On the role of knee joint in balance control and postural strategies: effects of total knee replacement in elderly subjects with knee osteoarthritis

Mid-vastus approach induces milder short-term effects on postural control compared to parapatellar approach in total knee arthroplasty

BACKGROUND

Mid-Vastus and Medial Parapatellar techniques are used for total knee arthroplasty. Their short-term effects within the first month after surgery are yet unexplored. The purpose of this study was to compare Mid-Vastus and Medial Parapatellar effects on knee strength and balance control, at 5 days, 2 weeks and one month after surgery. It was hypothesized that Mid-Vastus would induce milder effects on the dependent variables due to its less invasive nature.

METHODS

Twenty females, randomly assigned to either the Mid-Vastus or the Medial Parapatellar group performed knee flexion-extension force and 30 s of bipedal stance before, 5 days, 2 weeks and one month after surgery. Maximum force, weight distribution and travel distance of the Center of Pressure were calculated.

FINDINGS

Both groups showed decreased force output at all post-measurements compared to before surgery. Medial Parapatellar group showcased significantly higher travel distance at the 2 weeks measurement (Z = -2.268, p = .023, |r| = 0.507) compared to before surgery. This result was also imprinted on the travel distance of the non-surgical knee limb in the post (t = 3.259, p = .004, d = 1.456), 2 weeks (Z = -2.570, p = .009, |r| = 0.574) and one month measurement (t = 2.653, p = .016, d = 1.185).

INTERPRETATION

While force is affected for both approaches, Mid-Vastus approach does not affect postural control. Therefore, Mid-Vastus is a less invasive technique compared to Medial Parapatellar. This work highlights the differences between Mid-Vastus and Medial Parapatellar approaches at least until the first month of rehabilitation.

Postural stability computerized evaluation in total knee arthroplasty

PURPOSE

To evaluate the balance in patients with total knee arthroplasty (TKA) and knee osteoarthrosis (KOA), measured by postural stability computerized evaluation (PSCE), and to evaluate the effect of post-TKA patients' characteristics in their performance on PSCE.

MATERIALS AND METHODS

An observational cross-sectional study was conducted in two sets of patients: (A) patients with KOA and primary TKA surgery scheduled and (B) patients who underwent primary TKA >9 months. Sociodemographic, radiographic, clinical and PSCE parameters (using the Biodex Balance System) were assessed.

RESULTS

Post-TKA patients placed more load on the replaced knee than the contralateral osteoarthritic knee (p = 0.027). They had less imbalance on the balance tests performed with the eyes open, on stable (p = 0.032), and unstable platforms (p = 0.022). These patients also showed better postural stability in monopodalic stance, both standing on the TKA (p = 0.010) and contralateral knee (p = 0.017). Age, weight, pain on the operated knee, extension deficit on the operated knee, and Berg Balance Scale scores on post-TKA patients were significantly associated with their performance on PSCE tests.

CONCLUSIONS

PSCE can be useful to quantify the balance of post-TKA and KOA patients.

High tibial osteotomy improves balance control in patients with knee osteoarthritis and a varus deformity

BACKGROUND

Impaired knee stability is observed in patients with medial compartment knee osteoarthritis (OA) and varus malalignment. Although high tibial osteotomy (HTO) is widely used to treat OA-related knee varus deformity, its long-term influence on balance control in OA patients is poorly reported. This study aimed to evaluate the impact of HTO on balance control and assess its biological and functional significance.

METHODS

Thirty-two patients with medial compartment knee OA as well as varus deformity who were scheduled for HTO underwent static posturographic tests one month pre- and three months as well as one year postoperatively, respectively, along with forty matched control subjects. Radiographic and clinical evaluations were synchronously carried out on patients pre- and postoperatively.

RESULTS

Decreased postural sway was observed in patients one year after HTO. When compared to the control subjects, more postural sway was found in patients one month pre- and three months postoperatively. No difference was observed between the patients and control subjects one year postoperatively. The alignment and joint function of the affected knees significantly improved after HTO.

CONCLUSIONS

This study revealed that HTO improves balance control in patients with knee OA and varus deformity. Correct alignment and improved joint function enhance the likelihood of normal postural stability. Hence, this intervention allows the knee joint to recover its corrective compensatory role in postural regulation and should be taken into account for managing knee OA patients.

Self-reported pain and fatigue are associated with physical and cognitive function in middle to older-aged adults

Persistent fatigue is often reported in those with chronic musculoskeletal pain. Separately, both chronic pain and chronic fatigue contribute to physical and cognitive decline in older adults. Concurrent pain and fatigue symptoms may increase disability and diminish quality of life, though little data exist to show this. The purpose of this study was to examine associations between self-reported pain and fatigue, both independently and combined, with cognitive and physical function in middle-older-aged adults with chronic knee pain. Using a cross-sectional study design participants (n = 206, age 58.0 ± 8.3) completed questionnaires on pain and fatigue, a physical performance battery to assess physical function, and the Montreal Cognitive Assessment. Hierarchical regressions and moderation analyses were used to assess the relationship between the variables of interest. Pain and fatigue both predicted physical function (β = -0.305, p < 0.001; β = -0.219, p = 0.003, respectively), however only pain significantly predicted cognitive function (β = -0.295, p <0.001). A centered pain*fatigue interaction was a significant predictor of both cognitive function (β = -0.137, p = 0.049) and physical function (β = -0.146, p = 0.048). These findings indicate that self-reported fatigue may contribute primarily to decline in physical function among individuals with chronic pain, and less so to decline in cognitive function. Future studies should examine the impact of both cognitive and physical function decline together on overall disability and health.

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial

OBJECTIVES

To determine if a newer design of total knee replacement (TKR) (Journey II BCS) produces superior patient-reported outcomes scores and biomechanical outcomes than the older, more established design (Genesis II).

SETTING

Patients were recruited from an NHS University Hospital between July 2018 and October 2019 with surgery at two sites. Biomechanical and functional capacity measurements were at a University Movement and Exercise Laboratory.

PARTICIPANTS

80 participants undergoing single-stage TKR.

INTERVENTIONS

Patients were randomised to receive either the Journey II BCS (JII-BCS) or Genesis II TKR.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was the Oxford Knee Score (OKS), at 6 months. Secondary outcomes were: OKS Activity and Participation Questionnaire, EQ-5D-5L and UCLA Activity scores, Timed Up and Go Test, 6 min walk test, lower limb kinematics and lower limb muscle activity during walking and balance.

RESULTS

This study found no difference in the OKS between groups. The OKS scores for the JII-BCS and Genesis II groups were mean (SD) 42.97 (5.21) and 43.13 (5.20) respectively, adjusted effect size 0.35 (-2.01,2.71) p=0.771In secondary outcome measures, the Genesis II group demonstrated a significantly greater walking range-of-movement (50.62 (7.33) vs 46.07 (7.71) degrees, adjusted effect size, 3.14 (0.61,5.68) p=0.02) and higher peak knee flexion angular velocity during walking (mean (SD) 307.69 (38.96) vs 330.38 (41.40) degrees/second, adjusted effect size was 21.75 (4.54,38.96), p=0.01) and better postural control (smaller resultant centre of path length) during quiet standing than the JII-BCS group (mean (SD) 158.14 (65.40) vs 235.48 (176.94) mm, adjusted effect size, 59.91 (-105.98, -13.85) p=0.01.).

CONCLUSIONS

In this study population, the findings do not support the hypothesis that the Journey II BCS produces a better outcome than the Genesis II for the primary outcome of the OKS at 6 months after surgery.

TRIAL REGISTRATION NUMBER

ISRCTN32315753.

