Do Existing MRI Definitions of Knee Osteoarthritis Identify Knees That Will Develop Clinically Significant Disease Over Up To 11 Years of Follow-Up?

OBJECTIVES: In individuals without radiographic knee osteoarthritis (KOA), we investigated whether MRI-defined KOA at baseline was associated with incident radiographic and symptomatic disease during up to 11 years of follow-up. METHODS: Osteoarthritis Initiative participants without tibiofemoral radiographic KOA at baseline were assessed for MRI-based tibiofemoral cartilage damage, osteophyte presence, bone marrow lesions, and meniscal damage/extrusion. We defined MRI KOA using alternative, reported definitions (Def A and Def B). Kellgren-Lawrence (KL) grade, joint space narrowing (JSN), and frequent knee symptoms (Sx) were assessed at baseline, 1-, 2-, 3-, 4-, 6-, 8-, and 10/11-year follow-up visits. Incident tibiofemoral radiographic KOA (outcome) was defined as (1) KL ≥ 2, (2) KL ≥ 2 and JSN, or (3) KL ≥ 2 and Sx. Adjusted Cox proportional hazards regression models examined associations of baseline MRI-defined KOA (Def A and Def B) with incident outcomes during up to 11 years of follow-up. RESULTS: Among 1621 participants [mean age=58.8 (SD=9.0) years, mean BMI=27.2 (4.5) kg/m2, 59.5% women], 17% had MRI-defined KOA by Def A and 24% by Def B. Baseline MRI-defined KOA was associated with incident KL ≥ 2 [odds ratio=2.94 (95% CI=2.34-3.68) for Def A and 2.44 (95% CI=1.97-3.03) for Def B]. However, a substantial proportion of individuals with baseline MRI-defined KOA did not develop incident KL ≥ 2 during follow-up (59% for Def A and 64% for Def B). Findings were similar for the other two outcomes. CONCLUSIONS: Current MRI definitions of KOA do not adequately identify knees that will develop radiographic and symptomatic disease.

Sex Differences in Ambulatory Biomechanics: A Meta-Analysis Providinga Mechanistic Insight into Knee Osteoarthritis.

PURPOSE: Females typically present with a higher prevalence of knee osteoarthritis (KOA), and such a higher prevalence may be due to unique knee biomechanics during walking. However, the sex-dependent ambulatory mechanics has been yet to be clarified. To address this critical knowledge gap, this study implemented a series of computational approaches (1) to identify sex-related knee joint biomechanics during ambulation in persons with KOA and (2) to compare these biomechanical measures between individuals with vs. without KOA, stratified by sex. METHODS: We searched five electronic databases for studies reporting sex-specific knee biomechanics in persons with and/or without KOA. Summary estimates were computed using random-effects meta-analysis and stratified by sex. RESULTS: The systematic review identified eighteen studies (308 males and 383 females with KOA; 740 males and 995 females without KOA). A series of meta-analyses identified female-specific knee biomechanics in a disease-dependent manner. Females with KOA had lower first peak knee adduction moment and peak knee adduction compared to male counterparts. On the other hand, healthy females had lower peak knee flexion moment than male counterparts. Effect estimate in each meta-analysis display poor quality of evidence according to the GRADE approach. CONCLUSIONS: The current study is the first to consider sex as a biological variable into ambulatory mechanics in the development of KOA. We discovered that sex-dependent alterations in knee biomechanics is a function of the presence of KOA, indicating that KOA disease may be a driver of the sex-dependent biomechanical alterations or vice versa. Although no strong conclusion can be drawn because of the low quality of evidence, these findings provide new insight into the sex differences in ambulatory knee biomechanics and progression of KOA.

Association of Young-Onset Dementia with Pre-Existing Peripheral Vestibular Disorders.

