Decrease In Postural Stability Research Articles

Comparative Analysis of Bilateral Deficits in Elbow Flexion Strength: Functional vs. Analytical Assessment

Background: this study aimed to identify the influence of postural stability on upper-limb bilateral deficit (BLD), and to compare the assessment of strength generated during elbow flexion functionally vs. analytically in the dominant and nondominant arms. Methods: Twenty men participated in two sessions to evaluate the maximum isometric strength of elbow flexion. This evaluation was performed unilaterally with the dominant arm, unilaterally with the non-dominant arm, and bilaterally, both in the sitting position (SiP) and the standing position (StP). Results: The BLD when peak force was considered was lower for StP (−6.44 ± 5.58%) compared to SiP (−10.73 ± 6.17%) (p = 0.007). Regarding peak force, statistically significant differences were observed for comparisons between dominance (p < 0.001) and Position*Dominance (p = 0.02), but mean force differences were only observed for the dominance factor (p < 0.001). Greater mean and peak forces were always produced bilaterally compared to unilaterally (p < 0.001). Conclusions: a decrease in postural stability by performing elbow flexion exercises in a standing position accentuates BLD of peak force.

Changing the horizontal position of a fixed backpack load: The effect on postural stability in young adults.

Modifying the horizontal position of the load in a backpack will change the size of the external torque it creates on the wearer but the effect on postural stability is unclear. To determine if changing the horizontal position of a fixed backpack load affects postural stability in young adults. A backpack was attached to a steel frame with a bar protruding posteriorly. A fixed load (5% body mass) was placed at three distances along the bar - 0 m, 0.20 m, and 0.40 m. Centre of pressure (CoP) derived measurements were recorded from a force platform sampling at 100 Hz. For each condition participants performed three 90s narrow stance trials with their eyes closed whilst standing on a firm surface. A comparison was made across unloaded (no backpack) and loaded conditions. There was an immediate decrease in postural stability when a loaded backpack was worn. Only two of the CoP derived measures (Total Excursion - TEx, and Mean Velocity Total Excursion - MVel TEx) differed between the loaded at 0.20 m and loaded at 0 m conditions. All CoP derived measures differed between the loaded at 0.40 m and loaded at 0 m conditions. Furthermore, three of the CoP derived measures (Anterior/Posterior Root Mean Square - A/P RMSq, TEx, and MVel TEx) differed between the loaded at 0.40 m and loaded at 0.20 m conditions. The distribution of a load within a backpack must be carefully considered. The findings for the 0.40 m condition are important for the use and design of large backpacks used by multi-day hikers, travellers, and the military.

Light-Weight Wearable Gyroscopic Actuators Can Modulate Balance Performance and Gait Characteristics: A Proof-of-Concept Study.

Falling is a major cause of morbidity, and is often caused by a decrease in postural stability. A key component of postural stability is whole-body centroidal angular momentum, which can be influenced by control moment gyroscopes. In this proof-of-concept study, we explore the influence of our wearable robotic gyroscopic actuator "GyroPack" on the balance performance and gait characteristics of non-impaired individuals (seven female/eight male, 30 ± 7 years, 68.8 ± 8.4 kg). Participants performed a series of balance and walking tasks with and without wearing the GyroPack. The device displayed various control modes, which were hypothesised to positively, negatively, or neutrally impact postural control. When configured as a damper, the GyroPack increased mediolateral standing time and walking distance, on a balance beam, and decreased trunk angular velocity variability, while walking on a treadmill. When configured as a negative damper, both peak trunk angular rate and trunk angular velocity variability increased during treadmill walking. This exploratory study shows that gyroscopic actuators can influence balance and gait kinematics. Our results mirror the findings of our earlier studies; though, with more than 50% mass reduction of the device, practical and clinical applicability now appears within reach.

Features of postural control of elderly patients with osteoporosis: Overview

The study discusses the features of postural control of patients with senile and presenile osteoporosis. Age-related changes in the components and mechanisms of the postural control system are summarized. The main factors that are associated with osteoporosis and affect the postural balance, namely, reduced bone mineralization, postural deformities, pathological fractures, and sarcopenia, are discussed. The key problems of older patients with osteoporosis associated with a decrease in postural stability are considered. These problems are associated with an increased risk of falls and injuries, fear of falls, reduced functional mobility, and quality of life.
 On the analysis of literature sources, a hypothetical model of postural control and interaction between age-associated and osteoporosis-associated factors is proposed.