Fall classification, incidence and circumstances in patients undergoing total knee replacement

To propose a fall-classification framework for patients undergoing total knee replacement (TKR). In addition, we reinforced the available evidence on fall incidence and circumstances and compared the characteristics of fallers versus. nonfallers. Retrospective and prospective data were collected from 253 subjects with severe knee osteoarthritis who were waiting for primary TKR. Falls were classified considering the location of the destabilizing force, source of destabilization and fall precipitating factor. Fall incidence and circumstances were described; the characteristics of fallers and nonfallers in terms of functional and balance performance were compared with F-tests (95% CI). The fall incidence before surgery was 40.3% (95% CI 34.2% to 46.6%). This figure decreased to 13.1% (95% CI 9.2% to 18.0%) and to 23.4% (95% CI 17.8% to 29.6%) at 6 and 12 months after surgery, respectively. Most falls were caused by destabilizations in the base of support (n = 102, 72%) and were due to extrinsic factors (n = 78, 76%) and trip patterns. Significant differences between fallers and nonfallers were found in knee extensor strength and monopodal stability in the surgical limb (p < 0.05). Falls are prevalent in patients with severe knee osteoarthritis. Symptoms and functional performance improve after surgery, and fall incidence is reduced. Most fall events originate from disruptions in the base of support and are precipitated by extrinsic factors, generally trips during walking activities.

Balance control impairments in Fabry disease

Background

Fabry disease (FD) is a rare inherited lysosomal storage disorder caused by the deficiency of the enzyme alpha-galactosidase A. This deficiency leads to an accumulation of glycosphingolipids leading to progressive and multisystemic disease, including renal, cardiac, and neurological damages. FD may also have neuro-otological and visual impairments, which can generate postural control alterations, inner ear, and vision being involved in this function. This study aimed to evaluate the impact of FD on postural control.

Methods

In total, fourteen adult patients (8 men/6 women, mean age = 37.6 ± 11.4 years) and two children (mean age = 11 years) with FD and 19 healthy adults (12 men/7 women, mean age = 36.5 ± 16.9 years) and two healthy children (mean age = 10.5 years) took part in this study. Postural control was evaluated by a sensory organization test combining three visual situations (eyes open, eyes closed, and sway referenced visual surround motion) with two platform situations (stable platform and sway referenced platform motion), aiming to calculate a composite equilibrium score (CES), a high score being representative of good postural control. Somatosensory (R^SOM), visual (R^VIS), and vestibular (R^VEST) contributions to postural control were calculated, a low score reflecting a poor use of the indicated sensory input.

Results

The CES was lower in adult patients with FD compared with the healthy subjects (p < 0.001). R^VIS (p = 0.001) and R^VEST (p = 0.003) were lower in patients with FD compared with the control group, whereas no difference in R^SOM was observed.

Conclusion

Inner ear and visual pathologies associated with the central nervous system impairments are factors of postural control impairments. Physical activities, which can also be rehabilitative, by maintaining or increasing the weight of proprioception, may help diminish dependency on altered sensorial inputs.

Epigenetic aging, knee pain and physical performance in community-dwelling middle-to-older age adults

Knee pain is a leading cause of disability in the aging population and may indirectly accelerate biological aging processes. Chronological aging increases the risk of developing of knee pain and knee pain reduces physical function; however, limited data exist on how epigenetic aging, a known hallmark of biological aging shown to predict health span and mortality, may influence this relationship. The purpose of this study was to examine whether decreased physical performance associated with knee pain is mediated by markers of epigenetic aging. Participants (57.91 ± 8.04 years) with low impact knee pain (n = 95), high impact knee pain (n = 53) and pain-free controls (n = 26) completed self-reported pain, a blood draw and a short physical performance battery (SPPB) that included balance, walking, and sit to stand tasks. We employed an epigenetic clock previously associated with knee pain and shown to predict overall mortality risk (DNAmGrimAge). Bootstrapped-mediation analyses were used to determine associations of DNAmGrimAge and SPPB between pain groups. Those with high impact and low impact pain had a biologically older epigenetic age (5.14y ± 5.66 and 1.32y ± 5.41, respectively). However, while there were direct effects of pain on overall physical performance, these were not explained by epigenetic aging. Epigenetic aging only mediated the effect of pain on balance performance. Future work is needed to examine pain's impact on biological aging processes including epigenetic aging and its ultimate effect on physical function measures known to predict health span and mortality.

Nonlinear and Linear Measures in the Differentiation of Postural Control in Patients after Total Hip or Knee Replacement and Healthy Controls

Primary osteoarthritis treatments such as a total hip (THR) or knee (TKR) replacement lead to postural control changes reinforced by age. Balance tests such as standing with eyes open (EO) or closed (EC) give a possibility to calculate both linear and nonlinear indicators. This study aimed to find the group of linear and/or nonlinear measures that can differentiate healthy people and patients with TKR or THR from each other. This study enrolled 49 THR patients, 53 TKR patients, and 16 healthy controls. The center of pressure (CoP) path length, sample entropy (SampEn), fractal dimension (FD), and the largest Lyapunov exponent (LyE) were calculated separately for AP and ML directions from standing with EO/EC. Cluster analysis did not result in correct allocation to the groups according to all variables. The discriminant model included LyE (ML-EO, ML-EC, AP-EC), FD (AP-EO, ML-EC, AP-EC), CoP-path AP-EC, and SampEn AP-EC. Regression analysis showed that all nonlinear variables depend on the group. The CoP path length is different only in THR patients. It was concluded that standing with EC is a better way to assess the amount of regularity of CoP movement and attention paid to maintain balance. Nonlinear measures better differentiate TKR and THR patients from healthy controls.

A Portable Wearable Inertial System for Rehabilitation Monitoring and Evaluation of Patients With Total Knee Replacement

Knee osteoarthritis is a degenerative disease, which greatly affects the daily life of patients. Total knee replacement (TKR) is the most common method to treat knee joint disorders and relieve knee pain. Postoperative rehabilitation exercise is the key to restore knee joint function. However, there is a lack of a portable equipment for monitoring knee joint activity and a systematic assessment scheme. We have developed a portable rehabilitation monitoring and evaluation system based on the wearable inertial unit to estimate the knee range of motion (ROM). Ten TKR patients and ten healthy adults are recruited for the experiment, then the system performance is verified by professional rehabilitation equipment Baltimore Therapeutic Equipment (BTE) Primus RS. The average absolute difference between the knee ROM and BTE Primus RS of healthy subjects and patients ranges from 0.16° to 4.94°. In addition, the knee ROM of flexion-extension and gait activity between healthy subjects and patients showed significant differences. The proposed system is reliable and effective in monitoring and evaluating the rehabilitation progress of patients. The system proposed in this work is expected to be used for long-term effective supervision of patients in clinical and dwelling environments.

Postural Control and Adaptation Strategy of Young Adults on Unstable Surface

Balance control is essential for postural adjustment in physical activities. This study investigates the behavior of human postural control and the coordination and adaptation strategy of hip, knee, and ankle when standing on an unstable surface. Twenty participants were recruited. Four different conditions were investigated: a quiet bipedal stance with eyes open and eyes closed, and standing on an unstable surface with eyes open and eyes closed. Other than the joint angle, the standard body sway measures, such as sway area and sway velocity, were computed. A nonlinear time series measure, that is, sample entropy, was used to determine the regularity of the time series and body adaptability to change and perturbation. The results show that the body sway increases as the difficulty increases. This study also confirms the coordination of the hip, knee, and ankle to maintain body balance on the unstable surface by decreasing the joint angle and adopting a lower posture. Even though the individual joint has lower sample entropy value and is deemed to be rigid and less adaptive to perturbation, the postural control exhibits higher sample entropy value, particularly in the anterior–posterior direction, and has the ability to stabilize the body by manipulating the joints simultaneously. These outcomes suggest that an unstable surface not only challenges the human postural control, but also reduces the hip, knee, and ankle adaptability to perturbation, thus making it a great tool to train body balance.

Effects of total knee arthroplasty for primary knee osteoarthritis on postural balance: A systematic review

BACKGROUND

Knee osteoarthritis is often related to physical function impairment. Although total knee arthroplasty is considered effective for advanced cases of knee osteoarthritis, its effects on postural balance is a topic of debate.

