Postural Regulation Research Articles

The effect of posture regulation training on musculoskeletal disorders, fatigue level and job performance in intensive care nurses

BackgroundIntensive care units (ICUs) are one of the high-risk working areas in terms of musculoskeletal disability and ergonomic risks including the environment and posture factors. Correct posture technique is often ignored by nurses working in these units. This study was conducted to determine the effect of posture regulation training on work-related musculoskeletal disorders, fatigue level and job performance in nurses working in ICUs.MethodsThis quasi-experimental study with one-group pretest-posttest design included 64 intensive care nurses. The nurses received posture regulation training in three different sessions. The post-test was administered four months after the posture regulation training.ResultsThe nurses reported to frequently have aches, pains and discomfort in the neck, upper back and lumbar regions. After the posture regulation training, their level of pain, ache and discomfort in the neck, right and left shoulder, upper back, lower back and right/left foot areas decreased significantly (p < 0.05). The posture regulation training reduced the levels of behavior/severity and affect, which are sub-dimensions of fatigue, and increased the level of contribution to work, which is a sub-dimension of job performance (p < 0.05).ConclusionThe posture regulation training decreased the level of symptoms in the neck, shoulder, upper back, lower back and foot regions of intensive care nurses and partially improved their fatigue level and job performance. Therefore, posture regulation training should be added to in-service training programs and permanent measures should be taken for ergonomic risks in ICUs.

Teleoperation with automatic posture regulation and broad learning control for assembly tasks

Teleoperation with automatic posture regulation and broad learning control for assembly tasks

Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction.

Skeletal muscles are essential for locomotion, posture, and metabolic regulation. To understand physiological processes, exercise adaptation, and muscle-related disorders, it is critical to understand the molecular pathways that underlie skeletal muscle function. The process of muscle contraction, orchestrated by a complex interplay of molecular events, is at the core of skeletal muscle function. Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction. Within muscle fibers, calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force. Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling. The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis. Myogenic regulators coordinate the differentiation of myoblasts into mature muscle fibers. Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability. Several muscle-related diseases, including congenital myasthenic disorders, sarcopenia, muscular dystrophies, and metabolic myopathies, are underpinned by dysregulated molecular pathways in skeletal muscle. Therapeutic interventions aimed at preserving muscle mass and function, enhancing regeneration, and improving metabolic health hold promise by targeting specific molecular pathways. Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway, a critical regulator of myogenesis, muscle regeneration, and metabolic function, and the Hippo signaling pathway. In recent years, more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers, and at the neuromuscular junction. In fact, research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers. In this review, we will summarize and discuss the data on these two pathways, focusing on their concerted action next to their contribution to skeletal muscle biology. However, an in-depth discussion of the non-canonical Wnt pathway, the fibro/adipogenic precursors, or the mechanosensory aspects of these pathways is not the focus of this review.

Using wearable technology for Posture Regulation to Improve Surgical Ergonomics in the paediatric operating room: the UPRISE trial: a pilot study

BackgroundThe rising prevalence of work-related musculoskeletal disorders has numerous physical, financial, and mental repercussions for surgeons. This study aims to establish whether the use of a wearable posture device can improve the operating time spent in suboptimal, high-risk postures.MethodsSurgeons were recruited in Phase 1 of this prospective randomised study and baseline postural data was obtained. In Phase 2, participants were randomised to receive either a traditional educational workshop or intraoperative vibrations from the device to correct postural lapses. During minor elective day cases, intraoperative postural data was collected and stratified by forward flexion angle, into five risk categories (negligible to very high). Participants’ experience with the sensor was also assessed.ResultsA total of 100 surgical procedures (Phase 1: n = 50; Phase 2: n = 50) were performed by eight surgeons of varying seniority. Exposure to the educational intervention increased time spent in suboptimal posture (Phase 1 vs. Phase 2); 47.5% vs. 67.8%, p = 0.05. However, the vibrational intervention significantly reduced this time; 50.0% vs. 20.7%, p = 0.005. Procedure type didn’t influence posture although, laparoscopic interventions spent most time in negligible-risk postures; 47.7% vs. 49.3%, compared to open procedures. Surgical consultants spent less time in suboptimal posture compared to fellow/registrars; 30.3% vs. 72.6% (Phase 1) and 33.8% vs. 65.3% (Phase 2).ConclusionVibrational intervention from the device significantly decreased the time spent in suboptimal, high-risk postures. As procedure type wasn’t correlated with postural changes, surgeon-specific factors in regulating posture are paramount. Finally, surgeon experience was positively correlated with improved surgical ergonomics.

