Validity of the Nintendo Wii Balance Board to assess weight bearing asymmetry during sit-to-stand and return-to-sit task

Multimodal analysis of the biomechanical impact of knee angle on the Sit-to-Stand transition

BACKGROUND

The Sit-to-Stand (STS) transition is one of the most used activities of daily living and vital for independence. Neurological, or physical injuries impairing functional mobility or sensory feedback often require rehabilitative programs or therapeutic interventions. Understanding the biomechanical elements of daily movements and the interaction between these elements may help inform rehabilitation protocols and optimize targeted interventions, such as stimulation protocols.

RESEARCH QUESTION

What are the effects of different initial knee angle, arm facilitation and proprioceptive input on leg muscle activation patterns and balance during and after a sit-to-stand?

METHODS

EMG of four lower limb muscles were recorded in 20 healthy participants as well centre-of-pressure sway amplitude and velocity, as participants stood from a seated position. Initial knee angles were set to various levels of extension (80°, 90°, 100°) and surface stability and arm facilitation were altered using a foam mat or crossing arms. Data were analysed across 3 phases of the STS transition.

RESULTS

More extended knee angles resulted in greater mediolateral sway during each phase (p < .01) and had a detrimental effect on anterior-posterior sway in phases 1 and 3. EMG data suggested more extended initial knee angles also increased EMG activity of the Tibialis Anterior (p < .001) and Bicep Femoris (p < .02) within Phases 1 and 2 to assist lift and stabilisation.

SIGNIFICANCE

Findings of this study outline phase-based muscle involvement as well as the compounding effects of reduced proprioceptive input and knee angle, on difficulty of the STS transition. Such results emphasising the need to take sensory and mobility issues into consideration when designing rehabilitative programs or stimulation control systems.

Artificial Intelligence Distinguishes Pathological Gait: The Analysis of Markerless Motion Capture Gait Data Acquired by an iOS Application (TDPT-GT)

Distinguishing pathological gait is challenging in neurology because of the difficulty of capturing total body movement and its analysis. We aimed to obtain a convenient recording with an iPhone and establish an algorithm based on deep learning. From May 2021 to November 2022 at Yamagata University Hospital, Shiga University, and Takahata Town, patients with idiopathic normal pressure hydrocephalus (n = 48), Parkinson's disease (n = 21), and other neuromuscular diseases (n = 45) comprised the pathological gait group (n = 114), and the control group consisted of 160 healthy volunteers. iPhone application TDPT-GT captured the subjects walking in a circular path of about 1 meter in diameter, a markerless motion capture system, with an iPhone camera, which generated the three-axis 30 frames per second (fps) relative coordinates of 27 body points. A light gradient boosting machine (Light GBM) with stratified k-fold cross-validation (k = 5) was applied for gait collection for about 1 min per person. The median ability model tested 200 frames of each person's data for its distinction capability, which resulted in the area under a curve of 0.719. The pathological gait captured by the iPhone could be distinguished by artificial intelligence.

Effectiveness of the Epley maneuver versus Cawthorne-Cooksey vestibular exercises in the treatment of posterior semicircular canal benign paroxysmal positional vertigo (BPPV): A randomized controlled trial

OBJECTIVE

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo that mainly affects the posterior semicircular canal. Studies suggest that Epley maneuver could improve balance of patients, but Cawthorne-Cooksey vestibular exercises are still scarce. This study aimed to observe the effects of Cawthorne-Cooksey vestibular exercises applied after the Epley maneuver on balance, vertigo symptoms, and quality of life in posterior semicircular canal BPPV.

METHODS

Thirty-six patients with posterior semicircular canal BPPV were randomly assigned into Epley maneuver (EpleyM) and Epley maneuver and exercise (EpleyM&Exe) groups. All patients were treated with the Epley maneuver, while Cawthorne-Cooksey vestibular exercises were given to the EpleyM&Exe group as home exercises for 6 weeks. Their static and dynamic balance, vertigo symptoms, and quality of life were assessed at pre-, post-intervention (1st, 3rd and 6th weeks).