RESEARCH QUESTION

What are the effects of total knee arthroplasty for primary knee osteoarthritis on postural balance compared to preoperative status and/or to healthy controls?.

METHODS

Longitudinal studies (with more than 1-month follow-up) assessing postural balance measures (either clinical-based such as balance scales or laboratory-based such as postural sway) were considered eligible and selected in a 2-phase process. Six main electronic databases were searched, complemented by 3 grey literature sources. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tools.

RESULTS

A total of 19 studies were included for qualitative synthesis, of which 14 had low and 5 had a moderate risk of bias. The follow-up period ranged from 1-24 months. Most studies (n = 11) presented comparisons to preoperative status only. From these, 7 studies reported relevant improvements in postural balance, 2 reported partial improvements, and 2 no improvements. The remaining studies (n = 8) presented comparisons to healthy controls and, although improvements following total knee arthroplasty were consistently observed, only one study reported postural balance measures comparable to that of controls.

CONCLUSIONS

The majority of studies reported relevant improvements (especially in clinical-based measures) compared to preoperative evaluations, although inconsistencies were found possibly due to variability in studies' populations, assessment tools, and follow-up times. Despite this, persistent deficits in postural balance were commonly observed when compared to healthy controls.

SIGNIFICANCE

This evidence synthesis could better inform clinicians and researchers about the therapeutic effects and limitations of total knee arthroplasty concerning postural balance. Standardization of assessment tools is recommended to strengthen the certainty of cumulative evidence.

Activity Recommendations After Total Hip and Total Knee Arthroplasty

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A formal unsupervised activity program should be recommended to all patients recovering from total knee arthroplasty (TKA) and total hip arthroplasty (THA).

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In a subset of all patients undergoing TKA or THA, studies have found that an unsupervised activity program may be as efficacious as supervised physical therapy (PT) after surgery. Certain patients with inadequate independent function may continue to benefit from supervised PT.

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For TKA, supervised telerehabilitation has also been proven to be an effective modality, with studies suggesting equivalent efficacy compared with supervised in-person PT.

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Following TKA, there is no benefit to the use of continuous passive motion or cryotherapy devices, but there are promising benefits from the use of pedaling exercises, weight training, and balance and/or sensorimotor training as adjuncts to a multidisciplinary program after TKA.

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No standardized postoperative limitations exist following TKA, and the return to preoperative activities should be dictated by an individual's competency and should consist of methods to minimize high impact stress on the joint.

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Despite traditional postoperative protocols recommending range-of-motion restrictions after THA, it is reasonable to recommend that hip precautions may not be needed routinely following elective primary THA.

The trunk's contribution to postural control under challenging balance conditions

BACKGROUND

The double inverted pendulum model is imprecise when applied to studies of postural control. Although multijoint analyses have improved our understanding of how balance is maintained, the exact role of the trunk remains unclear.

RESEARCH QUESTIONS

What is the trunk's contribution in postural control with respect to the other joints and how do trunk muscles control trunk kinematics?

METHODS

Thirty-six healthy athletes (handball, karate, long jump) performed a highly challenging balance task while the ground support was dynamically tilted in the sagittal plane. The center of force (CoF) as well as lower limb joint angles and the trunk-pelvis angle were respectively measured with a force platform and inertial measurement units. The amplitude, sway path and standard deviation of the CoF and the joint angles were then calculated. Electromyography was used to record the activity of the rectus abdominis, external obliquus, and erector spinae muscles. Multiple linear regressions were computed to determine the joints' and muscles' contributions (β-coefficients) in predicting CoF variables and trunk kinematics, respectively.

RESULTS

The linear combination of joint kinematic variables accounted for between 33 % and 75 % of the variance in the CoF. The ankle had the highestβ and was a significant predictor of all CoF variables. The trunk yielded the second highest β-coefficient and was a significant predictor of the CoF sway path. Electromyography variables accounted for no more than 35 % of the variance in the trunk kinematics, and erector spinae activity was the only significant predictor.

SIGNIFICANCE

The trunk appears to be the second most important element during this specific postural task, in the magnitude of body sway in particular. But neuromuscular control of these trunk processes is difficult to characterize with surface electromyography only. The trunk should be taken into account when seeking to improve overall postural control (e.g. during training, rehabilitation).

Instrumented platforms for balance and proprioceptive assessment in patients with total knee replacement: A systematic review and meta-analysis

BACKGROUND

The functional outcome of total knee replacement (TKR) is usually satisfying. However, patients may show functional limitations for years after surgery, which have been ascribed to impairments in balance and proprioception, mainly during standing tasks. A number of instrumentations and parameters have been used, rising confusion for clinical decisions on the assessment of patients.

RESEARCH QUESTION

Which are the most widespread and consistent procedures to assess balance and proprioception following TKR?

METHODS

A literature review was conducted in Pubmed, PEDro, and Cochrane database. From a total sample of 112 articles, 23 original studies published between 2008 and 2019 met inclusion criteria. The primary outcomes selected were variables related to balance and proprioception assessment in static and dynamic tasks performed with instrumented platforms. Data from papers using the same instrumentation, on patients with unilateral TKA and at least 12 months postoperatively were synthesized quantitatively in a random effect meta-analysis.

RESULTS

Fourteen articles were appropriate for the review. A large variability was found both in the instrumentation and the parameters used. The Neurocom Balance Master System™ was the most used instrument (four articles). On a total population of 186 patients with unilateral TKR 12 months postoperatively, a low degree of heterogeneity was found adopting the random effect in the four tasks explored (Firm and Foam Surface both with Eyes Open and Eyes Closed).

SIGNIFICANCE

This review found a large variability in the instrumentation used to assess balance and proprioception in patients operated on TKR. The meta-analysis demonstrated that the Neurocom Balance Master System™ for static assessment of balance showed an acceptable consistency and can be considered as a reference for further studies. However, balance and proprioception impairments following TKR have not been widely quantified by means of instrumented platforms. Further research is needed to address this issue, and improve clinical practice.

What is actually happening inside the "cone of economy": compensatory mechanisms during a dynamic balance test

STUDY DESIGN

A nonrandomized, prospective, concurrent control cohort study.

OBJECTIVE

To further develop cone of economy (CoE) measurements by identifying compensatory mechanisms at the extremes of the CoE and comparing balance control strategies in a group of adult degenerative scoliosis (ADS) patients with non-scoliotic controls. The CoE concept was first proposed by Dubousset and is frequently referred to when assessing balance in spinal deformity patients. Recently, a method that quantifies the CoE of individual patients through 3D video kinematic and electromyography data was developed. However, this method lacks measurements that describe the motor control strategies utilized by spinal disorder patients to maintain balance.

PATIENT SAMPLE

Twenty ADS patients and 15 non-scoliotic controls.

METHODS

All test subjects were fitted with a full body marker set. Each subject performed a series of functional balance tests (Romberg's with eyes opened) while being recorded in a human motion capture system. Three-dimensional CoE dimensions, range of sway (RoS), overall sway and lower extremity and trunk range of motion (RoM) were measured and analyzed.

RESULTS

Patients with ADS demonstrated greater overall sway and RoS in the sagittal and coronal planes compared to controls. Moreover, ADS patients presented with more hip flexion and trunk flexion at maximal points of sway and more ankle, knee, hip and trunk RoM when swaying in comparison with controls.

CONCLUSIONS

ADS patients have larger CoE dimensions and increased sway when compared to non-scoliotic controls. ADS patients rely on a hip balance control "strategy" and lower extremity RoM to maintain balance, which differed from control subjects. Unlike prior attempts to define compensatory mechanisms in ADS patients, the described technique utilizes dynamic, three-dimensional measurements to define what is occurring within the CoE. By expanding on prior CoE measurements, we were able to define a unique dynamic balance control strategy for each patient.

Balance Training With a Dynamometric Platform Following Total Knee Replacement: A Randomized Controlled Trial

BACKGROUND AND PURPOSE

Sensorimotor training has proven to be an efficient approach for recovering balance control following total knee replacement (TKR). The purpose of this trial was to evaluate the influence of specific balance-targeted training using a dynamometric platform on the overall state of balance in older adults undergoing TKR.

