Biomechanical characteristics of stair ambulation in patients with knee OA: A systematic review with meta-analysis toward a better definition of clinical hallmarks

Criteria for knee flexion range of motion and quadriceps strength to ascend and descend stairs 1 year after bilateral total knee arthroplasty: A cross-sectional study

BackgroundStair ascent/descent pose significant challenges after total knee arthroplasty (TKA); however, the exact knee flexion range of motion (ROM) and quadriceps strength requirements remain unclear.ObjectiveTo establish criteria for knee flexion ROM and quadriceps strength to determine independence in stair ascent/descent and evaluate the accuracy of the combination of these factors in patients with bilateral TKA.MethodsPatients with bilateral TKA were cross-sectionally assessed at 1 year postoperatively for independence in stair ascent/descent. Receiver operating characteristic curves provided cutoff values for knee flexion ROM and quadriceps strength. The area under the curves (AUC) of each factor and logistic regression models including both factors were evaluated.ResultsEighty-two participants were included. Fifty-eight participants could independently ascend and 52 could descend stairs, with equal cutoff values for both: 121° for knee flexion ROM (AUC: 0.66 and 0.67) and 1.09 Nm/kg for quadriceps strength (AUC: 0.70 and 0.73). Logistic regression models produced AUCs of 0.73 and 0.76 for ascent and descent, respectively.ConclusionsA quadriceps strength of 1.09 Nm/kg is a useful cutoff for independent stair ascent/descent, but combining it with knee flexion ROM did not enhance accuracy. Other functions such as coordination of the knee or other joints may influence stair performance post-TKA.

Altered motor function during daily activities in patients eligible for high tibial osteotomy is primarily driven by knee varus deformity

Aims

Patients with knee osteoarthritis (OA) and varus deformity present altered gait parameters, especially a large knee adduction moment that is predictive of OA progression. The distinct role of each coexisting parameter, such as OA grade, varus deformity, and previous meniscectomy, in the setting of high tibial osteotomy is not clear. Therefore, the aim of this study was to analyze the motor function parameters in patients eligible for high tibial osteotomy during walking, stair ascending, and stair descending, and to evaluate the effect of OA grade, varus deformity, and meniscectomy.

Methods

A total of 52 patients with knee OA and varus deformity participated in this study, including 22 with previous partial meniscectomy, alongside 20 healthy controls. Imaging and motion-capture data during walking, stair ascending, and descending were acquired. Subject characteristics, joint kinematics, joint kinetics, and electromyography on-off activities were compared to evaluate statistically significant differences between the patients and healthy groups. Additionally, multiple linear regression evaluated the relationships between OA grade, varus deformity, and previous meniscectomy with motor function parameters.

Results

The patients group showed significantly higher knee adduction and rotation moments, lower hip adduction and ankle inversion, and higher knee adduction and trunk flexion compared with the healthy group, as well as significantly increased biceps femoris activity. In addition, larger varus deformity showed a more marked effect on the major motor function parameters compared with OA grade and previous meniscectomy, especially during walking.

Conclusion

Patients eligible for high tibial osteotomy move with altered motor function during daily activities, and the coexisting factors of OA grade, varus malalignment, and previous meniscectomy have different impacts, with varus deformity primarily affecting motor function. These findings help to detect the target that should be considered priority in the treatment of high tibial osteotomy, and highlight the importance of realigning the lower limb to possibly restore motor function.

Biomechanical analysis of step-up and step-down tasks in knee osteoarthritis: Insights from leading and trailing limbs

BACKGROUND

Stair climbing tests are pivotal when assessing physical performance in knee osteoarthritis patients, yet the biomechanical strategies that underpin poor stair climbing ability are heterogeneously reported. Single step tasks emulate a step-by-step gait pattern, an approach associated with knee pain when stair climbing. The objective of this study is to analyse the biomechanics and electromyography activity of both the leading and trailing limbs during single Step-up and Down tasks in knee osteoarthritis patients.

METHODS

Three-dimensional motion analysis captured biomechanical data of twenty participants with knee osteoarthritis (n = 20) and twenty four (n = 24) age matched controls completing isolated Step-Up and Step-Down tasks. Data was collected from both the leading and trailing limbs and analysed continuously using One-dimensional Statistical Parametric Mapping (α = 0.05).

FINDINGS

During Step-Up, knee osteoarthritis participants demonstrated kinematic (p < 0.001), kinetic (p = 0.045), and electromyography (p < 0.001) variance compared to control participants, whilst Step-Down induced elevated external knee adduction moments (p = 0.042). Across both tasks, knee osteoarthritis participants stood with increased lower limb flexion in quiet standing and spent a proportionally elevated time in transitional double stance during Step-Up (p = 0.02).

INTERPRETATION

Our study reveals that knee osteoarthritis patients display distinctive biomechanical strategies during single Step-Up and Down tasks, that deviate depending on whether the osteoarthritic knee is leading or trailing. Single-step tasks are a safer and practical alternative to other stair climbing tests. We hope that clinicians can use these findings to guide treatments that promote less effortful step and stair ambulation in knee osteoarthritis patients with advanced disease.

Factors, characteristics and influences of the changes of muscle activation patterns for patients with knee osteoarthritis: a review

BACKGROUND

Knee Osteoarthritis (KOA) is a prevalent condition worldwide, significantly diminishing quality of life and productivity. Except for the alignment change, muscle activation patterns (MAP) have garnered increasing attention as another crucial factor contributing to KOA.

OBJECTIVE

This study explores the factors, characteristics, and effects of MAP changes caused by KOA, providing a neuromuscular-based causal analysis for the rehabilitation treatment of KOA.

METHODS

Keywords including the association of MAP with KOA will be included. "Knee, Osteoarthritis, Electromyography(EMG), Muscle Activity patterns, activation amplitudes, activation time, Muscle Synergy, Co-contraction/activation" were used to search the databases of Science Direct, PubMed, Scopus, and Wiley. The criteria include studies from the past fifteen years that document changes in muscle contraction characteristics and causality analysis in patients with KOA. we compared MAP changes between individuals with and without KOA, such as the activation amplitudes, activation time, muscle synergy and co-contraction index(CCI). Additionally, we explored the potential relationship between muscle weakness, pain, and lower limb mechanical changes with the variations of MAP.

RESULTS

A total of 832 articles were reviewed, and 44 articles that met the inclusion criteria were selected for analysis. The changes in biomechanical structure, pain, and muscle atrophy may contribute to the formation and progression of the changes in MAP in KOA patients. In moderate KOA patients, the vastus lateralis (VL) and biceps femoris (BF) exhibits larger activation amplitudes, with earlier and longer activation times. The vastus medialis (VM) shows a delayed activation time relative to VL. Gastrocnemius activation time is prolonged during mid-gait, while the soleus exhibits lower activation amplitudes during the late stance phase. There are fewer, merged synergies with prolonged activation coefficients, and a higher percentage of unclassifiable synergies. Additionally, the CCI is positively correlated with task difficulty and symptoms. It is higher in the medial and lateral than hamstrings and quadriceps, and CCI specifically respond to joint stabilisation and load.

CONCLUSION

In patients with moderate KOA, changes in MAP are mainly related to symptoms and the difficulty of tasks. MAP changes primarily result in variations in amplitude, contraction duration, muscle synergy, and CCI. The MAP changes can subsequently affect the intermuscular structure, pain, joint loading, and stiffness.

CLINICAL IMPLICATIONS

These contribute to the progression of KOA and create a vicious cycle that accelerates disease advancement. Clinical rehabilitation treatments can target the MAP changes to break the cycle and help mitigate disease progression.

