Understanding Of Postural Control Research Articles

A neuromechanical model characterizing the motor planning and posture control in the voluntary lean in Parkinson’s disease

Parkinson’s disease targets patients’ cognitive and motor abilities, including postural control. Many studies have been carried out to introduce mathematical models for a better understanding of postural control in such patients and the relation between the model parameters and the clinical assessments. So far, these studies have addressed this connection merely in static tests, such as quiet stance. The aim of this study is to develop a model for voluntary lean, and as such, identify the model parameters for both PD patients and healthy subjects from experimental data. The proposed model comprises planning and control sections. The model parameters for the planning section were extracted from the time response characteristics. Parameters for the control section were identified based on the spatial characteristics of the center-of-pressure (COP) response using an optimization process. 24 PD patients along with 24 matched healthy subjects participated in the study. The results showed a significant difference between the two groups in terms of temporal parameters for the planning section. This difference emphasizes bradykinesia as an essential symptom of PD. Also, differences were found for the postural control section. In all directions, the proportional gain of the feedback controller was significantly larger in PD patients; however, the gain of the feedforward controller was significantly smaller in PD patients. Furthermore, the control gains were strongly correlated with the clinical scales (Functional Reach Test and Unified Parkinson's Disease Rating Scale) in certain directions. In conclusion, the new model helps to better understand and quantify some PD symptoms in voluntary lean tasks.

Assessment of Postural Control and Proprioception Using the Delos Postural Proprioceptive System

Background. Proper postural control and proprioception are essential for maintaining balance, preventing falls, and performing daily activities. Traditional methods of assessing postural control and proprioceptive function often lack objectivity and precision. The DPPS offers a promising solution by providing a quantitative and comprehensive evaluation of postural stability and proprioceptive performance.
 Methods. The DPPS utilises advanced sensor technology and computerised analysis to measure various parameters related to postural control, including stability indexes, weight distribution, sway patterns, and proprioceptive responses. It incorporates both static and dynamic tests, allowing for a comprehensive assessment of postural control in different conditions.
 Results. Numerous studies have demonstrated the effectiveness of the DPPS in evaluating postural control and proprioception in various populations, such as athletes, older adults, individuals with balance disorders, and patients undergoing rehabilitation. The DPPS has shown good reliability and validity, with its measurements correlating well with other established assessment tools. It has also proven to be sensitive in detecting changes in postural control and proprioceptive function over time.
 Conclusions. The DPPS represents a valuable tool for objective assessment and monitoring of postural control and proprioceptive function. Its ability to provide quantitative data in a reliable and sensitive manner makes it an attractive option for researchers, clinicians, and rehabilitation professionals. By enhancing our understanding of postural control and proprioception, the DPPS can contribute to the development of targeted interventions and personalised treatment strategies aimed at improving balance, preventing falls, and optimising functional performance.
 Keywords: Delos Postural Proprioceptive System, Postural control, Proprioception, Assessment, Balance.

Clinical Static Balance Assessment: A Narrative Review of Traditional and IMU-Based Posturography in Older Adults and Individuals with Incomplete Spinal Cord Injury.

Maintaining a stable upright posture is essential for performing activities of daily living, and impaired standing balance may impact an individual's quality of life. Therefore, accurate and sensitive methods for assessing static balance are crucial for identifying balance impairments, understanding the underlying mechanisms of the balance deficiencies, and developing targeted interventions to improve standing balance and prevent falls. This review paper first explores the methods to quantify standing balance. Then, it reviews traditional posturography and recent advancements in using wearable inertial measurement units (IMUs) to assess static balance in two populations: older adults and those with incomplete spinal cord injury (iSCI). The inclusion of these two groups is supported by their large representation among individuals with balance impairments. Also, each group exhibits distinct aspects in balance assessment due to diverse underlying causes associated with aging and neurological impairment. Given the high vulnerability of both demographics to balance impairments and falls, the significance of targeted interventions to improve standing balance and mitigate fall risk becomes apparent. Overall, this review highlights the importance of static balance assessment and the potential of emerging methods and technologies to improve our understanding of postural control in different populations.

Emotional state as a modulator of autonomic and somatic nervous system activity in postural control: a review.

Advances in our understanding of postural control have highlighted the need to examine the influence of higher brain centers in the modulation of this complex function. There is strong evidence of a link between emotional state, autonomic nervous system (ANS) activity and somatic nervous system (somatic NS) activity in postural control. For example, relationships have been demonstrated between postural threat, anxiety, fear of falling, balance confidence, and physiological arousal. Behaviorally, increased arousal has been associated with changes in velocity and amplitude of postural sway during quiet standing. The potential links between ANS and somatic NS, observed in control of posture, are associated with shared neuroanatomical connections within the central nervous system (CNS). The influence of emotional state on postural control likely reflects the important influence the limbic system has on these ANS/somatic NS control networks. This narrative review will highlight several examples of behaviors which routinely require coordination between the ANS and somatic NS, highlighting the importance of the neurofunctional link between these systems. Furthermore, we will extend beyond the more historical focus on threat models and examine how disordered/altered emotional state and ANS processing may influence postural control and assessment. Finally, this paper will discuss studies that have been important in uncovering the modulatory effect of emotional state on postural control including links that may inform our understanding of disordered control, such as that observed in individuals living with Parkinson's disease and discuss methodological tools that have the potential to advance understanding of this complex relationship.

