Relationship Between Posturography,Clinical Balance and Executive Function in Parkinson´s Disease

This study aimed to evaluate the relationship between posturography, clinical balance, and executive function tests in Parkinson´s disease (PD). Seventy-one people participated in the study. Static posturography evaluated the center of pressure fluctuations in quiet standing and dynamic posturography assessed sit-to-stand, tandem walk, and step over an obstacle. Functional balance was evaluated by Berg Balance Scale, MiniBESTest, and Timed Up and Go test. Executive function was assessed by Trail Making Test (TMT) and semantic verbal fluency test. Step over obstacle measures (percentage of body weight transfer and movement time) were moderately correlated to Timed Up and Go, part B of TMT and semantic verbal fluency (r > 0.40; p < 0.05 in all relationships). Stepping over an obstacle assesses the responses to internal perturbations. Participants with shorter movement times and higher percentage of body weight transfer (higher lift up index) on this task were also faster in Timed Up and Go, part B of TMT, and semantic verbal fluency. All these tasks require executive function (problem solving, sequencing, shifting attention), which is affected by PD and contribute to postural assessment.     

Effects of Visual Manipulation in Sit-to-Stand Movement in Children With Cerebral Palsy

The authors sought to verify the effects of vision on sit-to-stand (STS) movement performance by means of postural sway in children with cerebral palsy (CP) and typical children (TC). Participants were 42 TC and 21 children with CP. STS movement was assessed with eyes open and with eyes closed. Area and velocity of center of pressure sway were analyzed in each of the 3 STS phases. We observed greater postural sway during STS movement with eyes closed. Children with CP presented greater postural sway than TC did. Both groups exhibited greater postural instability with absence of vision expressing the role of vision to keep postural stability. Moreover, the greater postural instability was observed in children with CP.     

Four Weeks of Neuromuscular Training Improve Static and Dynamic Postural Control in Overweight and Obese Children: A Randomized Controlled Trial

Abstract

Thirty-two children with overweight or obesity were randomly divided into a neuromuscular training group (NTG) (n = 16) and a control group (CG) (n = 16). All individuals participated in the measurement of static postural control under two conditions: the double-leg stance with eyes open (EO) and eyes closed (EC). The center of pressure variables was obtained. mSEBT was used for dynamic postural control. Neuromuscular training was performed twice per week and lasted 4 weeks. The results of this study indicate that 4 weeks of neuromuscular training improve static and dynamic postural control in children with excess body weight.     

The Effect of Action Observation Training on Balance and Sit to Walk in Chronic Stroke: A Crossover Randomized Controlled Trial

The aim of this study was to investigate the effects of an action observation training on balance and sit to walk in chronic stroke. Twenty-four chronic stroke patients participated in this study. Participants were randomly allocated to either the landscape imagery observation physical training group (LIOPT) or the action observation physical training group (AOPT). LIOPT observed a landscape picture for 2 min 30 s while the AOPT group observed related video recording. Both groups underwent a physical training session after the observation session for 12 min 30 s and the sessions were repeated twice a day, 3 times a week for 6 weeks. Outcome measures included Time Up and Go Test (TUG), Dynamic Gait Index (DGI), Weight Distribution Index (WDI), and limit of stability (LOS). Between-group and within-group comparisons were analyzed using the Mann-Whitney U test and Wilcoxon signed rank test, respectively. The AOPT and LIOPT groups have shown statistically significant differences in TUG, DGI, WDI, and LOS over time. However, no significant difference was observed in terms of TUG, DGI and WDI, but only in LOS between groups. These findings suggest that action observation training and physical training are effective to improve sit to walk and balance ability of chronic stroke patients.     

Functional balance and dual-task reaction times in older adults are improved by virtual reality and biofeedback training.

Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in both traumatic brain injury (TBI) survivors and elderly subjects. Similarly, computer-based biofeedback (BF) training has resulted in decreased sway during quiet stance and decreased reaction times during a dual-task reaction time paradigm in elderly subjects. The objective of this study was to determine the effect of VR and BF training on balance and reaction time in older adults. Two groups of twelve healthy older adults completed 10-week training programs consisting of two 30-min sessions per week. VR training required that participants lean sideways to juggle a virtual ball. Participants in the BF group viewed a red dot representing their center of gravity on a screen and were required to move the dot to the four corners of the monitor. Measures of functional balance and mobility (Community Balance and Mobility Scale [CB&M]), sway during quiet stance, and reaction time during a dual task paradigm were recorded before training, as well as 1 week and 1 month after the end of the program. Both groups showed significant improvements on the CB&M, as well as decreased reaction times with training. Postural sway during quiet stance did not change significantly.     

