Test-retest reliability of center of pressure measures for postural control assessment in older cardiac patients

BackgroundElderly patients are a growing population in cardiac rehabilitation (CR). As postural control declines with age, assessment of impaired balance is important in older CR patients in order to predict fall risk and to initiate counteracting steps. Functional balance tests are subjective and lack adequate sensitivity to small differences, and are further subject to ceiling effects. A quantitative approach to measure postural control on a continuous scale is therefore desirable. Force plates are already used for this purpose in other clinical contexts, therefore could be a promising tool also for older CR patients. However, in this population the reliability of the assessment is not fully known.Research questionAnalysis of test-retest reliability of center of pressure (CoP) measures for the assessment of postural control using a force plate in older CR patients.Methods156 CR patients (≥75 years) were enrolled. CoP measures (path length (PL), mean velocity (MV), and 95% confidence ellipse area (95CEA)) were analyzed twice with an interval of two days in between (bipedal narrow stance, eyes open (EO) and closed (EC), three trials for each condition, 30 s per trial), using a force plate. For test-retest reliability estimation absolute differences (Δ: T0-T1), intraclass correlation coefficients (ICC) with 95% confidence intervals, standard error of measurement and minimal detectable change were calculated.ResultsUnder EO condition ICC were excellent for PL and MV (0.95) and good for 95CEA (0.88) with Δ of 10.1 cm (PL), 0.3 cm/sec (MV) and 1.5 cm² (95CEA) respectively. Under EC condition ICC were excellent (≥ 0.95) for all variables with larger Δ (PL: 21.7 cm; MV: 0.7 cm/sec; 95CEA: 2.4 cm²).SignificanceIn older CR patients, the assessment of CoP measures using a force plate shows good to excellent test-retest reliability.     

Evaluation of sitting and standing postural balance in cerebral palsy by center-of-pressure measurement using force plates: comparison with clinical measurements

BackgroundCenter-of-pressure (CoP) measurements have been studied for assessing balance control. While CoP measurements using force plates have been used to assess standing balance in children with cerebral palsy (CP), it has not been assessed in a sitting position, which specifically reflects trunk postural control.Research questionThe purpose of this study was to compare CoP measurements using force plates during both standing and sitting trials with the Pediatric Balance Scale (PBS) in children with spastic CP.MethodsWe recruited 26 children with spastic CP (7.8 ± 3.4 years, 4–13 years) and used the PBS, a validated evaluation tool that measures static and dynamic balance control. We took CoP measurements using force plates during sitting and standing. For both trials, subjects stayed still for 10 s with their eyes open or closed. We calculated the CoP velocity, mediolateral (ML) and anteroposterior (AP) velocity, and ML and AP displacements of CoP.Results and SignificanceDuring standing trials, static PBS standing scores negatively correlated with more AP displacement and velocity than ML displacement and velocity (p < 0.05). During sitting trials, dynamic PBS sitting scores negatively correlated with ML displacement and velocity (p < 0.05). CoP parameters in the ML direction of the sitting position and CoP parameters in the AP direction of the standing position may better reflect the balance control in children with spastic CP.     

Reliability of center of pressure measures of postural stability in healthy older adults: effects of postural task difficulty and cognitive load

Postural instability is a major risk factor of falling in the elderly. It is well documented that postural control may decline while performing a concurrent cognitive task and this effect increases with age. Despite the extensive use of dual tasking in balance assessment protocols, a lack of sufficient reliability information is evident. This study determines the reliability of the postural stability measures in older adults, assessed under single and dual-task conditions and different levels of postural difficulty. Sixteen older adults completed quiet stance postural measurements at three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed), with or without performing a concurrent backward counting task, in two sessions 1 week apart. Force plate data was used to calculate center of pressure (COP) parameters including mean velocity, phase plane portrait, area (95% confidence ellipse), standard deviation (SD) of amplitude, and SD of velocity. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), coefficient of variation (CV), and minimal metrically detectable change (MMDC) were calculated for each COP measure in all test conditions. Mean velocity, total phase plane, phase plane in ML direction, and SD of velocity in ML direction were the most reliable COP measures across all test conditions. ICC values were consistently higher in ML direction compared with AP direction. In general, velocity-related COP measures in ML direction showed to be highly reliable. Further research may explore the predictive and evaluative value of these COP parameters.     