A unified controller of global trajectory tracking and posture regulation for a car‐like mobile robot

SummaryThis work proposes a smooth time‐varying controller for trajectory tracking and posture regulation problems of car‐like mobile robots (CLMR). Currently, few studies focus on the control problems of CLMR's kinematic model. Global trajectory tracking or global posture stabilization controller for CLMR has not yet been proposed. In this study, we propose a global trajectory tracking controller for CLMR for the first time. By setting a specific reference trajectory, the controller is generalized to the posture stabilization task. Obstacle avoidance is also taken into consideration in posture stabilization task. Unlike the prototypical method of transforming the model into a nonholonomic chained‐form system, the proposed method is designed based on the original tracking error equation. Therefore our approach does not have singularities and has a global attraction region. Furthermore, the global convergence of the proposed controllers is strictly proved using the proof by contradiction and Barbalat's lemma. Finally, simulated and actual experiments on a car‐like robot demonstrate the effectiveness of the proposed control scheme.

Multifunctional role of the diaphragm: biomechanical analysis and new perspectives

This study explores the complex role of the diaphragm, traditionally considered essential in respiratory physiology, expanding understanding of its multifunctionality. Beyond respiratory mechanics, the diaphragm contributes to postural stabilization, lumbar support, and regulation of intra-abdominal pressure (IAP). By analyzing the diaphragm's eccentric contraction, we introduce two innovative concepts: "Diaphragm Antagonist Muscles" (DAM) and "Centration". DAM represents an evolution of the abdominal belt concept, integrating the pelvic floor and lower posterior trunk muscles. This muscular synergy is vital for respiratory dynamics and functions such as posture and integrity of the musculoskeletal, pressure, and postural systems. Centration, proposed as a conscious modulation skill of IAP, activates a neurophysiological interaction between the diaphragm, lower posterior trunk muscles, and the pelvic floor, revealing new implications of the diaphragm in sports, health, and kinesiological contexts.

Influence of Concurrent Exercise Training on Ankle Muscle Activation during Static and Proactive Postural Control on Older Adults with Sarcopenic Obesity: A Multicenter, Randomized, and Controlled Trial.

Sarcopenic obesity (SO), characterized by age-related muscle loss and excess body fat, significantly impairs postural control. However, limited research has explored the effects of concurrent exercise training on neuromuscular strategies during postural control in older adults with SO. The study enrolled 50 older adults with SO, split into an intervention group (IG, n = 25, mean age = 76.1 ± 3.5 years; mean BMI = 34.4 ± 4.0 kg/m2) and a control group (CG, n = 25, mean age = 75.9 ± 5.4 years; mean BMI = 32.9 ± 2.3 kg/m2). Participants in the IG were engaged in 60-min Total Mobility Plus Program (TMP) sessions three times a week for four months, while the CG maintained their typical daily activities. Standardized evaluations were conducted both before and after the intervention. These assessments included the Romberg and Timed Up and Go (TUG) tests, as well as the measurement of Center of Pressure (CoP) displacements parameters under various conditions. Additionally, ankle muscle activities were quantified during postural control evaluations and maximal voluntary contractions of plantar and dorsal flexors. Post-intervention results revealed a significant reduction of the standing time measured in the Romberg (-15.6%, p < 0.005) and TUG (-34.6%, p < 0.05) tests. Additionally, CoP area and velocity were notably reduced in various conditions (p < 0.05). Postural control improvements were associated with an increase of strength (p < 0.05) and decrease of ankle muscle activation (p < 0.05). These findings highlight the reversibility of neuromuscular system alterations associated with the synergistic effects of sarcopenia and obesity, emphasizing the trainability of postural control regulation within this population. By incorporating these insights into clinical practice and public health strategies, it seems possible to optimize the health and well-being of older adults with SO.

Imbalance and gait impairment in Parkinson's disease: discussing postural instability and ataxia.

Gait and balance difficulties pose significant clinical challenges in Parkinson's disease (PD). The impairment of physiological mechanisms responsible for maintaining natural orthostatism plays a central role in the pathophysiology of postural instability observed in PD. In addition to the well-known rigidity and abnormalities in muscles and joints, various brain regions involved in the regulation of posture, balance, and gait, such as the basal ganglia, cerebellum, and brainstem regions like the pontine peduncle nucleus, are affected in individuals with PD. The recognition of the cerebellum's role in PD has been increasingly acknowledged. Cortical areas and their connections are associated with freezing of gait, a type of frontal lobe ataxia commonly observed in PD. Furthermore, impairments in the peripheral nervous system, including those caused by levodopatherapy, can contribute to gait impairment and imbalance in PD patients. Consequently, individuals with PD may exhibit frontal ataxia, sensory ataxia, and even cerebellar ataxia as underlying causes of gait disturbances and imbalance, starting from the early stages of the disease. The complex interplay between dysfunctional brain regions, impaired cortical connections, and peripheral nervous system abnormalities contributes to the multifaceted nature of gait and balance difficulties in PD. Understanding the intricate mechanisms is crucial for the development of effective therapeutic approaches targeting these specific deficits in PD.