Effects of sensory manipulations on the dynamical structure of center-of-pressure trajectories of children with cerebral palsy during sitting

Aim: To investigate the effects of manipulating visual information and the compliance of the support surface on the area of sway and dynamical trajectories of center-of-pressure (CoP) in children with CP and children with typical development during static sitting. Methods: 32 typical children, 14 children with mild CP and 12 with moderate-to-severe CP were tested for CoP sway during static sitting under four sensory conditions: (1) eyes open on a rigid surface; (2) eyes closed on a rigid surface; (3) eyes open on foam; (4) eyes closed on foam. Results: Children with moderate-to-severe CP showed greater regularity and local stability of dynamical CoP trajectories and lower complexity in their motor patterns than typical children and children with mild CP. Moreover, removing vision and sitting on a compliant surface reduced the regularity of CoP trajectories. Conclusion: Children with CP were able to adjust the structure and complexity of their postural control responses to sensory challenges, although the structure of their postural responses was poorer than in typical children.     

Dynamics of postural control during bilateral stance – Effect of support area,visual input and age

The present study investigated the effect of support area, visual input and aging of the dynamics of postural control during bilateral stance. Fifteen young (22.1 ± 1.7 years) and fifteen older (68.3 ± 2.7 years) individuals completed four different 90 s bilateral stance trials: 1) shoulder wide feet distance with eyes open, 2) shoulder wide feet distance with eyes closed, 3) narrow feet distance with eyes open, and 4) narrow feet distance with eyes closed on a force plate form. The anterior (AP) and mediolateral (ML) center of pressure (COP) trajectories were calculated from the middle 60 s of the ground reaction forces and moments. Sample entropy (SaEn), correlation dimension (CoD), the largest Lyapunov exponent (LyE) and entropic half-life (ENT½) were calculated for the COP in both directions. In young individuals, a narrower support area resulted in a restricted movement solution space with lower SaEn, lower LyE and longer ENT½ in the executed motor control strategy, whereas it increased the CoD in the older individuals. During the eyes closed trials, SaEn, CoD and LyE increased and decreased ENT½ for both groups in the AP direction and increased SaEn and LyE in the ML direction for the older individuals alone. This indicates that aging is associated with direction- and task-dependent changes in the dynamics of the executed COP movements during postural stance tasks.     

Feasibility and acceptability of an exergame intervention for schizophrenia

ObjectivesTo evaluate the feasibility and acceptability of an exergame intervention as a tool to promote physical activity in outpatients with schizophrenia.DesignFeasibility/Acceptability Study and Quasi-Experimental Trial.MethodSixteen outpatients with schizophrenia received treatment as usual and they all completed an 8-week exergame intervention using Microsoft Kinect^® (20 min sessions, biweekly). Participants completed pre and post treatment assessments regarding functional mobility (Timed Up and Go Test), functional fitness performance (Senior Fitness Test), motor neurological soft signs (Brief Motor Scale), hand grip strength (digital dynamometer), static balance (force plate), speed of processing (Trail Making Test), schizophrenia-related symptoms (Positive and Negative Syndrome Scale) and functioning (Personal and Social Performance Scale). The EG group completed an acceptability questionnaire after the intervention.ResultsAttrition rate was 18.75% and 69.23% of the participants completed the intervention within the proposed schedule. Baseline clinical traits were not related to game performance indicators. Over 90% of the participants rated the intervention as satisfactory and interactive. Most participants (76.9%) agreed that this intervention promotes healthier lifestyles and is an acceptable alternative to perform physical activity. Repeated-measures MANOVA analyses found no significant multivariate effects for combined outcomes.ConclusionThis study established the feasibility and acceptability of an exergame intervention for outpatients with schizophrenia. The intervention proved to be an appealing alternative to physical activity. Future trials should include larger sample sizes, explore patients' adherence to home-based exergames and consider greater intervention dosage (length, session duration, and/or frequency) in order to achieve potential effects.     