In vivo kinematics during step ascent: Changes to the knee associated with osteoarthritis

BACKGROUND

Stair climbing is a kinematically demanding activity, essential for maintaining independence and quality of life, yet is often impaired in patients with knee osteoarthritis (OA). The purpose of this study was to examine differences in kinematics of a step-up movement between participants with osteoarthritis and asymptomatic controls.

METHODS

Thirty participants with end-stage OA awaiting total knee arthroplasty (TKA) and twenty-eight sex and age-similar asymptomatic participants were recruited. Participants performed a step-up task which was imaged via single-plane fluoroscopy. 3-dimensional prosthesis computer-aided design models were registered to the fluoroscopy, yielding in-vivo kinematic data. Kinematic variables of position, displacement, and rate-of-change in six degrees of freedom were compared between the two groups.

RESULTS

OA knees exhibited significantly different kinematics to asymptomatic knees during step-up. Knees with OA demonstrated a reduced terminal extension angle, inferior translation and increased internal rotation throughout the movement compared to asymptomatic. OA participants exhibited more variability in kinematic parameters compared to asymptomatic controls, reflecting the heterogeneity within OA pathology.

CONCLUSION

The findings of this study indicate that knee kinematics, particularly rotation, differ significantly between OA and asymptomatic knees during step-up. Optimising rotational profiles in OA knee management could help optimise patient function and inform rehabilitation and surgical protocols.

Whole-body angular momentum during stair ascent and descent in individuals with and without knee osteoarthritis

Given the higher fall risk and the fatal sequelae of falls on stairs, it is worthwhile to investigate the mechanism of dynamic balance control in individuals with knee osteoarthritis during stair negotiation. Whole-body angular momentum ([Formula: see text]) is widely used as a surrogate to reflect dynamic balance and failure to constrain [Formula: see text] may increase the fall risk. This study aimed to compare the range of [Formula: see text] between people with and without knee osteoarthritis during stair ascent and descent. Seven participants with symptomatic knee osteoarthritis and eight asymptomatic controls were instructed to ascend and descend an instrumented staircase at a fixed cadence. Kinematic and kinetic data were collected and range of [Formula: see text] in sagittal, frontal, and transverse planes were computed. The knee osteoarthritis group exhibited greater [Formula: see text] in the sagittal plane during both stair ascent (P = 0.005, Cohen's d = 1.7) and descent (P = 0.020, Cohen's d = 1.3) as well as in the transverse plane during stair descent (P = 0.015, Cohen's d = 1.3), than the control group. These observations may be explained by greater hip flexion (P < 0.05, Cohen's d > 1.12) and reduced knee flexion moment (P < 0.001, Cohen's d<-2.77) during stair ascent and descent, and decreased foot progression angle (P = 0.038, Cohen's d=-1.2) during stair descent, in individuals with knee osteoarthritis. No significant difference in frontal plane [Formula: see text] was found between the two groups (P > 0.05). Individuals with knee osteoarthritis exhibited greater whole-body angular momentum during stair negotiation when compared to asymptomatic controls. Our findings may provide mechanistic rationale for a greater fall risk among people with knee osteoarthritis.

Comparing Different Stretching Exercises on Pain, Stiffness, and Physical Function Disability in Older Adults With Knee Osteoarthritis

OBJECTIVE

To assess and compare the effects of different stretching exercise programs on pain, stiffness, and physical function disability in older adults with knee osteoarthritis (KOA).

DATA SOURCES

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline for network meta-analysis (NMA). Relevant randomized controlled trials were identified by searching 7 databases up to December 2022.

STUDY SELECTION

Inclusion criteria included (1) older adults with KOA; (2) intervention included stretching exercises; (3) control groups received no stretching exercise; and (4) outcome measurements included pain, stiffness, or physical function disability. Methodological quality was assessed using the Cochrane risk-of-bias tool for randomized trials version 2.

DATA EXTRACTION

NMA was performed using R and MetaInsight, with results presented as a standardized mean difference (SMD) with 95% confidence interval (CI).

DATA SYNTHESIS

We examined 17 studies, and NMA results indicated that proprioceptive neuromuscular facilitation (PNF) stretching, mind-body exercises, and multi-component exercise programs were effective in mitigating pain in older adults with KOA (SMD=2.54 [95% CI: 1.23; 3.84], SMD=1.09 [95% CI: 0.27; 1.92], SMD=0.57 [95% CI: 0.06; 1.09]). Moreover, mind-body exercises and multi-component exercises were the most effective programs in reducing stiffness (SMD=1.31 [95% CI: 0.12; 2.51]) and physical function disability (SMD=1.67 [95% CI: 0.01; 3.33]) in older adults with KOA, respectively.

CONCLUSION

Findings suggest that PNF stretching, mind-body exercises, and multi-component exercises can be incorporated into exercise programs to better mitigate pain, stiffness, and physical function disability in older adults with KOA.

Balancing Anterior and Posterior Cruciate Ligaments in Adults

BACKGROUND

The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) represent the central pivot of the knee. The balance between these two ligaments impacts the tibiofemoral biomechanics. Each structure is the opposite of the other in terms of anteroposterior translation and rotation.

AIM

The aim of this study was to find a correlation between the cross-sectional area of the ACL and PCL in adults.

MATERIAL AND METHODS

Magnetic resonance imaging (MRI) data analysis was conducted by a musculoskeletal radiologist using MRI planes tailored to the study's requirements. In all 62 studied patients, measurements were done according to the protocol.

RESULTS

The study observed three types of intercondylar notches: Type U was identified in 35% (22) of patients, type W in 27% (17), and type A in 37% (23). The median difference between the ACL and PCL areas was found to be statistically significant (p = 0.02). A significant difference in the area of the ACL was detected between Type A and Type U notches (p = 0.02), while no significant differences were found between Type A-W and Type W-U after post hoc corrections (p > 0.05). Additionally, no significant difference was observed in the mean area of the PCL across all three notch types (p = 0.1). In 68% of the cases, the ACL is no less than 60% of the PCL in area, and no more than 120%. The size of ACL and PCL in healthy individuals also depends on other factors like synergistic and antagonistic muscle activities, occupation, and the hip-knee-ankle axis. For example, if the PCL area is 0.79 cm² and the measured structure is round (during a reconstruction a hamstring graft is round), the diameter is 10 mm. A native ACL is, in 68% of the cases, no less than 7.7 mm, and no more than 10.9 mm.

CONCLUSION

The ACL-PCL size correlation helps in understanding the balance of the central pivot of the knee.

The Association of Stair Climbing Behaviors With Hazard of All-Cause Mortality in Adults With or At Risk of Knee Osteoarthritis

OBJECTIVE

To investigate the association of stair climbing difficulty and stair climbing frequency with the risk of all-cause mortality over 13 years in adults with or at high risk for knee OA.

METHODS

We used data from the Osteoarthritis Initiative (OAI), a prospective cohort study of community-dwelling adults with or at high risk for symptomatic knee OA. The exposures were stair climbing difficulty and frequency, assessed at baseline using self-report questionnaires. The outcome was all-cause mortality, assessed from baseline through 13 years of follow-up. Kaplan-Meier survival curves and Cox proportional hazards regression were used to investigate the association between stair climbing exposures and all-cause mortality.

RESULTS

Three hundred seven (6.81%) and 310 (6.84%) participants in the difficulty and frequency samples, respectively, died during 13 years of follow-up. Those who were limited in any capacity in terms of their stair climbing ability had 54% to 84% greater hazard of all-cause mortality, and those who climbed at least 7 flights of stairs per week had 38% lower hazard of all-cause mortality.

CONCLUSION

Adults with or at high risk for knee OA who report difficulty with climbing stairs or who infrequently use stairs are at greater hazard of all-cause mortality. Stair climbing difficulty and frequency are simple to collect and changes may occur early in OA progression, allowing for early intervention. Brief questions about stair climbing behaviors can serve as a functional vital sign within the clinician's toolbox.