Background: The relationship between young-onset dementia and peripheral vestibular disorders remained largely unknown although this association was observed in the older population. Objective: This case-control study aims to investigate the association of young-onset dementia with a pre-existing diagnosis of peripheral vestibular disorders using a population-based data from Taiwan's Longitudinal Health Insurance Database 2010. Methods: This study included 989 patients with young-onset dementia and 2967 propensity-score-matching controls. Differences in baseline characteristic between patients with young-onset dementia and controls were investigated using chi-square tests or t-tests. Multiple logistic regression models were employed to assess the association of young-onset dementia (outcome) with pre-existing peripheral vestibular disorders (predictor). Results: Compared to patients without young-onset dementia, those affected by this condition exhibited a statistically significantly higher rate of peripheral vestibular disorders (18.3% versus 8.2%, p < 0.001). Furthermore, our analysis found notable between-group disparities in the rates of Meniere's Disease (3.5% versus 2.0%, p= 0.015), benign paroxysmal positional vertigo (2.4% versus 1.1%, p= 0.006), and vestibular neuritis (2.4% versus 1.1%, p= 0.003). Multiple logistic regression analysis showed that the presence of prior peripheral vestibular disorders increased the odds of young-onset dementia [2.603 (95% CI = 2.105∼3.220)] after adjusting for age, sex, monthly income, geographic location, urbanization level, hyperlipidemia, diabetes, coronary heart disease, hearing loss, and hypertension. Conclusions: The study findings demonstrate a notable association between young-onset dementia and pre-existing peripheral vestibular disorders, suggesting that vestibular malfunction could play a role in the development of young-onset dementia.

Imposter phenomenon in physical therapists: A cross-sectional observational study.

Background and Aims: Imposter phenomenon (IP), or perceived fraudulence, describes an ongoing fear of exposure as a fraud or imposter, despite objective successes and accomplishments. Although there is a growing interest of IP in medicine, IP in the physical therapy profession has been minimally examined. We aimed to determine the prevalence and predictors of IP among licensed physical therapists in the United States. Methods: This cross-sectional observational study utilized an online survey to assess levels of IP using the Clance Imposter Phenomenon Scale. We assessed degrees of emotional exhaustion and job satisfaction and collected professional and demographic information. A multivariable logistic regression model examined factors associated with IP presence. Results: The mean IP score was 60.3 (SD: 15.1, range: 19-95). Fifty-five respondents (10.7%) had low IP, 196 (38.1%) moderate, 215 (41.8%) frequent, and 48 (9.3%) intense IP. The prevalence of IP, defined as frequent or intense IP, was 51.2%. Having manager/supervisor experience (odds ratio [OR] = 0.55, 95% confidence interval [CI] = 0.34-0.90) was associated with a reduced odds of IP presence. Holding a bachelor's or master's degree (vs. Doctor of Physical Therapy (DPT); OR = 2.31, 95% CI = 1.07-5.00), a history of or current mental health diagnosis (OR = 2.77, 95% CI = 1.69-4.54), and emotional exhaustion (moderate vs. low: OR = 5.37, 95% CI = 2.11-13.69; high vs. low: OR = 14.13, 95% CI = 5.56-35.89) were each associated with an increased odds of IP presence. Conclusions: IP is highly prevalent among licensed physical therapists. Seasoned clinicians with managerial roles seemed to be less susceptible to IP, whereas those with mental health diagnoses, emotional exhaustion, and those without a DPT degree may be more susceptible. Given its high prevalence and potential negative impact on burnout and career advancement, it is crucial to increase IP awareness and provide education on management strategies.

The Natural History of Knee Osteoarthritis Pain Experience and Risk Profiles.