RESULTS

Thirty-two patients completed the study (mean age: 46.91 ± 9.78 years). Epley maneuver applied alone and combined with Cawthorne-Cooksey vestibular exercises, was found to be effective in 25 patients (78.1%), 6 patients (18.8%) and 1 patient (3.1%) at the 1st, 3rd and 6th weeks, respectively. After 6 weeks, both groups had gained significant improvements in balance, vertigo symptoms, and quality of life (p < 0.001); however, there were no significant differences between the groups, except for the static dominant leg balance test (p = 0.022).

CONCLUSIONS

The Epley maneuver can be considered as the first option compared to Cawthorne-Cooksey vestibular exercises. Exercises do not appear to have any additional effects in improving posterior semicircular canal BPPV symptoms.

A review of center of pressure (COP) variables to quantify standing balance in elderly people: Algorithms and open-access code

Postural control is often quantified by recording the trajectory of the center of pressure (COP)-also called stabilogram-during human quiet standing. This quantification has many important applications, such as the early detection of balance degradation to prevent falls, a crucial task whose relevance increases with the aging of the population. Due to the complexity of the quantification process, the analyses of sway patterns have been performed empirically using a number of variables, such as ellipse confidence area or mean velocity. This study reviews and compares a wide range of state-of-the-art variables that are used to assess the risk of fall in elderly from a stabilogram. When appropriate, we discuss the hypothesis and mathematical assumptions that underlie these variables, and we propose a reproducible method to compute each of them. Additionally, we provide a statistical description of their behavior on two datasets recorded in two elderly populations and with different protocols, to hint at typical values of these variables. First, the balance of 133 elderly individuals, including 32 fallers, was measured on a relatively inexpensive, portable force platform (Wii Balance Board, Nintendo) with a 25-s open-eyes protocol. Second, the recordings of 76 elderly individuals, from an open access database commonly used to test static balance analyses, were used to compute the values of the variables on 60-s eyes-open recordings with a research laboratory standard force platform.

Comparison of the Effect and Complications of Sequential Bilateral Arthroplasty at Different Time Intervals and Simultaneous Bilateral Total Knee Arthroplasty: A Single-Centre Retrospective Cohort Study

INTRODUCTION

To the authors' knowledge, there is no current consensus regarding the optimal interprocedural interval for patients who have undergone bilateral total knee arthroplasty (BTKA). The purpose of this study is to evaluate complication rates and functional outcome in patients who have undergone BTKA (simultaneous or sequential at different time intervals), and to determine an optimal time frame for the second knee.

METHODS

Data from 315 patients who were able to tolerate simultaneous BTKA according to the anaesthesiologist's preoperative assessment between 2016 and 2020 were analysed retrospectively. According to the operative time interval, they were divided into simultaneous, ≤ 1-month sequential, 1- to 3-month sequential, and ≥ 3-month sequential BTKA groups. The primary outcomes were revision and readmission rates during the follow-up period, and the secondary outcomes were hospital length of stay (LOS), transfusion and postoperative complications.

RESULTS

There was no difference in the implant survival or readmission rate between the groups (p > 0.05). Multivariable linear regression showed that interprocedural interval and body mass index (BMI) affected LOS; the LOS of simultaneous BTKA was the shortest (p < 0.05). BMI was associated with an increased LOS of 0.25 days (95% CI 0.02-0.48, p = 0.03). A modified Poisson regression model showed that the odds of blood transfusion were reduced in sequential BTKAs of any interval (p < 0.05), and preoperative haemoglobin (Hb) was also a risk factor (RR 0.96, 95% CI 0.95-0.98, p < 0.001). The interprocedural interval was not a risk factor for postoperative cardiovascular and cerebrovascular complications.

CONCLUSION

For appropriate patients, simultaneous BTKA is beneficial. However, higher preoperative haemoglobin was required to mitigate the high blood transfusion rate associated with simultaneous surgeries. If suitable patients refuse simultaneous BTKA for other non-medical reasons, sequential BTKA with an interval greater than 1 month is recommended.

