Trunk movement asymmetry associated with pain, disability, and quadriceps strength asymmetry in individuals with knee osteoarthritis: a cross-sectional study

Efficacy of Mulligan joint mobilizations and trunk stabilization exercises versus isometric knee strengthening in the management of knee osteoarthritis: a randomized controlled trial

BACKGROUND

Knee osteoarthritis (KOA) progression is often influenced by biomechanical factors. Biomechanical interventions, such as Trunk stabilization exercise (TSE) and Mulligan joint mobilization (MWM), may offer relief from KOA symptoms and potentially slow disease progression. However, the comparative efficacy of these therapies remains uncertain. This study aimed to compare the efficacy of TSE, Mulligan joint mobilization, and isometric knee strengthening (KSE) on disability, pain severity, and aerobic exercise capacity in patients with KOA.

METHODOLOGY

A randomized controlled trial (RCT) with three intervention groups was conducted between September 2020 to February 2021. The study enrolled adults aged between 40 and 60 years with a confirmed KOA diagnosis recruited from the physical therapy clinic of the Sindh Institute of Physical Medicine and Rehabilitation, Pakistan. Participants were randomly assigned to receive 24 sessions of either TSE, MWM, or KSE. The knee's functionality was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), pain on a visual analogue scale (VAS), and two objective functional tests-the 6-minute walk test (6MWT) and the 11-stair climb test (SCT). These assessments were conducted at baseline, the third week, and the sixth week. Changes in outcome measures were analyzed using a mixed-design ANOVA with Bonferroni post-hoc analysis, with statistical significance set at a p-value < 0.05.

RESULT

Of the 60 participants, 22 (36.7%) were females, and 38 (63.3%) were males. Within-group analysis revealed a significant improvement in all outcome measures at the third week (p < 0.05) and sixth week (p < 0.05). Notably, the TSE group exhibited a greater reduction in mean difference (M.D) in VAS scores than the MWM and KSE groups across various measures in the third week. At rest, during stair ascent, and descent, the TSE group showed significant improvements in VAS scores: MWM (-2.05; -1.94; -1.94), TSE (-2.38; -2.5; -2.5), KSE (-1.05; -0.63; -0.63). Additionally, during sub-maximal exercise capacity assessment, the TSE group showed greater improvement (MWM 12.89; TSE 22.68; KSE 7.89), as well as in Knee Injury and Osteoarthritis Outcome Score for activities of daily living (KOOS-ADL) (MWM 20.84; TSE 28.84; KSE 12.68), and KOOS-pain (MWM 24.84; TSE 27.77; KSE 5.77) at the third-week assessment (p < 0.05). The TSE group demonstrated significant improvements (p < 0.05) across various measures in the sixth week. Specifically, improvements were observed in VAS scores at rest (MWM - 4.15; TSE - 4.42; KSE - 3.78), during stair ascent (MWM - 3.89; TSE - 4.88; KSE - 3.56) and descent (MWM - 3.78; TSE - 4.05; KSE - 2.94). Furthermore, significant improvements were noted in the stair climb test (MWM - 7.05; TSE - 7.16; KSE - 4.21), 6-minute walk test (6MWT) (MWM 22.42; TSE 37.6; KSE 13.84), KOOS-pain (MWM 41.47; TSE 49.11; KSE 28.73), and KOOS-ADL (MWM 40.31; TSE 50.57; KSE 26.05).

CONCLUSION

In this study in patients with KOA, TSE had greater efficacy compared to MWM and KSE in enhancing functional levels, reducing pain, improving sub-maximal exercise capacity, and performance on the stair climb test. Importantly, mean scores between the groups, particularly in the TSE group, reached the minimally important level, particularly in key areas such as pain, functional levels, sub-maximal exercise capacity, and stair climb performance. Clinicians should consider the significant pain reduction, improved functionality, and enhanced exercise capacity demonstrated by TSE, indicating its potential as a valuable therapeutic choice for individuals with KOA.

TRIAL NO

ClinicalTrials.gov = NCT04099017 23/9/2019.

Development and validation of a nomogram for predicting the risk of immediate postoperative deep vein thrombosis after open wedge high tibial osteotomy

PURPOSE

This study aimed to identify independent risk factors for immediate postoperative deep vein thrombosis (DVT) in patients with open wedge high tibial osteotomy (OWHTO) and to develop and validate a predictive nomogram.

METHODS

Patients who underwent OWHTO for knee osteoarthritis (KOA) from June 2017 to December 2021 were retrospectively analyzed. Baseline data and laboratory test results were collected, and the occurrence of DVT in the immediate postoperative period was regarded as the study outcome event. Multivariable logistic regression identified independent risk factors associated with a higher incidence of immediate postoperative DVT. The predictive nomogram was constructed based on the analysis results. The stability of the model was further assessed in this study using patients from January to September 2022 as an external validation set.