Anterior Intercondylar Notch Geometry in Relation to the Native Anterior Cruciate Ligament Size

BACKGROUND

The intercondylar notch (ICN) and the anterior cruciate ligament (ACL) are important structures in knee morphometry, with key roles in stabilizing the knee.

AIM

To determine the associations between the specific shape of the ICN (A-, W-, or U-shape) and the ACL size in patients with intact ACLs.

METHODS

Magnetic resonance imaging (MRI) scans were independently analyzed by two experts: one orthopedic surgeon and one imaging physician. In all cases, the following measurements were taken based on the existing definitions: ACL area, anterior ICN (aICN) area, ICN width, lateral trochlear inclination (LTI), and Insall-Salvati index.

RESULTS

A total of 65 cases (50.8% male; 33.8 ± 10.2 years mean age at inclusion) were included in the study. The ACL and aICN areas were significantly larger in patients with U-shaped compared with A-shaped and W-shaped ICNs: 0.50 (0.20-0.80) vs. 0.40 (0.20-0.80) vs. 0.40 (0.30-0.80), p = 0.011 and 1.16 (0.57-3.60) vs. 0.47 (0.15-0.95) vs. 0.37 (0.15-0.81), p < 0.001, respectively. Internal meniscal lesions were more common in cases with U-shaped ICNs (64.0%), while external ones were more common in W-shaped ICN cases (35.3%). None of the A-shaped cases had external chondral or meniscal lesions. The ACL area was significantly larger in males and internal meniscal injuries, with no differences between chondral lesions, external meniscal injuries, patellar chondral lesions, patella alta, or trochlear dysplasia.

CONCLUSION

The specific shape of the intercondylar notch was associated with the anterior cruciate ligament-anterior intercondylar notch (ACL-aICN) area size correlation, with a strong correlation between ACL and aICN area when the intercondylar notch was A-shaped or W-shaped, and a low correlation when the notch was U- shaped. The specific shape of the intercondylar notch (A-, W-, or U-shape) was associated with the occurrence of both internal and external meniscal injuries, with the U-shaped intercondylar notch morphometry being more frequent in cases with internal meniscal injuries and the W-shape being more common in cases with external meniscal injuries.

The effect of kinetic factors of dynamic knee valgus on patellofemoral pain: A systematic review and meta-analysis

The speculation of dynamic knee valgus (DKV) correlates with kinetic changes in the frontal plane that increased loading patellofemoral joint (PFJ). Therefore, it is the purpose of this systematic review and meta-analysis study is the effect of kinetic factors DKV on patellofemoral pain (PFP). The search strategy was carried out in the electronic databases of Cochrane Library, PubMed, Springer Link, Science Direct, Scopus. Studies limited to the period 2000 to 2020 were extracted. The quality of study was assessment by modified Downs and Black checklist. Mean and standard deviation were also used to calculate the effect size. There were selected 8 articles for the systematic review and Meta-analysis. The results showed that in PFP patients compared to healthy individuals have increase knee abduction moment (SMD = 0.75; 95% CI = [0.47 to 1.02]) and impulse (SMD = 0.79; 95% CI = [0.50 to 1.07]). Furthermore, PFP patients compared to healthy individuals have decrease onset (SMD = -0.60; 95% CI = [-1.03 to -0.17]) and during (SMD = -0.93; 95% CI = [-1.57 to -0.29]) gluteus medius (GMED); vis-à-vis, PFP patients compared to healthy individuals have increase onset (SMD = 0.10; 95% CI = [-0.34 to 0.54]) and during (SMD = 0.29; 95% CI = [-0.15 to 0.73]) adductors longus (AL). As a result; PFP patients compared to healthy individuals show decrease co-contraction GMED/AL (SMD = -1.03; 95% CI = [-1.83 to -0.24]). The kinetic factors of DKV of leading to PFJ contact area decreases and the loading in a smaller contact area on PFJ in the outer part of the patella. Eventually, this abnormal distribution of contact pressure leads to etiology and osteoarthritis of the PFP.

Bilateral Asymmetry in Knee and Hip Musculoskeletal Loading During Stair Ascending/Descending in Individuals with Unilateral Mild-to-Moderate Medial Knee Osteoarthritis

Most cases of unilateral knee osteoarthritis (OA) progress to bilateral OA within 10 years. Biomechanical asymmetries have been implicated in contralateral OA development; however, gait analysis alone does not consistently detect asymmetries in OA patient gait. Stair ambulation is a more demanding activity that may be more suited to reveal between-leg asymmetries in OA patients. The objective of this study was to investigate the between-leg biomechanical differences in patients with unilateral mild-to-moderate knee OA. Sixteen unilateral mild-to-moderate medial knee OA patients and 16 healthy individuals underwent kinematic and kinetic analysis of stair ascent and descent. Stair ascent produced higher loading and muscle forces in the unaffected limb compared to the OA limb, and stair descent produced lower loading on the OA limb compared to healthy subjects. These biomechanical differences were apparent in the ankle, knee, and hip joints. The implications of these findings are that OA patients rely more heavily on their unaffected sides than the affected side in stair ascent, a strategy that may be detrimental to the unaffected joint health. The reduction in affected limb loading in stair descent is thought to be related to minimizing pain.

Association between ankle torque and performance-based tests, self-reported pain, and physical function in patients with knee osteoarthritis

Objectives

This study aimed to investigate the association between ankle torque and performance-based tests, self-reported pain, and physical function in patients with knee osteoarthritis (OA).

Patients and methods

The cross-sectional study was conducted with 39 individuals (24 females, 15 males; mean age: 57.3±6.2 years; range, 40 to 65 years) with knee OA between January 2014 and July 2015. Ankle torque was determined using an isokinetic dynamometer. The 40-m fast-paced walk test and a stair climb test were used to assess functional performance. Self-reported pain and physical function were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Pearson's correlation coefficients were calculated to test correlations between the dependent variables (40-m fast-paced walk test, stair climb test, WOMAC pain and physical function domains, sex, age, body mass index, and radiologic evidence of OA) and the independent variables (mean plantar flexor torque and dorsiflexor peak torque). A multiple linear regression analysis was applied to quantify the association between the dependent and independent variables.

Results

Dorsiflexor and plantar flexor peak torques in the concentric and eccentric modes were negatively correlated with the 40-m fast-paced walk and stair climb tests (r=-0.33 to -0.51, p≤0.05). A negative correlation was found between concentric plantar flexor torque and the WOMAC physical function score (r=-0.35, p=0.03). No correlation was found between ankle torques and the WOMAC pain score (p>0.05). The multiple linear regression analysis showed that the eccentric plantar flexor and dorsiflexor torques were significantly associated with the stair climb test (β=-0.001, 95% confidence interval [CI]: -0.001 to 0.000, p=0.03, and β=-0.002, 95% CI: -0.004 to 0.000, p=0.05, respectively). No significant associations were found between concentric plantar flexor and dorsiflexor torques and the stair climb test (p>0.05). No significant associations were found between the ankle torques and the 40-m fast-paced walk test and WOMAC physical function (p>0.05).

Conclusion

Ankle torque plays an important role in functional performance. Thus, ankle torque deficit, especially eccentric plantar flexor and dorsiflexor torques, may exert a negative influence on stair climbing performance in patients with knee osteoarthritis.