The Use of Gamification in Patients Undergoing Hip Arthroplasty: Scoping Review

Objective: The use of gamification can promote health-related behavior. This article is the first attempt to provide a historical overview of the use of games in patients undergoing hip arthroplasty. Materials and Methods: We conducted a scoping review to map and characterize the games used for the person undergoing hip arthroplasty. To perform this review, the respective descriptors were identified using search syntax appropriate to each of the databases: MEDLINE_ (Medical Literature Analysis and Retrieval System Online), CINAHL_ (Cumulative Index to Nursing and Allied Health Literature), SPORTDiscus, in the Psychology and Behavioral Sciences Collection, SCOPUS, SciELO (Scientific Electronic Library Online), and PEDRo (Physiotherapy Evidence Database). Results: An initial 968 articles were identified, of which 7 articles were included. The domains of the games under analysis essentially focus on aspects of rehabilitation (n = 5), or related (n = 2), and mostly exergames (n = 6). However, the instruments, characteristics, and procedures used to evaluate the games in the included studies have little depth and large variability. Conclusion: Few games exist that support people who have undergone hip arthroplasty. Most of the games under review were exergames to support rehabilitation. Consequently, we recommend developing another type of game with a focus on monitoring, counseling, and/or social support for selfmanagement training in persons undergoing hip arthroplasty.

The Effects of Short-Term Visual Feedback Training on the Stability of the Roundhouse Kicking Technique in Young Karatekas

The aim of this study was to assess the efficacy of using real-time visual feedback (VF) during a one-week balance training intervention on postural sway parameters in young karatekas. Twenty-six young male karatekas (age = 14.0 ± 2.3 years) were randomly divided into two groups: real-time VF training (VFT; n = 14) and control (CTRL; n = 12). Their center of pressure (COP) displacement (path length, COPpl; distance from origin, COPod) was assessed pre- and post-training on a Wii Balance Board platform in two positions (Flex: knee of the supporting leg slightly bent, maximum hip and leg flexion of the other leg; Kick: knee of the supporting leg slightly bent, mawashi-geri posture for the kicking leg). Both groups trained twice a day for seven days, performing a one-legged stance on the non-dominant limb in the Kick position. During the training, VFT received real-time VF of COP displacement, while CTRL looked at a fixed point. No interaction effect was found (p > 0.05). VFT exhibited greater changes pre- and post-training in Flex COPpl (-25.2%, g = 1.5), Kick COPpl (-24.1%, g = 1.3), and Kick COPod (-44.1%, g = 1.0) compared to CTRL (-0.9--13.0%, g-range: 0.1-0.7). It is possible that superimposing real-time VF to a week-long balance training intervention could induce a greater sport-specific balance-training effect in young karatekas.

Digital bathroom scales with open source software provide valid dynamic ground reaction force data for assessment and biofeedback

BACKGROUND

Measuring dynamic vertical ground reaction force allows for assessment of important clinical and physical capacity factors such as weight bearing asymmetry, force distribution, and rate of force development. However, current technologies for accurately assessing ground reaction force are typically expensive.

RESEARCH QUESTION

The aim of this study was to examine the validity and reliability of obtaining static and dynamic ground reaction force data from low-cost modified digital bathroom scales.

METHODS

Four modified bathroom scales, two units each of two different brands, were examined. Repeated mechanical loading trials were performed with known loads ranging from 0.01 to 65 kg, with acquired data compared against the known loading to calculate accuracy, hysteresis, and non-linearity. Dynamic trials consisting of 5 times sit-to-stand and weight-shifting were performed by 32 adults. Absolute and relative agreement intraclass correlation coefficient, and Pearson's and Spearman's correlations were performed to determine validity and reliability for the mechanical tests. Bland-Altmann plots were created for each comparison. Mean absolute error (MAE) and unbiased cross-correlation were performed on the dynamic data, comparing the calibrated data to the known values from a Bertec force platform.

RESULTS

Hysteresis and non-linearity were excellent (<0.2 % full-scale), and mechanical test results showed excellent reliability and validity. Cross-correlation results for the dynamic data were excellent, however MAE for the more rapid sit-to-stand task was higher than the slower weight-shifting test. This may have been due to the low default sampling rate for the lowest noise setting of the HX711 amplifier (10 Hz).

