Test-retest reliability and responsiveness of centre of pressure measurements in patients with hip osteoarthritis

Implications of Stabilometric Assessment in Determining Functional Deficits in Patients with Severe Knee Osteoarthritis: Observational Study

Background: Osteoarthritis is one of the most frequent joint disorders in the world. The specialists in the field strongly support the role of physical exercise as a key component in the holistic management of arthrosis. The aim of the current study was to identify and assess the functional deficit of these patients and to identify means to alleviate it through pre-surgery physiotherapy programs. Methods: The study was conducted on two samples of patients: a witness sample, encompassing 126 subjects without pathologies at the level of their lower limbs, and a study sample, formed of 116 subjects diagnosed with severe gonarthrosis with total knee arthroplasty indication. The assessment protocol was accomplished with the GPS 400 stabilometric platform. Results: The barycenter differences within the support polygon, recorded for the two samples within sagittal deviation, emphasize that the barycenter shifting mainly towards the healthy lower limb will demand, from the individual, more intense rebalancing postural reactions that will place the center-of-gravity projection in the sagittal plane, closer to the central area of the support polygon. Conclusions: In the case of gonarthrosis and other joint disorders, the use of functional testing to assess body weight distribution and center-of-gravity imbalances represents a promising direction in the research on and management of these disorders, providing essential information for functional diagnosing and thus enabling the elaboration and monitoring of individualized functional rehabilitation plans.

Reliability of force plate-based measures of standing balance in the sub-acute stage of post-stroke recovery

Background

Difficulty controlling balance is one of the major contributors to the increased risk of falls among individuals with stroke. It is important to use reliable and objective measures to improve examination of balance impairments post-stroke, and to in turn inform clinical decision-making. The main objective of this study was to examine the relative and absolute reliabilities of force plate-based balance measures in quiet standing, in the sub-acute stage of stroke recovery.

Methods

Twenty-four people with sub-acute stroke (mean age = 61 years) performed two trials of quiet standing, each 30 s long. Sixteen force plate-based balance measures in the time, frequency, or nonlinear domains were calculated. Within-session test-retest reliabilities were investigated using intraclass correlation coefficient (ICC), standard error of measurement, and minimal detectable change.

Results

Mean speed of displacements of the centre of pressure along the anterior-posterior axis (ICC = 0.91; CI95 % = [0.83, 0.95]), and directional weight-bearing asymmetry (ICC = 0.91; CI95 % = [0.82, 0.95]) demonstrated high relative reliabilities, followed by the speed-based symmetry index and absolute weight-bearing asymmetry (both ICCs = 0.86; CI95 % = [0.74, 0.93]).

Conclusions

Mean speeds of centre of pressure, directional weight-bearing asymmetry, and speed-based symmetry index are the most reliable force plate-based measures that were evaluated in our study, and can be included in the balance assessments of individuals within the sub-acute stage of post-stroke recovery. These findings can better inform clinicians about the specific balance problems experienced by people in this population.

Wireless pressure insoles for measuring ground reaction forces and trajectories of the centre of pressure during functional activities

Wireless pressure insoles may enable the assessment of movement biomechanics in a real-world setting, and thus play an important role in the recommendation of clinical management, but they are not yet a gold standard due to the unknown accuracy and reliability with respect to different functional activities. Here, we compare novel wireless pressure insoles with force plates and examine the test-retest reliability of the insoles for measuring vertical ground reaction forces (vGRFs) and trajectories of the center of pressure (COP). In this observational study, healthy adults underwent two data collection sessions during one day. The Bland-Altman analysis was used to compare the outcomes measured with the two instruments during squats, jumps, and the sit-to-stand test. Test-retest reliability was assessed by the interclass correlation coefficient and the standard error of measurement for the outcomes during squats, jumps, walking, and stair ambulation. Trajectories of the COP in the anterior-posterior direction were comparable between the two systems during all activities. The insoles consistently measured shorter trajectories of the COP in the medial-lateral direction (except jumps) and lower vGRFs than the force plates. Test-retest reliability of the insoles was fair to high or excellent for all outcomes during all activities. In conclusion, the insoles provide reliable measures of vGRFs and trajectories of the COP during multiple functional activities in healthy adults. Although the insoles do not produce identical results to the force plate, the qualitative similarity and consistency between the two systems confirm the insoles can be used to measure these outcomes, based on the purpose and accuracy required.

