Differences In Postural Stability Research Articles

Advanced conservative treatment of complete acute rupture of the lateral ankle ligaments: Verifying by stabilometry

BackgroundThe aim of this study was to investigate the result of the specific conservative treatment of acute lateral ankle ligaments rupture and verify the effect of this therapy by stabilometry. Methods17 young athletes were examined after acute lateral ankle sprain (grade III). Diagnosis was based on musculoskeletal ultrasound examinations. Pressure plate evaluated postural stability after conservative treatment at regular intervals during 1year. ResultsThere were no significant differences in postural stability in double-leg stance between limbs. In single-leg stance, COP confidence ellipse (p=0,011) and COP excursion in sagittal plane (p=0,000) were significantly higher for the injured leg when compared with the uninjured leg only one week after removing the cast. ConclusionsAfter conservative treatment of grade III injuries with STABHA, immobilization with full weight bearing on the injured leg for 6 weeks and rehabilitation, stabilometry results showed that none of the patients had impaired postural stability or were at risk of functional ankle instability in the monitored period.

難治性めまい患者に対する個別リハビリテーションの効果 (第2報)

In Japan there are few reports of vestibular rehabilitation for patients with dizziness being provided by physical therapists compared to other countries around the world. One of the most frequently used outcome measures for vestibular rehabilitation is the Dizziness Handicap Inventory (DHI) which is divided into 3 categories; physical, emotional and functional and consists of 25 questions. There are many reports that the total score of the DHI is used for evaluating outcomes, however, there are few reports about analyzing the individualized questions of the DHI. The purpose of this study was to investigate the effectiveness of vestibular rehabilitation for patients with dizziness using the DHI, and to analyze the individualized questions of the DHI after vestibular rehabilitation. Twenty-six patients who had suffered from dizziness for more than 3 months participated in this study. Postural stability and Japanese-DHI (J-DHI) were measured before and after 3 months of vestibular rehabilitation. The results showed that there were significant differences in postural stability and total scores of the J-DHI before and after vestibular rehabilitation. Five of nine J-DHI questions pertaining to physical activity and quick head movements did not improve; however, the J-DHI total score did improve. The results of this study indicate that vestibular rehabilitation may not be effective for physical activity and quick head movements. The exact amount of physical activity and quick head movements were not evaluated in this study and should be in future investigations.

A longitudinal investigation into the progression of dynamic postural stability performance in adolescents

Adolescent female athletes have a higher incidence of certain non-contact lower limb injuries compared to their male counterparts. Decreased postural stability is an established risk factor for lower limb injuries; however developmental-related sex differences in postural stability during adolescence have not been investigated. The objectives of this study were to longitudinally examine changes over time, and potential sex differences in dynamic postural stability performance in adolescents. One hundred and eighty four adolescent athletes participated (mean age=13±0.34 years). Participants were assessed, using the Star Excursion Balance Test (SEBT) at baseline (T1) and at 6 (T2), 12 (T3), 18 (T4) and 24 (T5) months. At each time-point, participants performed 3 trials of the anterior, posterior-medial and posterior-lateral directions of the SEBT on each limb. Reach distance for each direction was averaged across the 3 trials normalised to leg length. General linear mixed model analyses were carried out on each of the dependant variables (reach directions) with sex and time as the categorical independent variables. There was a significant sex×time interaction for the posterior-lateral reach distance scores. There were no significant sex×time interactions for any of the other reach directions. Males increased performance on the posterior-lateral reach direction from T1 to T5, while females only increased performance until T3. Young males and females demonstrate diverging postural stability profiles during adolescence.

Sex Differences in Landing Biomechanics and Postural Stability During Adolescence: A Systematic Review with Meta-Analyses.