The study aimed to characterize the natural history of the pain experience, concurrently considering intermittent and constant pain over 4 years, and determine baseline factors associated with unfavorable trajectories in individuals with chronic knee pain. The Osteoarthritis Initiative (OAI) is a prospective, observational study of people with or at higher risk for knee osteoarthritis. The Intermittent and Constant Osteoarthritis Pain (ICOAP) was assessed annually at 48-to-96-month OAI visits. Twenty-eight baseline sociodemographic, knee-specific, and health-related characteristics were assessed. Group-based dual-trajectory modeling identified pain experience patterns indicated by ICOAP intermittent and constant pain scores over 4 years. Multivariable multinomial logistic regression models determined baseline factors associated with membership in each dual-trajectory group. Four longitudinal pain experience patterns were identified (n = 3,584, mean age = 64.8 [standard deviation 9.0] years, BMI = 28.6 [5.0] kg/m2; 57.9% women). Group 1 (37.7%) had minimal intermittent and no constant pain; Group 2 (35.1%) had mild intermittent and no constant pain; Group 3 (18.5%) had mild intermittent and low-grade constant pain; and Group 4 (8.7%) had moderate intermittent and constant pain. Baseline widespread pain, knee stiffness, back pain, hip pain, ankle pain, obesity, depressive symptoms, more advanced radiographic disease, and analgesic use were each associated with an increased risk of membership in less favorable Groups 2, 3, and 4. These distinct courses of pain experience may be driven by different underlying pain mechanisms. The benchmarked ICOAP scores could be used to stratify patients and tailor management. Addressing and preventing the development of modifiable risks (eg, widespread pain and knee joint stiffness) may reduce the chance of belonging to unfavorable dual-trajectory groups. PERSPECTIVE: Concurrently tracking intermittent versus constant pain experience, group-based dual-trajectory modeling identified 4 distinct pain experience patterns over 4 years. The benchmarked ICOAP scores in these dual trajectories could aid in stratifying patients for tailored management strategies and intensity of care.

Association of Chronic Otitis Media with Sjogren's Syndrome: A Case-Control Study.

There is a paucity of large-scale population-based study whether patients with Sjögren's syndrome are at higher risk of chronic otitis media. This study aimed to investigate the association of chronic otitis media with Sjögren's syndrome by utilizing the representative dataset of the Taiwanese population. We identified 9473 patients with chronic otitis media as cases. We used propensity score matching to select 28,419 controls. We used multiple logistic regression analysis to examine the association of chronic otitis media with prior Sjögren's syndrome after adjusting for age, sex, monthly income category, geographic location and urbanization level of the patient's residence, allergic rhinitis, chronic rhinosinusitis and tonsillitis and adenoiditis. Chi-square tests showed a statistically significant difference in Sjögren's syndrome between patients with chronic otitis media and controls (4.89% vs. 2.93%, p < 0.001). In addition, we found patients with chronic otitis media were more likely to have Sjögren's syndrome (OR = 1.698, 95% CI = 1.509~1.910) relative to controls after adjusting for age, income, geographic location, residential urbanization level, allergic rhinitis, chronic rhinosinusitis and tonsillitis and adenoiditis. We also found that of the male patients, patients with chronic otitis media had a greater tendency to Sjögren's syndrome than controls (adjusted OR = 1.982, 95% CI = 1.584~2.481). Similarly, a statistically significant association between Sjögren's syndrome and chronic otitis media remains in female sampled patients (adjusted OR = 1.604, 95% CI = 1.396~1.842). We found that patients with Sjögren's syndrome were associated with the occurrence of chronic otitis media. It may guide physicians as they counsel patients with Sjögren's syndrome on the possibility of chronic otitis media occurrence.

Modifiable physical and behavioural factors associated with widespread pain in older adults with radiographic evidence of knee osteoarthritis.