Effects of core strengthening on balance in patients with hip osteoarthritis: a randomised controlled trial

Osteoarthritis is a condition commonly present in the elderly, with many having altered balance, aggravated with weak lower limb and core musculature predisposing them to falls. Despite the knowledge about the link between balance and core stability, studies investigating the importance of core stability exercise and their impact on balance are limited. Therefore, the authors aimed to explore whether core strengthening exercises in combination with hip exercises, when compared to a hip exercise programme and a control group, led to better improvements in balance in patients with hip osteoarthritis. In order to meet these aims, this paper reports the outcomes of a randomized, three-arm parallel, assessor-blinded, controlled clinical trial. Fifty-one participants awaiting a total hip replacement were recruited into this study. All patients were randomly allocated to a control, hip exercise group and hip and core exercise group. All participants were assessed for core muscle strength using a pressure biofeedback unit and balance using the four-stage balance test. The control group had no intervention. A 12-week hip and core exercise programme did not result in improvements over and above the hip exercise group in balance scores. However an improvement in core stability was noted for the hip and core exercise group ( P  = 0.001). Therefore, this study concluded that both exercise groups are resulted in improved balance with the core and hip exercise group noted to have added improvements, but the difference between the groups was not statistically significant.

The Frail'BESTest: an adaptation of the "balance evaluation system test" for frail older adults; Concurrent validity, responsiveness, validity for fall prediction and detection of slower walkers

BACKGROUND

The Frail'BESTest was developed in order to include frail older adults when they are using the BESTest. Recently, psychometrics properties (internal coherence, systems usefulness, complementarity and inter-rater reliability) of the Frail'BESTest were tested. To complete these analyses, this study will aim the assessment of its concurrent validity, responsiveness, predictive validity on falls occurrence, and slower walkers detection.

METHODS

The correlation between the Frail'BESTest and the Gait Speed Test permitted to assess concurrent validity. The variation between the initial test score and the score obtained after the completion of a rehabilitation program was used to evaluate responsiveness with MANOVA analysis and standard response mean (SRM) calculation. Predictive validity was assessed with receiver-operating characteristic curves and area under the curve (AUC) analysis regarding falls occurrence. Slower walkers detection thresholds were computed by receiver-operating characteristic curves for the Frail'BESTest and the Tinetti test.

RESULTS

The concurrent validity of the test was good (r = 0.74; p < 0.001). The Standard Error of measurement was at 2.81 points and the Minimal Detectable Change at 7.79 points for the total score of the Frail'BESTest. The SRM was at 0.41 for the Tinetti test and 0.56 for the Frail'BESTest. The AUC, computed according to fall occurrence, was at 0.71 for the Gait Speed test, 0.673 for the Tinetti test and 0.693 for the Frail'BESTest. Both the Tinetti (AUC = 0.87) and the Frail'BESTest (AUC = 0.88) were found suitable for tracking slower walkers.

CONCLUSION

Concurrent validity and responsiveness of the Frail'BESTest were good. As for the Tinetti and the Frail'BESTest, they were unable to predict efficiently falls occurrence in the tested sample. The Frail'BESTest seems enough sensitive to spot the slower walkers efficiently, using a 15/20 threshold method. The Frail'BESTest was found to be a valid and responsive clinical test, therefore it can be recommended as an outcome measure in clinical practice.

Body Balance after Fascial Therapy in Athletes with Soft Lower Limb Muscle Injuries

Background: Most injuries in competitive sports are due to overstrain and excessive muscular and fascial tension. This study aimed to assess the effects of a single session of fascial therapy on balance and lower limb weight-bearing in professional athletes following a lower limb soft-tissue injury. Methods: A pedobarographic platform was used to assess the weight-bearing on both lower limbs and corporal balance. A total of 41 athletes with an acute soft-tissue injury involving the quadriceps femoris muscle were included in the study. Each patient underwent myofascial therapy in the injured limb only. The therapy was intended to release tension and improve proprioception. Results: The injured and healthy limbs showed significant asymmetry in body weight distribution. Before treatment, the patients bore less weight on the injured limb than on the healthy limb. After fascial therapy, eyes-closed tests showed an improved weight distribution symmetry between the two lower limbs. There were no significant differences in the values of the evaluated balance parameters between those measured at baseline and those measured after the therapy, measured after the rehabilitation session. Conclusions: A single fascial therapy session has a beneficial effect on corporal balance in runners with an injured lower limb.

A comparison of two techniques for center of pressure measurements

Introduction

Force platforms and pressure-measuring insoles are the most common tools used for measuring center of pressure. Earlier studies to assess these instruments suffered from limited sample sizes or an inadequate range of participant foot sizes. The purpose of this study was to propose new methods to extract and calculate comparably accurate center of pressure for the Kistler® force platform and Medilogic® insoles.

Methods

Center of pressure data were collected from 65 participants wearing pressure-measuring insoles (six different sizes). Participants walked over consecutive force platforms for three trials while wearing pressure-measuring insoles within socks. Onset force thresholds and center of pressure segment length thresholds were used to determine accurate center of pressure path length and width. A single step for each foot and trial was extracted from both instruments.