RESULTS

741 patients were enrolled in the study, of which 547 were used in the training cohort and the other 194 for the validation cohort. Multivariate analysis revealed a higher Kellgren-Lawrence (K-L) grade (III vs. I-II OR 3.09, 95% CI 0.93-10.23. IV vs. I-II OR 5.23, 95% CI 1.27-21.48.), platelet to hemoglobin ratio (PHR) > 2.25 (OR 6.10, 95% CI 2.43-15.33), Low levels of albumin (ALB) (OR 0.79, 95% CI 0.70-0.90), LDL-C > 3.40 (OR 3.06, 95% CI 1.22-7.65), D-dimer > 1.26 (OR 2.83, 95% CI 1.16-6.87) and BMI ≥ 28 (OR 2.57, 95% CI 1.02-6.50) were the independent risk factors of immediate postoperative DVT. The concordance index (C-index) and Brier score of the nomogram were 0.832 and 0.036 in the training set, and the corrected values after internal validation were 0.795 and 0.038, respectively. The receiver-operating characteristic (ROC) curve, the calibration curve, the Hosmer-Lemeshow test, and the decision curve analysis (DCA) performed well in both the training and validation cohorts.

CONCLUSION

This study developed a personalized predictive nomogram with six predictors, which allows surgeons to stratify risk and recommended immediate ultrasound scans for patients with any of these factors.

LEVEL OF EVIDENCE

III.

Innovative multidimensional gait evaluation using IMU in multiple sclerosis: introducing the semiogram

Background

Quantifying gait using inertial measurement units has gained increasing interest in recent years. Highly degraded gaits, especially in neurological impaired patients, challenge gait detection algorithms and require specific segmentation and analysis tools. Thus, the outcomes of these devices must be rigorously tested for both robustness and relevancy in order to recommend their routine use. In this study, we propose a multidimensional score to quantify and visualize gait, which can be used in neurological routine follow-up. We assessed the reliability and clinical coherence of this method in a group of severely disabled patients with progressive multiple sclerosis (pMS), who display highly degraded gait patterns, as well as in an age-matched healthy subjects (HS) group.

Methods

Twenty-two participants with pMS and nineteen HS were included in this 18-month longitudinal follow-up study. During the follow-up period, all participants completed a 10-meter walk test with a U-turn and back, twice at M0, M6, M12, and M18. Average speed and seven clinical criteria (sturdiness, springiness, steadiness, stability, smoothness, synchronization, and symmetry) were evaluated using 17 gait parameters selected from the literature. The variation of these parameters from HS values was combined to generate a multidimensional visual tool, referred to as a semiogram.

Results

For both cohorts, all criteria showed moderate to very high test-retest reliability for intra-session measurements. Inter-session quantification was also moderate to highly reliable for all criteria except smoothness, which was not reliable for HS participants. All partial scores, except for the stability score, differed between the two populations. All partial scores were correlated with an objective but not subjective quantification of gait severity in the pMS population. A deficit in the pyramidal tract was associated with altered scores in all criteria, whereas deficits in cerebellar, sensitive, bulbar, and cognitive deficits were associated with decreased scores in only a subset of gait criteria.

Conclusions

The proposed multidimensional gait quantification represents an innovative approach to monitoring gait disorders. It provides a reliable and informative biomarker for assessing the severity of gait impairments in individuals with pMS. Additionally, it holds the potential for discriminating between various underlying causes of gait alterations in pMS.

Inertial Sensor Location for Ground Reaction Force and Gait Event Detection Using Reservoir Computing in Gait

Inertial measurement units (IMUs) have shown promising outcomes for estimating gait event detection (GED) and ground reaction force (GRF). This study aims to determine the best sensor location for GED and GRF prediction in gait using data from IMUs for healthy and medial knee osteoarthritis (MKOA) individuals. In this study, 27 healthy and 18 MKOA individuals participated. Participants walked at different speeds on an instrumented treadmill. Five synchronized IMUs (Physilog®, 200 Hz) were placed on the lower limb (top of the shoe, heel, above medial malleolus, middle and front of tibia, and on medial of shank close to knee joint). To predict GRF and GED, an artificial neural network known as reservoir computing was trained using combinations of acceleration signals retrieved from each IMU. For GRF prediction, the best sensor location was top of the shoe for 72.2% and 41.7% of individuals in the healthy and MKOA populations, respectively, based on the minimum value of the mean absolute error (MAE). For GED, the minimum MAE value for both groups was for middle and front of tibia, then top of the shoe. This study demonstrates that top of the shoe is the best sensor location for GED and GRF prediction.