The adolescent 'growth spurt' results in rapid growth of the skeletal system. It has been theorised that absence of a concomitant increase in muscular adaptations in female athletes may predispose them to an increased risk of anterior cruciate ligament injuries. To determine if sex differences exist in landing biomechanics and postural stability of adolescent athletes; with a further objective of determining if such differences are propagated during adolescence. The following databases were searched: MEDLINE, EMBASE, CINAHL, PEDro, PubMed, SPORTDiscus and Web of Science. Research papers were identified by including search terms for neuromuscular control, lower limb and pubertal development. Studies were required to be written in English; report on biomechanical analyses; include landing or postural control tasks; be cross-sectional or longitudinal; and include healthy adolescent/pubertal subjects. A modified version of the Strengthening the Reporting of Observational studies in Epidemiology checklist was used to rate methodological quality. Meta-analyses were performed when more than one study reported on an outcome measure. Sixteen articles were included. The overall methodological quality of evaluated studies was low (mean score=5.75/10 points). Adolescent females exhibited increased knee valgus with increasing maturity. There was no consensus on sex differences in postural stability. With increasing maturation, females are characterized by increased knee valgus during landing tasks. To date, no research has longitudinally investigated postural stability development during adolescence in females, despite the importance of postural control training in injury prevention programmes. Therefore, further research on this topic is warranted.

Quantification of the Balance Error Scoring System with Mobile Technology.

The aim of this project was to develop a biomechanically based quantification of the Balance Error Scoring System (BESS) using data derived from the accelerometer and gyroscope of a mobile tablet device. Thirty-two healthy young adults completed the BESS while an iPad was positioned at the sacrum. Data from the iPad were compared to position data gathered from a three-dimensional motion capture system. Peak-to-peak (P2P), normalized path length (NPL), and root mean squared (RMS) were calculated for each system and compared. Additionally, a 95% ellipsoid volume, iBESS volume, was calculated using center of mass (CoM) movements in the anteroposterior (AP), mediolateral (ML), and trunk rotation planes of movement to provide a comprehensive, 3D metric of postural stability. Across all kinematic outcomes, data from the iPad were significantly correlated with the same outcomes derived from the motion capture system (rho range, 0.37-0.94; P < 0.05). The iBESS volume metric was able to detect a difference in postural stability across stance and surface, showing a significant increase in volume in increasingly difficult conditions, whereas traditional error scoring was not as sensitive to these factors. The kinematic data provided by the iPad are of sufficient quality relative to motion capture data to accurately quantify postural stability in healthy young adults. The iBESS volume provides a more sensitive measure of postural stability than error scoring alone, particularly in conditions 1 and 4, which often suffer from floor effects, and condition 5, which can experience ceiling effects. The iBESS metric is ideally suited for clinical and in the field applications in which characterizing postural stability is of interest.

Modulation of reactive response to slip-like perturbations: effect of explicit cues on paretic versus non-paretic side stepping and fall-risk.

This study aimed to examine the effect of explicit cuing on reactive stepping with the paretic limb during slip-like perturbations in stroke survivors and to identify differences in postural stability and fall-risk while stepping with either limb. Eleven chronic hemiparetic stroke survivors received slip-like stance perturbations in no-cue (implicit, no instructions) and cued (explicit, instructions to step with paretic limb) conditions. Frequency of stepping with the paretic limb was recorded. Differences between non-paretic and paretic steps for falls, number of compensatory steps, relative center-of-mass position (X COM/BOS), and velocity (Ẋ(COM/BOS)), and vertical limb support (hip descent-Z hip) were analyzed. Stepping with the paretic limb increased from 6% in no-cue condition to 42% in cued condition with no significant difference in number of falls and steps regardless of stepping limb. At liftoff of the compensatory step, stability was greater (anterior X COM/BOS) with paretic than non-paretic limb stepping whereas, at touchdown (TD) of the step, stability with paretic limb reduced (posterior X COM/BOS and Ẋ(COM/BOS)) due to a smaller compensatory step taken with the paretic versus non-paretic limb. There was no significant difference in peak Z hip regardless of stepping limb; however, the timing of peak Z hip differed (occuring prior to TD during non-paretic stepping and post-TD during paretic stepping). Thus, fall onset was earlier with non-paretic versus paretic stepping. The results support that explicit cueing can facilitate initiation of reactive step from the paretic limb as compared with the no-cue condition. Stepping with the paretic limb in the cued condition however altered time of fall onset. Regardless of the stepping side, individuals demonstrated a fall risk suggesting the need for interventions focusing on reactive step training with both the limbs.