Sensory organization of postural control after long term space flight.

Alterations in motor control systems is an inevitable consequence of space flights of any duration. After the flight, the crew-members have significant difficulties with maintaining upright balance and locomotion, which last several days following landing. At the same time, the specific mechanisms of these effects remain unclear. The aim of the study was to assess effects of long-term space flight on postural control and to define the changes of sensory organization caused by microgravity. 33 cosmonauts of Russian Space Agency, the members of International Space Station (ISS) flights of duration between 166 and 196 days took part in this study. Computerized Dynamic Posturography (CDP) tests, which include assessment of visual, proprioceptive and vestibular function in postural stability, was performed twice before the flight and on the 3rd, 7th, and 10th days after landing. The video analysis of ankle and hip joints fluctuations was performed to investigate the basis of postural changes. Exposure to long-term space flight was followed by considerable changes of postural stability (-27% of Equilibrium Score value in the most complicated test, SOT5m). Changes in postural strategies to maintain balance were observed in the tests which provide the challenge for vestibular system. In particular, increased hip joint involvement (+100% in median value and +135% in 3rd quartile of hip angle fluctuation RMS in SOT5m) into postural control process was revealed. Decrease of postural stability after long-term space flight was associated with alterations in vestibular system and biomechanically was revealed by increased hip strategy which is less accurate, but simpler in terms of the central control.

To Compare the Effects of Footwear in Young Female’s Postural Balance in Prolonged Standing and Sitting Job

Background: Footwear has an essential role in raising well-being of any person. Many females have wearheel or flat footwear on their daily basis as if they are working or not. Footwear creates discomfort whichleads to pain in foot, and results in alteration of balance. Most of the working places requires prolongedperiod of standing which is possibly associated with musculoskeletal disorders,likely affects our health andacute trauma from the working places. Prolonged sitting and standing can directly affect the weight-bearingjoints majorly the hip, knee and ankle joint which in turn leads to deformities and effects balance. Changesin this composite system results in the risk of falls and loss of stability.Objective: The objective of the study was to identify the effects of footwear in young female’s posturalbalance in prolonged standing and sitting job.Materials and Method: 100 healthy females were taken for the study age 18-35 years but only 60 wereselected for the study. The subject had to perform Rhomberg test and tandem walk for balance assessment.Result: On analysis, it was found that in rhomberg balance test, 73.33% population were positive with thetest. 8.33% population were positive with the eyes opened and 65% population were positive with the eyesclosed and in tandem walk, 31.66% population is positive who were unable to complete the test.Conclusion: In conclusion, the balance tests shows that, wearing footwear for prolonged hours of standingand sitting job,states that the balance and postural control worsening which is associated with decreasein postural stability and increase in the risk of falls.. According to the study balance is more effected inprolonged sitting than in prolonged standing

Inclination angles during cross-slope roof walking

Residential roofers have the highest rate of falls in the construction sector with injuries and fatalities costing billions of dollars annually. The sloped roof surface is the most predominant component within the residential roof work environment. Postural stability on a sloped work environment is not well studied. Calculating inclination angles (IAs) using the lateral ankle marker could be a quality measure to determine how cross-slope roof walking will influence stability.Will cross-slope roof-walking effect anterior-posterior (AP) and medial–lateral (ML) IAs in adult males?Eleven adult males participated in two testing sessions—level and cross-slope roof gait session on a 6/12 pitched roof segment. Changes in AP and ML IAs between conditions were compared at: heel strike (HS) and toe off (TO). Legs were analyzed separately due to the cross-slope walking. The left foot was ‘higher’ on the sloped roof and the right was ‘lower.’Significant increases (p ≤ 0.006) in IAs were observed due to the sloped roof in all conditions except the AP ‘lower’ leg (p = 0.136).Increases in IA suggest a decrease in postural stability as the body will result in greater sway compared to a natural posture. Increases in AP IAs may cause slipping in the anterior or posterior direction as the normal force will decrease during HS and TO. In the ML direction, fall risk is increased and more stress is placed on the hip abductors in order to reduce falling. Thus traversing a sloped roof surface reduces stability of healthy workers and escalates injury/fall risk factors.