Objective gait assessment in individuals with knee osteoarthritis using inertial sensors: A systematic review and meta-analysis

BACKGROUND

Objective assessment of gait using inertial sensors has shown promising results for functional evaluations in individuals with knee osteoarthritis (OA). However, the large number of possible outcome measures calls for a systematic evaluation of most relevant parameters to be used for scientific and clinical purposes.

AIM

This systematic review and meta-analysis aimed to identify gait parameters derived from inertial sensors that reflect gait deviations in individuals with knee OA compared to healthy control subjects (HC).

METHODS

A systematic search was conducted in five electronic databases (Medline, Embase, Web of Science, CINAHL, IEEE) to identify eligible articles. Risk of bias was assessed using a modified version of the Downs and Black scale. Data regarding study population, experimental procedures, and biomechanical outcomes were extracted. When a gait parameter was reported by a sufficient number of studies, a random-effects meta-analysis was conducted using the inverse variance method.

RESULTS

Twenty-three articles comparing gait between 411 individuals with knee OA and 507 HC were included. Individuals with knee OA had a lower gait speed than HC (standardized mean difference = -1.65), driven by smaller strides with a longer duration. Stride time variability was slightly higher in individuals with knee OA than in HC. Individuals with knee OA walked with a lower range of motion of the knee during the swing phase, less lumbar motion in the coronal plane, and a lower foot strike and toe-off angle compared to HC.

SIGNIFICANCE

This review shows that inertial sensors can detect gait impairments in individuals with knee OA. Large standardized mean differences found on spatiotemporal parameters support their applicability as sensitive endpoints for mobility in individuals with knee OA. More advanced measures, including kinematics of knee and trunk, may reveal gait adaptations that are more specific to knee OA, but compelling evidence was lacking.

Validation of the international classification of functioning, disability, and health (ICF) core sets for musculoskeletal conditions in a primary health care setting from physiotherapists' perspective using the Delphi method

PURPOSE

To analyze the possibilities of using ICF core sets for musculoskeletal conditions in primary care physiotherapy units of the Health Service of "Castilla y León" (Spain).

METHODS

A three-round Delphi study was conducted by physiotherapists working in a primary care setting. The data obtained were linked to second-level ICF categories and their relevance was assessed by the participants. The most relevant categories were compared with those present in the existing ICF core sets for musculoskeletal conditions.

RESULTS

Eighty-four physiotherapists participated in the survey. The consensus was reached for 45 ICF categories and 5 personal factors after the survey. Thirty-five of these categories were present in the Comprehensive Core Set for post-acute Musculoskeletal Conditions. In addition, 35 categories present in the core set were not considered relevant from the participants' perspective.

CONCLUSIONS

Physiotherapists mainly considered movement-related categories as relevant. The ICF core set for post-acute musculoskeletal conditions comprises many of these categories and can therefore be taken as a basis for the adoption of ICF in the clinical context.

RELEVANCE

Primary care physiotherapists should be aware of the advantages of using ICF in their clinical settings.Implications for RehabilitationThis study shows which body functions and structures, activities and participation, environmental factors, and personal characteristics are relevant from primary care physiotherapists' perspective assessing persons with musculoskeletal conditions.The Comprehensive ICF Core Set for Subacute Musculoskeletal Conditions includes most of the categories identified in this study, but they need to be refined to fully represent the primary care physiotherapists' perspective.The results of this study support the use of the Comprehensive ICF Core Set for Subacute Musculoskeletal Conditions as a basis for operationalizing ICF in this clinical setting.

Sex differences in the regularity and symmetry of gait in older adults with and without knee osteoarthritis

BACKGROUND

Three-dimensional (3D) motion measured at the lower back during walking can describe the regularity and symmetry of gait that may be related to osteoarthritis (OA) and functional status. However, gait speed and inherent sex differences, regardless of the presence of OA, may confound these measures. Therefore, there is a need to understand the effect of OA separately among males and females, without the confounding influence of gait speed.

OBJECTIVE

To investigate the difference in 3D gait regularity and symmetry measures between gait speed-matched males and females with and without knee OA.

METHOD

Gait regularity and symmetry were computed as autocorrelations of pelvic accelerations during treadmill walking in four groups of older adults: healthy asymptomatic females (AsymF; n = 44), healthy asymptomatic males (AsymM; n = 45), females diagnosed with knee OA (OAF; n = 44), and males diagnosed with knee OA (OAM; n = 45). Data were obtained from a larger research database, allowing for the matching of gait speed between groups. The main effect of OA, sex, and interaction effect between them was examined for the 3D gait regularity and symmetry measures at an alpha level of 0.05.