Time to boundary function to assess upright stance in blind children.

The goal of this preliminary study was to assess the difference in postural stability between blind and sighted children using the Time to Boundary function (TtB). The experiment was conducted in twelve children (6-12 yrs), six of them had no visual impairment, and other six had congenital blindness. The participants stood on RotoBit force plate maintaining upright stance in static conditions. Each blind subject executed the task three times, each sighted subject executed the task six times, three with eyes closed (EC) and three with eyes open (EO). For all subjects each repetition lasted 30 s. The Centre of Pressure (CoP) coordinates, extracted directly from a force plate, are used to calculate four classical parameters (sway path, sway area, mean amplitude and mean frequency) and a predictive variable called Time to Boundary (TtB). The latter is the time it would take the CoP, given its instantaneous trajectory, to contact a stability boundary. Descriptive statistics were calculated for all parameters. Twoway ANOVA test was done considering the visual condition (EO, EC, BLIND) and the repetitions (RP) as a factor. In the first comparison (BLIND/EO) the results showed significant difference for all the parameters except for TtB. In the second comparison (BLIND/EC) the results showed significant difference only for TtB. In the third comparison (EO/EC) the results showed significant difference for all the calculated parameters. Therefore the TtB would be used to asses the postural control in children with blindness.

Young Females Exhibit Decreased Coronal Plane Postural Stability Compared to Young Males.

Female athletes are at significantly higher risk of noncontact ACL injury than males, particularly in pivoting sports such as soccer and basketball. Sex-based differences in proprioception and core stability may contribute to this elevated risk. This study evaluates a novel method of assessing dynamic stability to test the hypothesis that healthy adolescent controls have sex-based differences in postural stability. Seventy-nine male and 72 female subjects completed three rounds of dynamic postural stability testing. During the assessment, subjects attempted to stabilize their torso and upper body in response to random movements of the platform. The total time a subject lasted on the platform and dynamic motion analysis (DMA) score, a summation of motion in five planes throughout testing, was calculated for each subject. The average score for each subject was included in the analysis. Males lasted longer on the platform (98 ± 14s) than females (94 ± 13s) (p = 0.04). Coronal plane and rotation stability differed significantly between genders (323 ± 126 vs. 365 ± 128, p = 0.04) and (318 ± 82 vs. 403 ± 153, p = 0.0002), respectively. No statistically significant difference was seen in the other planes of motion. Females have less dynamic postural stability than their male counterparts in the coronal plane based on a novel assessment tool. This finding may contribute to better understanding of sex-based differences in rates of injury such as noncontact ACL tears.

Dynamic postural stability differences between male and female players with and without ankle sprain

ObjectivesTo evaluate dynamic stability index (DSI) differences between males and females for different jump directions. To examine both preseason DSI differences between players with and without a history of ankle sprain, and between players with and without an ankle sprain during the subsequent season. DesignProspective cohort design. SettingLaboratory. Participants47 male (22.9 ± 3.9 y) and 19 female (21.5 ± 2.9 y) sub-elite and elite team sport players. Main outcome measuresAnkle sprain history was collected using an injury history questionnaire. DSI of a single-leg hop-stabilization task measured preseason was collected using force plates and calculated using a Matlab program. Ankle sprains were reported during the subsequent season. ResultsMale players demonstrated larger DSI than female players on forward medial/lateral stability index (MLSI) and vertical stability index (VSI), diagonal VSI, and lateral anterior/posterior stability index (APSI) and VSI. Forward, diagonal and lateral dynamic postural stability indices (DPSI) were larger for males (p < 0.001). No significant differences were found between players with and without a previous ankle sprain nor between players with and without an ankle sprain during the subsequent season. ConclusionMale players showed larger DSI scores than female players, indicating lower dynamic stability. Sex-specific training sessions or prevention programs should be developed.

