Investigation of Age-Related Changes in Physiological Kinetic Tremor

Abstract

Tremor is the most common movement disorder characterized by repetitive and stereotyped movements. Most investigations on tremor attempt to understand its relation to neuromuscular dysfunctions. Therefore, there is a lack of studies that aim to investigate the complex relation between the physiological tremor and aging, especially in kinetic conditions. In this context, the main motivation of this research was to quantify age-related changes in the kinetic tremor of clinically healthy individuals. For this, a number of features extracted from tremor activity, obtained from digitized drawings of Archimedes' spirals, were analyzed. In total, 59 subjects participated in the experiments. These individuals were divided into seven groups according to their ages and two types of analysis were carried out. First, the tremor activity of young and elderly adults was investigated by means of traditional features commonly used in tremor analysis, and secondly, linear discriminant analysis (LDA) was employed for the study of the correlation between age and tremor. The results showed significant statistical differences between the kinetic tremor activity of the young and elderly groups. Furthermore, it was found that LDA allowed for the estimate of a unique feature, so-called LDA-value, which showed to be linearly correlated with age.

Bridging the gap between robotic technology and health care

“…Strokes are the third most common cause of death worldwide after heart disease and cancer (The Stroke Association, UK, 2008), and the most common cause of acquired physical disability. Tremor on the other hand, is one of the major causes of functional disability and the most common disorder in neurological practice, affecting mostly the elderly population [19][20][21]. Chronic neurological pain can worsen due to anxiety/stress and other factors.…”

Analysis of the relationship between EEG signal and aging through Linear Discriminant Analysis (LDA)

“…The technique used in this study to estimate the LDA-value, was originally described by Cavalheiro et al (2009) in a study that examines the relationship between postural control and aging, using Genetic Algorithms (GA) as a search method to solve optimization problems (Wright, 1991). It was recently used to study the correlation between human tremor and aging in Almeida et al (2010), justifying its applicability in the context of this research between EEG and aging. The steps of the method consisted of:…”

Human Tremor: Origins, Detection and Quantification

“…Thus, besides the methods employed in the clinical evaluation, many others are applied to evaluate the tremor in the laboratory. The most common methods are accelerometry, electromyography (EMG) and spirography [5]. The biomechanical analysis of the tremor involves qualitative and quantitative aspects, and its main methods of measuring are electromyography (EMG), magnetic tracker system, active optical markers, accelerometers, gyroscopes and spirography.…”

“…Digitizing tablet was used by Almeida (2010) [5] with a technique known as spirography. This technique consists in the reproduction by the patient of the Archimedes' spiral according to an ideal model.…”

“…Some examples of pathological tremor, i.e. associated to neurological disorder factors, are the cerebellar, essential and parkinsonian tremor [5], and others, such as in psychogenic, orthostatic and neuropathic tremor, which are considered relatively rare in the medical literature [6].…”