Memory-based Human Postural Regulation Control: An Asynchronous Semi-Markov Model Approach

Memory-based Human Postural Regulation Control: An Asynchronous Semi-Markov Model Approach

Pitch posture regulation in Peking geckos (Gekko swinhonis): assessing the role of tails before take-off in upward jumping

Abstract Small vertebrates, such as geckos, often use their tails to regulate their posture after take-off and suppress abnormal rotations in mid-air (such as sliding and falling). However, research on tail function before take-off remains scarce, particularly when animals overcome gravity to jump upward. This study examined tailed and tailless geckos’ ability to jump over obstacles. The tails swung up and reached their upper limits during take-off, corresponding to a continuous increase in their trunk elevation angle. Compared to tailless geckos, geckos with intact tails had lower body and tail angular velocities. In addition, tailed geckos achieved larger take-off angles and higher jumps; moreover, their take-off angles were consistent with their velocity angles. Theoretical analyses demonstrated that the tail and its upward swing before take-off could benefit lifting the forelimb and hindlimbs off the ground, expanding the stability area of their centre of mass (COM). A robot prototype verified the effect of the tail and its swing on trunk elevation before take-off. Other parameters, such as the posture of the hindlimbs (support length and angle) and initial angle of the trunk, affect posture regulation. This study significantly extends our knowledge in animal locomotion and provides indispensable information for improving robot jumping ability.

Autonomic nervous system and postural control regulation during orthostatic test as putative markers of physical resilience among community-dwelling older adults

IntroductionWe examined whether autonomic nervous system (ANS) and postural control regulation during orthostatic test reflect physical resilience by studying their associations with maximal walking speed and mortality. MethodsThe participants were community-dwelling Finnish men (n = 303) and women (n = 386) aged 75, 80, and 85 years at baseline. Systolic and diastolic blood pressure (BP), heart rate, heart rate variability (HRV), respiratory rate, and postural sway were obtained using a digital sphygmomanometer, a single-channel ECG, and thigh- and chest-worn accelerometers. Linear and Cox regression models were used to estimate the associations of the physiological indices with maximal 10-m walking speed and 5-year mortality separately for sexes. ResultsBetter maintenance of BP under orthostatic stress was associated with faster walking speed in women and lower mortality hazard in men. Greater HRV in terms of low frequency power and lower respiration rate in supine position and smaller orthostatic changes in these were associated with faster walking speed especially in women. Less postural sway after standing up was associated with faster walking speed in women (−0.057, SE 0.022, p = 0.011) and more postural sway with increased mortality hazard in men (HR 1.71, 95 % CI 1.20–2.43) even after controlling for BP responses. ConclusionsIn addition to ANS regulation at rest and under stress, adaptation of postural control system to orthostasis may be used in quantifying older adults' physical resilience. Wearable sensors capturing stimulus-response patterns and natural fluctuations of body functions may provide opportunities to monitor and incorporate different subsystems' resilience also in free-living conditions.

Posture of Healthy Subjects Modulated by Transcutaneous Spinal Cord Stimulation.

Transcutaneous electrical stimulation of the spinal cord is used to restore locomotion and body weight support in patients with severe motor disorders. We studied the effects of this non-invasive stimulation on postural control in healthy subjects. Stimulation at the L1-L2 vertebrae was performed to activate the extensor muscles of the lower limbs. Because postural regulation depends on the cognitive style, the effects of the stimulation were analyzed separately in field-dependent (FD) and field-independent (FI) participants. During the study, FD and FI participants (N = 16, 25 ± 5 years, all right dominant leg) stood on a force platform in a soundproof chamber with their eyes closed. Stimulation was applied in the midline between the L1 and L2 vertebrae or over the left or right dorsal roots of the spinal cord; under the control condition, there was no stimulation. Stimulation destabilized posture in healthy subjects, whereas patients with movement disorders usually showed an improvement in postural control. In the FD participants, left dorsal root and midline stimulation increased several postural parameters by up to 30%. Dorsal root stimulation on the side of the supporting leg reduced postural control, while stimulation on the side of the dominant leg did not. No significant changes were observed in the FI participants.