Size estimates of action-relevant space remain invariant in the face of systematic changes to postural stability and arousal.

Perceptual estimates of action-relevant space have been reported to vary dependent on postural stability and concomitant changes in arousal. These findings contribute to current theories proposing that perception may be embodied. However, systematic manipulations to postural stability have not been tested, and a causal relationship between postural stability and perceptual estimates remains to be proven. We manipulated postural stability by asking participants to stand in three differently stable postures on a force plate measuring postural sway. Participants looked at and imagined traversing wooden beams of different widths and then provided perceptual estimates of the beams' widths. They also rated their level of arousal. Manipulation checks revealed that the different postures resulted in systematic differences in body sway. This systematic variation in postural stability was accompanied by significant differences in self-reported arousal. Yet, despite systematic differences in postural stability and levels of arousal perceptual estimates of the beams' widths remained invariant.

보행 시 여성노인의 자세안정성과 지면형태가 하지 근활성도에 미치는 영향

8>  HB  * $7 ,  1 2* $1 ,,45 1$- $ 0   1 2* $7 ,  ,;  * $E1,45 1$ $ 95* 1: 95* 5 * 8  : ;*8  ABSTRACTObjective:The purpose of this study was to analyze the effects of lower limb muscle activity on postural stability and ground type in elderly women subjects. Method:Forty two subjects participated in the experiment (high group - age: 74.29±4.13 yr, height: 152.44±5.54 cm, weight: 57.43±6.16 kg, BMI: 24.77±2.99, low group - age: 77.67±5.16 yr, height: 151.40±3.93 cm, weight: 60.92±6.40 kg, BMI: 26.59±2.57). Wireless EMG with eight channels was used. Ground types were classified as flat and cushion. Results:In the double-support phase, left and right rectus femoris, left biceps femoris, left and right tibialis anterior, and left gastrocnemius did not show a significant difference in postural stability according to ground type. However right biceps femoris and gastrocnemius showed higher muscle activity in the elderly women group with lower postural stability. In the single-support phase, left and right rectus femoris, right biceps femoris, and left and right tibialis anterior did not show a significant difference in postural stability according to ground type. In addition, left biceps femoris had higher muscle activity in the elderly women group with lower postural stability. Left gastrocnemius had higher muscle activity in the elderly women group with higher postural stability and right gastrocnemius had higher muscle activity in the elderly women group on cushion ground.Conclusion:In a dynamic postural stability and cushion ground, biceps femoris and gastrocnemius muscle activity were high. As a result, biceps femoris and gastrocnemius muscle strengthening exercise on cushion ground could be beneficial in the prevention of falling.Keywords: EMG, Gait, Stability, Elderly Women, Cushion Ground, Lower Limb

Assessment of postural stability in young healthy subjects based on directional features of posturographic data: vision and gender effects.

Directional characteristics of postural sway and their impact on postural stability control (PSC) still need to be clarified. To assess the directional characteristics of PSC, center-of-pressure (COP) while standing quiet was recorded and analyzed in 46 young healthy subjects. The participants completed five 60-s trials with 'eyes open' and five with 'eyes closed'. The control asymmetry was characterized using three standardized COP measures: mean sway velocity (V), sway ratio (SR), and sway directional index (DI). The COP data were low-pass filtered at 10 Hz. In such conditions the V, SR and DI revealed consistent and unique differences in both the anteroposterior (AP) and the mediolateral (ML) controls. Each of the COP measures showed the involvement of different neuromuscular and biomechanical mechanisms in the stabilization of standing posture. The DI documented a very stable proportion between frontal and saggital controls, with roughly 60% of the swaying movements being performed in the AP direction. The AP DI was significantly higher in comparison with the ML value (0.71±0.04 vs. 0.55±0.06). This proportion remained at the same level in both experimental groups and it was only slightly affected by the visual conditions. Analysis of the SR confirmed that to maintain stable stance the neuromuscular system must allocate 50% more effort to control AP stability. The results also documented gender-related differences in postural stability. Generally the female subjects appeared to have lower postural stability as evidenced by higher COM and COP velocities. Consequently the higher SR values observed in the female group indicate a need for higher neuromuscular efforts to maintain stable posture. The introduced here set of COP measures proved to be a valuable standard for static posturography, creating the opportunity for improved and reliable assessment of postural stability.