SIGNIFICANCE

In summary, our results suggest that digital bathroom scales can be easily and inexpensively modified to obtain accurate vertical ground reaction force data, with sensitivity to detect changes of as little as 0.01 kg.

Postadychute-AG, Detection, and Prevention of the Risk of Falling Among Elderly People in Nursing Homes: Protocol of a Multicentre and Prospective Intervention Study

Introduction: While falls among the elderly is a public health issue, because of the social, medical, and economic burden they represent, the tools to predict falls are limited. Posturography has been developed to distinguish fallers from non-fallers, however, there is too little data to show how predictions change as older adults' physical abilities improve. The Postadychute-AG clinical trial aims to evaluate the evolution of posturographic parameters in relation to the improvement of balance through adapted physical activity (APA) programs. Methods: In this prospective, multicentre clinical trial, institutionalized seniors over 65 years of age will be followed for a period of 6 months through computer-assisted posturography and automatic gait analysis. During the entire duration of the follow-up, they will benefit from a monthly measurement of their postural and locomotion capacities through a recording of their static balance and gait thanks to a software developed for this purpose. The data gathered will be correlated with the daily record of falls in the institution. Static and dynamic balance measurements aim to extract biomechanical markers and compare them with functional assessments of motor skills (Berg Balance Scale and Mini Motor Test), expecting their superiority in predicting the number of falls. Participants will be followed for 3 months without APA and 3 months with APA in homogeneous group exercises. An analysis of variance will evaluate the variability of monthly measures of balance in order to record the minimum clinically detectable change (MDC) as participants improve their physical condition through APA. Discussion: Previous studies have stated the MDC through repeated measurements of balance but, to our knowledge, none appear to have implemented monthly measurements of balance and gait. Combined with a reliable measure of the number of falls per person, motor capacities and other precipitating factors, this study aims to provide biomechanical markers predictive of fall risk with their sensitivity to improvement in clinical status over the medium term. This trial could provide the basis for posturographic and gait variable values for these elderly people and provide a solution to distinguish those most at risk to be implemented in current practice in nursing homes. Trial Registration: ID-RCB 2017-A02545-48. Protocol Version: Version 4.2 dated January 8, 2020.

A Novel Simplified System to Estimate Lower-Limb Joint Moments during Sit-to-Stand

To provide effective diagnosis and rehabilitation, the evaluation of joint moments during sit-to-stand is essential. The conventional systems for the evaluation, which use motion capture cameras, are quite accurate. However, the systems are not widely used in clinics due to their high cost, inconvenience, and the fact they require lots of space. To solve these problems, some studies have attempted to use inertial sensors only, but they were still inconvenient and inaccurate with asymmetric weight-bearing. We propose a novel joint moment estimation system that can evaluate both symmetric and asymmetric sit-to-stands. To make a simplified system, the proposal is based on a kinematic model that estimates segment angles using a single inertial sensor attached to the shank and a force plate. The system was evaluated with 16 healthy people through symmetric and asymmetric weight-bearing sit-to-stand. The results showed that the proposed system (1) has good accuracy in estimating joint moments (root mean square error < 0.110 Nm/kg) with high correlation (correlation coefficient > 0.99) and (2) is clinically relevant due to its simplicity and applicability of asymmetric sit-to-stand.

Adversarial autoencoder for visualization and classification of human activity: Application to a low-cost commercial force plate

The ability to visualize and interpret high dimensional time-series data will be critical as wearable and other sensors are adopted in rehabilitation protocols. This study proposes a latent space representation of high dimensional time-series data for data visualization. For that purpose, a deep learning model called Adversarial AutoEncoder (AAE) is proposed to perform efficient data dimensionality reduction by considering unsupervised and semi-supervised adversarial training. Eighteen subjects were recruited for the experiment and performed two sets of exercises (upper and lower body) on the Wii Balance Board. Then, the accuracy of the latent space representation is evaluated on both sets of exercises separately. Data dimensionality reduction with conventional Machine Learning (ML) and supervised Deep Learning (DL) classification are also performed to compare the efficiency of AAE approaches. The results showed that AAE can outperform conventional ML approaches while providing close results to DL supervised classification. AAE approaches for data visualization are a promising approach to monitor the subject's movements and detect adverse events or similarity with previous data, providing an intuitive way to monitor the patient's progress and provide potential information for rehabilitation tracking.