Impaired postural control of axial segments in children with cerebral palsy

BackgroundSensorimotor control of axial segments, which develops during childhood and is not mature until adolescence, is essential for the development of balance control during motor activities. Children with cerebral palsy (CP) have deficits in postural control when standing or walking, including less stabilization of the head and trunk which could affect postural control.Research questionIs dynamic stabilization of axial segments during an unstable sitting task deficient in children with CP compared to typically developing children? Is this deficit correlated with the deficit of postural control during standing?MethodSeventeen children with CP (GMFCS I-II) and 17 typically-developing children from 6 to 12 years old were rated on the Trunk Control Measurement Scale (TCMS). In addition, posturography was evaluated in participants while they maintained their balance in stable sitting, unstable sitting, and quiet standing, under “eyes open” and “eyes closed” conditions. In sitting tasks, the participants had to remain stable while being prevented from using the lower and upper limbs (i.e. to ensure the involvement of axial segments alone).ResultsChildren with CP compared to TD children had significantly larger surface area, mean velocity and RMS values of CoP displacements measured during the unstable sitting task and the standing task, under both “eyes open” and “eyes closed” conditions. No significant group effects were observed during the stable sitting task. The TCMS total score was significantly lower, indicating trunk postural deficit, in the CP group than in the TD group and was significantly correlated with postural variables in the sitting and standing tasks.SignificanceChildren with CP indeed have a specific impairment in the postural control of axial segments. Since the postural control of axial segments is important for standing and walking, its impairment should be taken into account in rehabilitation programs for children with CP.     

Effectiveness of interactive computer play on balance and postural control for children with cerebral palsy: A systematic review

BackgroundInteractive computer play (ICP) becomes popular in rehabilitation for children with cerebral palsy (CP). With the nature of ICP, it could be an effective intervention specifically to improve balance and postural control for children with CP. The present paper aimed to review the effectiveness of ICP on postural control and balance for children with CP.MethodsElectronic databases including Medline, AMED, EBSCOhost, PsycINFO, Embase, the Cochrane Library and the DARE were searched up to September 2018. Studies were included if (1) participants were aged under 18 and had CP, (2) ICP intervention was performed, (3) an explicit objective was postural control and balance of the participants, and (4) results were fully published in English-language peer-reviewed journals. Characteristics of study participants, ICP protocols and study results were extracted. Level of evidence of each studies was graded using the guidelines from the American Academy of Cerebral Palsy and Developmental Medicine. Methodological quality was graded using the Physiotherapy Evidence Database (PEDro) scale. Effect sizes were calculated on available data.ResultsTwenty studies were included, with nine of level I or II evidence. Most studies had fair methodological rigor. Huge variations in the study designs and protocols of ICP were found among the studies.ConclusionsICP seemed to be more effective than conventional therapy in improving postural control and balance, with medium to large effect sizes for children with mild to moderate severity of CP. Future studies of high methodological rigour are required to verify the role of on-site guidance of the children during ICP and the effect on children with more severe CP.     