OBJECTIVE: To identify modifiable physical and behavioural factors associated with widespread pain (WSP) in older adults with radiographic evidence of knee osteoarthritis (OA). METHODS: Cross-sectional initial visit data of participants with radiographic knee OA (Kellgren-Lawrence grade of ≥2) from the Osteoarthritis Initiative Study were analysed. WSP was defined as pain on both sides of the body, above and below the waist, and in the axial skeleton. Time (hrs/d) spent participating in sitting and moderate-strenuous physical activities were calculated from the Physical Activity Scale for the Elderly questionnaire. Physical function was quantified using gait speed and the chair stand test. Restless sleep was assessed using an item on the CES-D Scale. Logistic regression models were constructed to examine the strength of the associations between primary exposures and WSP in unadjusted and adjusted analyses. RESULTS: Among the 2637 participants (mean age 62.6 years, 58.6% female), 16.8% met the criteria for WSP. All primary measures of interest were related to WSP in unadjusted analyses. In adjusted multivariable analysis, slow gait speed (adjusted odds ratio [aOR] 1.43; 95% CI 1.01, 2.02), lower chair stand rate (aOR 0.98; 95% CI 0.97-0.99), and restless sleep (aOR 1.61; 95% CI 1.25-2.08) maintained significant associations with WSP. CONCLUSION: Poor sleep behaviours and low physical function capacity are associated with WSP in adults with radiographic knee OA. These findings highlight the importance of assessing sleep, physical function, and pain distribution in this population. Interventions to improve physical function and sleep behaviours should be investigated as potential strategies to mitigate WSP.

Ambulatory support moment contribution patterns and MRI-detected tibiofemoral and patellofemoral disease worsening in adults with knee osteoarthritis: A preliminary study.

We investigated whether baseline sagittal-plane ankle, knee, and hip contribution to the total support moment (TSM) are each associated with baseline-to-2-year tibiofemoral and patellofemoral tissue damage worsening in adults with knee osteoarthritis. Ambulatory lower-limb kinetics were captured and computed. TSM is the sum of ankle, knee, and hip extensor moments at each instant during gait. Ankle, knee, and hip contributions to TSM were computed as joint moments divided by TSM, expressed as percentages. Participants underwent MRI of both knees at baseline and 2 years later. Logistic regression models assessed associations of baseline ankle contribution to TSM with baseline-to-2-year cartilage damage and bone marrow lesion worsening, adjusted for age, sex, BMI, gait speed, disease severity, and pain. We used similar analytic approaches for knee and hip contributions to TSM. Sample included 391 knees from 204 persons (age[SD]: 64[10] years; 76.5% women). Greater ankle contribution may be associated with increased odds of tibiofemoral cartilage damage worsening (OR = 2.38; 95% CI: 1.02-5.57) and decreased odds of patellofemoral bone marrow lesion worsening (OR = 0.14; 95% CI: 0.03-0.73). The ORs for greater knee contribution were in the protective range for tibiofemoral compartment and in the deleterious range for patellofemoral. Greater hip contribution may be associated with increased odds of tibiofemoral worsening (OR = 2.71; 95% CI: 1.17-6.30). Greater ankle contribution to TSM may be associated with baseline-to-2-year tibiofemoral worsening, but patellofemoral tissue preservation. Conversely, greater knee contribution may be associated with patellofemoral worsening, but tibiofemoral preservation. Preliminary findings illustrate potential challenges in developing biomechanical interventions beneficial to both tibiofemoral and patellofemoral compartments.

Assessment of Mobile Health Applications for Management of Knee and/or Hip Osteoarthritis Using the Mobile Application Rating Scale.

BACKGROUND: Mobile health applications (apps) can help individuals with knee and/or hip osteoarthritis (OA) learn about, monitor, and manage their condition. These apps have not been formally evaluated. OBJECTIVE: The aim of this study was to evaluate the publicly available mobile health apps for individuals with knee and/or hip OA using a systematic review. METHODS: We searched the Apple App Store, Android Google Play, and Amazon Appstore using the terms "arthritis," "osteoarthritis," "hip OA," "knee OA," "hip," "knee," "rehabilitation," "rehab," and "physical therapy" in December of 2021. Applications that met the inclusion/exclusion criteria were reviewed using the Mobile Application Rating Scale (MARS; 29 items across 6 sections, each rated at 1-5). RESULTS: Among 1104 identified apps, 94 met the inclusion/exclusion criteria for MARS appraisal. Fourteen apps met the predetermined score thresholds for final summary. Of the 14 apps appraised, the total overall mean app score on the MARS ranged from 3.12 to 4.20 (mean, 3.51 ± 0.37). Although app features varied, common features were symptom tracking, exercise recommendations, education, goal setting, and improving well-being. Many apps allowed for sharing with health care providers and included some measures to protect privacy. Jointfully Osteoarthritis was the top-rated app in both the Apple App Store and Android Google Play. CONCLUSIONS: The majority of the apps we identified for knee and/or hip OA did not meet predetermined score thresholds for final summary. Many failed to provide comprehensive education and deliver management plans and lacked scientific testing. Future research should focus on apps that fit the needs of health care providers and patients including quality information, structured exercise programs tailored to individual needs, secure communication methods, and health information protection.