Vestibular and Cardiovascular Responses After Long-Duration Spaceflight.

BACKGROUND: The vestibulo-sympathetic reflex operates during orthostatically challenging movements to initiate cardiovascular responses in advance of a baroreceptor-mediated response. The objective of this study was to determine whether there was an association between changes in vestibular function and cardiovascular responses during a prone-to-stand movement in astronauts after return from long-duration spaceflight.METHODS: Thirteen crewmembers who participated in International Space Station missions were tested before spaceflight and 1 d after landing. Vestibular function was evaluated by computerized dynamic posturography while their head was erect and while they performed dynamic head tilts. Heart rate and mean arterial blood pressure were measured while the subjects were in prone and standing positions.RESULTS: The 21.4% increase in the astronauts' heart rate during the prone to stand maneuver after spaceflight correlated significantly with their spaceflight-induced 48.7% decrease in postural stability during dynamic head tilts. The larger mean arterial pressure in the prone position after spaceflight compared to preflight (+7%) also correlated with the postflight decrease in postural stability during dynamic head tilts.CONCLUSION: These results indicate that an appropriate vestibular function is important to evoke optimum vestibulo-sympathetic response during orthostatically challenging voluntary movements performed after spaceflight. They also suggest that there may be a greater need to generate an anticipatory cardiovascular response after spaceflight.Deshpande N, Laurie SS, Lee SMC, Miller CA, Mulavara AP, Peters BT,Reschke MF, Stenger MB, Taylor LC, Wood SJ, Clément GR, Bloomberg JJ. Vestibular and cardiovascular responses after long-duration spaceflight. Aerosp Med Hum Perform. 2020; 91(8):621-627.

To Compare The Effects Of Footwear In Young Female’s Postural Balance In Prolonged Standing And Sitting Job.

Background: Footwear has an essential role in raising well-being of any person. Many females have wear heel or flat footwear on their daily basis as if they are working or not. Footwear creates discomfort which leads to pain in foot, and results in alteration of balance. Most of the working places requires prolonged period of standing which is possibly associated with musculoskeletal disorders ,likely affects our health and acute trauma from the working places. Prolonged sitting and standing can directly affect the weight-bearing joints majorly the hip , knee and ankle joint which in turn leads to deformities and effects balance. Changes in this composite system results in the risk of falls and loss of stability. Objective: The objective of the study was to identify the effects of footwear in young female’s postural balance in prolonged standing and sitting job. Materials and Methods: 100 healthy females were taken for the study og age 18-35 years but only 60 were selected for the study. The subject had to perform Rhomberg test and tandem walk for balance assessment. Result: On analysis, it was found that in rhomberg balance test, 73.33% population were positive with the test.8.33% population were positive with the eyes opened and 65% population were positive with the eyes closed and in tandem walk, 31.66% population is positive who were unable to complete the test. Conclusion: In conclusion, the balance tests shows that, wearing footwear for prolonged hours of standing and sitting job,states that the balance and postural control worsening which is associated with decrease in postural stability and increase in the risk of falls. According to the study balance is more effected in prolonged sitting than in prolonged standing.

Je älter der Bergwanderer, umso schwerer die Verletzung – eine retrospektive Analyse der Bergwanderunfälle aus den Schweizer Alpen in den Jahren 2009–2018

The Older the Hiker, the More Severe the Injury - a Retrospective Analysis of Mountain Hiking Accidents in the Swiss Alps from 2009 to 2018 Abstract. Hiking is a regular activity of the elderly, however, the question of a relationship between age and the severity of a mountaineering accident is still unanswered. A total of 10 185 hikers was analyzed between the years 2009 and 2018. For every mountain accident, the NACA score was available allowing to conduct regression analysis between age and NACA scores. The results show that elderly hikers had higher NACA scores compared to younger ones, implying more severe events in the elderly. The tendency of more severe mountain accidents can be attributed to several reasons. Especially emphasized should be falls that are probably favoured by the age-dependent decrease of postural stability, turning a fall into a downfall, predisposing more severe events.