Insole-Based Estimation of Vertical Ground Reaction Force Using One-Step Learning With Probabilistic Regression and Data Augmentation

An insole-based estimation of the vertical ground reaction force (vGRF) is proposed as an alternative to costly force plates for the evaluation of pathological gait. However, machine learning techniques for estimation still rely on the use of force plates. Moreover, measuring plural walking steps in order to prevent overfitting induces fall risks and physically taxes the patients. Therefore, this paper presents an accessible and efficient learning scheme for the insole-based estimation of vGRF. In this system, we employ a low-cost scale as an alternative to force plates. Then, we use Gaussian process regression (GPR) to learn a model in order to estimate vGRF without overfitting of small-sized data sets corrupted by measurement errors and noise of the devices. In addition, we propose a "one-step learning" scheme based on a probabilistic data augmentation. This approach augments actual measurements of a minimum (just one) walking step to a virtual data set for plural steps by considering their typical variability between steps. In experiments, the GPR models learned from two walking steps estimated vGRF with mean errors of 8% or under for entire/local magnitudes. Moreover, the learning from one step with probabilistic augmentation enhanced the estimation accuracy.

The contralateral knee may not be a valid control for biomechanical outcomes after unilateral total knee arthroplasty

BACKGROUND

Although unilateral symptoms and unilateral total knee arthroplasty (TKA) are common, many patients have bilateral radiographic osteoarthritis (OA). Because the contralateral (non-operated) limb is often used as a comparison for clinical and biomechanical outcomes, it is important to know if the presence of OA influences movement patterns in either limb.

RESEARCH QUESTION

The purpose of this study was to compare bilateral sagittal plane biomechanics between subjects with and without contralateral knee OA after unilateral TKA.

METHODS

Fifty-three subjects who underwent unilateral TKA underwent three-dimensional gait analysis 6-24 months after surgery participated in this cross-sectional study. Kellgren-Lawrence (KL) OA severity in the contralateral limb was measured, and subjects were classified into either a non-OA (KL 0 or 1) or OA (KL 2-4) group. Mixed-model ANOVA tests with factors of group and limb were used to compare biomechanical measures. In the presence of a significant interaction effect, post-hoc comparisons were performed.

RESULTS

The OA group had more knee flexion at initial contact, less knee flexion and extension excursions, and less knee extension in the contralateral limb compared to the non-OA group. The non-OA group had significant differences between limbs, with more knee flexion at initial contact, less knee joint excursion, and less peak knee extension on the operated limb compared to the contralateral limb, whereas there were no limb differences for the OA group. Kinetic variables were not different in the ANOVA models.

SIGNIFICANCE AND INTERPRETATION

Subjects with contralateral knee OA have more symmetrical gait, although they adopt a more abnormal and stiff-legged gait pattern bilaterally. Researchers and clinicians should consider radiographic disease severity, not just symptoms, in the contralateral limb when identifying appropriate subject samples for unilateral biomechanical studies. Symmetrical movement patterns between limbs after surgery should not be the sole factor upon which movement recovery is based.

Concurrent Validity of Depth-Sensing Cameras for Noncontact ACL Injury Screening During Side-Cut Maneuvers in Adolescent Athletes: A Preliminary Study

Anterior cruciate ligament (ACL) injury is one of the most common knee injuries among adolescent athletes. Majority of the ACL injuries occur due to pivoting, sudden deceleration, and direction change without contact with any player. Preventive interventions can reduce risks of the ACL injury, thus developing a clinician friendly biomechanical assessment tool to identify athletes with such risk factors is crucial. In this study, the authors investigated the concurrent validity of a commercially available depth sensor, Microsoft Kinect, as a cost-effective alternative to the gold-standard 3-dimensional motion analysis systems in noncontact ACL screening for adolescent athletes during side-cut maneuvers. Study participants performed 45° side-cut maneuvers while collecting data from both systems concurrently. The sagittal and frontal plane kinematics were analyzed during the full stance phase and the first 20% of the stance (early deceleration). Absolute agreement (range: ICC = .767-.989) and consistency (range: ICC = .799-.992) were excellent for all measures except early deceleration frontal plane hip angle, which displayed good absolute agreement (ICC = .643) and consistency (ICC = .625). Findings showed that the Kinect has the potential to be an effective clinical assessment tool for sagittal and frontal plane trunk, hip, and knee kinematics during the side-cut maneuvers.