METHODS

This was a randomized controlled clinical trial conducted at a university hospital rehabilitation unit. Patients meeting the inclusion criteria were randomly assigned to a control group or an experimental group. Both groups participated in the same 4-week postoperative rehabilitation training protocol. Participants in the experimental group performed additional balance training with a dynamometric platform consisting of tests related to stability challenges, weight-shifting, and moving to the limits of stability. The primary outcome measure was the overall state of balance rated according to the Berg Balance Scale. Secondary outcomes in terms of balance were the Timed Up and Go Test, Functional Reach Test, and Romberg open and closed-eyes tests. Data processing included between-group analysis of covariance, minimal detectable change assessment for the primary outcome measure, and effect size estimation. Confidence intervals (CIs) were set at 95%.

RESULTS

Forty-three participants meeting the inclusion criteria and having signed the informed consent were randomly assigned to 2 groups. Thirty-seven completed the training (86.1%). Significant between-group differences in balance performance were found as measured with the Berg Balance Scale (P = .03) and Functional Reach Test (P = .04) with a CI = 95%. Significant differences were not recorded for the Timed Up and Go Test or Romberg open and closed-eyes tests (P > .05). Furthermore, Cohen's effect size resulted in a value of d = 0.97, suggesting a high practical significance of the trial.

DISCUSSION AND CONCLUSIONS

According to the Berg Balance Scale and Functional Reach Test, participants with TKR who have followed a 4-week training program using a dynamometric platform improved balance performance to a higher extent than a control group training without such a device. The inclusion of this instrument in the functional training protocol may be beneficial for recovering balance following TKR.

Comparison of high-frequency intensive balneotherapy with low-frequency balneotherapy combined with land-based exercise on postural control in symptomatic knee osteoarthritis: a randomized clinical trial

Knee osteoarthritis (KOA) can generate postural control impairments which can increase fall risk. Land-based exercise (LBE) and balneotherapy are two modalities currently prescribed, but the impact of the latter on balance control has not been studied. This study aimed to compare two programs of balneotherapy with or without LBE to improve postural control, looking at frequency and duration of treatment. A total of 236 KOA patients (mean age = 64 years) were included in this prospective and randomized study: 122 patients went through 3 weeks of standardized continuous balneotherapy (high frequency/short duration) program (Gr1) and 114 went through 3 weeks of discontinuous (low frequency) balneotherapy program followed by 3 weeks of LBE (Gr2). The total number of treatment sessions was the same for both groups. Posturography was carried out before balneotherapy (W0) and at 3 (W3), 6 (W6), and 12 (W12) weeks after the beginning of treatment. Postural control increased in Gr1 from W0 to W3 and from W0 to W12 and in Gr2 from W0 to W6 and from W3 to W6. The improvement was greater in Gr1 from W0 to W3 and from W6 to W12 and in Gr2 from W3 to W6. High-frequency intensive balneotherapy improved posture control at 3 weeks, while low-frequency balneotherapy did not. This improvement persisted over a 12-week assessment period at the same level. LBE generated an improvement that did not persist over time. Sustained improvement of postural control requires high-frequency repetition of consecutive balneotherapy sessions.

Comparing single and multi-joint methods to detect knee joint proprioception deficits post primary unilateral total knee arthroplasty

BACKGROUND

The use of various single-joint proprioception measurements has resulted in contradictory findings after knee arthroplasty. The use of balance as a surrogate measure to assess knee proprioception post-operation has resulted in further confusion. The aim of this study was to measure single joint knee proprioception in participants after unilateral knee arthroplasty, and compares it to multi-joint balance.

METHODS

Eleven participants at 1 year after unilateral total knee arthroplasty and twelve age-matched controls were enrolled. The threshold to detect passive motion and the sensory organization test were used to measure single joint knee proprioception and multi-joint balance respectively. Two-way ANOVA and independent t-tests were used to measure differences between and within groups. Regression analysis was used to measure the association between proprioception and balance measurements.

FINDINGS

Surgical knees demonstrated significantly more deficient proprioception compared to the non-surgical knees and both knees of the control groups during flexion (P < 0.01) and extension (P < 0.05). Non-surgical knees showed similar proprioception to both knees of the control group during flexion and extension. Within the knee arthroplasty group, only deficiencies during flexion showed significant correlation with Sensory Organization Test visual ratio. No additional differences between both groups during balance measurements, nor any correlations between local joint proprioception and balance were seen.

INTERPRETATION

These findings indicate deficient surgical knee proprioception in participants one year after unilateral total knee arthroplasty. Limited associations between measurements indicate that balance may be a poor measure of single-joint proprioception.

Risk factors for falls in patients with total hip arthroplasty and total knee arthroplasty: a systematic review and meta-analysis

OBJECTIVE

Falls are common after total hip arthroplasty (THA) and total knee arthroplasty (TKA). While previous studies have investigated various risk factors for falls in patients following THA and TKA, no systematic reviews have summarized these risk factors. Therefore, the current systematic review aimed to summarize evidence regarding risk factors for falls in patients after THA and/or TKA.

METHODS

MEDLINE, EMBASE, CINAHL, SPORTDiscus, and Physiotherapy Evidence Database (from inception to June 30, 2018) were searched. The methodological quality and quality of evidence of the included studies were assessed by two independent reviewers. Relevant data regarding participants' characteristics, study design, follow-up time points, and identified risk factors were extracted. Meta-analyses and narrative syntheses were performed.

RESULTS

Twelve studies with a total of 1,292,689 participants were included. Twenty-nine identified risk factors for post-THA/TKA falls were classified into either inpatient or post-discharge risk factors. Key risk factors for both post-THA and/or post-TKA inpatient falls that showed moderate level of evidence included: postoperative complications or comorbidities and revision THA/TKA. Likewise, risk factors for post-discharge falls after THA and/or TKA that demonstrated moderate level of evidence included: medications, psychiatric diseases, living alone, prior history of TKA, falls history and female gender. The quality of the included studies varied and sample sizes were not justified.

CONCLUSIONS

This review summarized both non-modifiable and modifiable risk factors for post-THA/TKA falls. Our findings highlight the importance of developing strategies to lower the falls risk among patients following THA/TKA.

How proprioception changes before and after total knee arthroplasty: A systematic review

BACKGROUND

Proprioception is one of the most significant factors in balance, joint stability, graceful movement, coordination, and injury prevention. It involves a wide set of receptors located within joints, muscles, and tendons. Given the neurophysiological processes involved in proprioception response are multiple and complex, there is not one single method to measure it. Particularly, proprioception of the knee joint, whether it is healthy, affected by osteoarthritis, or after replacement, is the most investigated by in literature.

RESEARCH QUESTION

This review addresses the analysis of proprioception in the knee joint before and after total knee arthroplasty (TKA). The aim is to obtain an overview of the proprioceptive skills in subjects who suffered from osteoarthritis and were subjected to knee replacement, evaluating changes in proprioception before and after the surgery.

METHODS

The research was conducted within four databases: Web of Science®, PubMed Central®, Cochrane®, and PEDro®, between January 2008 and February 2018. Accurate exclusion criteria and selection strategy were applied to screen the 170 articles found.

RESULTS

Ultimately, 13 papers were fully evaluated and included in this review, divided into two classes: i) works directly measuring proprioception, ii) studies indirectly evaluating proprioception. Contrasting results emerged from the analysis, and no consensus was found in the literature about the improvement or worsening in proprioception before and after TKA.

SIGNIFICANCE

Since currently there is high variability in methods, protocol and parameters used to evaluate knee proprioception, further investigations based on a consistent dataset, a well-defined protocol, measurable outcomes, timeline follow-ups, and rehabilitation programs should be performed in order to obtain reliable results on the effects of TKA on knee proprioception and balance.

