abilities. The composite equilibrium score from the sensory organization protocol of the Equitest was used as the dependent variable for the regression analysis. The independent variables included: 1) strategy score; 2) path sway during voluntary body displacement; 3) percent peak torque of knee flexion relative to that of knee extension (%PTKFKE); 4) peak torque of inversion of the ankle at (PTINV); 5) dorsiflexion ROM; and 6) medium loop latency (EMG). The model produced a significant overall relationship accounting for 88% of the variability in equilibrium scores. Positive and significant coefficients indicated a predicted increase in the equilibrium composite score with increases in the strategy score, PTINV and %PTKFKE. These results suggest that postural control of persons with Parkinsonism can be strongly predicted by these three variables.

Analysis of sway in Parkinson's disease using a new inclinometry‐based method

“…The prevailing method has been force platform posturography, although many other methods have been introduced 4, 5, 11–13. Force platform studies have mainly been focused on altered reflex patterns3–5, 7, 10 and changes in center of foot pressure9, 10 elicited by various stimuli. Postural sway during free quiet standing has been studied less frequently.…”

“…In the laboratory, the amount of postural sway reflecting balance disorders in PD has previously been assessed indirectly by recording ground reaction forces as a subject stands on a platform equipped with force transducers 3–7. This method has been used to evaluate postural stability under varying sensory conditions8–10 and to investigate postural reflexes 3–7, 10. Movements of the center of gravity have also been measured with a platform‐mounted potentiometer attached to the body 4, 5, 11.…”

Motor learning benefits of self-controlled practice in persons with Parkinson's disease

“…People with PD show atypical behaviors such as postural instability, tremor at rest, rigidity, and bradykinesia [2]. Postural instability, considered a primary risk factor for falls in persons with PD [3], is related to increased latencies in response to perturbation, ankle muscle weakness, degraded perception of stability limits and disequilibrium [4]. About two thirds of individuals with PD report falling within the past 12 months [5].…”

Functional brain imaging of multi-sensory vestibular processing during computerized dynamic posturography using near-infrared spectroscopy

“…While in some cases balance problems may be due to uncompensated vestibular deficits, dynamic posturography specifically evaluates overall balance ability and provides information on potential fall risk (Furman and Whitney, 2000). In particular, multi-sensory integration dysfunction is often the cause of secondary balance problems associated with brain disorders including multiple sclerosis (Jackson et al, 1995), stroke (Bonan et al, 2004a; Bonan et al, 2004b; Ikai et al, 2003), Parkinson’s (Nocera et al, 2010; Toole et al, 1996) and Alzheimer’s (Suttanon et al, 2012). The SOT paradigm consists of a standard set of six conditions as described by Nashner and Peters (Nashner and Peters, 1990) where visual and proprioceptive information is altered or removed.…”