Development and Assessment of a Low-Cost Clinical Gait Analysis System

Clinically, measuring gait kinematics and ground reaction force (GRF) is useful to determine the effectiveness of treatment. However, it is inconvenient and expensive to maintain a laboratory-grade gait analysis system in most clinics. The purpose of this study was to validate a Wii Balance Board, Kinovea motion-tracking software, and a video camera as a portable, low-cost system, and overground gait analysis system. We validated this low-cost system against a multicamera Vicon system and research-grade force platform (Advanced Mechanical Technology, Inc). After validation trials with known weights and angles, 5 subjects walked across an instrumented walkway for multiple times (n = 8/subject). We collected vertical GRF and segment angles. Average GRF data from the 2 systems were similar, with peak GRF errors below 3.5%BW. However, variability in the balance board's sampling rate led to large GRF errors early and late in stance, when the GRF changed rapidly. The thigh, shank, and foot angle measurements were similar between the single and multicamera, but the pelvis angle was far less accurate. The proposed system has the potential to provide accurate segment angles and peak GRF at low cost but does not match the accuracy of the multicamera system and force platform, in part because of the Wii Balance Board's variable sampling rate.

The effect of time restricted visual sensory input on asymmetry of ground reaction force components in female children

The association between visual sensory and the asymmetry index of sit-to-stand ground reaction force characteristics is not fully understood. Therefore, the purpose of this study was to investigate asymmetry index of sit-to-stand ground reaction forces, their times-to-peak, vertical loading rate, impulses, and free moment in blind and sighted children. 15 female children with congenital blindness and 30 healthy girls with no visual impairments volunteered to participate in this study. The girls with congenital blindness were placed in one group and the girls with no visual impairments were randomly divided into two groups of 15. The two condition groups consisted of, one eyes open and the other, eyes closed. The participants in the eyes closed group were asked to close their eyes for 20 min before the test, whereas those in the eyes open group kept their eyes open. Kinematic and kinetic data were collected using an eight-camera motion analysis system synchronized with two force plates embedded in the floor. A MANOVA test was run for between-group comparisons. There were no distinctive biomechanical alternations in all axes of ground reaction forces and their times-to-peak, vertical loading rate, impulses and free moments in congenital blindness and eyes closed groups compared with the eyes open group. However, eyes closed was associated with increased total time and second phase duration of sit-to-stand performance by 69% (p = 0.008) and 62% (p = 0.008), respectively. These findings reveal that individuals who are visually restricted in the short term, do not develop stereotypical movement strategies for sit-to-stand.

Balance assessment during squatting exercise: A comparison between laboratory grade force plate and a commercial, low-cost device

Testing balance through squatting exercise is a central part of many rehabilitation programs and sports and plays also an important role in clinical evaluation of residual motor ability. The assessment of center of pressure (CoP) displacement and its parametrization is commonly used to describe and analyze squat movement and the laboratory-grade force plates (FP) are the gold standard for measuring balance performances from a dynamic view-point. However, the Nintendo Wii Balance Board (NWBB) has been recently proposed as an inexpensive and easily available device for measuring ground reaction force and CoP displacement in standing balance tasks. Thus, this study aimed to compare the NWBB-CoP data with those obtained from a laboratory FP during a dynamic motor task, such as the squat task. CoP data of forty-eight subjects were acquired simultaneously from a NWBB and a FP and the analyses were performed over the descending squatting phase. Outcomes showed a very high correlation (r) and limited root-mean-square differences between CoP trajectories in anterior-posterior (r > 0.99, 1.63 ± 1.27 mm) and medial-lateral (r > 0.98, 1.01 ± 0.75 mm) direction. Spatial parameters computed from CoP displacement and ground reaction force peak presented fixed biases between NWBB and FP. Errors showed a high consistency (standard deviation < 2.4% of the FP outcomes) and a random spread distribution around the mean difference. Mean velocity is the only parameter which exhibited a tendency towards proportional values. Findings of this study suggested the NWBB as a valid device for the assessment and parametrization of CoP displacement during squatting movement.