Influence of meteorological elements on balance control and pain in patients with symptomatic knee osteoarthritis.

This study aimed to determine if pain and balance control are related to meteorological modifications in patients with knee osteoarthritis (OA). One hundred and thirteen patients with knee OA (mean age=65±9years old, 78 women) participated in this study. Static posturography was performed, sway area covered and sway path traveled by the center of foot pressure being recorded under six standing postural conditions that combine three visual situations (eyes open, eyes closed, vision altered) with two platform situations (firm and foam supports). Knee pain score was assessed using a visual analog scale. Balance control and pain measurements recorded in the morning were correlated with the meteorological data. Morning and daily values for temperature, precipitation, sunshine, height of rain in 1h, wind speed, humidity, and atmospheric pressure were obtained from the nearest data collecting weather station. The relationship between postural control, pain, and weather variations were assessed for each patient on a given day with multiple linear regressions. A decrease of postural stability was observed when atmospheric pressure and maximum humidity decreased in the morning (p<0.05) and when atmospheric pressure decreased within a day (p<0.05). Patient's knee pain was more enhanced when it is warmer in the morning (p<0.05) and when it is wetter and warmer within a day (p<0.05). The relationship between weather, pain, and postural control can help patients and health professionals to better manage daily activities.

Static postural control assessment during pregnancy

&lt;p&gt;The hormonal and anatomic changes during pregnancy affect the musculoskeletal system and may lead to instability of static postural control and increased risk of falls. The aim of this study was to analyze changes in static postural control during the three trimesters of pregnancy, using variables derived from the center of pressure. This is a descriptive study in which posturographic tests were applied in four still standing positions, for three trials, with a combination of different visual conditions (eyes open - EO/eyes closed - EC) and support base configurations on 20 non-pregnant women (C) and 13 pregnant women during the gestational period (G1, G2 and G3). For static postural control assessment, a force plate (Bertec®) was used, and the variables analyzed were statokinesigram area, displacement amplitude, displacement velocity and sway frequency. The results demonstrate that, early in pregnancy, the woman's body seems to already change postural control, probably due to increased mobility of the sacroiliac joint and pubic symphysis caused by hormonal factors, and during the trimesters there is a decrease in postural stability, observed as an increase in the elliptical areas, amplitudes of center of pressure displacement and velocity of center of pressure displacement.&lt;/p&gt;

Static postural control assessment during pregnancy

The hormonal and anatomic changes during pregnancy affect the musculoskeletal system and may lead to instability of static postural control and increased risk of falls. The aim of this study was to analyze changes in static postural control during the three trimesters of pregnancy, using variables derived from the center of pressure. This is a descriptive study in which posturographic tests were applied in four still standing positions, for three trials, with a combination of different visual conditions (eyes open - EO/eyes closed - EC) and support base configurations on 20 non-pregnant women (C) and 13 pregnant women during the gestational period (G1, G2 and G3). For static postural control assessment, a force plate (Bertec®) was used, and the variables analyzed were statokinesigram area, displacement amplitude, displacement velocity and sway frequency. The results demonstrate that, early in pregnancy, the woman's body seems to already change postural control, probably due to increased mobility of the sacroiliac joint and pubic symphysis caused by hormonal factors, and during the trimesters there is a decrease in postural stability, observed as an increase in the elliptical areas, amplitudes of center of pressure displacement and velocity of center of pressure displacement.