Instability training, assessing the impact of level of difficulty on balance: A randomized clinical trial

BACKGROUND

Most human movements are executed while in a state of postural instability. For this reason, instability training is a highly-specific method that is intended to improve balance and postural control. This research aimed to determine the effect of instability training on the balance of individuals with similar baseline abilities, who initiated training within different stability conditions.

RESEARCH QUESTION

Does the level of difficulty with which instability training is performed determine improvements in balance?

METHOD

A two-arm randomized trial was undertaken, for which 22 and 21 participants were included in the experimental and control groups, respectively. The experimental group performed balance training on unstable surfaces and the control group implemented the same training on stable ground. The primary outcome was the Y-Balance Test (YBT); the Emery test, Functional Reach test, and platform measures were the secondary outcomes. Confidence intervals were set at 95% and Cohen's f statistic was used to estimate effect size.

RESULTS

Dynamic balance, as measured by the YBT, showed significant Time improvements in both groups for right (p <  0.001, f = 0.53) and left (p =  0.005, f=0.33) limbs. Similar results were found in the Emery test and Functional Reach test. No statistical Group and Time*Group interactions were found. None of the proposals modified the center of pressure excursions.

SIGNIFICANCE

Instability training is a safe and effective approach to enhance balance. However, the findings deduced that the level of difficulty (instability) with which participants with similar abilities initiate the training is not a determining factor in the balance improvements achieved. It follows that instability training may be either used as an alternative or as an additional method to train for balance on a stable ground.

Left/right limb judgement task performance following total knee replacement

PURPOSE

Working body schema (WBS) of the limbs may be indirectly assessed using left/right limb judgement (LRLJ) task performance. This study aimed to investigate if: 1) Total Knee Replacement (TKR) patients perform LRLJ tasks with reference to their WBS; 2) patients have a disrupted WBS following a TKR for the replaced knee compared to the contralateral knee; and 3) lower limb-based LRLJ task performance changes following post-surgical rehabilitation using change in upper limb-based LRLJ task performance as a control.

METHODS

In a convenience sample (n= 18, age 69 ± 7 yrs, 12F 6M) of TKR patients < 1 month post-surgery, WBS was assessed using LRLJ task performance for the upper (pictures of the hand) and lower limb (pictures of the foot) before and after rehabilitation. Accuracy and response time (RT) were analysed using a series of 2 × 2 × 2 ANOVAs.

RESULTS

LRLJ task performance for images corresponding with the operated and non-operated side were comparable for accuracy (p= 0.83) and RT (p= 0.28). Accuracy for hand images was comparable from baseline to post-rehabilitation (p= 0.54) whereas accuracy for feet images increased significantly (p= 0.03). Responses for awkward posture images were significantly slower than for more natural posture images (p= 0.001).

CONCLUSIONS

LRLJ task performance data reflected the typical biomechanical constraints indicative of implicit motor imagery being performed by patients. There was no evidence of a disrupted LRLJ task performance for the replaced knee compared to the contralateral knee. Following post-surgical rehabilitation, patients' lower limb LRLJ task performance improved whilst upper limb LRLJ task performance remained unchanged. These findings are the first to show that WBS improves with rehabilitation following TKR, and this may explain some of the clinical improvements observed. Undertaking LRLJ tasks could theoretically be a useful adjunct to current post-TKR rehabilitation.

Comparison of sit-to-stand and static standing balance ability between patients with total knee arthroplasty and elderly healthy subjects

BACKGROUND

Identifying the functional status of patients after total knee arthroplasty is important. This study aimed to examine the differences in sit-to-stand and static standing ability balance between patients who underwent total knee arthroplasty and healthy participants.

METHODS

Twenty patients (mean age 70.05 years) who underwent total knee arthroplasty and 20 healthy participants (mean age 69.20 years) participated in this study. To assess the participants' sit-to-stand, the Good Balance System (Metitur Ltd, Finland) was used to measure each participant's mediolateral center of pressure (COP) displacement and time required to complete the sit-to-stand movement. To assess the participants' static standing balance, the Good Balance System was used to measure each patient's mediolateral COP displacement, anteroposterior COP displacement, and velocity moment when standing with eyes open and with eyes closed.

RESULTS

A significant difference was found in the mediolateral COP displacement and the time required to complete the sit-to-stand movement in the two groups (P< 0.05). A significant difference was also found in the mediolateral and anteroposterior COP displacement and the velocity moment when standing with eyes open and with eyes closed in the two groups (P< 0.05).

CONCLUSIONS

Patients who had total knee arthroplasty showed decreased sit-to-stand and static standing balance ability compared with the control group in the initial period after surgery.

Postural awareness and its relation to pain: validation of an innovative instrument measuring awareness of body posture in patients with chronic pain

Background

Habitual postural patterns are associated with musculoskeletal pain, and improving a maladaptive posture requires postural awareness in order to lead to clinical improvements. This study aimed to develop and evaluate the psychometric properties of an innovative postural awareness scale.

Methods

A 12-item Postural Awareness Scale (PAS) was developed and administered to 512 chronic pain patients (50.3 ± 11.4 years, 91.6% female, 37.1% spinal/shoulder pain) to assess its factor structure and reliability. To determine convergent validity, measures of body awareness, body responsiveness, body image, and mindfulness were correlated with the PAS, as were clinical measures of pain intensity, disability, and mental health. Sensitivity to change was assessed in 202 outpatients participating in a 10-week multimodal mind-body program.

Results

Factor analysis revealed two factors (Ease/Familiarity with Postural Awareness and Need for Attention Regulation with Postural Awareness) that explained 50.8% of the variance. Cronbach’s alpha for the complete scale was 0.80; Spearman-Brown coefficient of split-half reliability was 0.67; and intra-class correlation was ICC_2,1 = 0.75 (95% confidence interval = 0.71, 0.78). Significant positive correlations were found for body awareness (r = 0.23), body responsiveness (r = 0.41), body image (r = 0.22–0.32), and mindfulness (r = 0.38); negative correlations for pain intensity (r = − 0.14), disability (r = − 0.12), depression (r = − 0.23), and stress (r = − 0.29). Postural awareness scores increased with a mind-body program (p < 0.001); changes in the PAS were negatively correlated with changes in pain intensity (r = − 0.35) in patients with spinal/shoulder pain.

Conclusion

Self-reported postural awareness is associated with clinical symptoms in chronic pain patients; improvements in postural awareness are longitudinally associated with reduced pain in patients with spinal/shoulder pain.

Effect of sleep deprivation on diurnal variation of vertical perception and postural control

The aim of the study was to test the effect of total sleep deprivation on performance and time-of-day pattern of subjective visual vertical (SVV) and postural control. Nineteen healthy, young participants (4 women and 15 men 21.9 ± 1.2 yr) were engaged in two counterbalanced experimental sessions with or without total sleep deprivation. Oral temperature, Karolinska Sleepiness Scale, and visual analogic scale for fatigue, postural control, and SVV were randomly measured every 4 h, from 0600 to 2200. A linear mixed model was used to capture the effect of time of day and sleep condition as factors. A classical adjusted COSINOR function was then used to modelize this daily variation. After the control night of sleep, SVV as well as oral temperature, sleepiness, and fatigue showed significant time-of-day variation, contrasting with measures of postural control which remained stable across the day. After sleep deprivation, SVV showed no diurnal variation, but its mean deviation value increased by 29%. Postural control capability also decreased after sleep deprivation, with a higher center of pressure surface (+70.4%) and total length (+7.37%) but remained stable throughout the day. These results further confirm the negative effect of sleep loss on postural control capability. Even if a direct relationship cannot be confirmed, the disruption of SVV capacity after sleep deprivation could strongly play a role in postural control capacity changes. Sleep deprivation should be considered as a potent factor involved in balance loss and subsequent fall. NEW & NOTEWORTHY The topic of sleep deprivation and postural control is not understood, with discrepancy among results. This study described that postural control displays a stable level throughout the day and that sleep deprivation, even if it increases postural sway, does not affect this stable diurnal pattern. The modification of the perception of the vertical level after sleep deprivation could strongly play a role in the observed changes in postural control capacity.