Postural orientation: age-related changes in variability and time-to-boundary

The relation between age-specific postural instability and the detection of stability boundaries was examined. Balance control was investigated under different visual conditions (eyes open/closed) and postural orientations (forward/backward lean) while standing on a force platform. Dependent variables included center of pressure variability and the time-to-contact of the center of pressure with the stability boundaries around the feet (i.e., time-to-boundary). While leaning maximally, older individuals (ages 55-69) showed increased center of pressure variability compared to no lean, while younger subjects (ages 24-38) showed a decrease. These significant differences were found only in anterior-posterior direction. No significant age-specific differences were found between eyes open and eyes closed conditions. Time-to-boundary analysis revealed reduced spatio-temporal stability margins in older individuals in both anterior-posterior and medio-lateral directions. Time-to-boundary variability, however, was not significantly different between the groups in both medio-lateral and anterior-posterior direction. These results show the importance of boundary relevant center of pressure measures in the study of postural control, especially concerning the lateral instability often observed in older adults.     

Unilateral Stability and Visual Feedback Body Control Improves After Three-Month Resistance Training in Overweight Individuals

The authors evaluated the effect of 3 months of resistance and aerobic training (3 sessions/week) on body balance in a group of 25 overweight and obese individuals. Prior to and after the training, they performed static and task-oriented balance tests under various conditions. Mean center of pressure (CoP) velocity and mean trace length of the CoP in the y-axis registered during a one-legged stance significantly decreased after the resistance training (19.1%, p = .024; 29.3%, p = .009). Mean trace length of the CoP in the y-axis decreased significantly also during a bipedal stance on a foam surface with eyes open and closed (10.9%, p = .040; 18.2%, p = .027). In addition, mean CoP distance and mean squared CoP distance in the anteroposterior direction during a visually guided center of mass (CoM) tracking task significantly improved (14.7%, p = .033; 28.2%, p = .016). However, only mean trace length of the CoP in the y-axis during a bipedal stance on a foam surface with eyes open and closed significantly decreased after the aerobic training (10.3%, p = .047; 16.5%, p = .029). It may be concluded that resistance training is more efficient for the improvement of the anteroposterior unilateral stability and the accuracy of the regulation of the CoM anteroposterior position than aerobic training in overweight and obese individuals.     

Standing balance of children with developmental coordination disorder under altered sensory conditions

Maintenance of standing balance requires that sensory inputs be organized with the motor system. Current data regarding the influence of sensory inputs on standing balance in children with developmental coordination disorder (DCD) are limited. This study compared the influence of sensory organization and each sensory input on the standing stability between a group of 20 children, 4-6 years old, with DCD and an age- and gender-matched control group of 20 children. Three types of visual inputs (eyes open, eyes closed, or unreliable vision) and two types of somatosensory inputs (fixed or compliant foot support) were varied factorially to yield six sensory conditions. Standing stability was measured with a Kistler force plate for 30s and expressed as the center of pressure sway area. The results showed that the standing stability of the children with DCD was significantly poorer than that of the control children under all sensory conditions, especially when the somatosensory input was unreliable (compliant foot support) compared to when it was reliable (fixed foot support). The effectiveness of an individual sensory system, when it was the dominant source of sensory input, did not significantly differ between the groups. The results suggest that children with DCD experience more difficulty coping with altered sensory inputs, and that such difficulty is more likely due to a deficit in sensory organization rather than compromised effectiveness of individual sensory systems.     

Application of virtual reality graphics in assessment of concussion.

Abnormal balance in individuals suffering from traumatic brain injury (TBI) has been documented in numerous recent studies. However, specific mechanisms causing balance deficits have not been systematically examined. This paper demonstrated the destabilizing effect of visual field motion, induced by virtual reality graphics in concussed individuals but not in normal controls. Fifty five student-athletes at risk for concussion participated in this study prior to injury and 10 of these subjects who suffered MTBI were tested again on day 3, day 10, and day 30 after the incident. Postural responses to visual field motion were recorded using a virtual reality (VR) environment in conjunction with balance (AMTI force plate) and motion tracking (Flock of Birds) technologies. Two experimental conditions were introduced where subjects passively viewed VR scenes or actively manipulated the visual field motion. Long-lasting destabilizing effects of visual field motion were revealed, although subjects were asymptomatic when standard balance tests were introduced. The findings demonstrate that advanced VR technology may detect residual symptoms of concussion at least 30 days post-injury.     