Attention and postural control in patients with conversion paresis

ObjectiveCurrent theories of conversion disorder (CD) propose that motor symptoms are related to heightened self-monitoring and excessive cognitive control of movements. We tested this hypothesis using quantification of performance on a continuous perceptuo-motor task involving quiet standing. MethodsTwelve CD patients and matched controls maintained static balance on a force platform under various attention conditions: (1) with eyes open; (2) with eyes closed (requiring enhanced attention to proprioceptive information to regulate posture); and (3) while performing an attention demanding cognitive task. ResultsCompared to controls, CD patients displayed a greater decrease in postural stability in the ‘eyes-closed’ versus ‘eyes-open’ condition. In contrast, cognitive distraction led to a normalization of balance in CD. Moreover, sensitivity to the balance interventions correlated significantly with trauma reports and dissociative symptoms. ConclusionThese results indicate that attention plays a crucial role in postural control in CD. More specifically, patients seem to inadvertently use deliberate control of posture (i.e., cognitive investment) of an otherwise nearly automatized perceptuo-motor task. Attentional distraction resulted in a temporary normalization of balance, which may be used to train individuals with CD to guide their attention in a more effective way.

Postural stability during static strain before and after a submaximal aerobic bicycle test in athletes

The aim of study was to investigate static balance control in wrestlers (n = 31) and effects of fatigue on postural regulation in two position: bipedal stance and squat position with open eyes prior to and 2 min after bicycle PWC(170) test. A force platform ("Ritm". Russia) was used to determine static balance control. We found a minimum difference in postural control between wrestlers and controls prior to exercise in bipedal stance. In squat position linear and angular (all p < 0.001) sway velocity of centre of pressure were lower in wrestlers and were negatively correlated to PWC(170) index (r = 0.454 and r = 455, p < 0.001 with linear and angular sway velocities respectively) indicating that 20% dispersion of sway velocities in static strain position may be determined to physical working capacity. After PWC(170) test all parameters of sway were increased in both groups both in bipedal stance (p < 0.01) and squat position (p < 0.001) indicating an important role of muscular fatigue in the decrease of postural stability in both groups. Linear velocity after PWC(170) in bipedal stance increased to an equal extent in both groups but the increases of velocities of sway of centre of pressure in squat position were lower in athletes (ANOVA, p = 0.037 for linear and p = 0.008 for angular sway velocities respectively) and were negatively correlated to an extent of recovery of heart rate after PWC(170) indicating some contribution (6.5-14.2% of dispersion of linear and angular sway velocities) of an recovery rate to maintenance of a high level of postural stability in an static strain position in wrestlers during physical fatigue.

Einfluss von Konstitution und Belastung auf die posturale Stabilität

In order for balance to be maintained, the postural control system must process above all visual, vestibular and proprioceptive information and translate this input into appropriate motor responses. The influence of bodily constitution and physical activity on motor responses and thus on postural stability is still unclear. To use computerized dynamic posturography (CDP) to investigate the influence of body height, body mass index (BMI), regular sporting activity and acute maximal exercise on balance. Eighty-four subjects completed a standardized questionnaire on their height, BMI and sporting activity. We then assessed the postural stability of the subjects. Seventeen further subjects performed a maximal exercise test on a bicycle ergometer. We used CDP and a predefined protocol to assess balance at rest, at maximal exercise and then at 5-minute intervals until recovery. Body height and regular physical activity did not influence balance ability. By contrast, BMI and acute physical exercise had a strong effect. Immediately after maximal exercise, postural stability deteriorated by 44% compared to the baseline level (p<0.017). Complete recovery occurred within only 15 minutes. Whereas body height and regular physical activity do not influence balance performance, a high BMI value and acute maximal exercise lead to a considerable decrease in postural stability. Our results can thus explain the increasing risk of injury after strenuous physical activity, especially in association with sports that require excellent balance.

The evaluation of athletic footwear on postural stability in older adults: an exploratory study

Background A decrease in postural stability may increase the risk of falling in the older adult. The relationship between athletic footwear and postural stability has been reported in previous studies with conflicting results. The aim of the current study is to evaluate differences between two different types of athletic footwear and barefeet, in relation to postural stability in asymptomatic older adults. Methods Twenty-one older adults (mean: 74 SD: 5 years) were recruited from a University-based clinic. The cross-sectional study evaluated two different walking shoes (shoe 1: ASICS Gel Odyssey ™ ; shoe 2: ASICS Cardio Velcro ™ ) and barefoot. Participants gave informed consent and attended a laboratory setting where they carried out standard tests of quiet standing balance of 30 seconds duration on a Tekscan Matscan ® pressure mat. Each participant performed three repetitions of bipedal standing with eyes open and eyes closed under three randomised conditions. Two-way, repeated measures, withingroups Analysis of Variance (ANOVA) examined significant differences between the three footwear conditions and two vision conditions in terms of postural sway in quiet standing. Postural sway was measured as centre of pressure excursions in an anterior-posterior (AP) and medio-lateral (ML) direction (cm). Results The results demonstrated a significant difference (p 0.05).