Effects of task context during standing reach on postural control in young and older adults: A pilot study

Reaching is an important component of daily activities with goals to interact and acquire objects in the environment. The task context of reaching, as determined by the behavioral goal and the properties of the object, can influence the control of posture and movements. This study examined age differences in postural stability during a forward reach under two task contexts, grasping versus pointing to a target. Young and older participants living in the community performed the tasks from the standing position. They reached forward, grasped or pointed to a target, and then returned to an upright posture as fast as possible. Postural stability was analyzed using the center of pressure (COP) during two phases of the task: the reaching movement phase and the returning movement phase. In the grasping context, the COP path deviations were significantly larger in older compare to young participants during both the reach and the return movement phases. In addition, during the return movement phase, only older participants showed a context-dependent increase in COP path deviations after grasping compared to pointing. The results highlight the impact of task context on postural stability during standing reach in young and older adults. Interventions for older adults with balance problems should consider incorporating activities that involve the interaction with objects of various properties in the environment. Future studies are necessary to investigate the factors underlying the person-environment interplay of postural control and the adaptation of anticipatory postural control associated with object interaction during functional tasks in older adults.

Dominant side in single-leg stance stability during floor oscillations at various frequencies

BackgroundWe investigated lateral dominance in the postural stability of single-leg stance with anteroposterior floor oscillations at various frequencies.MethodsThirty adults maintained a single-leg stance on a force platform for 20 seconds per trial. Trials were performed with no oscillation (static condition) and with anteroposterior floor oscillations (2.5-cm amplitude) at six frequencies: 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5 Hz (dynamic condition). A set of three trials was performed on each leg in each oscillation frequency in random order. The mean speed of the center of pressure in the anteroposterior direction (CoPap) was calculated as an index of postural stability, and frequency analysis of CoPap sway was performed. Footedness for carrying out mobilizing activities was assessed with a questionnaire.ResultsCoPap speed exponentially increased as oscillation frequency increased in both legs. The frequency analysis of CoPap showed a peak <0.3 Hz at no oscillation. The frequency components at 0.25-Hz oscillation included common components with no oscillation and those at 1.5-Hz oscillation showed the maximum amplitude among all conditions. Postural stability showed no significant difference between left- and right-leg stance at no oscillation and oscillations ≤1.25 Hz, but at 1.5-Hz oscillation was significantly higher in the right-leg stance than in the left-leg stance. For the lateral dominance of postural stability at individual levels, the lateral difference in postural stability at no oscillation was positively correlated with that at 0.25-Hz oscillation (r = 0.51) and negatively correlated with that at 1.5-Hz oscillation (r = -0.53). For 70% of subjects, the dominant side of postural stability was different at no oscillation and 1.5-Hz oscillation. In the subjects with left- or right-side dominance at no oscillation, 94% or 38% changed their dominant side at 1.5-Hz oscillation, with a significant difference between these percentages. In the 1.5-Hz oscillation, 73% of subjects had concordance between the dominant side of postural stability and that of mobilizing footedness.ConclusionIn static conditions, there was no lateral dominance of stability during single-leg stance. At 1.5-Hz oscillation, the highest frequency, right-side dominance of postural stability was recognized. Functional role in supporting leg may be divided between left and right legs according to the change of balance condition from static to dynamic.