Versatile clinical movement analysis using statistical parametric mapping in MovementRx

Clinical gait analysis is an important biomechanics field that is often influenced by subjectivity in time-varying analysis leading to type I and II errors. Statistical Parametric Mapping can operate on all time-varying joint dynamics simultaneously, thereby overcoming subjectivity errors. We present MovementRx, the first gait analysis modelling application that correctly models the deviations of joints kinematics and kinetics both in 3 and 1 degrees of freedom; presented with easy-to-understand color maps for clinicians with limited statistical training. MovementRx is a python-based versatile GUI-enabled movement analysis decision support system, that provides a holistic view of all lower limb joints fundamental to the kinematic/kinetic chain related to functional gait. The user can cascade the view from single 3D multivariate result down to specific single joint individual 1D scalar movement component in a simple, coherent, objective, and visually intuitive manner. We highlight MovementRx benefit by presenting a case-study of a right knee osteoarthritis (OA) patient with otherwise undetected postintervention contralateral OA predisposition. MovementRx detected elevated frontal plane moments of the patient's unaffected knee. The patient also revealed a surprising adverse compensation to the contralateral limb.

Gait strategies for individuals with knee osteoarthritis when transitioning between floor and stair walking

Objective: Individuals with knee osteoarthritis are at higher risk for falls during transitions between floor and stair walking due to their reduced lower extremity function. However, the adjust gait characteristics of knee osteoarthritis subjects for dealing with stair transitions have not been explored. We aimed to investigate gait strategies in individuals with knee osteoarthritis compared to age-matched individuals without knee OA during the transition between walking on floor and stairs. Method: Gait of 30 individuals with knee osteoarthritis and 30 individuals without knee osteoarthritis during floor-to-stair and stair-to-floor walking transitions were accessed using a 3D motion capture system. Foot-tread clearance, and angles of lower extremity joints and trunk at Foot-tread clearance timepoint were analyzed by using biomechanical software (Visual 3D). Results: Compared with asymptomatic control group, the knee osteoarthritis group demonstrated no difference in vertical Foot-tread clearance and horizontal Foot-tread clearance during stair transitions. However, ankle dorsiflexion (p = 0.01) decreased, hip flexion (p = 0.02) and trunk lateral tilt (p = 0.02) increased in knee osteoarthritis group during the stair ascent transition. Moreover, trunk lateral tilt to the support side (p = 0.003) and pelvic rotation (p = 0.03) increased, while hip abduction of the swing leg (p = 0.03) decreased during the stair descent transition in individuals with knee osteoarthritis. Conclusion: Increased trunk lateral tilt and altered angle of hip may be a strategy utilized by individuals with knee OA to increase the foot clearance ability and compensate for the disease-related loss of lower extremity strength, range of motion, and balance. However, compensatory manifestations, such as the increased lateral tilt of the trunk and movement of the gravity center may enhance the risk of falls and result in more abnormal knee joint loading.

The biomechanical fingerprint of hip and knee osteoarthritis patients during activities of daily living

BACKGROUND

Osteoarthritis is a highly prevalent disease affecting the hip and knee joint and is characterized by load-mediated pain and decreased quality of life. Dependent on involved joint, patients present antalgic movement compensations, aiming to decrease loading on the involved joint. However, the associated alterations in mechanical loading of the ipsi- and contra-lateral lower limb joints, are less documented. Here, we documented the biomechanical fingerprint of end-stage hip and knee osteoarthritis patients in terms of ipsilateral and contralateral hip and knee loading during walking and stair ambulation.

METHODS

Three-dimensional motion-analysis was performed in 20 hip, 18 knee osteoarthritis patients and 12 controls during level walking and stair ambulation. Joint contact forces were calculated using a standard musculoskeletal modelling workflow in Opensim. Involved and contralateral hip and knee joint loading was compared against healthy controls using independent t-tests (p < 0.05).

FINDINGS

Both hip and knee cohorts significantly decreased loading of the involved joint during gait and stair ambulation. Hip osteoarthritis patients presented no signs of ipsilateral knee nor contralateral leg overloading, during walking and stair ascending. However, knee osteoarthritis patients significantly increased loading at the ipsilateral hip, and contralateral hip and knee joints during stair ambulation compared to controls.

INTERPRETATION

The biomechanical fingerprint in knee and hip osteoarthritis patients confirmed antalgic movement strategies to unload the involved leg during gait. Only during stair ambulation in knee osteoarthritis patients, movement adaptations were confirmed that induced unbalanced intra- and inter-limb loading conditions, which are known risk factors for secondary osteoarthritis.

Factors associated with self-rated difficulty to descend stairs in persons with knee osteoarthritis

BACKGROUND

Difficulty descending stairs is common in persons with knee osteoarthritis (OA). Clinically, it is important to know if and how this is explained by objectively measured difficulty to descend stairs, muscle weakness, pain, fear of movement, or knee joint status.

OBJECTIVE

To identify the potential of these factors to explain self-reported difficulty descending stairs.

DESIGN

Cross sectional, case-control.

SETTING

Hospital outpatient and physiotherapy clinic.

PARTICIPANTS

Twenty-eight men and women with knee OA (age 62.2 SD 5.9 years) and 31 controls (age 50.0 SD 8.5 years).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Using multivariate statistics, group comparisons were made for lower extremity kinematics (incorporating hip, knee, and ankle angles) and stance time in stair descent and lower extremity muscle strength. Then, a stepwise linear regression analysis was performed within the OA group to explain self-reported difficulties in stair descent where pain, kinesiophobia, radiographic signs, and outcomes that differed from controls for stair-descent kinematics and muscle strength were independent variables.

RESULTS

Multivariate statistics showed that the OA group displayed different all-over lower extremity kinematics (F_8,42 = 2.44 p = .029, η²  = 0.32) and a longer stance time (F_3,50 = 6.46; p = .001, η²  = 0.28) in stair descent and lower muscle strength (F_7,47 = 2.39; p = .035, η²  = 0.26) compared to controls. Regression analysis within the OA group to explain self-rated difficulties to descend stairs showed that the strongest association with kinesiophobia (ß = 0.607, p = .001) that combined with pain last week and radiographic signs explained almost 100% (ß = 0.972). Stair descent kinematics and strength variables that differed between groups did not explain self-rated difficulties to descend stairs.

CONCLUSION

Kinesiophobia and pain rather than stair-descent kinematics and reduced muscle-strength explained self-rated difficulties in stair descent in the OA group.

Biomechanical risk factors for knee osteoarthritis and lower back pain in lower limb amputees: protocol for a systematic review

INTRODUCTION

There is a limited research exploring biomechanical risk factors for the development of knee osteoarthritis (KOA) and lower back pain (LBP) between lower limb amputee subgroups, (eg, transtibial amputees (TTA) vs transfemoral amputees (TFA), or TTA dysvascular vs TTA traumatic). Previous reviews have focused primarily on studies where symptoms of KOA or LBP are present, however, due to limited study numbers, this hinders their scope and ability to compare between amputee subgroups. Therefore, the aim of this systematic review is to descriptively compare biomechanical risk factors for developing KOA and LBP between lower limb amputee subgroups, irrespective of whether KOA or LBP was present.

METHODS AND ANALYSIS

This review is currently in progress and screening results are presented alongside the protocol to highlight challenges encountered during data extraction. Five electronic databases were searched (Medline-Web of Science, PubMed, CINAHL, Embase and Scopus). Eligible studies were observational or interventional, reporting biomechanical gait outcomes for individual legs in adult lower limb amputees during flat walking, incline/decline walking or stair ascent/descent. Two reviewers screened for eligibility and level of agreement was assessed using Cohen's Kappa. Data extraction is ongoing. Risk of bias will be assessed using a modified Downs and Black method, and outcome measures will be descriptively synthesised.

ETHICS AND DISSEMINATION

There are no ethical considerations for this systematic review. Due to its scope, results are expected to be published in three separate manuscripts: (1) biomechanical risk factors of KOA between TTA and TFA, relative to non-amputees, (2) biomechanical risk factors of LBP between TTA and TFA, relative to non-amputees and (3) biomechanical risk factors of KOA and LBP between TTA with traumatic or dysvascular causes, relative to non-amputees.