Effects of systolic blood pressure (SBP) on a postural stability in elderly men subjected to moderate exercise

The aim of the study was to assess the effects of SPB on a range of postural stability changes occurring after moderate exercise in elderly people. Twenty-seven males from the age of 65–81 years old (mean 71.6 ± 4.9 years) took part in the study. The postural stability during bipedal quiet standing was tested directly before and after 10-min of exercise on a cycloergometer. The level of exercise intensity was predefined on the basis of subject's heart rate (HR). The study demonstrated that only small fractions of variation in post-exercise values of path length and area 95% could be explained by SPB at rest by the application of linear model ( R 2 = 5.3%, or 10.8%, respectively). The application of non-linear model, graphically represented by a parabola, revealed that the percentages of variations in path length and area 95% which could be explained by the systolic blood pressure (SBP) at rest amounted to 24.1% and 36.6%, respectively. Therefore, lower or higher values of SBP are related to the risk of increased path length and area 95%, which in turn are reflected in a temporary decrease in postural stability.

Alterações ortopédicas em crianças e adolescentes obesos

INTRODUÇÃO: A obesidade infanto-juvenil é um problema muito frequente e implica complicações que podem estar presentes precocemente, como as alterações ortopédicas. OBJETIVO: descrever as alterações que atingem o aparelho locomotor em crianças e adolescentes com sobrepeso e obesidade. METODOLOGIA: Foram consultadas as bases de dados MEDLINE, SciELO, LILACS, ISI e base de dados da Universidade de Standford, com a combinação dos seguintes descritores: "obesidade", "complicações", "criança", "dores músculo-esqueléticas", "postura", "alterações ortopédicas", "marcha" e seus respectivos sinônimos em inglês. RESULTADOS: Pôde-se observar que as crianças e adolescentes obesos são mais predispostos a apresentar essas complicações ortopédicas que os indivíduos eutróficos, e os principais problemas relatados foram as alterações posturais, como hiperlordose lombar e joelhos valgos, e dores músculo-esqueléticas, principalmente na coluna lombar e membros inferiores. Os principais fatores que causam esses problemas não são bem definidos, mas incluem aumento da sobrecarga articular associado à fragilidade óssea em fase de crescimento e à diminuição da estabilidade postural, o que conduz ao aumento das necessidades mecânicas regionais. CONCLUSÃO: A identificação precoce dessas disfunções é fundamental para que essas crianças recebam tratamento multidisciplinar adequado.

The relationship between postural stability and virtual environment adaptation

Currently little is known about how adaptive responses to virtual environments are different between individuals who experience sickness related symptoms and those who do not. It is believed that sensory interactions between visually perceived self-motion and static inertial cues from vestibular and/or proprioceptive sensory systems contribute to the development of adaptation symptoms. The aim of this study was to evaluate the relationship between adaptation symptoms and postural stability in a virtual environment (VE) driving simulator. In addition, the role of sensory interaction was assessed using direct electrical stimulation techniques of the vestibular and cutaneous sensory systems. Posture performance was measured using centre of pressure measures of single leg stance tests during eyes open and eyes closed conditions. Correlation analysis of postural measures and symptom scores were conducted, as well as analysis of variance of posture performance between SICK and WELL individuals. Results indicate that posture stability is negatively correlated to symptom reporting. WELL individuals displayed the greatest decrease in postural stability during eyes open single leg stance following VE simulation. Application of a secondary sensory stimulation (vestibular or cutaneous) resulted in increased visual dependency for postural control following simulation. Combined, these results suggest that sensory interactions drive postural changes that are observed following VE simulation and are related to how visual information is used to control posture.