RESULTS

There was no main effect of OA on any variable, but there was a significant main effect of sex on mediolateral and anteroposterior gait regularity measures. Specifically, females demonstrated significantly greater gait regularity, most notably in the mediolateral directions compared to males.

CONCLUSION

Older adult females were found to display significantly greater mediolateral gait regularity as compared to males, regardless of the presence of OA. Further, this difference exists among matched gait speeds, suggesting it is not the result of gait speed. Overall, these results highlight the importance of sex-specific analyses and considering gait speed when examining gait acceleration patterns near the center of mass for both cross sectional and longitudinal gait assessments.

Movement Quality Parameters during Gait Assessed by a Single Accelerometer in Subjects with Osteoarthritis and Following Total Joint Arthroplasty

This study’s aim is threefold: (I) Evaluate movement quality parameters of gait in people with hip or knee osteoarthritis (OA) compared to asymptomatic controls from a single trunk-worn 3D accelerometer. (II) Evaluate the sensitivity of these parameters to capture changes at 6-weeks, 3-, 6-, and 12-months following total knee arthroplasty (TKA). (III) Investigate whether observed changes in movement quality from 6-weeks and 12-months post-TKA relates to changes in patient-reported outcome measures (PROMs). We invited 20 asymptomatic controls, 20 people with hip OA, 18 people pre- and post-TKA to our movement lap. They wore a single trunk-worn accelerometer and walked at a self-selected speed. Movement quality parameters (symmetry, complexity, smoothness, and dynamic stability) were calculated from the 3D acceleration signal. Between groups and between timepoints comparisons were made, and changes in movement quality were correlated with PROMs. We found significant differences in symmetry and stability in both OA groups. Post-TKA, most parameters reflected an initial decrease in movement quality at 6-weeks post-TKA, which mostly normalised 6-months post-TKA. Finally, improved movement quality relates to improvements in PROMs. Thus, a single accelerometer can characterise movement quality in both OA groups and post-TKA. The correlation shows the potential to monitor movement quality in a clinical setting to inform objective, data-driven personalised rehabilitation.

Comparison of the Asymmetries in Foot Posture and Properties of Gastrocnemius Muscle and Achilles Tendon Between Patients With Unilateral and Bilateral Knee Osteoarthritis

Background: Asymmetrical foot posture and properties alterations of the gastrocnemius muscle (GM) and Achilles tendon (AT) were observed in knee osteoarthritis (KOA). We aimed to investigate the inter-limbs asymmetries in foot posture and the properties of GM and AT and explore the association between them.

Methods: A total of 62 subjects with unilateral or bilateral KOA were included in this study: 30 patients with unilateral pain and 32 patients with bilateral pain were assigned to the bilateral group (BG) and unilateral group (UG), respectively. The relatively serious leg (RSL) and relatively moderate leg (RML) were judged according to the severity of symptoms assessed by using visual analogue scale (VAS) motion. Foot posture and asymmetrical foot posture scores were assessed based on Foot Posture index (FPI-6). Subsequently, all the participants received an assessment for properties of GM and AT, including tone/tension (Hz), stiffness (N/m), and elasticity. We calculated the asymmetry index of AT (Asy_-AT) in both legs and the difference of muscle properties between medial and lateral gastrocnemius (D_-MLG) in the ipsilateral limb.

Results: Asymmetry of foot posture was categorized into three types including normal, asymmetry, and severe asymmetry. The percentage of subjects classified as normal was higher in the BG (62.5%) than in the UG (36.67%), p < 0.05. Tension of AT and tone of lateral gastrocnemius (LG) in RSL were higher than those in RML (15.71 ± 0.91 vs. 15.23 ± 1.01; 25.31 ± 2.09 vs. 23.96 ± 2.08, p < 0.01 and p < 0.01, respectively), and stiffness of AT in the RSL was higher than that in RML (676.58 ± 111.45 vs. 625.66 ± 111.19, p < 0.01). Meanwhile, a positive relationship was found between ipsilateral FPI and tone of MG and LG in the left leg (0.246 per degree, 95% CI: −0.001, 0.129; p = 0.054 and 0.293 per degree, 95% CI: −0.014, 0.157; p = 0.021, respectively) and right leg (0.363 per degree, 95% CI: 0.033, 0.146; p = 0.004 and 0.272 per degree, 95% CI: 0.007, −0.144; p = 0.032, respectively). Moreover, a positive link was observed between asymmetrical FPI scores and K/L grade (0.291 per degree, 95% CI: 0.018, 0.216; p = 0.022). Furthermore, a significantly greater Asy_-AT(tension) was detected in the UG than that in the BG (UG vs. UG: 8.20 ± 5.09% vs. 5.11 ± 4.72%, p < 0.01). Additionally, an increased asymmetrical FPI score (i.e., more severe asymmetry) was significantly associated with increases in Asy_-AT(tension) and Asy_{-AT(stiffness)} (0.42 per degree, 95% CI: 0.533, 1.881; p = 0.001 and 0.369 per degree, 95% CI: 0.596, 2.82; p = 0.003, respectively).