PROSPERO REGISTRATION NUMBER

CRD42020158247.

Identification of Early Knee Osteoarthritis Based on Knee Joint Trajectory during Stair Climbing

Patients with knee osteoarthritis show low stair climbing ability, but a diagnosis of stair performance time is not enough to identify the early stages of knee osteoarthritis. Therefore, we developed an indicator named range of the knee joint trajectory (RKJT) as a kinematic parameter to express more detailed characteristics than stair performance time. To achieve this, we used our developed "IR-Locomotion", a markerless measurement system that can track the knee joint trajectory when climbing stairs. This study aimed to test whether the RKJT effectively identifies patients with early knee osteoarthritis even after controlling stair performance time. Forty-seven adults with moderate to severe knee pain (mean age 59.2 years; 68.1% women) underwent the radiographic examination (Kellgren and Lawrence grade) of both knees and a stair climbing test on 11 stairs. The RKJT during the stair climbing test was calculated by "IR-Locomotion". A generalized linear mixed model was used to evaluate the discriminative capability of RKJT on early knee osteoarthritis (i.e., Kellgren and Lawrence grade of 1). As expected, patients with early knee osteoarthritis showed larger RKJT than non-radiographic controls (95% confidence interval: 1.007, 1.076). Notably, this finding was consistent even after adjusting stair performance time.

Proprioceptive Neuromuscular Facilitation Improves Symptoms Among Older Adults With Knee Osteoarthritis During Stair Ascending: A Randomized Controlled Trial

OBJECTIVE

This study aimed to investigate the effects of a 6-wk proprioceptive neuromuscular facilitation stretching on pain, proprioception, joint range of motion, and joint moments during stair ascending among older adults with knee osteoarthritis.

DESIGN

This study is a randomized, controlled, and assessor-blinded trial. Thirty-six older adults with knee osteoarthritis were randomly assigned to the proprioceptive neuromuscular facilitation and the control groups. They received proprioceptive neuromuscular facilitation stretching and health lecture series, respectively, for 6 wks. Final data analysis included 14 participants of the proprioceptive neuromuscular facilitation group and 13 of the control group. Pain score, joint proprioception, range of motion, and joint moments during stair ascending were measured before and after the stretching. Two-way (group by time) analysis of variance with repeated measures was used to evaluate stretching effects.

RESULTS

Significant interactions were detected in pain score, joint proprioception, external knee adduction moment, and external knee extension moment. Compared with week 0, the pain score, joint proprioception threshold, and external knee adduction moment decreased, whereas the external knee extension moment increased among older adults in the proprioceptive neuromuscular facilitation group at week 7.

CONCLUSIONS

Proprioceptive neuromuscular facilitation could be recommended as one of the clinical treatments for knee osteoarthritis to relieve pain, improve proprioception, and balance load distribution between medial and lateral compartments at the knee.

Functional manifestations of early knee osteoarthritis: a systematic review and meta-analysis

Early detection of knee osteoarthritis (KOA) can improve treatment outcomes and prevent its progression. The aim of this systematic review was to identify the functional changes in early KOA. Electronic journal databases and platforms, including PubMed, the Physiotherapy Evidence Database, the Cochrane Central Register of Controlled Trials, and Scopus were searched. The inclusion criteria were as follows: (1) studies comparing patients with early KOA with an age-matched control group and (2) studies with objectively measured functional changes as outcomes. Studies that included individuals with Kellgren and Lawrence (K/L) grades > 2- were excluded. A random-effects model was constructed to calculate pooled standardized mean differences (SMDs). A total of nine articles were included in this systematic review. Seven studies used classification criteria to define early KOA, including knee pain; a K/L grade of 0, 1, or 2- (osteophytes only) for the medial compartment; and the presence of two out of four MRI criteria. The remaining two studies included K/L grade 1 confirmed by radiography. Early KOA participants had a significantly longer timed up-and-go test (TUG) time (pooled SMD: 0.57; 95% confidence interval: 0.15, 0.98). The two groups had similar knee extension muscle strength at 90° knee flexion. The quality of evidence for each measured outcome was "very low." In this review, longer TUG was identified as a functional manifestation of early KOA. Further studies involving functional assessments are needed to develop a screening method to detect early KOA. Key Points • There is a need for diagnostic criteria that include functional changes in patients with early knee osteoarthritis, since radiographic facilities are not available everywhere. • In this review, a long timed up-and-go test time was identified as a functional manifestation of early knee osteoarthritis. • If the findings of this study can be replicated, measurement of TUG may allow for earlier detection of knee osteoarthritis outside the hospital and in routine clinical practice without the use of MRI or X-rays.

Construct validity and reliability of the 2-minute step test in patients with knee osteoarthritis

Objective

To validate and evaluate the intra- and inter-rater reliability of the 2-min step test (2MST) in measuring the functional performance of patients with knee pain associated with osteoarthritis (OA).

Methods

Forty-one patients with knee OA was included. Two examiners assessed the patients at two times with interval between the test and retest from 7 to 14 days. All executions of 2MST were recorded in real time by the examiners and were also recorded by video. The intraclass correlation coefficient (ICC) and 95% confidence interval (CI), standard error of measurement (SEM) and minimum detectable difference (MDD) were used to determine reliability. In the construct validity, we correlate the score of the 2MST with the other instruments used in the study: The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Numerical Pain Scale (NPS), Pain-Related Catastrophizing Thoughts Scale (PCTS) and Chronic Pain Self-Efficacy Scale (PSEQ). The agreement between the face-to-face assessment and the evaluation based on the video record was assessed using the Bland-Altman methodology in the 4 moments of the 2MST.

Results

2MST presented excellent intra- (ICC = 0.94, SEM = 4.47, MDD = 12.40) and inter-rater reliability (ICC = 0.97, SEM = 3.07, MDD = 8.52). The agreement was acceptable between face-to-face assessments and the analyzes performed on video. All instruments showed a statistically significant correlation with 2MST, except the PCTS. A correlation magnitude above 0.50 was found between the 2MST and pain and function domains of the WOMAC, and a correlation magnitude between 0.30 and 0.50 with the joint stiffness domain of the WOMAC, NRPS and PSEQ.

Conclusion

2MST proved to be valid for assessing functional capacity in patients with knee OA, with excellent reliability.

Reliability, validity and responsiveness of the Step Up and Down (StUD) test for individuals with symptomatic knee osteoarthritis

BACKGROUND

Stair climbing test (SCT) has been suggested as the first task affected in individuals with symptomatic knee osteoarthritis (KOA). However, there are environmental barriers for the execution of the 9- to 12-step SCT. Thus, we developed a feasible one-step SCT that could be completed in 15s.

OBJECTIVE

To check the clinimetric properties of the 15s Step Up and Down (StUD) test in individuals with KOA.

DESIGN

Prospective validity study.

METHOD

Eighty-two individuals with KOA participated in this study. The test-retest reliability of the StUD test was measured with a 1-week interval. The construct validity and responsiveness were assessed by testing predefined hypotheses. For this, the 30s Chair Stand Test (30CS), Timed Up and Go Test (TUG), quadriceps strength, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lequesne Algofunctional Index were used as comparator instruments.

RESULTS

The StUD test presented good test-retest reliability (ICC = 0.87; 95% CI = 0.79-0.91) and showed a moderate to good correlation with the 30CS (r = 0.65), TUG (r = -0.56), and quadriceps strength (r = 0.41). We found a higher correlation between the StUD test and the performance-based tests than the patient-reported outcome measures. The StUD test was responsive, with five out of the six (83.3%) hypotheses confirmed.