Analysis of center of mass and center of pressure displacement in the transverse plane during gait termination in children with cerebral palsy

BackgroundWhile gait termination is challenging for children with spastic cerebral palsy (CCP), few studies have quantitatively assessed this issue.Research questionWhat are the characteristics of center of mass (COM) and center of pressure (COP) displacement during gait termination in CCP, and how do they compare with those in children with typical development (CTD)?MethodsThis cross-sectional study included 13 adults with typical development (19.85 ± 0.52 years), 12 CTD (10.41 ± 2.98 years), and 16 CCP (11.15 ± 2.71 years). Participants were instructed to immediately stop walking when a stop sign appeared on a screen, which was placed at the end of an 8-m walkway. COM and COP were determined via 3-dimensional motion analysis and force plate data. Differences between the groups were assessed using the two sample t-test or Wilcoxon rank sum test. The level of statistical significance was set at P < 0.05.ResultsThe normalized time for stopping in CCP (4.556 ± 0.602) was higher than that in CTD (3.617 ± 0.545, P < 0.001). The normalized COP displacement (P < 0.001) and divergence between COM and COP (P < 0.001) in the mediolateral (ML) direction were significantly higher in CCP than CTD. However, the normalized divergence between COM and COP in the anteroposterior (AP) direction in CCP was lower than that in CTD (P = 0.034).SignificanceThe more minor divergence between COM and COP in the AP direction and the more significant COP displacement in the ML direction cause difficulty to exert braking force during gait termination. Thus, CCP require a longer time for gait termination. This finding may facilitate the development of interventions for improving gait in CCP.     

Reliability of centre of pressure summary measures of postural steadiness in healthy young adults

This study aimed to (1) estimate the reliability of 36 centre of pressure (COP) summary measures in healthy participants and (2) identify the main sources of variability in order to estimate the most appropriate measurement strategies to improve reliability. Twelve healthy males performed, on two separate days, eight 1-min trials of quiet standing on a force platform in two conditions [eyes open (EO) and eyes closed (EC)]. The generalizability theory was used as a framework to estimate the magnitude of the different variance components (Subject, Trial, Day and all interactions) and the reliability of the measures corresponding to various simulations of measurement strategies. Reliability of the COP summary measures was poor to moderate. Intra-class correlation coefficients were generally higher with EO (mean: 0.46, range: 0.03-0.76) than with EC (mean: 0.41, range 0.02-0.72) across all summary measures. The majority of the variance was attributed to Subject (2%-76%), Subject x Day (0%-24%) and Subject x Day x Trial (16%-79%) variance components depending on the summary measure and condition. The reliability could be improved more efficiently by averaging measurements between-days than by increasing the number of trials during 1 day. For the majority of the summary measures, acceptable reliability can be achieved when at least seven or more trials are averaged during the same testing day.     

Validity and variability of center of pressure measures to quantify trunk control in stroke patients during quiet sitting and reaching tasks

BackgroundIn the immediate period following stroke, sitting balance is one of the most important predictors of functional recovery at discharge after rehabilitation. Thus, sitting balance determines the content of the early phase of stroke rehabilitation and an appropriate measurement tool is important.Research QuestionThe aim of this study is to investigate the concurrent validity of center of pressure (CoP) excursions of patients seated on a force plate, as well as to examine the daily variability of trunk control after stroke.MethodsTwenty stroke patients at an inpatient rehabilitation clinic underwent two assessment sessions, on average eight hours apart. Each session comprised two trials: quiet sitting for 30 s; extended reaching in forward, backward, left and right directions. The Trunk Impairment Scale (TIS) was measured during the first session. CoP excursions were measured to determine the outcomes of sway area and sway velocity during stable sitting and the maximal excursions in frontal and sagittal planes during the reaching tasks.ResultsHigh Spearman’s correlations (0.72, 0.79) were found between the TIS and the frontal and sagittal excursions. However, only low correlations between the TIS and the sway area and sway velocity were observed. Within sessions, all CoP outcomes showed high ICCs (0.73–1.00). Between sessions, high ICCs (0.86-0.93) were found except for sway velocity (ICC 0.51). Sway velocity increased significantly between sessions.SignificanceFrontal and sagittal CoP excursions during reaching tasks appear to be valid measurement parameters to evaluate trunk control in patients after stroke. Only small variability was observed and no significant differences between consecutive days.     