Test-retest reliability of the Wii Balance Board for assessing standing balance in young people with intellectual disability

Objectives: The main objective was to identify the test-retest reliability of the Wii Balance Board (WBB) for assessing standing balance when administered to a population of people with intellectual disability (ID). A secondary objective was to provide information regarding the reliability of the WBB, taking into account the severity of cognitive impairment. Methods: The WBB was administered two times to a group of 50 people (mean age: 20.44 ± 5.73 years) with mild (n=32), moderate (n=6), or severe ID (n=12) within a 15-day period. The relative reliability of the WBB for the 'standing balance with open eyes' test was analyzed by means of intraclass correlation coefficients (ICCs). The standard error measurement and the minimum detectable change were used to identify absolute reliability. Results: For the whole sample, the WBB showed a fair (ICC=0.71), poor (ICC=0.66), and excellent (ICC=0.99) relative reliability for assessing weight-bearing asymmetry, center of pressure, path length, and sway area, respectively. In people with moderate/severe ID, statistically significant differences between the WBB test and retest scores were found. The absolute reliability of the WBB was considered poor. Conclusion: The WBB showed accurate adequate test-retest reliability for assessing standing balance in young people with ID. When using this device with people with moderate/severe ID, it is advisable to perform several testing trials, in order to avoid a possible learning effect. Standard error of measurement and minimal detectable change were high, indicating that this device might not be sensitive enough to properly identify static balance changes in this population.

Quantification of the sit-to-stand movement for monitoring age-related motor deterioration using the Nintendo Wii Balance Board

Simple methods for quantitative evaluations of individual motor performance are crucial for the early detection of motor deterioration. Sit-to-stand movement from a chair is a mechanically demanding component of activities of daily living. Here, we developed a novel method using the ground reaction force and center of pressure measured from the Nintendo Wii Balance Board to quantify sit-to-stand movement (sit-to-stand score) and investigated the age-related change in the sit-to-stand score as a method to evaluate reduction in motor performance. The study enrolled 503 participants (mean age ± standard deviation, 51.0 ± 19.7 years; range, 20-88 years; male/female ratio, 226/277) without any known musculoskeletal conditions that limit sit-to-stand movement, which were divided into seven 10-year age groups. The participants were instructed to stand up as quickly as possible, and the sit-to-stand score was calculated as the combination of the speed and balance indices, which have a tradeoff relationship. We also performed the timed up and go test, a well-known clinical test used to evaluate an individual's mobility. There were significant differences in the sit-to-stand score and timed up and go time among age groups. The mean sit-to-stand score for 60s, 70s, and 80s were 77%, 68%, and 53% of that for the 20s, respectively. The timed up and go test confirmed the age-related decrease in mobility of the participants. In addition, the sit-to-stand score measured using the Wii Balance Board was compared with that from a laboratory-graded force plate using the Bland-Altman plot (bias = -3.1 [ms]-1, 95% limit of agreement: -11.0 to 3.9 [ms]-1). The sit-to-stand score has good inter-device reliability (intraclass correlation coefficient = 0.87). Furthermore, the test-retest reliability is substantial (intraclass correlation coefficient = 0.64). Thus, the proposed STS score will be useful to detect the early deterioration of motor performance.

Influence of weight bearing visual feedback on movement symmetry during sit to stand task

BACKGROUND

Weight-bearing asymmetry is common in individuals with hip osteoarthritis and after total hip arthroplasty. Including symmetry training to the rehabilitation programs may normalize movement strategies during dynamic tasks. The purpose of this study was to evaluate the immediate influences of real-time visual feedback of weight distribution on the interlimb movement symmetry during the sit-to-stand task, before and after total hip arthroplasty, and to determine whether physical impairments affect the response to visual feedback.