CONCLUSION

StUD test showed good reliability, adequate validity and responsiveness. Our findings suggest that StUD is a useful performance-based test for individuals with KOA.

The Relationship Between Changes in Movement and Activity Limitation or Pain in People With Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To report whether changes in knee joint movement parameters recorded during functional activities relate to change in activity limitation or pain after an exercise intervention in people with knee osteoarthritis (OA).

DESIGN

Etiology systematic review.

LITERATURE SEARCH

Four databases (MEDLINE, Embase, CINAHL, and AMED) were searched up to January 22, 2021.

STUDY SELECTION CRITERIA

Randomized controlled trials or cohort studies of exercise interventions for people with knee OA that assessed change in knee joint movement parameters (moments, kinematics, or muscle activity) and clinical outcomes (activity limitation or pain).

DATA SYNTHESIS

A descriptive synthesis of functional activities, movement parameters, and clinical outcomes.

RESULTS

From 3182 articles, 22 studies met the inclusion criteria, and almost all were of low quality. Gait was the only investigated functional activity. After exercise, gait parameters changed 26% of the time, and clinical outcomes improved 90% of the time. A relationship between group-level changes in gait parameters and clinical outcomes occurred 24.5% of the time. Two studies directly investigated an individual-level relationship, reporting only 1 significant association out of 8 correlations tested.

CONCLUSION

Most studies reported no change in gait-related movement parameters despite improvement in clinical outcomes, challenging the belief that changing movement parameters is always clinically important in people with knee OA. J Orthop Sports Phys Ther 2021;51(10):492-502. doi:10.2519/jospt.2021.10418.

Associations Between Obesity With Low Muscle Mass and Physical Function in Patients With End-Stage Knee Osteoarthritis

Objective

To investigate the prevalence of obesity with low muscle mass and its impact on physical function, quality of life (QOL) and pain in patients with end-stage knee osteoarthritis over 65 years old.

Methods

In this cross-sectional study, we assessed a total of 562 patients. After separating the group into males and females, we divided patients into 4 further groups: normal BMI with normal muscle mass, obesity with normal muscle mass, normal BMI with low muscle mass and obesity with low muscle mass. All patients completed stair climbing test (SCT), 6-minute walk test, timed up and go test (TUG), instrumental gait analysis, Western Ontario McMaster Universities Osteoarthritis Index, VAS, and EuroQOL 5 dimensions questionnaire.

Results

Obesity with low muscle mass was diagnosed in 6 males subjects (7.8%) and 9 female subjects (1.9%). Patients with obesity and low muscle mass performed the SCT-ascent and descent significantly slower than other body composition groups in both males and females. TUG in males and gait speed in females were also significantly slower in the obesity with low muscle mass group. Stepwise multiple linear regression analysis revealed that in males, obesity with low muscle mass was significantly predictive of SCT ascent (β = 0.409, p < 0.001), SCT-descent (β = 0.405, p < 0.001), and TUG (β = 0.283, p = 0.009), and in females, obesity with low muscle mass was significantly predictive of SCT-ascent (β = 0.231, p < 0.001), SCT-descent (β = 0.183, p < 0.001), and gait speed (β=-0.129, p = 0.004).

Conclusions

This study confirms that the combination of obesity and low muscle mass is associated with impaired physical function in patients with end-stage knee osteoarthritis.

Human Activity Recognition for People with Knee Osteoarthritis-A Proof-of-Concept

Clinicians lack objective means for monitoring if their knee osteoarthritis patients are improving outside of the clinic (e.g., at home). Previous human activity recognition (HAR) models using wearable sensor data have only used data from healthy people and such models are typically imprecise for people who have medical conditions affecting movement. HAR models designed for people with knee osteoarthritis have classified rehabilitation exercises but not the clinically relevant activities of transitioning from a chair, negotiating stairs and walking, which are commonly monitored for improvement during therapy for this condition. Therefore, it is unknown if a HAR model trained on data from people who have knee osteoarthritis can be accurate in classifying these three clinically relevant activities. Therefore, we collected inertial measurement unit (IMU) data from 18 participants with knee osteoarthritis and trained convolutional neural network models to identify chair, stairs and walking activities, and phases. The model accuracy was 85% at the first level of classification (activity), 89-97% at the second (direction of movement) and 60-67% at the third level (phase). This study is the first proof-of-concept that an accurate HAR system can be developed using IMU data from people with knee osteoarthritis to classify activities and phases of activities.

Intermittent vibrational stimulation enhances mobility during stair navigation in patients with knee pain

BACKGROUND

Reduced quadriceps function and proprioception can cause decreased mobility during stair navigation in patients with knee pain. Patients can benefit from interventions to mitigate pain and restore quadriceps function. Activating the somatosensory system via intermittent vibrational stimulation has the potential to improve stair navigation mobility in patients with knee pain by moderating quadriceps inhibition and enhancing proprioception.

RESEARCH QUESTION

What are the effects of intermittent vibrational stimulus synchronized to stair ambulation on muscle activity, kinematics, kinetics, and pain using a randomized controlled clinical trial design.

METHODS

Thirty-eight patients with knee pain were enrolled into a blinded cross-over study, and twenty-nine patients completed all assessments and analyses. Subjects were randomly assigned sequentially to both an active Treatment A (active) and passive Treatment B (passive) worn at the knee during ambulation for 4 weeks with a 2-week washout period between treatments.

RESULTS

Knee pain during stair navigation was significantly reduced only with Treatment A (P = 0.007). During ascent, Treatment A (active) significantly increased vastus lateralis activation (P = 0.01), increased knee flexion moment (P = 0.04) and decreased trunk flexion angles (P = 0.015) between baseline and 4-week follow-up. After using passive Treatment B, there were no significant differences in pain (P = 0.19), knee flexion moment (P = 0.09), and trunk flexion angles (P = 0.23). Changes in muscle function correlated significantly with changes in knee flexion moment and trunk flexion with Treatment A (P < 0.015). Descending differed from ascending in response to Treatment A with significantly decreased knee flexion moment(P = 0.04), hip(P = 0.02) and ankle(P = 0.04) flexion angles. Treatment B significantly reduced hip flexion angles (P = 0.005) but not knee flexion moment (P = 0.85).

SIGNIFICANCE

The results of this study suggest that intermittent vibration can improve joint motion and loading during stair navigation by enhancing quadriceps function during stair ascent and improving movement control during stair descent by modifying an adaptive flexed movement pattern in the lower limb.

Lower limb kinematics improvement after genicular nerve blockade in patients with knee osteoarthritis: a milestone study using inertial sensors

Background

Genicular nerve blockade is a possible treatment for patients with knee osteoarthritis. Pain relief and improvement in functioning is expected. This procedure could be of major interest for patients in low-income countries where total knee arthroplasty is not available for the population. This study aims at assessing the immediate benefits on pain, gait, and stairs kinematics after a genicular nerve blockade in patients suffering from knee osteoarthritis in Cameroun.

Methods

A prospective study was carried out on 26 subjects in Cameroun. A genicular nerve blockade was performed on 14 women with painful knee osteoarthritis grade 2–4. Lower limb joint angles were recorded with inertial sensors before and 1 h after injection. Patient-reported outcomes of pain and perceived difficulty were collected, as well as 10 m and 6 min walking tests. A reliability analysis of inertial sensors was performed on a sample of 12 healthy subjects by calculating the intraclass correlation coefficient and the standard error of measurement.

Results

Pain and perceived difficulty decreased significantly (p < 0.001). Cadence increased significantly in stairs climbing (upstairs: + 7.7 steps/min; downstairs: + 7.6 steps/min). There was an improvement for hip sagittal range of motion during gait (+ 9.3°) and pelvis transverse range of motion in walking upstairs (− 3.3°). Angular speed range of the knee in the sagittal plane and of the hip in the frontal plane increased significantly in stairs descent (+ 53.7°/s, + 94.5°/s).