Usual dose of caffeine has a positive effect on somatosensory related postural stability in hemiparetic stroke patients.

ObjectiveTo evaluate the effect of caffeine on balance control of hemiparetic stroke patients, we investigated the difference in postural stability before and after drinking coffee by observing changes in stability index (SI) from posturography.MethodsThirty patients with history of stroke and 15 age-matched healthy subjects participated in this study. Effect of group factor (of the control and stroke groups) and treatment factor (pre- and post-drinking of coffee) on SI were tested in three conditions: with eyes opened, with eyes closed, and with a pillow support. The effects of these factors on visual deprivation and somatosensory change of subjects were also tested.ResultsUnder all conditions, SI was higher in the stroke group than in the control group. Under eyes-open condition, the treatment factor was not statistically significant. Under eyes-closed condition, the interaction between group and treatment factor was statistically significant. After the subjects drank coffee, SI in the control group was increased. However, SI in the stroke group was decreased. Under pillow-supported condition, the interaction between group and treatment factor appeared marginally significant. For visual deprivation effect, the interaction between treatment and group factor was statistically significant. After caffeine consumption, the visual deprivation effect was increased in control group but decreased in the stroke group. For somatosensory change effect, the interaction between group and treatment factor was not statistically significant.ConclusionPostural stability of hemiparetic stroke patients related to somatosensory information was improved after intake of usual dose of caffeine.

Sport-Specific Balance

This review includes the latest findings based on experimental studies addressing sport-specific balance, an area of research that has grown dramatically in recent years. The main objectives of this work were to investigate the postural sway response to different forms of exercise under laboratory and sport-specific conditions, to examine how this effect can vary with expertise, and to provide examples of the association of impaired balance with sport performance and/or increasing risk of injury. In doing so, sports where body balance is one of the limiting factors of performance were analyzed. While there are no significant differences in postural stability between athletes of different specializations and physically active individuals during standing in a standard upright position (e.g., bipedal stance), they have a better ability to maintain balance in specific conditions (e.g., while standing on a narrow area of support). Differences in magnitude of balance impairment after specific exercises (rebound jumps, repeated rotations, etc.) and mainly in speed of its readjustment to baseline are also observed. Besides some evidence on an association of greater postural sway with the increasing risk of injuries, there are many myths related to the negative influence of impaired balance on sport performance. Though this may be true for shooting or archery, findings have shown that in many other sports, highly skilled athletes are able to perform successfully in spite of increased postural sway. These findings may contribute to better understanding of the postural control system under various performance requirements. It may provide useful knowledge for designing training programs for specific sports.

Analysis of differences in postural stability in people with adult scoliosis and non specific low back pain

Methods Cotrel method was used to assess Cobb angle (CA) on plan x-ray. Using 14 markers, a two optoelectronic infrared cameras (Gemini, BTS spa, Milano, Italy) was used to perform a stabilometric test when patients were keeping a quite standing position with an eyes open trial (EOT), and eyes closed (ECT), and a distance between their feet (FD) as preferred. The Area of Reference Marker on the Ground (C7) (ARMG), Average Marker Speed (AMS) and length of the marker’s trajectory on the ground (LMG) were evaluated during ST.

Motor Difficulties in Autism Spectrum Disorder: Linking Symptom Severity and Postural Stability

Postural stability is a fundamental aspect of motor ability that allows individuals to sustain and maintain the desired physical position of one's body. The present study examined postural stability in average-IQ adolescents and adults with Autism Spectrum Disorder (ASD). Twenty-six individuals with ASD and 26 age-and-IQ-matched individuals with typical development stood on one leg or two legs with eyes opened or closed on a Wii balance board. Results indicated significant group differences in postural stability during one-legged standing, but there were no significant group differences during two-legged standing. This suggests that static balance during more complex standing postures is impaired in average-IQ individuals with ASD. Further, current ASD symptoms were related to postural stability during two-legged standing in individuals with ASD. Future directions and clinical implications are discussed.