Reliability and validity of the Edinburgh Visual Gait Score for cerebral palsy when used by inexperienced observers

The Edinburgh Visual Gait Score (EVGS) for cerebral palsy has been validated for observer reliability and validity for observers experienced in gait analysis. This study investigated the reliability and validity of the EVGS for observers inexperienced in gait analysis. Six medical students used the score to analyse videotapes from the original study by Read et al. [Read HS, Hazlewood ME, Hillman SJ, Prescott RJ, Robb JE. Edinburgh visual gait score for use in cerebral palsy. J Pediatr Orthop 2003;23:296-301]. These were viewed on two separate occasions to provide inter- and intra-observer reliability, and the results of the numerical items were compared to those from three-dimensional (3D) gait analyses for validity. Observer agreement was tested using Coefficient of Repeatability (CoR), percentage of complete agreement and the kappa statistic. The CoR for inter-observer agreement for inexperienced observers was 5.99/5.07 (Session 1/Session 2) compared to 4.60/3.95 (Session 1/Session 2) for experienced observers. The CoR for intra-observer agreement for inexperienced observers was 5.15 compared to 4.21 for experienced observers. There was complete agreement for 52% of the 10 numerical items with 3D-gait analysis data for inexperienced observers compared to 64% for experienced observers. Ranking of reliability of individual items was similar between the two groups and was generally best for events occurring at the foot and ankle. Observations of gait events by the inexperienced observers using the EVGS were reasonably reliable but not very accurate when compared to experienced observers and 3D-gait analysis.     

Reliability of COP-based postural sway measures and age-related differences

The objectives of this study were to assess the within-day and between-day reliability of several center of pressure (COP)-based measures of postural sway and identify whether there were age-related differences in reliability. Thirty-two healthy individuals (16 younger and 16 older) participated. COP was recorded during quiet upright stance on 4 different days, and a variety of measures determined: mean velocity, median power frequency, RMS distance, sway area, and two fractal measures derived from Hurst rescaled range analysis (HR/S) and detrended fluctuation analysis (DFA). Intraclass correlation coefficient (ICC) and standard error of measurement (SEM) were used to quantify reliability. Mean velocity was the most reliable measure. DFA exponents had relatively better reliability than HR/S exponents. In general, within-day reliability was better than between-day. In comparison with younger participants, older participants exhibited better relative reliability (ICC) for all COP measures and comparable absolute reliability (SEM) except for mean velocity and sway area. These results may be useful in guiding the future selection and interpretation of COP-based measures.     

The comparison of regional spinal curvatures and movements in sitting posture in ambulatory children with cerebral palsy having minimal-to-moderate functional limitations

AimTo examine the regional spinal curvatures and movements in the sagittal and frontal planes during sitting position, and the ability to act independently in patients with CP and to compare the differences between children and adolescents with minimal-to-moderate functional limitations.MethodTwenty-one participants diagnosed with CP aged 5–16 years were included. The participants’ Gross Motor Function Classification System (GMFCS) levels were determined and those at levels I (minimal functional limitation group: minFLG) or II-III (moderate functional limitation group: modFLG) were included. Spinal curvatures, mobilities, and inclinations in the sagittal and frontal planes were evaluated in the sitting position using a hand-held, computer-assisted non-invasive electromechanical device. Participants’ functional independence levels were assessed with the Functional Independence Measure (WeeFIM).ResultsIn the sagittal plane, there were no differences in terms of spinal curvatures between the minFLG and modFLG (p > 0.05). Spinal mobility degrees for flexion (thoracic and lumbar regions and total spine), extension (sacral region), and total spine mobility scores were significantly greater in the minFLG (p < 0.05). In the frontal plane, lumbar spinal curvature significantly increased, and total spine mobility in the right/left lateral motions and functional independence decreased in the modFLG (p < 0.05).InterpretationThe children/adolescents with minimal functional limitations had greater spinal mobility during flexion, extension, and lateral flexions. Spinal curvatures were similar between groups in the sagittal plane. The lumbar region posture scores in the frontal plane observed as lordoscoliosis were higher, and functional independence was lower in the modFLG.     