Conclusions

This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon. This is the first study objectifying this effect, through wearable sensors.

Trial registration

Pan African Clinical Trial Registry, PACTR202004822698484. Registered 28 March 2020 - Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03836-8.

An impaired healing model of osteochondral defect in papain-induced arthritis

Background

Osteochondral defects (OCD) are common in osteoarthritis (OA) and difficult to heal. Numerous tissue engineering approaches and novel biomaterials are developed to solve this challenging condition. Although most of the novel methods can successfully treat osteochondral defects in preclinical trials, their clinical application in OA patients is not satisfactory, due to a high spontaneous recovery rate of many preclinical animal models by ignoring the inflammatory environment. In this study, we developed a sustained osteochondral defect model in osteoarthritic rabbits and compared the cartilage and subchondral bone regeneration in normal and arthritic environments.

Methods

Rabbits were injected with papain (1.25%) in the right knee joints (OA group), and saline in the left knee joints (Non-OA group) at day 1 and day 3. One week later a cylindrical osteochondral defect of 3.2 mm in diameter and 3 mm depth was made in the femoral patellar groove. After 16 weeks, newly regenerated cartilage and bone inside the defect were evaluated by micro-CT, histomorphology and immunohistochemistry.

Results

One week after papain injection, extracellular matrix in the OA group demonstrated dramatically less safranin O staining intensity than in the non-OA group. Until 13 weeks of post-surgery, knee width remained significantly higher in the OA group than the non-OA control group. Sixteen weeks after surgery, the OA group had 11.3% lower International Cartilage Regeneration and Joint Preservation Society score and 32.5% lower O’Driscoll score than the non-OA group. There were less sulfated glycosaminoglycan and type II collagen but 74.1% more MMP-3 protein in the regenerated cartilage of the OA group compared with the non-OA group. As to the regenerated bone, bone volume fraction, trabecular thickness and trabecular number were all about 28% lower, while the bone mineral density was 26.7% higher in the OA group compared to the non-OA group. Dynamic histomorphometry parameters including percent labeled perimeter, mineral apposition rate and bone formation rate were lower in the OA group than in the non-OA group. Immunohistochemistry data showed that the OA group had 15.9% less type I collagen than the non-OA group.

Conclusion

The present study successfully established a non-self-healing osteochondral defect rabbit model in papain-induced OA, which was well simulating the clinical feature and pathology. In addition, we confirmed that both cartilage and subchondral bone regeneration were further impaired in arthritic environment.

The translational potential of this article

The present study provides an osteochondral defect in a small osteoarthritic model. This non-self-healing model and the evaluation protocol could be used to evaluate the efficacy and study the mechanism of newly developed biomaterials or tissue engineering methods preclinically; as methods tested in reliable preclinical models are expected to achieve improved success rate when tested clinically for treatment of OCD in OA patients.

The Effect of Electroacupuncture on Dynamic Balance during Stair Climbing for Elderly Patients with Knee Osteoarthritis

Background

Poor balance is one of the risk factors for falls in patients with knee osteoarthritis (KOA), which is related to the symptoms. Electroacupuncture (EA) is one of the traditional Chinese conservative methods commonly used to improve the symptoms in patients with KOA.

Objective

To assess whether EA increases the dynamic balance during stair negotiation among patients with KOA.

Methods

A total of 40 KOA patients were assigned to two groups randomly (true electroacupuncture vs. mock electroacupuncture). Acupoints around the knee were selected in the true electroacupuncture (TEA) group with electrical stimulation (2 Hz). In the mock electroacupuncture (MEA) group, about 2 cm next to the above acupoints, the needles were inserted superficially without electrical stimulation. All the participants received 11 sessions of stimulation treatment in three weeks. The primary outcome was margin of stability (MOS). Secondary outcomes included hip kinematics and kinetics as well as pain.

Results

There was no significant difference between the two groups for self-reported pain (p=0.585). During ascent, there was no difference between groups in MOS value in both directions, which was the anterior-posterior (A/P) direction and medial-lateral (M/L) direction at initial contact and toe-off as well as the midstance in the gait cycle, and no difference for the hip kinematics and kinetics between the groups was detected (p > 0.05). For descent, at the toe-off event, the TEA group was more unstable as compared to the MEA group in the A/P direction (p=0.029) but not in the M/L direction, and the hip showed a larger internal rotator moment (p=0.049); at the midstance, the TEA group showed a lower abductor moment than the MEA group (p=0.003).

Conclusions

Based on the assessment results from the chosen patients with KOA, the TEA did not demonstrate a significant effect in improving the dynamic balance during stair negotiation in comparison with the MEA. This finding does not support EA as a conservative treatment to improve the dynamic balance in such patients.

Proprioceptive neuromuscular facilitation improves pain and descending mechanics among elderly with knee osteoarthritis

PURPOSE

Knee osteoarthritis (KOA) is a common disease that causes pain and limits functionality in the elderly during daily activities, especially during stair descent. Proprioceptive neuromuscular facilitation (PNF) practices promote multiple-plane joint movements, which relieve pain and increase joint range of motion (ROM). This study aims to examine the effects of a 12-week PNF intervention on pain relief, passive and active joint ROM, external knee adduction moment (KAM), and hip adduction moment (HAM) in the elderly with KOA during stair descent.

MATERIALS AND METHODS

Seventy-six elderly who were diagnosed with KOA were assessed for eligibility and, 36 of them met the inclusive criteria, were randomly divided into two groups: the twelve-week PNF intervention group and the control group. Pain score was measured by the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Passive joint ROM was measured using a goniometer. Active joint ROM, KAM, and HAM during stair descent were measured using a motion analysis system with a force platform. All the data were recorded at weeks 0, 6, and 12.

RESULTS

Compared to the control group, the PNF group showed a decreased pain score; increased passive hip, knee, and ankle ROM; a decreased minimum knee flexion angle, and increased HAM during stair descent.

PERSPECTIVE

Proprioceptive neuromuscular facilitation intervention is a successful method to relieve symptoms of KOA. It relieves pain without increasing KAM, enhances passive ROM, increases active knee flexion ROM, and increases HAM during stair descent in the elderly with KOA.

Transcutaneous Electrical Nerve Stimulation Improves Stair Climbing Capacity in People with Knee Osteoarthritis

This study aimed to examine the effect of transcutaneous electrical nerve stimulation (TENS) on stair climbing capacity in individuals with pre-radiographic to mild knee osteoarthritis (OA). This is a secondary analysis of data from a single, participant-blinded, randomized controlled trial with a pre-post design. Participants with pre-radiographic to mild knee OA (mean age, 59.1 years; 72.9% women) were randomly assigned into two groups, a TENS (n = 30) and a sham-TENS groups (n = 29). TENS or sham-TENS treatments were applied to all participants by using the prototype TENS device with pre-specified parameters. The primary outcome measures included valid and reliable functional measures for stair climbing (stair-climb test [SCT]), visual analog scale for knee pain during the SCT, and quadriceps muscle strength. TENS improved SCT time by 0.41 s (95% confidence interval [CI]: 0.07, 0.75). The time reduction in the transition phase explains the TENS therapeutic effect. Post-hoc correlation analyses revealed a non-significant but positive relationship between the pain relief effect and improved 11-step SCT time in the TENS group but not in the sham-TENS group. These results indicate that the TENS intervention may be an option for reducing the burden of early-stage knee OA.