Early self-managed focal sensorimotor rehabilitative training enhances functional mobility and sensorimotor function in patients following total knee replacement: a controlled clinical trial

OBJECTIVE

To assess the effects of early self-managed focal sensorimotor training compared to functional exercise training after total knee replacement on functional mobility and sensorimotor function.

DESIGN

A single-blind controlled clinical trial.

SETTING

University Hospital of Rion, Greece.

SUBJECTS

A total of 52 participants following total knee replacement.

OUTCOME MEASURES

The primary outcome was the Timed Up and Go Test and the secondary outcomes were balance, joint position error, the Knee Outcome Survey Activities of Daily Living Scale, and pain. Patients were assessed on three separate occasions (presurgery, 8 weeks post surgery, and 14 weeks post surgery).

INTERVENTION

Participants were randomized to either focal sensorimotor exercise training (experimental group) or functional exercise training (control group). Both groups received a 12-week home-based programme prescribed for 3-5 sessions/week (35-45 minutes).

RESULTS

Consistently greater improvements ( F_2,98 = 4.3 to 24.8; P < 0.05) in group mean scores favour the experimental group compared to the control group: Timed Up and Go (7.8 ± 2.9 seconds vs. 4.6 ± 2.6 seconds); balance (2.1 ± 0.9° vs. 0.7 ± 1.2°); joint position error (13.8 ± 7.3° vs. 6.2 ± 9.1°); Knee Outcome Survey Activities of Daily Living Scale (44.2 ± 11.3 vs. 26.1 ± 11.4); and pain (5.9 ± 1.3 cm vs. 4.6 ± 1.1 cm). Patterns of improvement for the experimental group over time were represented by a relative effect size range of 1.3-6.5.

CONCLUSIONS

Overall, the magnitude of improvements in functional mobility and sensorimotor function endorses using focal sensorimotor training as an effective mode of rehabilitation following knee replacement.

Effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability

[Purpose] This study examined the effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability. [Subjects and Methods] Twenty eight adults with functional ankle instability, divided randomly into an experimental group, which performed visual feedback balance training for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Bio rescue was used for balance ability. It measured limit of stability at one minute. For ankle instability was measured using Cumberland ankle instability tool (CAIT). This measure was performed before and after the experiments in each group. [Results] The experimental group had significant increase in the Limit of Stability and CAIT score. The control group had significant increase in CAIT score. While the Limit of Stability increased without significance. [Conclusion] In conclusion, visual feedback balance training can be recommended as a treatment method for patients with functional ankle instability.

Effects of visual and cognitive interference on joint contributions in perturbed standing: a temporal and spectral analysis

Postural balance requires using joint strategies which may be changed from normal conditions by interfering with the sensory information. The goal of the present study was to quantitatively evaluate the role of the joint mechanisms during perturbed stance. Visual and cognitive interference was imposed to sixteen healthy young males under rotational toes-down or up perturbations. Power spectral analysis was employed to distinguish the joint contribution and their in- or out-phase co-works. Results showed that addition of cognitive loads reduce the stability by increasing the center of mass (CoM) power to three times greater. Besides the CoM, the knee and hip powers were also significantly enhanced by the cognitive loads (p < .004), but the ankle was not influenced by cognition involvement (p > .05). Elimination of the vision had lower effect on the time and spectral functions of the knee and hip while the ankle rotations were increased due to the lack of visual feedback (p = .001). The toes-down perturbations resulted in more prominent contribution of the knee while the toes-up evoked the hip joint to keep the balance more than the other joints. Addition of the cognitive loads hindered the reactions of the joint mechanisms and vision caused more conservative responses of the joints.

The effect of primary total knee arthroplasty on the incidence of falls and balance-related functions in patients with osteoarthritis

Knee osteoarthritis (OA) is an established risk factor for falls and balance impairment. This study investigated the incidence of falls, balance-related outcomes and risk factors for falls before and after primary total knee arthroplasty (TKA). Three hundred seventy-six OA patients scheduled to undergo TKA were included. Falls data within the preoperative, first postoperative and second postoperative years were collected, balance-related functions were assessed using the Assessment of Quality of Life (AQoL), WOMAC, Falls Efficacy Scale International (FES-I), Activities-specific Balance Confidence (ABC), knee extension strength, Berg Balance Scale (BBS) and Timed Up and Go (TUG) before surgery and 1 and 2 years after surgery. Compared with preoperative values, the incidence of falls significantly decreased (14.89%, 6.23% and 3.14% within the preoperative, first postoperative and second postoperative years, respectively) and the AQoL, WOMAC, FES-I, ABC, knee extension strength, BBS and TUG significantly improved after TKA. Logistic regression analysis revealed that Kellgren-Lawrence grade ≥ 3 of the contralateral knee was an independent risk factor for falls before and after TKA. Conclusively, primary TKA is associated with a reduced incidence of falls and improved balance-related functions, and the contralateral knee should be considered in the design of fall-prevention strategies in patients with OA.

Comparison of an Innovative Rehabilitation, Combining Reduced Conventional Rehabilitation with Balneotherapy, and a Conventional Rehabilitation after Anterior Cruciate Ligament Reconstruction in Athletes

Background

Instability of the knee, related to anterior cruciate ligament injury, is treated by surgical reconstruction. During recovery, a loss of proprioceptive input can have a significant impact. Few studies have evaluated the benefits of rehabilitation of the knee in aquatic environment on functional outcomes.

Objective

This study aimed to compare an innovative rehabilitation protocol combining reduced conventional rehabilitation with aquatic rehabilitation, with a conventional rehabilitation, according to the National French Health Authority, in terms of kinetics, development of proprioceptive skills, and functional improvement of the knee.

Methods

67 patients, who were amateur or professional athletes, were randomized into two groups: 35 patients followed the conventional rehabilitation protocol (Gr1) and 32 patients followed the innovative rehabilitation protocol (Gr2). Patients were evaluated before surgery, and at 2 weeks, 1, 2, and 6 months after surgery using posturography, and evaluation of muscular strength, walking performance and proprioception. This study is multicenter, prospective, randomized, and controlled with a group of patients following conventional rehabilitation (level of evidence I).

Results

For the same quality of postural control, Gr2 relied more on somesthesia than Gr1 at 6 months. The affected side had an impact on postural control and in particular on the preoperative lateralization, at 2 weeks and at 1 month. Lateralization depended on the affected knee, with less important lateralization in Gr2 preoperatively and at 1 month. The quadriceps muscular strength was higher in Gr2 than in Gr1 at 2 and 6 months and muscle strength of the external hamstring was greater in Gr2 than in Gr1 at 6 months. The isokinetic test showed a greater quadriceps muscular strength in Gr2. Gr2 showed a greater walking distance than Gr1 at one month. Gr2 showed an improvement in the proprioceptive capacities of the operated limb in flexion for the first 2 months.

Conclusion

The effectiveness of the innovative rehabilitation program permits faster recovery, allowing for an earlier return to social, sporting, and professional activities. Faster retrieval of knee function following aquatic rehabilitation would prevent both short-term risk of lesions of the contralateral limb due to overcompensation and long-term risk of surgery due to osteoarthritis.

Registration of clinical trials

NCT02225613.

Factors associated with balance function in patients with knee osteoarthritis: An integrative review

This integrative review is to identify the factors associated with balance function in patients with knee osteoarthritis and explore the relationship between these factors and balance function. Osteoarthritis commonly occurs in elderly people. Patients with knee osteoarthritis have balance impairment, and maintaining knee stability is important for such patients to prevent accidental injuries caused by falling. Therefore, it is important to clarify the factors related to balance function in patients with knee osteoarthritis. The PubMed, Science Direct, CINAHL, Ovid, ProQuest, CNKI, WanFang databases were searched, and relevant articles published up to December 2015 were included. Twenty articles were included in the analysis. Age, gender, dominant limb, foot length, knee alignment, diurnal variation, and meniscus tears were the non-modifiable factors, whereas body mass index, knee pain, muscle strength, joint range of motion, severity, and cognitive loading were the modifiable factors. Knee sleeve and custom-molded insoles showed protective effects against knee osteoarthritis.