Reliability and validity of Edinburgh visual gait score as an evaluation tool for children with cerebral palsy

Assessment of gait abnormalities in cerebral palsy (CP) is challenging, and access to instrumented gait analysis is not always feasible. Therefore, many observational gait analysis scales have been devised. This study aimed to evaluate the interobserver reliability, intraobserver reliability, and validity of Edinburgh visual gait score (EVGS). Video of 30 children with spastic CP were reviewed by 7 raters (10 children each in GMFCS levels I, II, and III, age 6–12 years). Three observers had high level of experience in gait analysis (10+ years), two had medium level (2–5 years) and two had no previous experience (orthopedic fellows). Interobserver reliability was evaluated using percentage of complete agreement and kappa values. Criterion validity was evaluated by comparing EVGS scores with 3DGA data taken from the same video visit. Interobserver agreement was 60–90% and Kappa values were 0.18–0.85 for the 17 items in EVGS. Reliability was higher for distal segments (foot/ankle/knee 63–90%; trunk/pelvis/hip 60–76%), with greater experience (high 66–91%, medium 62–90%, no-experience 41–87%), with more EVGS practice (1st 10 videos 52–88%, last 10 videos 64–97%) and when used with higher functioning children (GMFCS I 65–96%, II 58-90%, III 35–65%). Intraobserver agreement was 64–92%. Agreement between EVGS and 3DGA was 52–73%. We believe that having EVGS as part of the standardized gait evaluation is helpful in optimizing the visual scoring. EVGS can be a supportive tool that adds quantitative data instead of only qualitative assessment to a video only gait evaluation.     

Center of pressure and the projection of the time-course of sitting skill acquisition

A normal time-course for the acquisition of sitting is essential. A delay in sitting may affect other developmental milestones, resulting in deficiencies in overall skill. Therefore, our aim was to identify variables whose measures at the very beginning of sitting would allow for the projection of the evolution of the sitting skill. Center of pressure data were collected from the postural sway of twenty-six typically developing infants while sitting on a force platform with a beginning ability to sit upright. Spatial, temporal and frequency variables of postural sway were obtained from both the medial/lateral and anterior/posterior directions of sway. Discriminant function analysis was conducted to identify potential predictors of the duration between onset and fully independent sitting. Gender (p = 0.025), median frequency (p = 0.006), and correlation dimension (p = 0.002) were identified to be predictive of grouping with 73.1% correct classification of the participating infants into short, mid, and long delay groups. In conclusion, measures taken at the earliest stage of sitting may allow the projection of the time-course to achieve independent sitting for typical infants. This approach may be useful for monitoring typical development.     

Reliability and validity of an activity monitor (IDEEA) in the determination of temporal-spatial gait parameters in individuals with cerebral palsy

This study evaluated within- and between-session reliability and validity of temporal–spatial gait parameters derived from the intelligent device for energy expenditure and activity (IDEEA) activity monitor (Minisun, Fresno, CA) in subjects with cerebral palsy, using three-dimensional gait analysis (3-DGA) as the criterion standard. Twenty-five subjects with cerebral palsy (mean age 14.1 years, range 8–23) and 30 control subjects (mean age 14.2 years, range 7–24) completed two 3-DGA, 1 week apart with simultaneous IDEEA data collection. The IDEEA had lower within-session reliability than the 3-DGA for both groups, indicated by greater measurement errors and wider repeatability values for all temporal–spatial parameters. Between-session reliability of 3-DGA was high for both groups with intra-class correlation coefficients (ICC) >0.80. The IDEEA monitor showed high between-session reliability for control subjects (ICC 0.71–0.89), but lower reliability in subjects with cerebral palsy, particularly for walking velocity and stride length (ICC 0.53 and 0.62, respectively). Validity comparison between IDEEA and 3-DGA measures using Bland Altman 95% limits of agreement showed a measurement bias, with the IDEEA over-estimating step and stride length and underestimating cadence in both subject groups compared to 3-DGA. The 95% limits of agreement were smaller in controls (step ±0.20 m; stride ±0.27 m; walking velocity ±0.28 m/s) than in subjects with cerebral palsy (step ±0.36 m; stride ±0.37 m; velocity ±0.58 m/s). Modifications may be necessary to improve the reliability and validity of the IDEEA in children, particularly for use in neurological conditions.     