Lower Extremity Kinetics for Balance Control in Children With Cerebral Palsy

The authors examined and compared the effect of support-surface perturbations of various magnitudes on lower extremity kinetics of 7 children with cerebral palsy (CP) and 8 typically developing (TD) children. Results showed that the highest velocity tolerated without stepping was slower in children with CP than in either age-matched TD or younger TD children. Multimodal torque profiles were more frequent in children with CP than in TD controls. TD groups temporally and spatially organized torque activation, whereas children with CP activated all joints simultaneously and showed altered torque contribution patterns among joints. Those results suggest that impairments in reactive postural control in children with CP result not only from developmental delay but also from pathology. Evidence for pathology included increased numbers of torque bursts required to regain stability and less efficient temporal and spatial organization of torque activation patterns.     

Changes in dynamic balance control over time in children with and without Developmental Coordination Disorder

The aim of this study was to examine differences in underlying adaptations of dynamic balance in children with and without Developmental Coordination Disorder (DCD) during a Wii Fit game and to measure changes over time and after intervention.Twenty-eight children with DCD and 21 typically developing (TD) children participated in the study. Analyses of force plate variables showed that the TD group initially used a longer path length for the ski slope descent and tended toward more variation in Center of Pressure (CoP) displacement in lateral direction than the children with DCD. In contrast, the TD group showed a trend of fewer reversals per cm in both AP and lateral direction. After the nonintervention period, the TD group improved performance by decreasing the path length, while the DCD group improved by increasing the path length and by decreasing the number of reversals. After intervention, no changes were found in sway characteristics. Individual analyses within the DCD group showed that the path length per run fell more often within the 95% confidence Interval of the faultless runs. In conclusion both TD and DCD children modify the underlying kinetics of dynamic balance control, but in different ways and both lead to better performance.     

Improving dynamic balance by self-controlled feedback in children with cerebral palsy

AimsMaintaining balance is an important topic for participation of children with Cerebral Palsy (CP) in their own activities. Purpose of the present study was to investigate the effect of self-controlled and yoked-group feedback on dynamic balance of children with Spastic Hemiplegic Cerebral Palsy (SHCP).MethodsUsing Convenience Sampling Method, twenty students with Cerebral Palsy, aged 8–10 years old, were selected from special schools and divided into the Self-Controlled (SC) and Yoked feedback groups. Children in SC group requested feedback when necessary during the acquisition phase; in contrast, participants in yoked group replicated the feedback schedule of their counterparts in SC group without any choice. Modified Star Excursion Balance Test (SEBT) was used for both dynamic balance intervention and assessment. To analyze the data, Multivariate Analysis of Covariance (MANCOVA) and Analysis of Covariance (ANCOVA) Tests were performed at p < 0.05.ResultsBased on MANCOVA test results, a significant difference were found between SC and Yoked groups after controlling for pretest at least in one balance variables (anterior, posterolateral, and posteromedial). Results of ANCOVA test showed a significant difference between the balance variables in the anterior, Posterolateral, and posteromedial directions in children with cerebral palsy.ConclusionsFindings of our study support the idea that requested feedback in SC conditions could have more benefits for motor learning since it is adjusted with the needs and preferences of children.     

Postural control in children with and without neurofibromatosis type 1

Previous research has evaluated the motor proficiency of children with neurofibromatosis type 1 (NF1) and found delays on the balance subtest. However the balance subtest was found to have low sensitivity for identifying balance impairments. This study examines the differences in postural control between children with NF1 and peers with typical development using a force plate. A single limb stance test on a force plate was completed for all participants. The force plate variables, center of pressure maximum distance in the anterior/posterior direction (COPmax A/P) and center of pressure velocity (COPvel A/P) were compared between groups. The NF1 group’s performance was significantly poorer than the control group in both COPmax A/P (p = .01) and COPvel A/P (p = .01). When separated into specific age ranges, only the children in the NF1 group between 5 and 12 years of age demonstrated statistically significant differences in the COP variables. The COP variables for the 13- to 18-year-old group were not significantly different. These results indicate that young children with NF1 have poor postural control. However, postural control appears to improve with maturation.     