Cortical Disinhibition Drives Freezing of Gait in Parkinson's Disease and an Exploratory Repetitive Transcranial Magnetic Stimulation Study.

Dysfunction of the primary motor cortex, participating in regulation of posture and gait, is implicated in freezing of gait (FOG) in Parkinson's disease (PD). The aim was to reveal the mechanisms of "OFF-period" FOG (OFF-FOG) and "levodopa-unresponsive" FOG (ONOFF-FOG) in PD. We measured the transcranial magnetic stimulation (TMS) indicators and gait parameters in 21 healthy controls (HCs), 15 PD patients with ONOFF-FOG, 15 PD patients with OFF-FOG, and 15 PD patients without FOG (Non-FOG) in "ON" and "OFF" medication conditions. Difference of TMS indicators in the four groups and two conditions and its correlations with gait parameters were explored. Additionally, we explored the effect of 10 Hz repetitive TMS on gait and TMS indicators in ONOFF-FOG patients. In "OFF" condition, short interval intracortical inhibition (SICI) exhibited remarkable attenuation in FOG patients (both ONOFF-FOG and OFF-FOG) compared to Non-FOG patients and HCs. The weakening of SICI correlated with impaired gait characteristics in FOG. However, in "ON" condition, SICI in ONOFF-FOG patients reduced compared to OFF-FOG patients. Pharmacological treatment significantly improved SICI and gait in OFF-FOG patients, and high-frequency repetitive TMS distinctly improved gait in ONOFF-FOG patients, accompanied by enhanced SICI. Motor cortex disinhibition, represented by decreased SICI, is related to FOG in PD. Refractory freezing in ONOFF-FOG patients correlated with the their reduced SICI insensitive to dopaminergic medication. SICI can serve as an indicator of the severity of impaired gait characteristics in FOG and reflect treatments efficacy for FOG in PD patients. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

High tibial osteotomy improves balance control in patients with knee osteoarthritis and a varus deformity

BackgroundImpaired knee stability is observed in patients with medial compartment knee osteoarthritis (OA) and varus malalignment. Although high tibial osteotomy (HTO) is widely used to treat OA-related knee varus deformity, its long-term influence on balance control in OA patients is poorly reported. This study aimed to evaluate the impact of HTO on balance control and assess its biological and functional significance.MethodsThirty-two patients with medial compartment knee OA as well as varus deformity who were scheduled for HTO underwent static posturographic tests one month pre- and three months as well as one year postoperatively, respectively, along with forty matched control subjects. Radiographic and clinical evaluations were synchronously carried out on patients pre- and postoperatively.ResultsDecreased postural sway was observed in patients one year after HTO. When compared to the control subjects, more postural sway was found in patients one month pre- and three months postoperatively. No difference was observed between the patients and control subjects one year postoperatively. The alignment and joint function of the affected knees significantly improved after HTO.ConclusionsThis study revealed that HTO improves balance control in patients with knee OA and varus deformity. Correct alignment and improved joint function enhance the likelihood of normal postural stability. Hence, this intervention allows the knee joint to recover its corrective compensatory role in postural regulation and should be taken into account for managing knee OA patients.

Dynamics of postural regulation in patients during the recovery period after ischemic stroke

Dynamics of postural regulation in patients during the recovery period after ischemic stroke

Facilitating or disturbing? An investigation about the effects of auditory frequencies on prefrontal cortex activation and postural sway.

Auditory stimulation activates brain areas associated with higher cognitive processes, like the prefrontal cortex (PFC), and plays a role in postural control regulation. However, the effects of specific frequency stimuli on upright posture maintenance and PFC activation patterns remain unknown. Therefore, the study aims at filling this gap. Twenty healthy adults performed static double- and single-leg stance tasks of 60s each under four auditory conditions: 500, 1000, 1500, and 2000 Hz, binaurally delivered through headphones, and in quiet condition. Functional near-infrared spectroscopy was used to measure PFC activation through changes in oxygenated hemoglobin concentration, while an inertial sensor (sealed at the L5 vertebra level) quantified postural sway parameters. Perceived discomfort and pleasantness were rated through a 0-100 visual analogue scale (VAS). Results showed that in both motor tasks, different PFC activation patterns were displayed at the different auditory frequencies and the postural performance worsened with auditory stimuli, compared to quiet conditions. VAS results showed that higher frequencies were considered more discomfortable than lower ones. Present data prove that specific sound frequencies play a significant role in cognitive resources recruitment and in the regulation of postural control. Furthermore, it supports the importance of exploring the relationship among tones, cortical activity, and posture, also considering possible applications with neurological populations and people with hearing dysfunctions.