Reliability and validity of the Visual Gait Assessment Scale for children with hemiplegic cerebral palsy when used by experienced and inexperienced observers

This study investigated the reliability and validity of the Visual Gait Assessment Scale when used by experienced and inexperienced observers. Four experienced and six inexperienced observers viewed videotaped footage of four children with hemiplegic cerebral palsy on two separate occasions. Validity of the Scale was obtained by comparison with three-dimensional gait analysis (3DGA). The experienced observers generally had higher inter-observer and intra-observer reliability than the inexperienced observers. Both groups showed higher agreement for assessments made at the ankle and foot than at the knee and hip. The experienced observers had slightly higher agreement with 3DGA than the inexperienced observers. The inexperienced observers showed a learning effect and had higher inter-observer agreement and higher agreement with 3DGA in the second assessment of the videotapes. This scale can be used by inexperienced observers but is limited to observations in the sagittal plane and by poor reliability at the knee and hip for experienced and inexperienced observers.     

The potential of an automated system to identify the upper limb component of a controlled sitting posture

Full trunk control in sitting is demonstrated only when the head-trunk are aligned and upper limbs remain free of contact from mechanical support. These components represent a Controlled Kinetic Chain and can be evaluated in people with neuromotor disability using the Segmental Assessment of Trunk Control (SATCo) when a therapist provides manual trunk support at different segmental levels. However, the SATCo, as with other clinical assessments of control, is subjective. The SATCo was translated to objective rules relating the position of the hands and elbows to the head-trunk and then tested to determine the extent to which this automated objective method replicated the clinical judgement.Clinical evaluation used video to determine whether the upper limb was free of mechanical support while the objective evaluation used 3D motion capture of the trunk and upper limbs with a classification rule. The agreement between clinical and objective classification was calculated for three conditions of a distance-from-support-surface threshold parameter in five healthy adults and five children with cerebral palsy.The unfitted (zero-threshold values) method replicated the clinical judgement in part (68.26% ± 15.7, adults, 48.3% ± 33.9 children). The fitted (level-of-support determined) agreement showed that the process could be refined using trial specific parameters (88.32% ± 5.3 adults, 89.84% ± 10.2 children). The fixed-values agreement showed high values when using general group parameters (80.80% ± 3.1 adults, 74.31% ± 21.5 children).This objective classification of the upper limb component of trunk control largely captures the clinical evaluation. It provides the first stages in development of a clinically-friendly fully automated method.     

Reliability and validity of the Turkish version of Fullerton Advanced Balance Scale in cerebral palsy

BackgroundThe Fullerton Advanced Balance Scale (FAB) is a multi-item balance assessment test designed to measure balance in relatively higher functioning individuals. The aim of this study was to examine the reliability and validity of the Turkish version of the FAB (FAB-T) in children with cerebral palsy (CP).Research questionIs the Turkish version of the Fullerton Advance Balance Scale valid and reliable in determining balance problems in children with cerebral palsy and determining the underlying cause of this condition?MethodsForty-six children with CP participated in this study. Rasch analysis was used to investigate item adherence. Internal consistency of the FAB-T was established using Cronbach's alpha coefficient. Test-retest reliability was also evaluated. In addition, to assess concurrent validity, FAB-T scores were compared with the Pediatric Balance Scale (PBS) using the Spearman correlation coefficient.ResultsThe FAB-T showed satisfactory internal consistency (Cronbach's alpha value=0.94) and excellent test-retest reliability (ICC=0.99). The FAB and the PBS exhibited concurrent positive validity (r = 0.913; p < 0.001). All items of the FAB-T were found to fit the Rasch Model (Chi-square 16.01(df=20), p = 0.716).SignificanceThe FAB-T is a reliable and valid tool that can be used to measure balance skills and to identify the source of the problem in children with CP.     