Effects of tai chi on postural control during dual-task stair negotiation in knee osteoarthritis: a randomised controlled trial protocol

INTRODUCTION

Stair ascent and descent require complex integration between sensory and motor systems; individuals with knee osteoarthritis (KOA) have an elevated risk for falls and fall injuries, which may be in part due to poor dynamic postural control during locomotion. Tai chi exercise has been shown to reduce fall risks in the ageing population and is recommended as one of the non-pharmocological therapies for people with KOA. However, neuromuscular mechanisms underlying the benefits of tai chi for persons with KOA are not clearly understood. Postural control deficits in performing a primary motor task may be more pronounced when required to simultaneously attend to a cognitive task. This single-blind, parallel design randomised controlled trial (RCT) aims to evaluate the effects of a 12-week tai chi programme versus balance and postural control training on neuromechanical characteristics during dual-task stair negotiation.

METHODS AND ANALYSIS

Sixty-six participants with KOA will be randomised into either tai chi or balance and postural control training, each at 60 min per session, twice weekly for 12 weeks. Assessed at baseline and 12 weeks (ie, postintervention), the primary outcomes are attention cost and dynamic postural stability during dual-task stair negotiation. Secondary outcomes include balance and proprioception, foot clearances, self-reported symptoms and function. A telephone follow-up to assess symptoms and function will be conducted at 20 weeks. The findings will help determine whether tai chi is beneficial on dynamic stability and in reducing fall risks in older adults with KOA patients in community.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (#2018KY-006-1). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR1800018028.

Timed Stair-Climbing as a Surrogate Marker for Sarcopenia Measurements in Predicting Surgical Outcomes

BACKGROUND

Estimating sarcopenia by measuring psoas muscle density (PMD) has been advocated as a method to accurately predict post-operative morbidity. The aim of the present study was to determine whether the Timed Stair Climb (TSC) could be used to replace PMD measurements in predicting morbidity.

METHODS

Patients were prospectively enrolled from March 2014-2015 and were eligible if they were undergoing an abdominal operation. PMD was measured using pre-operative CT scans obtained within 90 days of surgery. Ninety-day complications were assessed using the Accordion Severity Grading System. Multivariable analysis was performed to identify risk factors associated with operative morbidity.

RESULTS

Of the patients, 298 were enrolled and completed TSC prior to undergoing an operation. Using the According Grading System, a grade 2 or higher complication occurred in 72 (24. 2%) patients with 8 (2.7%) deaths. There was an indirect relationship between PMD and TSC (P < 0.0001) and a direct relationship between TSC and complications (P = 0.04). On multivariable analysis decreasing PMD (P = 0.018) and increasing TSC (P = 0.026) were predictive of post-operative morbidity. Receiver operating characteristic curves demonstrated that the TSC was superior to both the ACS NSQIP Risk Calculator and PMD in predicting outcomes (TSC vs. PMD, P = 0.012; PMD vs. ACS NSQIP, P = 0.013; TSC vs. ACS NSQIP, P < 0.0001).

CONCLUSION

TSC, PMD, and the ACS NSQIP calculator are all useful tools; however, the TSC is superior in predicting post-operative morbidity.

Knee adduction moments are not increased in obese knee osteoarthritis patients during stair negotiation

BACKGROUND

Negotiating stairs is an important activity of daily living that is also associated with large loads on the knee joint. In medial compartment knee osteoarthritis, the knee adduction moment during level walking is considered a marker for disease severity. It could be argued that the discriminative capability of this parameter is even better if tested in a strenuous stair negotiation task.

RESEARCH QUESTION

What is the relation with knee osteoarthritis on the knee adduction moment during the stance phase of both stair ascent and descent in patients with and without obesity?

METHODS

This case control study included 22 lean controls, 16 lean knee osteoarthritis patients, and 14 obese knee osteoarthritis patients. All subjects ascended and descended a two-step staircase at a self-selected, comfortable speed. Three-dimensional motion analysis was performed to evaluate the knee adduction moment during stair negotiation.

RESULTS

Obese knee osteoarthritis patients show a prolonged stance time together with a more flattened knee adduction moment curve during stair ascent. Normalized knee adduction moment impulse, as well as the first and second peaks were not different between groups. During stair descent, a similar increase in stance time was found for both osteoarthritis groups.

SIGNIFICANCE

The absence of a significant effect of groups on the normalized knee adduction moment during stair negotiation may be explained by a lower ambulatory speed in the obese knee osteoarthritis group, that effectively lowers vertical ground reaction force. Decreasing ambulatory speed may be an effective strategy to lower knee adduction moment during stair negotiation.

Stair climbing ability in patients with early knee osteoarthritis: Defining the clinical hallmarks of early disease

BACKGROUND

A growing clinical interest has been shown towards identifying knee osteoarthritis (OA) patients at earlier stages. The early detection of knee OA may allow for more effective interventions.

RESEARCH QUESTION

The aim of this study was to determine the discriminative ability of a stair-climb test (SCT) in identifying patients with early knee OA, and to determine if descending stair time during the SCT is better than ascending stair time for the identification of these patients.

METHODS

This study was a secondary, cross-sectional analysis of baseline data from a randomized controlled trial. Adults with moderate to severe knee pain were enrolled (n = 57; mean age 58.9 years; 71.9% women). Each participant performed an 11-step SCT (11-SCT) while wearing shoes with a pressure sensor insole. A receiver operating characteristic analysis was used to examine the discriminative power of 11-SCT for identifying early knee OA (Kellgren and Lawrence grade 1). The discriminative power was also compared between the ascending and descending 11-SCT time as evaluated by the pressure sensor.

RESULTS

The 11-SCT time in patients with early knee OA was 0.55 s longer than that in those with symptomatic non-radiographic OA. A one-second increase in the 11-SCT time was significantly associated with 1.9-fold increased odds of early knee OA being present. The 11-SCT value with the best balance of sensitivity and specificity for identifying early knee OA was 8.33 s (area under the curve: 0.711). The descending time was not significantly better than the ascending time for identifying early knee OA.

SIGNIFICANCE

This study determined the time values of an 11-SCT that may be useful for identifying early knee OA patients. These preliminary findings may serve as the foundation for future studies investigating the clinical hallmarks associated with early knee OA.

Concurrent validity and measurement error of stair climb test in people with pre-radiographic to mild knee osteoarthritis

BACKGROUND

Stair climbing is the task first affected in patients with knee osteoarthritis (OA); therefore, the precise measurement of time required to climb stairs is important to identify mobility limitations, particularly in the early phase of knee OA.

RESEARCH QUESTION

This study aimed to examine the test-retest reliability, measurement error, and concurrent validity of the stopwatch-based stair-climb test (SCT) in adults with pre-radiographic to mild knee OA.

METHODS

Fifty-nine participants (mean age, 59.1 [range, 50-69] years; 72.9% female) with Kellgren and Lawrence grade ≤2 disease underwent an 11-step SCT (11-SCT) in accordance with the Osteoarthritis Research Society International recommended method while wearing pressure sensor-mounted standard shoes that is used as a gold standard procedure. Test-retest reliability, measurement errors, and the concurrent validity of the stopwatch-based 11-SCT were evaluated.

RESULTS

The test-retest reliability of the stopwatch-based 11-SCT was excellent (intra-class correlation coefficient_1,1 [ICC_1,1], 0.952; 95% confidence interval [CI], 0.560 to 0.985; p <  0.001) and the minimal detectable change₉₅ was 0.102 s. Concurrent validity was excellent (ICC_2,1: 0.957; 95% CI: 0.661 to 0.986; p <  0.001).

SIGNIFICANCE

The stopwatch-based 11-SCT had high test-retest reliability and high concurrent validity, which justify its clinical use for identifying mobility limitations in individuals with pre-radiographic to mild knee OA. A difference of 0.2 s in the stopwatch-based 11-SCT time would be considered a true difference beyond a 95% measurement error.