Results

A strong correlation was observed between instruments in center of pressure length (4.12 ± 6.72% difference, r = 0.74). Center of pressure width varied and was weakly correlated (–7.04 ± 4.48% difference, r = 0.11).

Conclusions

The results indicate that both instruments can measure center of pressure path length consistently and with comparable accuracy (differences < 10%). There were differences between instruments in measuring center of pressure path width, which were attributed to the limited number of sensors across the width of the insoles.

Plantar pressure distribution during standing in women with end-stage hip osteoarthritis

BACKGROUND

Patients with hip osteoarthritis (OA) experience abnormal movement patterns and reduced loading of the affected leg. The plantar contacts the ground and receives force from the ground. Plantar pressure distribution may differ in patients with hip OA compared to healthy adults and may influence physical functioning in these patients.

RESEARCH QUESTION

We investigated whether plantar pressure distribution during standing differed between patients with hip OA and healthy adults. We also analyzed the relationship between plantar pressure distribution and walking ability and the factors affecting plantar pressure distribution.

METHODS

Maximum plantar pressure distribution during standing for 20 seconds was investigated in patients with hip OA (n = 62; OA group) and in healthy adults (n = 53; Control group). Statistical comparisons between these groups were made using Fisher's exact test and residual analysis. In the OA group, leg length discrepancy, range of hip extension, leg loading, knee extensor strength, and 10 m walking time were assessed; multiple linear regression and logistic regression analyses were used to examine the relationships between these factors and maximum plantar pressure distribution.

RESULTS

Maximum plantar pressure distribution was different between the OA and control groups. In the OA group, maximum plantar pressure distribution was one of the significant predictors of 10 m walking time. Additionally, leg length discrepancy was a significant predictor of maximum plantar pressure distribution in this group.

SIGNIFICANCE

During standing, the proportion of patients for whom the maximum plantar pressure region was the heel tended to be lower in the group with hip OA compared to the healthy adults. Plantar pressure distribution may have an importance for evaluating walking ability in patients with hip OA. Correcting leg length discrepancy and loading under the heel could adjust plantar pressure distribution in patients with hip OA.

Balance performance in older adults with hip osteoarthritis: A systematic review

BACKGROUND

The hip is one of the most common joints affected by osteoarthritis (OA) and it has been identified as a key risk factors for falls. Physical impairments associated with OA, such as joint pain, muscle weakness, joint stiffness and sensory dysfunction, can all negatively affect balance and increase risk of falling.

QUESTION

Is balance performance altered in older adults with hip osteoarthritis? To determine whether static, dynamic, reactive or functional balance performance is altered in older people with hip osteoarthritis.

METHODS

Quantitative measures of postural control, including clinical and lab-based assessment of static, dynamic, reactive and/or functional balance performance, compared with a healthy control group or to the asymptomatic limb.

RESULTS

A total of 5407 articles were identified and 14 papers were included (10 with standardised mean different (SMD) data, four without SMD data). Based on data from single studies, there were medium/large effects for increased medio-lateral displacement when standing with eyes open, increased anterior-posterior and total sway path length when standing with eyes closed, greater overall instability when standing on an unstable surface, and increased displacement toward the stance leg in a lateral step in hip OA compared with controls.

CONCLUSION

Balance impairments were identified in some measures, limiting the conclusions as to whether balance deficits are a problem in hip OA. Inconsistent findings suggest that balance may not be a primary contributor to increased falls risk in older adults with hip OA. Other factors, such as musculoskeletal deficits, may contribute to higher falls rate in this population.

Reliability analysis of a sensitive and independent stabilometry parameter set

Recent studies have suggested reduced independent and sensitive parameter sets for stabilometry measurements based on correlation and variance analyses. However, the reliability of these recommended parameter sets has not been studied in the literature or not in every stance type used in stabilometry assessments, for example, single leg stances. The goal of this study is to evaluate the test-retest reliability of different time-based and frequency-based parameters that are calculated from the center of pressure (CoP) during bipedal and single leg stance for 30- and 60-second measurement intervals. Thirty healthy subjects performed repeated standing trials in a bipedal stance with eyes open and eyes closed conditions and in a single leg stance with eyes open for 60 seconds. A force distribution measuring plate was used to record the CoP. The reliability of the CoP parameters was characterized by using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimal detectable change (MDC), coefficient of variation (CV) and CV compliance rate (CVCR). Based on the ICC, SEM and MDC results, many parameters yielded fair to good reliability values, while the CoP path length yielded the highest reliability (smallest ICC > 0.67 (0.54–0.79), largest SEM% = 19.2%). Usually, frequency type parameters and extreme value parameters yielded poor reliability values. There were differences in the reliability of the maximum CoP velocity (better with 30 seconds) and mean power frequency (better with 60 seconds) parameters between the different sampling intervals.