Conclusions: The stiffness and tension of AT and the tone of LG in RSL were higher than those in RML in KOA patients, and inter-limbs foot posture and tension of AT were more asymmetrical in unilateral KOA patients compared to patients with bilateral KOA. Notably, foot posture, as an important biomechanical factor, was significantly associated with properties of GM, AT, and K/L grade in KOA patients.

Analysis of characteristics required for gait evaluation of patients with knee osteoarthritis using a wireless accelerometer

BACKGROUND

Knee osteoarthritis (KOA) is associated with reduced quality of life due to knee pain and gait disturbance. However, the evaluation of KOA is mainly based on images and patient-reported outcome measures (PROMs), which are said to be insufficient for functional evaluation. Recently, gait analysis using an accelerometer has been used for functional evaluation of KOA patients. Nevertheless, evaluation of the entire body motion is insufficient. The aim of this study was to clarify the gait characteristics of KOA patients using the distribution of scalar products and the interval time of heel contact during spontaneous walking and to compare them with healthy subjects.

METHODS

Participants wore a three-axis accelerometer sensor on the third lumbar vertebra and walked for 6 min on a flat path at a free walking speed. The sum of a composite vector (CV) scalar product and a histogram for distribution were used for body motion evaluation. The CV consisted of a synthesis of acceleration data from three axes. In addition to the summation of the CV, a histogram can be created to evaluate in detail the magnitude of the waves. The amount of variation was measured in the left-right and front-back directions. Variability was evaluated from the distribution of heel contact duration between both feet measured from the vertical acceleration.

RESULTS

KOA patients showed a smaller sum of CV that converged to small acceleration in the distribution when compared with healthy subjects. In the KOA group, the amount of variation in the forward and backward directions was greater than that in the forward direction. The variability of heel-ground interval time was greater in the KOA group than in healthy subjects.

CONCLUSION

KOA patients walked with less overall body movement, with limited movable range of the knee joint and pain-avoiding motion. The gait of the KOA group was considered unstable, with long time intervals between peaks. The increase in the amount of forward variation was thought to be due to the effect of trunk forward bending during walking. The clinical relevance of this study is that it was possible to evaluate KOA patients' gait quantitatively and qualitatively.

Low Back Pain as a Risk Factor for Recurrent Falls in People With Knee Osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) has been suggested to increase the risk of falls. Low back pain (LBP) is a potential risk factor for falls in people with knee OA, but this issue has not been addressed adequately in previous studies. The objective of this study was to investigate the relationship between LBP and falls in people with knee OA in a 12-month period.

METHODS

Participants with knee OA (Kellgren/Lawrence [K/L] grade ≥1) completed questionnaires for LBP and falls that occurred in the preceding 12 months. Binary and ordinal logistic regression analyses were performed to assess the relationship between LBP or moderate-to-severe LBP (numeric rating scale ≥4 points) and any fall (≥1 fall) or recurrent falls (≥2 falls) after adjustment for age, sex, K/L grade, knee pain severity, and quadriceps strength. Sensitivity analyses were performed excluding people with sciatica, nonchronic LBP, K/L grade 1, and those receiving pain medications.

RESULTS

We included 189 participants (ages 61-90 years, 78.3% women) in this study. Of these participants, 41 (21.6%) reported falls in the preceding 12 months. People with any LBP (n = 101) and those with moderate-to-severe LBP (n = 45) had 2.7- and 3.7-times higher odds of recurrent falls, respectively. Sensitivity analyses revealed a strong correlation between moderate-to-severe LBP and recurrent falls.

CONCLUSION

Thorough investigation of LBP as a risk factor for recurrent falls in people with knee OA may provide a novel insight into the pathomechanics of recurrent falls in this population.

Independent and sensitive gait parameters for objective evaluation in knee and hip osteoarthritis using wearable sensors

Background

Although it is well-established that osteoarthritis (OA) impairs daily-life gait, objective gait assessments are not part of routine clinical evaluation. Wearable inertial sensors provide an easily accessible and fast way to routinely evaluate gait quality in clinical settings. However, during these assessments, more complex and meaningful aspects of daily-life gait, including turning, dual-task performance, and upper body motion, are often overlooked. The aim of this study was therefore to investigate turning, dual-task performance, and upper body motion in individuals with knee or hip OA in addition to more commonly assessed spatiotemporal gait parameters using wearable sensors.