Reliability and validity of 2-dimensional video analysis for a running task: A systematic review.

OBJECTIVE: Evaluate the reliability and validity of 2-dimensional (2D) video-based motion analysis during running. METHODS: A systematic search of MEDLINE, Cochrane Library, EMBASE, CINAHL, PEDro, SPORTDiscus, and IEEE Xplore was conducted in March 2020 and updated in May 2021. We included studies assessing reliability and/or validity of 2D video-based motion analysis (gold standard: 3D motion analysis) during running. RESULTS: 11 studies (251 runners; mean age range: 18.7-37.0 years; 57.4% female; 63.7% injury-free) met inclusion criteria. Eight studies examined kinematics of the pelvis/hip, eight of the knee, and six of the ankle/foot. Low-to-moderate risk of bias was present in all studies. Heterogeneous study designs, measurement methods, and statistical approaches across studies precluded statistical synthesis. Intrarater reliability [Interclass correlation coefficient (ICC) range: 0.56-1.00; kappa range: 0.49-0.81] was better than interrater reliability (ICC range: 0.31-1.00; kappa range 0.00-0.85). ICC values for validity were poor to good (0.06-0.89). One study examining foot strike pattern found good to excellent validity (using Gwet AC statistics) when movement kinematics were categorized. CONCLUSIONS: A wide range of methods were reported in 2D video-based motion analysis of joint angular kinematics during a running task. Further research to develop standardized 2D video-based motion analysis for running is needed. Categorizing movement patterns may be more useful than angularly quantifying joint kinematics.

What do we actually know about a common cause of plantar heel pain? A scoping review of heel fat pad syndrome.

BACKGROUND: The heel fat pad is an important structure of the foot as it functions as a cushion to absorb shock and distribute plantar force during ambulation. Clinical practice guidelines or decision support platforms emphasize that heel fat pad syndrome (HFPS) is a distinct pathology contributing to plantar heel pain. We aimed to identify and synthesize the prevalence, etiology and diagnostic criteria, and conservative management of HFPS. METHODS: A comprehensive search was conducted in May 2021 and updated in April 2022, using MEDLINE, Scopus, Cinahl, EMBASE, Cochrane Library, SPORTDiscus, and PEDro and ClinicalTrials.gov and the World Health Organization's International Clinical Trials Registry Platform (ICTRP) for pertinent registrations. We included all study types and designs describing the prevalence; etiology and diagnostic criteria; and non-pharmacological, non-surgical interventions for HFPS. RESULTS: We found a small body of original research for HFPS (n = 7). Many excluded full-text articles were expert-opinion articles or studies of heel fat pad in participants with plantar fasciitis/fasciopathy or unspecified heel pain. HFPS may be the second leading cause of plantar heel pain, based on two studies. A number of differentiating pain characteristics and behaviors may aid in diagnosing HFPS vs. plantar fasciopathy. Thinning heel fat pad confirmed by ultrasonography may provide imaging corroboration. Randomized controlled trials assessing the efficacy of viscoelastic heel cups or arch taping for managing HFPS do not exist. CONCLUSIONS: The research literature for HFPS is sparse and sometimes lacking scientific rigor. We have identified a substantial knowledge gap for this condition, frequent inattention to distinguishing HFPS from plantar fasciopathy when describing plantar heel pain, and an absence of robust clinical trials to support the commonly recommended conservative management of HFPS.