The impact of Wii Fit intervention on dynamic balance control in children with probable Developmental Coordination Disorder and balance problems

The aim of this study was to examine differences in the performance of children with probable Developmental Coordination Disorder (p-DCD) and balance problems (BP) and typical developing children (TD) on a Wii Fit task and to measure the effect on balance skills after a Wii Fit intervention.Twenty-eight children with BP and 20 TD-children participated in the study. Motor performance was assessed with the Movement Assessment Battery for Children (MABC2), three subtests of the Bruininks Oseretsky Test (BOT2): Bilateral Coordination, Balance and Running Speed & Agility, and a Wii Fit ski slalom test. The TD children and half of the children in the BP group were tested before and after a 6 weeks non-intervention period. All children with BP received 6 weeks of Wii Fit intervention (with games other than the ski game) and were tested before and afterwards.Children with BP were less proficient than TD children in playing the Wii Fit ski slalom game. Training with the Wii Fit improved their motor performance. The improvement was significantly larger after intervention than after a period of non-intervention. Therefore the change cannot solely be attributed to spontaneous development or test–retest effect. Nearly all children enjoyed participation during the 6 weeks of intervention. Our study shows that Wii Fit intervention is effective and is potentially a method to support treatment of (dynamic) balance control problems in children.     

Slow gait as a motor marker of mild cognitive impairment? the relationships between functional mobility and mild cognitive impairment

The purpose of this study was to evaluate the association between functional mobility and mild cognitive impairment in older adults. A total of 800 older adults were recruited (653 controls and 147 subjects with MCI [88 subjects with aMCI and 59 subjects with naMCI]). Motor performance was measured with the Timed Up and Go test (TUG). The demographic factors associated with MCI were: age (OR = 1.05; 95% CI: 1.01–1.09) and the level of education (OR = 0.73; 95% CI: 0.68–0.79). An independent clinical factor associated with MCI was the TUG (OR = 1.14; 95% CI: 1.03–1.27). In the aMCI group, the relation between the TUG and cognitive status occurred (OR = 1.15; 95% CI: 1.02–1.31), whereas in the naMCI group this relationship was not observed. There is an association between cognitive dysfunction and impaired motor performance in older adults with MCI.     

Head and Trunk Control While Walking in Older Adults with Diabetes: Effects of Balance Confidence

Investigations of gait in older adults with diabetes mellitus (DM) have been primarily focused on lower limb biomechanical parameters. Yet, the upper body accounts for two thirds of the body's mass, and head and trunk control are critical for balance. The authors examined head and trunk control during self-selected comfortable, fast, and dual-task walking and the relationship between balance confidence and potential head-trunk stiffening strategies in older adults with DM without diagnosed diabetic peripheral neuropathy (DPN). Twelve older adults with DM without diagnosed DPN (DM group) and 12 without DM (no-DM group) were recruited. Walking speed, peak-to-peak head and trunk roll displacement, head and trunk roll velocity, and head-trunk correlation were measured while walking at a self-selected comfortable or fastest possible speed with or without a secondary cognitive task. The Activities-specific Balance Confidence scale measured balance confidence. Subtle group differences in axial segmental control (lower trunk roll velocity; higher head-trunk correlation) were apparent in older adults with DM even in the absence of DPN. Balance confidence was 19% lower in the DM group than in the no-DM group, and partially explained (34%) the group difference in head-trunk stiffening. These results emphasize the need for proactive monitoring of postural control and balance confidence before the onset of DPN.     

Effects of an external focus of attention and target occlusion on performance in virtual reality

The use of virtual reality as a training mechanism continues to gain popularity as equipment becomes more readily available. It is important to not only understand the relationship between virtual reality training and motor learning, but to understand the extent to which practice manipulations enhance performance in virtual reality. One common practice manipulation is adopting an external focus of attention, which has been shown to facilitate motor learning in a variety tasks. The purposes of the present study were to investigate the effectiveness of an external focus of attention and the effects of target occlusion times in virtual reality. Fifty-six participants performed a single-leg long jump during baseline, training, and retention and were randomly assigned to either an external or control group. During baseline and retention, all participants performed the task in both a virtual reality (VR) and real world (RW) environments. Training was all done in VR where participants were provided an external focus cue or no cue. Results revealed that individuals jumped significantly further in RW than VR in both baseline and retention (p < .001). During training, the external group jumped significantly further than control (p < .05). These results suggest that the adoption of an external focus improves performance during training. However, we did not see a benefit of an external focus in retention. These findings should be taken into consideration when using virtual reality as a training tool when performance must be transferred to a real world environment.