Effect of autogenous osteochondral mosaicplasty on the balance control of patients with cartilage defects of the knee: a pilot study

BackgroundAutogenous osteochondral mosaicplasty (AOM) is a widely used optimal surgical technique for cartilage repair in young patients with focal articular cartilage defects. However, the alterations in balance control in these patients after AOM have not been sufficiently investigated. This study aimed to compare different balance control performances between the patients with knee cartilage defects and healthy controls before and after AOM, as well as evaluate the influence of AOM on balance control in these patients.MethodsStatic posturographic tests were performed in twenty-four patients who were scheduled for AOM two weeks pre-, three months, and one year postoperatively, along with thirty matched controls, respectively. All participants underwent posturography under four standing conditions: eyes open and closed, without and with foam support to assess the balance control ability. Subsequently, patient-reported outcome measures (PROMs) were synchronously obtained and analyzed.ResultsCompared to the control subjects, less efficient balance control was observed in study patients at three testing phases (p < 0.05), whereas no alterations in postural control were visible in these patients within a year following AOM (p > 0.05). Significant improvements were found in all PROMs such as the International Knee Documentation Committee, the Lysholm Knee Score, and the visual analogue scale in the study patients postoperatively (p < 0.01).ConclusionThe results indicated that patients with knee cartilage defects have a prominent balance control deficit compared to healthy individuals. Furthermore, AOM does not improve balance control in these patients for at least one year postoperatively, and more effective approaches for postural regulation are required for the management of cartilage defect patients.

FUNCTIONAL STATE OF THE AUTONOMIC NERVOUS SYSTEM IN ELDERLY PERSONS WITH POSTURAL INSTABILITY

Background. Preservation of postural balance allows the elderly people to remain mobile and lead an active lifestyle. There is evidence of the contribution of the ANS to the coordination of postural responses and the maintenance of postural stability in young adults. However, similar data for the elderly is not enough and this issue requires further study.&#x0D; Purpose. To reveal the peculiarities of ANS functioning in elderly people with postural instability.&#x0D; Materials and methods. In 120 women aged 60-74 years, a survey, anthropometry, assessment of the dynamic component of postural balance by stabilometry and heart rate variability by cardiointervalography were performed. The study group included elderly people with postural instability (60 people), the control group included 60 women who did not report such facts. Data analysis was performed using “SPSS 27.0”.&#x0D; Results. The state of postural balance in the study group was characterized by a decrease in walking speed (p = 0.008) and a rise index when moving from the right leg (p = 0.016), an increase in the speed of oscillations of the center of body mass in the lifting phase (p = 0.047), oscillations of the center of gravity during rotation when moving on the left (p=&lt;0.001) and right (p=0.003) legs, turn time when moving on the left (p=0.44) and right (p=0.36) legs.&#x0D; Conclusion. The results demonstrate a decrease in the quality and efficiency of postural balance regulation in elderly women with postural instability. We did not reveal any significant differences in the indicators characterizing the activity of different parts of the ANS depending on the facts of postural instability.

Identification of Physiological and Pathological Patterns of Vertical Posture Regulation Using a Kohonen Neural Network with Stabilometry Data

Identification of Physiological and Pathological Patterns of Vertical Posture Regulation Using a Kohonen Neural Network with Stabilometry Data

Identification of pathobiomechanical markers of statokinesiograms on the example of neural network identification of a post-stroke state

The purpose of this study is neural network modeling and determination of the parameters of statokinesiograms, which are carriers of useful information about the features of postural regulation, which determined the obtained trajectory of movements of the human center of mass. A technique for obtaining informative markers by identifying clustering centroids based on self-organizing Kohonen neural networks with the Euclidean metric has been developed. Kohonen networks trained without a teacher (that is, without the use of a priori diagnostic information about the state of the subjects) are a powerful and informative method that allows you to obtain not only graphic, but also mathematical markers of health disorders in subjects, to explore the biomechanics of micromovements of the center of pressure based on a flexible mathematical apparatus – neural network cluster analysis. On the example of the identification of the post-stroke state, a neural network analysis of stabilometric data was carried out and a method for identifying pathobiomechanical markers of statokinesiograms was shown, which made it possible to standardize the type affiliation of the groups of subjects. With the help of neural networks, it was possible to identify clusters that are amenable to biomedical interpretation with a reliability of up to 95.9 %, which determines the theoretical significance of the results obtained. Decision trees and a supervised multilayer neural network were also considered. A multilayer neural net-work made it possible to identify markers of health disorders with a probability of 71.9 %.