Effects of kinesio taping to the quadriceps femoris muscles on functions of elderly women

[Purpose] The purpose of this study is to investigate effects of kinesio taping to the quadriceps femoris on functions of elderly women. [Subjects and Methods] The subjects of this study were 22 elderly women with osteoarthritis, who were divided into two groups of a general exercise group 12 elderly and a kinesiology taping group 12 elderly. Two groups underwent a 30-min exercise for strengthening the lower limb muscles three times per week for four weeks. After the exercise, the kinesiology taping group was treated by the kinesio taping. Kinesio tapes were attached to the quadriceps femoris, three times per week for four weeks. The Korean Western Ontario and McMaster Universities Osteoarthritis Index, sit to standing, and Time up & Go test were used for assessment before and after the intervention. [Results] As a result, the kinesiology taping group showed significant differences in the Korean Western Ontario and McMaster Universities Osteoarthritis Index, sit to standing, and Time up & Go test between pre- and post-intervention, while the general exercise group showed no significant differences in pre- and post-intervention. There was a significant difference in between-group comparison. [Conclusion] The kinesio taping for the quadriceps femoris was effective on improving functions of elderly women with osteoarthritis.

Influence of meteorological elements on balance control and pain in patients with symptomatic knee osteoarthritis

This study aimed to determine if pain and balance control are related to meteorological modifications in patients with knee osteoarthritis (OA). One hundred and thirteen patients with knee OA (mean age = 65 ± 9 years old, 78 women) participated in this study. Static posturography was performed, sway area covered and sway path traveled by the center of foot pressure being recorded under six standing postural conditions that combine three visual situations (eyes open, eyes closed, vision altered) with two platform situations (firm and foam supports). Knee pain score was assessed using a visual analog scale. Balance control and pain measurements recorded in the morning were correlated with the meteorological data. Morning and daily values for temperature, precipitation, sunshine, height of rain in 1 h, wind speed, humidity, and atmospheric pressure were obtained from the nearest data collecting weather station. The relationship between postural control, pain, and weather variations were assessed for each patient on a given day with multiple linear regressions. A decrease of postural stability was observed when atmospheric pressure and maximum humidity decreased in the morning (p < 0.05) and when atmospheric pressure decreased within a day (p < 0.05). Patient's knee pain was more enhanced when it is warmer in the morning (p < 0.05) and when it is wetter and warmer within a day (p < 0.05). The relationship between weather, pain, and postural control can help patients and health professionals to better manage daily activities.

The effect of total knee arthroplasty on patients' balance and incidence of falls: a systematic review

PURPOSE

Despite the high incidence of falls in patients with OA, few studies have explored whether falls risk is affected after patients undergo total knee arthroplasty (TKA). Therefore, the aim of this systematic review was to identify the extent of the effects of TKA on balance and incidence of falls by critically reviewing the available literature.

METHODS

A systematic review of published literature sources was conducted up to March 2014. All studies assessing balance and incidence of falls after TKA (without physiotherapeutic intervention) were included. The methodological quality of each study was reviewed using the Critical Appraisal Skill Programme tool.

RESULTS

Thirteen studies were included, comprising of ten cohort studies (Level II) and three studies with Level of evidence III.

CONCLUSIONS

Findings provide evidence that TKA improves significantly single-limb standing balance (~60%) and dynamic balance up to 1-year following surgery (Level of evidence II). Moreover, TKA influences positively fear of falling and incidence of falls by switching 54.2 % of pre-operative fallers to post-operative non-fallers (Level of evidence II-III). It is highlighted that knee extension strength, proprioception and symmetrization of postural strategies have not fully recovered post-TKA and influence balance performance. Clinically, these persistent deficits need to be mitigated by physiotherapy even before TKA takes place.

Standing balance post total knee arthroplasty: sensitivity to change analysis from four to twelve weeks in 466 patients

OBJECTIVE

Little is known about how static standing balance changes post total knee arthroplasty (TKA). The primary aim of this study was to examine the sensitivity to change and redundancy of center of pressure (COP) variables post-TKA. The secondary aim was to compare the sensitivity of these measures to standard clinical assessments of one repetition maximum knee extension strength and fast pace gait speed.

DESIGN

466 participants performed instrumented double-limb standing balance tests with eyes open at 4 and 12 weeks post-TKA. Measures of COP standard deviation, amplitude, root mean square (RMS), path length, detrended fluctuation analysis (DFA) and signal frequency content for the medial-lateral (ML) and anterior-posterior (AP) axes were examined.

RESULTS

Significant decreases in total path length, ML variables related to sway velocity and AP signal complexity and frequency were observed. Inter-session Cohen's d effect size (ES) revealed the strongest effect was for high velocity ML path length, with a 12% decrease in this rapid sway. This variable, along with AP mean instantaneous frequency and AP DFA, were the only ones significantly different with effect sizes >0.20 and non-redundant (Spearman's rho <0.75). The ES of COP-derived variables (maximum = 0.45) were lower than gait speed (1.40) and knee extensor strength (1.54).

CONCLUSION

Increased high velocity ML sway is present at four compared to 12 weeks post-TKA. This augmented rapid sway may provide increased challenges to the postural control system at a time coinciding with reduced strength levels, which could have implications for physical function during activities of daily living.

Greek Physiotherapists' Perspectives on Rehabilitation Following Total Knee Replacement: a Descriptive Survey

BACKGROUND AND PURPOSE

In Greece, as in many countries, there is a scarcity of evidence in the type of physiotherapy services offered for the rehabilitation of total knee replacement (TKR). Despite the number of TKRs annually performed in Greece (over 10,000), there are no available clinical guidelines as to the content of best physiotherapy practice. The aim of this nationwide survey undertaken by physiotherapists treating TKR patients post-operatively was to record standard practice and services available in Greece.

METHODS

Design: cross-country survey Ten per cent of all registered physiotherapists working in public/private sectors were recruited. The developed survey comprised of questions regarding therapists' profile, protocols implemented at different stages of rehabilitation and the aims and modalities used.

RESULTS

A 58.7% response rate was achieved, where 36% (47/132) of respondents were treating patients in the inpatient phase and 64% (85/132) after hospital discharge. Patients in Greece are discharged with a home-based exercise program (56.7%) and, to a lesser extent, are referred to rehabilitation centres (13.3%). Strengthening, range of movement and functionality seemed to be the primary goals especially in the inpatient phase, whereas in the outpatient phase, apart from the larger differences identified, functionality and balance training were more frequently reported.

CONCLUSIONS

No significant variations in practice were found during inpatient rehabilitation, whilst there seemed to be diversity across outpatient physiotherapy programs. The current survey suggests that patient's general health and psychological and behavioural issues are the criteria by which physiotherapists select the volume of implemented exercise and progression. However, no specific guidelines were followed. Copyright © 2016 John Wiley & Sons, Ltd.

Proprioception and Knee Arthroplasty: A Literature Review

Proprioceptive mechanoreceptors provide neural feedback for position in space and are critical for three-dimensional interaction. Proprioception is decreased with osteoarthritis of the knees, which leads to increased risk of falling. As the prevalence of osteoarthritis increases so does the need for total knee arthroplasty (TKA), and knowing the effect of TKA on proprioception is essential. This article reviews the literature regarding proprioception and its relationship to balance, aging, osteoarthritis, and the effect of TKA on proprioception. Knee arthroplasty involving retention of the cruciate ligaments is also reviewed, as well the evidence of proprioception in the posterior cruciate ligament after TKA.