Knee Confidence Trajectories Over Eight Years and Factors Associated With Poor Trajectories in Individuals With or at Risk for Knee Osteoarthritis.

OBJECTIVE: To identify distinct trajectories of lack of knee confidence over an 8-year follow-up period and to examine baseline factors associated with poor trajectories in individuals with or at risk for knee osteoarthritis (OA). METHODS: The Osteoarthritis Initiative is a prospective cohort study of individuals with or at high risk for knee OA. Confidence in the knees was assessed within the Knee Injury and Osteoarthritis Outcome Score instrument querying how much the individual is troubled by lack of confidence in his/her knee(s), rated as not-at-all (score = 0), mildly (score = 1), moderately (score = 2), severely (score = 3), and extremely (score = 4) troubled, reported annually from baseline to 96 months. Lack of knee confidence was defined as a score of ≥2. We used latent class models to identify subgroups that share similar underlying knee confidence trajectories over an 8-year period and multivariable multinomial logistic regression models to examine baseline factors associated with poor trajectories. RESULTS: Among 4,515 participants (mean ± SD age 61.2 ± 9.2 years, mean ± SD BMI 28.6 ± 4.8 kg/m2 ; 2,640 [58.5%] women), 4 distinct knee confidence trajectories were identified: persistently good (65.6%); declining (9.1%); poor, improving (13.9%); and persistently poor (11.4%). Baseline predictors associated with persistently poor confidence (reference: persistently good) were younger age, male sex, higher body mass index (BMI), depressive symptoms, more advanced radiographic disease, worse knee pain, weaker knee extensors, history of knee injury and surgery, and reported hip and/or ankle pain. CONCLUSION: Findings suggest the dynamic nature of self-reported knee confidence and that addressing modifiable factors (e.g., BMI, knee strength, depressive symptoms, and lower extremity pain) may improve its long-term course.

Patterns of video-based motion analysis use among sports physical therapists.

OBJECTIVE: Examine video-based motion analysis (VBMA) use among sports physical therapists. DESIGN: Cross-sectional observation. SETTING: Survey, online-platform. PARTICIPANTS: American Academy of Sports Physical Therapy members (n = 261). MAIN OUTCOME MEASURES: VBMA use frequency, reasons for use, facilitators/barriers, tools used, factors associated with use. RESULTS: 194 (74.3%) used VBMA but 163 (84%) use it for ≤ 25% of their caseload. Most (57.7%) used their personal device to capture VBMA. Commonly cited reasons for use were movement analysis (93.8%) and patient education (87.6%). Barriers to use included time (30.7%), unfamiliarity with device/equipment (19.2%), and lack of device/equipment (18.4%). Younger age, advanced training, and greater time spent with return patients were each associated with use. For every 5-year increase of age, there was a 12% reduced likelihood of VBMA use (OR = 0.88; 95% CI = 0.77-1.00). Board-certified sports clinical specialists were more likely to use vs. those without additional certifications/degrees (OR = 3.27; 95% CI = 1.33-8.02). Spending 30-59 (vs. <30) minutes with return patients increased the odds of use (ORs range: 2.71 to 3.85). CONCLUSION: Most respondents used VBMA, albeit infrequently. Those younger, with advanced training, and spending ≥30 min with return patients were more likely to use VBMA. Future research should investigate whether VBMA use enhances patient outcomes.

Sleep Disturbance Trajectories in Osteoarthritis.