Postural Stability in Patients With Knee Osteoarthritis: Comparison With Controls and Evaluation of Relationships Between Postural Stability Scores and International Classification of Functioning, Disability and Health Components

ObjectivesTo assess the differences in postural stability between patients with knee osteoarthritis and controls without knee osteoarthritis, and to evaluate possible relations between postural stability scores and International Classification of Functioning, Disability and Health (ICF) components. DesignAn age-matched, case-controlled trial with a cross-sectional design. SettingA teaching hospital. ParticipantsPatients with knee osteoarthritis (n=73) and age-matched controls (n=60). InterventionsData on patients’ postural stability and additional health-related variables were collected using various instruments. These included the Hospital Anxiety and Depression Scale, the Multidimensional Fatigue Inventory, the World Health Organization Quality of Life Brief Version, the physical function test (chair-rising time), the Chinese version of the Western Ontario and McMaster Universities Osteoarthritis Index, the Chinese version of the Knee Injury and Osteoarthritis Outcome Score, and the Biodex Stability System. Main Outcome MeasuresA comparison of postural stability in patients with knee osteoarthritis versus that of controls was performed. The relation between postural stability scores for patients with knee osteoarthritis and ICF components was evaluated. Pearson correlation tests were used to determine the variables that correlated with postural stability among these patients. ResultsPatients with knee osteoarthritis displayed lower overall postural stability than controls (scores of 0.7 vs. 0.5, P=.006) and scored lower on the environmental domain of the World Health Organization Quality of Life Brief Version (62.2 vs 66.8, P=.014). For patients with knee osteoarthritis, postural stability was weakly associated with the ICF components of body functions and structures, including pain (r=.33–.34, P=.004), physical fatigue (r=.28, P=.016), and reduced motivation (r=.30, P=.011). Weak to moderate associations between postural stability and the ICF components of activities and participation were found; the relevant ICF variables included reduced activity (r=.38, P=.001), physical domain and function (r=.34–.48, P=.001 to P<.004), activities of daily living (r=.51, P<.001), and sports and recreation (r=.35, P=.003). A moderate association between postural stability and the ICF components of personal and environmental factors was observed, including age (r=.52, P<.001) and quality of life (r=0.4, P=.001). ConclusionsPatients with knee osteoarthritis displayed lower postural stability and achieved lower scores in the environmental domain of quality-of-life measures than did controls. The postural stability of patients with knee osteoarthritis was weakly to moderately associated with the following ICF components: body functions and structures, activities and participation, and personal and environmental factors.

Gender Differences in Postural Stability Among Children

This study aimed to examine the gender differences in postural stability among 8–12 year-old children. Twenty-six children participated in this repeated measures study to measure the centre of pressure (COP) under one normal condition (CONTROL: hard surface, eyes open, and looking straight ahead) and two challenging sensory conditions (ECHB: eyes closed and head back; and EOCS: eyes open and compliant surface) in randomized order. Girls had significantly lower COP path velocity (COP-PV, p < 0.05, medium effect), smaller radial displacement (COP-RD, p < 0.05, medium effect), and lower area velocity (COP-AV, p < 0.05, medium effect) as compared to boys when the three conditions were pooled. Gender differences were found in the percentage changes in COP-RD during ECHB (p < 0.05, large effect) and EOCS (p < 0.05, medium effect), and in COP-AV during both ECHB and EOCS conditions (p < 0.05, medium effect). Postural stability performance of girls had higher correlations with age (−0.62 vs. −0.40), body mass (−0.60 vs. −0.42), foot length (−0.68 vs. −0.45), and physical activity level (−0.45 vs. 0.02), as compared to boys. Girls had better postural stability than boys but were more affected by altered sensory input information. Girls are more capable of integrating their sensory inputs, whereas boys treat each sensory input somewhat separately and rely more on somatosensory feedback. Exercises such as standing on unstable surfaces with eyes open instead of eye closed and head back are more beneficial to children’s postural stability control system.