Movement patterns during the process of standing up in children with spastic diplegia

AbstractThe analysis of the movement patterns of children with spastic diplegia (SD) during the process of standing up can contribute to a better understanding of postural control. The purpose of this study was to describe the movement patterns during this task in children with SD and typical development and to analyze the differences according to their age group. Participated 40 children (38-154 months), 20 children with SD and 20 children with typical development. The participants were instructed to lie down in a supine position and quickly stand up (10 trials). Motor task sessions were videotaped and subsequently analyzed. Children with SD had more asymmetrical and less efficient movement patterns in the Upper Limbs (UL), Axial Region (AR) and Lower Limbs (LL). The oldest group of children with SD did not have more mature and efficient movement patterns, and the oldest children with typical development have more mature and efficient movement patterns in the UL and AR.

The effect of aging on respiratory synergy.

[Purpose] The purpose of this study was to investigate the effect of aging on respiratory synergy, through the comparison of an elderly group and a young group, to help further understanding of postural control in the elderly. [Subjects and Methods] Ten community-dwelling elderly subjects and ten young subjects performed standing under two different respiratory conditions: quiet breathing and apnea. Center of foot pressure displacement and joint angular movements of the head, trunk, pelvis, hips, knees and ankles were measured. [Results] The results of this study showed that the elderly group had a respiratory synergy different from that of the young group. The elderly group in quiet stance used significantly more hip and pelvis movements when compensating for respiratory disturbance than standing with apnea, while the young group used significantly more whole body segments. There were no differences in angular displacements in the quiet stance between the elderly and the young groups. [Conclusion] The elderly group demonstrated a respiratory synergy pattern different from that of the young group. The findings indicate that aging changes the respiratory synergy pattern and this change is not due to decreased functioning of the ankle joint alone.

Auxiliary Sensory Cues Improve Automatic Postural Responses in Individuals With Diabetic Neuropathy

Background. A loss of sensation in the lower limbs, observed in individuals with diabetes as well as elderly individuals, contributes to postural instability, altered gait patterns, increased risk of falling, and decreased quality of life. Objective. To determine if somatosensory cues delivered to sensate areas of the lower limbs above the ankle joints enhance the control of posture in individuals with peripheral neuropathy. Methods. Twelve subjects with sensory neuropathy due to diabetes participated in static and dynamic balance tests with and without auxiliary sensory cues provided to the lower limbs without stabilizing the ankle joints. During the tests the subjects were required to stand on a fixed or moving computer-controlled platform with their eyes open or closed. Equilibrium scores and response latency were obtained. Results. For all tests, equilibrium scores were significantly larger in experiments with auxiliary sensory cues in comparison with conditions without cues (P < .05). Smaller latency scores were recorded in conditions with auxiliary sensory information. The results indicate that auxiliary sensory cues improved automatic postural responses. Conclusions. The observed enhancement of automatic postural responses has clinical implications that aid in the understanding of postural control in individuals with peripheral neuropathy. Future controlled trials could examine whether devices that provide auxiliary sensory cues can improve balance, mobility, and the performance of daily activities.

Dynamic postural stability during sit‐to‐walk transitions in Parkinson disease patients

In an effort to further our understanding of postural control in Parkinson's disease, we biomechanically evaluated the sit to walk task and its component tasks, sit to stand (STS) and gait initiation (GI) in 12 healthy older adults and 12 persons with Parkinson's disease (PWP). Performance was evaluated utilizing motion capture and two force plates. The major finding of this study was the inability of the PWP to appropriately merge the sequential component tasks (STS and GI) during STW. The PWP rose to nearly full height and had a longer delay between seat-off and gait initiation (P = 0.003 and P < 0.001, respectively) during STW. Additionally, the PWP moved with slower velocities leading to shorter, slower steps and decreased separation of the center of mass and center of pressure. These observed motor sequencing disturbances may be due to a disease related disability or limitations in proprioception, movement speed, muscular strength, and reduced general mobility.

The Influence of Concurrent Cognitive Tasks on Postural Sway in Children

The purpose of this study was to examine the influence of concurrent tasks on postural sway in children. Nineteen fourth-grade students, while standing on a balance platform, were asked to stand still, count backward, and read second-grade level sentences. The AMTI Accusway System was used to calculate the length of center of pressure path (LCOP), sway range (SR), and variability (SV) in mediolateral (ML) and anteroposterior (AP) directions of sway. Analysis of variance revealed a main effect of cognitive task condition for SR-AP, SR-ML, SV-AP, and SV-ML. Post hoc comparisons revealed lower values of those four dependent measures for the counting backward task than for the standing still task and lower SV-AP for the counting backward task than for the reading task. In addition, there was a trend toward greater LCOP when performing a concurrent cognitive task. The demands of concurrent cognitive tasks while standing affect postural sway in children. The findings of this study contribute to our understanding of postural control in children and may explain why improvements in postural skills attained in clinical settings may not transfer to improved performance in other settings.