Effects of Unilateral Cochlear Implantation on Balance Control and Sensory Organization in Adult Patients with Profound Hearing Loss

Many studies were interested in the consequence of vestibular dysfunction related to cochlear implantation on balance control. This pilot study aimed to assess the effects of unilateral cochlear implantation on the modalities of balance control and sensorimotor strategies. Posturographic and vestibular evaluations were performed in 10 patients (55 ± 20 years) with profound hearing loss who were candidates to undergo unilateral multichannel cochlear implantation. The evaluation was carried out shortly before and one year after surgery. Posturographic tests were also performed in 10 age-matched healthy participants (63 ± 16 years). Vestibular compensation was observed within one year. In addition, postural performances of the patients increased within one year after cochlear implantation, especially in the more complex situations, in which sensory information is either unavailable or conflicting. Before surgery, postural performances were higher in the control group compared to the patients' group. One year after cochlear implantation, postural control was close to normalize. The improvement of postural performance could be explained by a mechanism of vestibular compensation. In addition, the recovery of auditory information which is the consequence of cochlear implantation could lead to an extended exploration of the environment possibly favoring the development of new balance strategies.

Prediction of Balance Compensation After Vestibular Schwannoma Surgery

Background Balance compensation after vestibular schwannoma (VS) surgery is under the influence of specific preoperative patient and tumor characteristics. Objective To prospectively identify potential prognostic factors for balance recovery, we compared the respective influence of these preoperative characteristics on balance compensation after VS surgery. Methods In 50 patients scheduled for VS surgical ablation, we measured postural control before surgery (BS), 8 (AS8) days after, and 90 (AS90) days after surgery. Based on factors found previously in the literature, we evaluated age, body mass index and preoperative physical activity (PA), tumor grade, vestibular status, and preference for visual cues to control balance as potential prognostic factors using stepwise multiple regression models. Results An asymmetric vestibular function was the sole significant explanatory factor for impaired balance performance BS, whereas the preoperative PA alone significantly contributed to higher performance at AS8. An evaluation of patients' balance recovery over time showed that PA and vestibular status were the 2 significant predictive factors for short-term postural compensation (BS to AS8), whereas none of these preoperative factors was significantly predictive for medium-term postoperative postural recovery (AS8 to AS90). Conclusions We identified specific preoperative patient and vestibular function characteristics that may predict postoperative balance recovery after VS surgery. Better preoperative characterization of these factors in each patient could inform more personalized presurgical and postsurgical management, leading to a better, more rapid balance recovery, earlier return to normal daily activities and work, improved quality of life, and reduced medical and societal costs.

Diurnal variation on balance control in patients with symptomatic knee osteoarthritis

OBJECTIVE

Increasing evidence supports balance control impairment in older adult patients with knee osteoarthritis (OA). However, there is limited data on diurnal variation of balance control in these patients. This study aimed to investigate postural stability in older adult patients with symptomatic knee OA during different periods in a daytime.

METHODS

Two-hundred and forty-one patients with OA knee (median age=65 ± 12 years; 82 males) were enrolled in this study. Static posturography was performed under four standing conditions: eyes open and eyes closed, without and with foam support. To assess diurnal postural variations, testing sessions were defined as follows: 8-10 am, 10-12 am, 1 pm-3 pm, 3 pm-5 pm. Influence of sex, age, height, weight, and body mass index on postural stability was evaluated. Knee pain was also assessed in these four testing sessions.

RESULTS

Postural control was in particular less efficient in the late morning than in the early afternoon (p<0.05). Diurnal variation of balance control was more noticeable in older, heavier, and male patients (p<0.05). Patients' knee pain was more pronounced in the morning than in the afternoon (p<0.001).

CONCLUSION

Balance stability of patients with OA knee was different during a daytime. Altered postural performance in the morning could be explained by joint pain. This diurnal variation should be taken into account in the daily management of knee OA.

Postural stability in relation to anthropometric and functional characteristics in women with knee osteoarthritis following total knee arthroplasty

INTRODUCTION

Due to the controversial information about postural stability in patients with lower limb joints osteoarthritis (OA), the following main questions are raised: how serious is the postural stability disturbance and which factors have an impact on postural stability before and after total knee arthroplasty (TKA).

MATERIALS AND METHODS

Force plate was used to assess postural stability and custom-made dynamometer was used to assess isometric maximal voluntary contraction (MVC) force of leg extensor muscles; besides, knee pain and knee range of motion (ROM) was evaluated in 14 female patients (aged 46-68 years) with knee OA 1 day before, and 3 and 6 months following TKA and once in healthy controls (aged 48-70). Relationship between postural stability during standing and selected anthropometric and functional characteristics were investigated with Spearman's correlation coefficients.

RESULTS

Remarkable reduction of knee pain and improvement in active ROM for the operated leg were shown after unilateral TKA. MVC force of leg extensor muscles achieved the preoperative level half a year after TKA. The centre of pressure (COP) of sway displacement in anterioposterior (AP) and mediolateral direction and the equivalent area of COP sway for the operated leg did not differ before, 3 and 6 months after TKA and compared to the non-operated leg. The trace speed was 6 months after TKA equal to the preoperative level. Only the COP of sway displacement in AP direction is significantly greater in knee OA patients both before and after TKA compared with healthy controls.

CONCLUSIONS

Knee OA patients' postural stability characteristics did not differ significantly both before and after TKA. Compared to healthy controls, the COP of sway displacement in AP direction is mostly disturbed. Correlation analysis confirms that increased postural sway is associated with an increased equivalent area of COP. In knee OA patients higher body mass index ensures reduced trace speed and lower knee ROM.

LEVEL OF EVIDENCE

Prospective comparative study, Level II.

Preoperative asymmetry in load distribution during quiet stance persists following total knee arthroplasty

PURPOSE

Preoperative function has been shown to persist posttotal knee arthroplasty. However, it remains unclear whether asymmetries are task specific. Therefore, we investigated postoperative asymmetries in loading during quiet stance and walking gait.

METHODS

Ten patients with end-stage knee osteoarthritis scheduled for total knee arthroplasty were studied at baseline (preoperative), 6-week, 3- and 6-month postoperative. Load distribution and balance were quantified during quiet stance. Furthermore, dynamic loading was quantified during walking gait. Patient satisfaction was assessed using the Knee Osteoarthritis and injury Outcome Score.

RESULTS

Preoperatively, load distribution was significantly different between limbs, with approximately 70% of the load through the contralateral or 'good' side. Asymmetries persisted and up to 6-month postoperative during quiet stance. No significant change was found in balance. During walking, preoperative loading asymmetry was present; however, no significant postoperative loading asymmetries were identified.

CONCLUSIONS

Total knee arthroplasty does not appear to significantly change load distribution or balance 6-month postoperative during quiet stance; however, during walking gait, symmetry appears to be restored. This could be potentially improved through enhanced rehabilitation.

LEVEL OF EVIDENCE

Therapeutic study, Level IV.

Improved single-limb balance after total knee arthroplasty

PURPOSE

Unsteady ambulation shortly after total knee arthroplasty (TKA) may cause falling. Postural sway may predict the risk of falling. This prospective single-blinded observational study therefore evaluated the effects of TKA on single-limb standing balance (SLSB) and factors related to change in SLSB.

METHODS

Patients with varus deformity and medial compartment degeneration were evaluated between September and December 2010. The Western Ontario and McMaster Universities Osteoarthritis Index and Kellgren/Lawrence scale were assessed, as were varus angle, number of painful knees, isometric peak torque of the quadriceps femoris, balance index of double limbs, and postural sway of single limbs.

RESULTS

Twelve patients were enrolled and 11 were analysed. The mean ± SD postural sway of single limbs (i.e., SLSB) was reduced significantly after TKA, from 30.3 ± 20.8 cm to 18.5 ± 9.3 cm (p = 0.02). Amelioration was in proportion to pre-operative postural sway (β = 0.92).

CONCLUSIONS

SLSB in patients with varus knees with osteoarthritis was improved significantly 11 days after TKA. Poorer pre-operative SLSB was associated with better post-operative SLSB. TKA may be useful for the immediate reduction of falling in patients with osteoarthritis.