Reliability of center of pressure measures within and between sessions in individuals post-stroke and healthy controls

BackgroundKnowing the reliability of the center of pressure (COP) is important for interpreting balance deficits post-stroke, especially when the balance deficits can necessitate the use of short duration trials. The novel aspect of this reliability study was to examine the center of pressure measures using two adjacent force platforms between and within sessions in stroke and controls. After stroke, it is important to understand the contribution of the paretic and non-paretic leg to the motor control of standing balance. Because there is a considerable body of knowledge on COP reliability on a single platform, we chose to examine reliability using two adjacent platforms which has not been examined previously in stroke.MethodsTwenty participants post-stroke and 22 controls performed an arm raise, load drop and quiet stance balance task while standing on two adjacent force platforms, on two separate days. Intraclass correlations coefficient (ICC_2,1) and percentage standard error of measurement (SEM%) were calculated for COP velocity, ellipse area, anterior–posterior (AP) displacement, and medial–lateral (ML) displacement.ResultsBetween sessions, COP velocity was the most reliable with high ICCs and low SEM% across groups and tasks and ellipse area was less reliable with low ICCs across groups and tasks. COP measures were less reliable during the arm raise than load drop post-stroke. Within session reliability was high for COP velocity and ML displacement requiring no more than six trials across tasks.ConclusionsThe COP velocity was the most reliable measure with high ICCs between sessions and the high reliability was achieved with fewer trials in both groups in a single session.     

Reliability and validity of the gait classification system in children with cerebral palsy (GCS-CP)

BackgroundGait classification systems (GCS) may enable clinicians to differentiate gait patterns into clinically significant categories that assist in clinical decision-making and assessment of outcomes. Davids and Bagley in 2014 [1] described a GCS for children with cerebral palsy (GCS-CP). The purpose of our study was to use the GCS-CP for the first time on a sample of patients with CP and to evaluate the reliability and utility of the classification system.MethodsThe gait of 131 children with CP was retrospectively reviewed and classified according to Davids and Bagley’s classification using two-dimensional (2D) video and three-dimensional (3D) lower limb kinematics and kinetics. Gross Motor Function Classification System (GMFCS) levels were determined, and the Gait Profile Scores (GPS) calculated to characterize the sample concerning gait classification. The comparison between the groups was performed using the Kruskal-Wallis test with respect to the non-normal distribution of the data. The intrarater and interrater reliability was determined using the Kappa index (k) statistics with 95% CI.ResultsAll GCS-CP groups were represented within the evaluated sample. Of the 131 cases evaluated, 127 (96.95%) were able to be classified with respect to sagittal plane stance phase gait deviations. All patients in the sample were able to be classified with respect to sagittal plane swing phase and transverse plane gait deviations. The interrater reliability was 0.596 and 0.485 for the first and second levels of the classification, respectively, according to the Fleiss’s Kappa statistics. Intrarater reliability was 0.776 and 0.714 for the raters one and two, respectively, according to the Cohen’s Kappa statistics.SignificanceThe GCS-CP exhibited clinical utility, successfully classifying almost all subjects with CP in two planes, based upon kinematic and kinetic data. The classification is valid and has moderate interrater and moderate to substantial intrarater reliability.     

Reliability and validity of self-reported sitting and breaks from sitting in the workplace

Objectives

Prolonged sitting is a health risk factor which is ubiquitous to the workplace, and breaking up prolonged sitting is widely recommended. This study evaluated the test–retest reliability and concurrent validity of a self-report measure of duration of sitting and breaks from sitting in the workplace.