BACKGROUND/OBJECTIVE: Sleep disturbance is common among adults with osteoarthritis (OA), but little is known about patterns over time. In this cohort study, we identified restless sleep trajectories and associated factors in adults with or at high risk for knee OA. METHODS: Longitudinal (2004-2014) restless sleep (≥3 nights/week) annual reports over 8 years from 4359 Osteoarthritis Initiative participants were analyzed. Group-based trajectory modeling identified heterogeneous temporal patterns. Logistic regression identified baseline health and behavioral predictors of trajectory membership. RESULTS: Four restless sleep trajectory groups were identified: good (69.7%, persistently low restless sleep probabilities), worsening (9.1%), improving (11.7%), and poor (9.5%, persistently high). Among 2 groups initially having low restless sleep prevalence, the worsening trajectory group had an increased likelihood of baseline cardiovascular disease (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.01-2.33), pulmonary disease (OR, 1.48; 95% CI, 1.07-2.05), lower physical activity (OR, 1.29; 95% CI, 1.03-1.61), knee pain (OR, 1.04; 95% CI, 1.00-1.07), depressive symptoms (OR, 1.03; 95% CI, 1.01-1.06), and a decreased likelihood of better mental health (OR, 0.97; 95% CI, 0.95-0.98) at baseline. Among 2 groups initially having high restless sleep prevalence, the poor group had an increased likelihood of baseline depressive symptoms (OR, 1.03; 95% CI, 1.00-1.05). CONCLUSIONS: Four trajectories of restless sleep over 8 years were identified using data collected from over 4000 older adults aged 45 to 79 years with or at higher risk for knee OA. The presence of depressive symptoms, less physical activity, knee pain, poor mental health, cardiovascular disease, or pulmonary disease was each associated with unfavorable trajectories.

Plane Dependent Subject-Specific Neuromuscular Training for Knee Rehabilitation.

Knee injuries at risk of post-traumatic knee osteoarthritis (PTOA) and knee osteoarthritis (OA) are closely associated with knee transverse plane and/or frontal plane instability and excessive loading. However, most existing training and rehabilitation devices involve mainly movements in the sagittal plane. An offaxis elliptical training system was developed to train and evaluate neuromuscular control about the off-axes (knee varus/valgus and tibial rotation) as well as the main flexion/extension axis (sagittal movements). Effects of the offaxis elliptical training system in improving either transverse or frontal neuromuscular control depending on subjects' need (Pivoting group, Sliding group) were demonstrated through 6-week subject-specific neuromuscular training in subjects with knee injuries at risk of PTOA or medial knee osteoarthritis. The combined pivoting and sliding group, named as offxis group demonstrated significant reduction in pivoting instability, minimum pivoting angle, and sliding instability. The pivoting group showed more reduction in pivoting instability, maximum and minimum pivoting angle than the sliding group. On the other hand, the sliding group showed more reduction in sliding instability, maximum and minimum sliding distance than the pivoting group. Based on these findings, the offaxis elliptical trainer system can potentially be used as a therapeutic and research tool to train human subjects for plane-dependent improvements in their neuromuscular control during functional weight-bearing stepping movements.

Video-Based Motion Analysis Use: A National Survey of Orthopedic Physical Therapists.

OBJECTIVES: Motion analysis is performed by physical therapists to assess and improve movement. Two-dimensional video-based motion analysis (VBMA) is available for smartphones/tablets and requires little to no equipment or cost. Research on VBMA use in clinical practice is limited. The purpose of this study was to examine the current use of VBMA in orthopedic physical therapist practice. METHODS: Members of the Academy of Orthopaedic Physical Therapy completed an online survey. Questions examined frequency of VBMA use, reasons for use, facilitators/barriers, device/apps used, practice patterns, other certificates/degrees, and demographic information. RESULTS: Among the final analysis sample of 477 respondents, 228 (47.8%) use VBMA. Of 228 VBMA users, 91.2% reported using it for ≤25% of their caseload, and 57.9% reported using their personal device to capture movement. Reasons for using VBMA included visual feedback for patient education (91.7%), analysis of movement (91.2%), and assessment of progress (51.8%). Barriers to use included lack of device/equipment (48.8%), lack of space (48.6%), and time restraint (32.1%). Those with ≤20 years of clinical experience (odds ratio [OR] = 1.83, 95% CI = 1.21-2.76), residency training (OR = 2.49, 95% CI = 1.14-5.43), and fellowship training (OR = 2.97, 95% CI = 1.32-6.66), and those from the West region of the United States (OR = 1.66, 95% CI = 1.07-2.56) were more likely to use VBMA. CONCLUSIONS: More than 50% of surveyed orthopedic physical therapists do not use VBMA in clinical practice. Future research should be directed toward assessing reliability and validity of VBMA use by smartphones, tablets, and apps and examining whether VBMA use enhances treatment outcomes. Data security, patient confidentiality, and integration into the electronic medical record should be addressed. IMPACT: This study is the first to our knowledge to describe the use of VBMA in orthopedic physical therapist practice in the United States. It is the first step in understanding how VBMA is used and might be used to enhance clinical assessment and treatment outcomes.