METHODS

Subjects before and after total hip arthroplasty participated in three- dimensional motion analysis. Subjects completed 3 trials of sit-to-stand task in two conditions; "without visual feedback" and "with visual feedback". Outcome measures were the interlimb symmetry of vertical ground reaction force, and joint kinematics and kinetics. Pain and strength of lower limbs were assessed.

FINDINGS

Compared to "without visual feedback" condition, subjects moved with greater symmetry of vertical ground reaction force and joint kinetics when visual feedback was received. However, subjects continued to demonstrate interlimb difference for joint kinetics and vertical ground reaction force in the visual feedback condition. The increase in symmetry was not strongly influenced by physical impairments and subjects before and after total hip arthroplasty responded similarly to the feedback.

INTERPRETATIONS

We concluded that in a single session, the visual feedback of weight bearing distribution had a positive immediate effect on movement symmetry during the sit-to-stand task. Future studies that assess long-term retention and functional benefits are warranted before visual feedback is incorporated in rehabilitation for this patient population.

Influence of virtual reality on postural balance and quality of life of pregnant women: controlled clinical trial randomized

Abstract Introduction: During pregnancy women undergo several transformations, which promote changes in their gravity center (GC) and can result in postural and balance changes. Objective: To evaluate the influence of Nintendo WiiFit Plus® on postural balance and quality of life of pregnant women in the third trimester. Methods: 250 pregnant women enrolled through a non-probabilistic sampling process. The sample consisted of 32 women selected according to the eligibility criteria (nulliparity; low-risk pregnancy, absence of musculoskeletal disorders or surgical procedures in the spine, pelvis, hip or knee), musculoskeletal disorders, allocated as follows: 17 pregnant women in the control group (CG) and 15 pregnant women in the experimental group (EG). The intervention was performed in 12 sessions of 30 minutes each, three times a week. Sociodemographic and obstetric data were presented as median and interquartile range (25% - 75%). A comparison of the relative values of variables before and after the exercise program was performed using the 2x2 ANOVA test (5% significance level). Results: There were no significant statistical differences in variables related to postural balance (P > 0.06) and quality of life (P > 0.13). Conclusion: The use of Nintendo WiiFit Plus games was not able to promote improvement in postural balance and quality of life of the pregnant women studied.

Reliability and concurrent validity of instrumented balance error scoring system using a portable force plate system

OBJECTIVES

The Balance Error Scoring System (BESS) is a commonly used test in adolescents and young adults. Affordability and portability of newer force plates has led to instrumentation of many clinical balance tests including the BESS. Despite the higher precision of force plate measures compared with clinical scoring, it is unclear if the instrumented BESS demonstrate concurrent validity and reliability when compared with the original BESS. The purpose of this study was to examine the reliability and concurrent validity of instrumented BESS testing using a commercially available force plate system.

METHODS

Thirty-six participants participated in the initial testing day (17 male/19 female, M = 15.9 years, SD = 1.5 years). The test-retest sample consisted of 26 participants who completed the same testing procedure after 1 week. For all testing sessions, participants performed the BESS while standing on a portable force plate system. Number of errors and sway velocity were obtained. Concurrent validity was established through correlation analysis examining the relationship between the original and the instrumented BESS scores. Reliability was established using Intraclass Correlation Coefficient (ICC3,1) computed for the instrumented and the original BESS.

RESULTS

A significant moderate relationship exists between the total scores of the original and the instrumented BESS (rs = 0.54, p = 0.001). Despite a range of reliability scores for the different conditions in the instrumented BESS (ICC3,1 = 0.19-0.61) and the clinically scored BESS (ICC3,1 = 0.13-0.71), the reliability score for the total test score was the same for the instrumented and the clinical test (ICC3,1 = 0.74).

CONCLUSION

Although the instrumented BESS may appear to demonstrate concurrent validity against the original BESS, instrumentation did not improve its reliability. Future research should examine if the instrumented BESS demonstrates validity against laboratory level force plates and if it is able to overcome the ceiling effect reported for the clinical BESS test.