Methods

Gait was compared between individuals with unilateral knee (n = 25) or hip OA (n = 26) scheduled for joint replacement, and healthy controls (n = 27). For 2 min, participants walked back and forth along a 6-m trajectory making 180° turns, with and without a secondary cognitive task. Gait parameters were collected using 4 inertial measurement units on the feet and trunk. To test if dual-task gait, turning, and upper body motion had added value above spatiotemporal parameters, a factor analysis was conducted. Effect sizes were computed as standardized mean difference between OA groups and healthy controls to identify parameters from these gait domains that were sensitive to knee or hip OA.

Results

Four independent domains of gait were obtained: speed-spatial, speed-temporal, dual-task cost, and upper body motion. Turning parameters constituted a gait domain together with cadence. From the domains that were obtained, stride length (speed-spatial) and cadence (speed-temporal) had the strongest effect sizes for both knee and hip OA. Upper body motion (lumbar sagittal range of motion), showed a strong effect size when comparing hip OA with healthy controls. Parameters reflecting dual-task cost were not sensitive to knee or hip OA.

Conclusions

Besides more commonly reported spatiotemporal parameters, only upper body motion provided non-redundant and sensitive parameters representing gait adaptations in individuals with hip OA. Turning parameters were sensitive to knee and hip OA, but were not independent from speed-related gait parameters. Dual-task parameters had limited additional value for evaluating gait in knee and hip OA, although dual-task cost constituted a separate gait domain. Future steps should include testing responsiveness of these gait domains to interventions aiming to improve mobility.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04074-2.

Contralateral Limb Effect on Gait Asymmetry and Ipsilateral Pain in a Patient with Knee Osteoarthritis: A Proof-of-Concept Case Report

CASE

A 77-year-old woman with knee osteoarthritis (OA) complained of right (ipsilateral) knee pain for more than 5 years with gait asymmetry. The OA and quadriceps muscle weakness were more severe in the left (contralateral) knee, but she had no pain. Bracing of the left knee led to decreased gait asymmetry, as determined with an inertial measurement unit, and reduced pain in the right knee.

CONCLUSION

This case highlights the contralateral knee effect on ipsilateral chronic knee pain, possibly through gait asymmetry. These findings provide a mechanistic insight into knee OA-related pain in patients with gait asymmetry and suggest a new rehabilitative approach.

Wearable Inertial Sensors for Gait Analysis in Adults with Osteoarthritis-A Scoping Review

Our objective was to conduct a scoping review which summarizes the growing body of literature using wearable inertial sensors for gait analysis in lower limb osteoarthritis. We searched six databases using predetermined search terms which highlighted the broad areas of inertial sensors, gait, and osteoarthritis. Two authors independently conducted title and abstract reviews, followed by two authors independently completing full-text screenings. Study quality was also assessed by two independent raters and data were extracted by one reviewer in areas such as study design, osteoarthritis sample, protocols, and inertial sensor outcomes. A total of 72 articles were included, which studied the gait of 2159 adults with osteoarthritis (OA) using inertial sensors. The most common location of OA studied was the knee (n = 46), followed by the hip (n = 22), and the ankle (n = 7). The back (n = 41) and the shank (n = 40) were the most common placements for inertial sensors. The three most prevalent biomechanical outcomes studied were: mean spatiotemporal parameters (n = 45), segment or joint angles (n = 33), and linear acceleration magnitudes (n = 22). Our findings demonstrate exceptional growth in this field in the last 5 years. Nevertheless, there remains a need for more longitudinal study designs, patient-specific models, free-living assessments, and a push for "Code Reuse" to maximize the unique capabilities of these devices and ultimately improve how we diagnose and treat this debilitating disease.

Gait initiation and lateral wedge insole for individuals with early knee osteoarthritis

BACKGROUND

People with knee osteoarthritis are at higher risk of postural deficits and locomotor adaptations which could be manifested in transient tasks like gait initiation. To better understand the effect of early knee osteoarthritis on gait initiation, we measured the gait initiation in two groups of early knee osteoarthritis and healthy age-matched controls and assessed the effect of lateral wedge insole in knee osteoarthritis group.

METHODS

Twenty-one individuals with early knee osteoarthritis, mean (SD) age = 53.1 (7.4, years), and 19 age- and sex-matched asymptomatic healthy individuals, mean (SD) age = 47.5 (11.2, years), participated. Centre of pressure trajectories were used to quantify the two phases of gait initiation in barefoot condition: anticipatory postural adjustment, and locomotor phase. The immediate and four-week effect of lateral wedge insole and shod condition were also compared for individuals in knee osteoarthritis group.

FINDINGS

Longer duration of anticipatory postural adjustment phase (P = 0.046), locomotor phase (P = 0.049), and total duration of gait initiation (P = 0.035) with lower length and velocity of the center of pressure trajectories in anticipatory postural adjustment phase (P = 0.002, and 0.008, respectively) were observed in knee osteoarthritis group compared to controls. Lateral wedge insole could increase the length and velocity of the centre of pressure in locomotor phase compared to barefoot condition (P = 0.001, and 0.002, respectively).

INTERPRETATION

Our study outlined that people with early knee osteoarthritis adopt different gait initiation strategies mainly in postural preparation phase. The potential effect of lateral wedge insole was shown with better performance of the locomotor phase.

CLINICAL TRIAL REGISTRY NUMBER

IRCT2016060628310N1.

Identification of Body Behaviors and Facial Expressions Associated with Induced Orthopedic Pain in Four Equine Pain Scales

Simple Summary

Pain scales are tools developed to improve pain assessment in horses. They are based on behaviors and/or facial expressions, and the observer allocates a score based on the character of the behavior or facial expression. Little is known about behaviors and facial expressions at rest in horses with orthopedic pain since pain is mainly assessed by lameness evaluation during movement. The aim of this study was to describe how closely equine behaviors and facial expressions are associated with movement asymmetry and to identify combinations of behavior and expressions present in horses with induced orthopedic pain. Orthopedic pain was induced in eight horses and assessed in two ways; using four existing equine pain scales at rest, and by measuring movement asymmetry during movement. The association of behavior and facial expression items in the pain scales with actual lameness was analyzed. Posture-related behavior showed the strongest association, while facial expressions varied between horses. These results show that pain scales for orthopedic pain assessment would benefit from including posture, head position, location in the box stall, focus, interactive behavior, and facial expressions. This could improve orthopedic pain detection in horses during rest with mild lameness.

Abstract

Equine orthopedic pain scales are targeted towards horses with moderate to severe orthopedic pain. Improved assessment of pain behavior and pain-related facial expressions at rest may refine orthopedic pain detection for mild lameness grades. Therefore, this study explored pain-related behaviors and facial expressions and sought to identify frequently occurring combinations. Orthopedic pain was induced by intra-articular LPS in eight horses, and objective movement asymmetry analyses were performed before and after induction together with pain assessments at rest. Three observers independently assessed horses in their box stalls, using four equine pain scales simultaneously. Increase in movement asymmetry after induction was used as a proxy for pain. Behaviors and facial expressions commonly co-occurred and were strongly associated with movement asymmetry. Posture-related scale items were the strongest predictors of movement asymmetry. Display of facial expressions at rest varied between horses but, when present, were strongly associated with movement asymmetry. Reliability of facial expression items was lower than reliability of behavioral items. These findings suggest that five body behaviors (posture, head position, location in the box stall, focus, and interactive behavior) should be included in a scale for live assessment of mild orthopedic pain. We also recommend inclusion of facial expressions in pain assessment.

Accelerometer Measurement of Trunk Lateral Fluctuation During Walking Following Total Knee Arthroplasty in Patients With Osteoarthritis

This study aimed to clarify the effect of total knee arthroplasty (TKA) on trunk fluctuation and regularity of gait in patients with knee osteoarthritis by an accelerometer. The participants included 18 patients with knee osteoarthritis undergoing TKA. The gait at a comfortable velocity was assessed pre- and post-TKA by a triaxial accelerometer attached to the neck and lumbar regions. Measurement post-TKA was performed 4 weeks after surgery. Trunk fluctuation was estimated by the root mean square (RMS) of acceleration and RMS ratio (the ratio of RMS in each direction to the total RMS). Regularity of gait was estimated using the autocorrelation function. The results showed that TKA significantly decreased the RMS ratio in mediolateral acceleration of the neck and lumbar regions and reduced gait regularity. TKA appears to reduce compensatory trunk motion through the improvement of knee function. An assessment of trunk fluctuation using an accelerometer is useful for the clinical assessment of patients with knee osteoarthritis pre- and post-TKA.

Quadriceps Strength and Mortality in Older Patients With Heart Failure

BACKGROUND

This study was performed to test the hypothesis that low quadriceps isometric strength (QIS) is associated with greater risk of mortality and has the additive prognostic significance to the severity of heart failure (HF) and gait speed in older patients with HF.

METHODS

A retrospective cohort study was performed in 1273 patients ≥ 60 years of age with HF (mean age 75 ± 8 years, 59.1% men); all of whom were evaluated during hospitalization for usual gait speed and maximal QIS. The QIS was expressed relative to body mass (% BM). The endpoint was all-cause mortality.

RESULTS

Over a median follow-up period of 1.59 years (interquartile range, 0.58 to 3.42 years), 224 patients died. The cutoff value based on the Youden index for the QIS discriminating those at high risk of mortality was 36.2% BM for overall, and we defined less than this cutoff point of QIS as low QIS. After adjustment for the HF risk score, the hazard ratio in low QIS was 1.55 for overall (95% confidence interval [CI], 1.17-2.06). The addition of low QIS to the HF risk score and gait speed was associated with significant increases in both net reclassification improvement (NRI, 0.239 for overall; 95% CI, 0.096-0.381) and integrated discrimination improvement (IDI, 0.004 for overall; 95% CI, 0.001-0.009) for all-cause mortality.

CONCLUSION

Low QIS was strongly associated with poor prognosis and showed complementary prognostic predictive capability to the HF risk score and gait speed in older patients with HF.

Association between Foot Posture Asymmetry and Static Stability in Patients with Knee Osteoarthritis: A Case-Control Study

Background

Interlimb asymmetries are considered to be closely related to knee osteoarthritis (KOA), but foot posture asymmetries in patients with KOA are scarcely reported.

Objectives

We aimed to explore the asymmetrical difference in foot posture between the healthy adults and KOA patients and the relationship between foot posture asymmetry and static stability.

Methods

21 subjects suffering from KOA in the patient group (PG) and 21 healthy adults in the control group (CG) were included in this study. Foot postures on both feet were evaluated by using the foot posture index (FPI); subsequently, asymmetrical FPI scores between two feet were calculated for the two groups. Meanwhile, all the participants were tested with a standing on Dynamic and Static Balancing Instrument (Pro-kin 254P, TecnoBody Company, Italy) for bilateral stability assessment, and center of pressure (COP) parameters including sway length (SL, mm) and sway area (SA, mm²) were recorded.

Results

Compared to CG, a larger percentage of supinated feet was examined in relatively severe legs (5, 23.81%), relatively moderate legs (4, 19.05%), and merged results (9, 21.43%) of PG (P < 0.05), and the percentage of severe asymmetry (38.1%) was higher in the PG (P < 0.05). Moreover, these relationships between the absolute value of asymmetry score and SL or SA were significant in CG and PG, the P values below 0.01.

Conclusions

Foot posture asymmetry is significantly associated with static stability both in KOA patients and healthy adults, and more severe asymmetry in foot posture was observed in KOA patients, so it is critical to evaluate foot posture asymmetry for treatment and rehabilitation for patients with KOA.

Effect of improvement in quadriceps strength asymmetry on trunk movement asymmetry after total knee arthroplasty

BACKGROUND

Patients with knee osteoarthritis (OA) demonstrate trunk movement asymmetry during walking; this asymmetry is associated with disability and quadriceps strength asymmetry.

RESEARCH QUESTION

What are the differences between trunk movement asymmetries before and after total knee arthroplasty (TKA) and associations between the changes in trunk movement asymmetry and quadriceps strength asymmetry?

METHODS

In this prospective cohort study, 27 patients (mean age, 71.0 years; women, 85.2%) were assessed at 1 month before and 6 months after surgery. Trunk movement asymmetry (harmonic ratio) was assessed at their preferred pace using a triaxial accelerometer. The isometric quadriceps strength was evaluated using a hand-held dynamometer, and the quadriceps strength inter-limb absolute difference was calculated. Multivariate analyses were performed to compare the trunk movement asymmetries before and after surgery with covariate adjustment (gait pain, gait velocity, and non-operated-limb Kellgren and Lawrence [K&L] grade) and to investigate the association between the changes in trunk movement asymmetry and quadriceps strength inter-limb difference with covariate adjustment (age, sex, and non-operated-limb K&L grade).

RESULTS

The trunk movement asymmetry in the medio-lateral (mean difference, 0.61; 95% confidence interval [CI], 0.22 to 1.00) and antero-posterior (mean difference, 1.15; 95% CI, 0.48 to 1.83) directions significantly decreased postoperatively compared with the preoperative results. A decreased quadriceps strength inter-limb difference was significantly associated with a decreased medio-lateral trunk movement asymmetry (β = 0.68; 95% CI, 0.30 to 1.06).

SIGNIFICANCE

TKA plays an important role in the improvement of trunk stability during walking in patients with knee OA. Decreasing quadriceps strength asymmetry may be a key to improving trunk movement asymmetry.