Association of Long-term Strenuous Physical Activity and Extensive Sitting With Incident Radiographic Knee Osteoarthritis.

Importance: Persons with knee symptoms recognize the health benefits of engaging in physical activity, but uncertainty persists about whether regular strenuous physical activity or exercise can accelerate tissue damage. A sedentary lifestyle of inactivity or underloading may also be associated with deleterious joint health. Objective: To establish whether long-term strenuous physical activity participation and extensive sitting behavior are each associated with increased risk of developing radiographic knee osteoarthritis (KOA) in individuals at high risk for the disease. Design, Setting, and Participants: This cohort study analyzed data from the Osteoarthritis Initiative, a prospective longitudinal cohort study of men and women with or at an increased risk of developing symptomatic, radiographic KOA. Community-dwelling adults were recruited from 4 US sites (Baltimore, Maryland; Columbus, Ohio; Pittsburgh, Pennsylvania; and Pawtucket, Rhode Island) and were followed up for up to 10 years. Individuals were included if they had a baseline Kellgren and Lawrence grade of 0 in both knees and completed a PASE (Physical Activity Scale for the Elderly) questionnaire at baseline and at least 2 follow-up visits over an 8-year interval. Data analyses were conducted from May 2018 to November 2018. Exposures: Baseline to 8-year trajectories of strenuous physical activity participation and extensive sitting behavior were identified using group-based trajectory models. Main Outcomes and Measures: Incident radiographic KOA, defined as Kellgren and Lawrence grade 2 or higher in either knee by the 10-year follow-up visit. Results: A total of 1194 participants were included in the sample (697 women [58.4%]), with a baseline mean (SD) age of 58.4 (8.9) years and mean body mass index (BMI) of 26.8 (4.5). Four distinct trajectories of weekly hours spent in strenuous physical activities and 3 distinct trajectories of extensive sitting were identified. Long-term engagement in low-to-moderate physical activities (adjusted odds ratio [OR], 0.69; 95% CI, 0.48-1.01) or any strenuous physical activities (adjusted OR, 0.75; 95% CI, 0.53-1.07) was not associated with 10-year incident radiographic KOA. Persistent extensive sitting was not associated with incident KOA. Despite relatively mild symptoms and high function in this early-stage sample, 594 participants (49.7%) did not engage in any strenuous physical activities (ie, 0 h/wk) across 8 years, and 507 (42.5%) engaged in persistent moderate-to-high frequency of extensive sitting. Older age, higher BMI, more severe knee pain, non-college graduate educational level, weaker quadriceps, and depression were each associated with a persistent lack of engagement in strenuous physical activities. Conclusions and Relevance: Results from this study appeared to show no association between long-term strenuous physical activity participation and incident radiographic KOA. The findings raise the possibility of a protective association between incident KOA and a low-to-moderate level of strenuous physical activities.

Association between Pre-Intervention Physical Activity Level and Treatment Response to Exercise Therapy in Persons with Knee Osteoarthritis - An Exploratory Study.

OBJECTIVE: Examine whether pre-intervention physical activity (PA) level is associated with achieving a positive treatment response of pain and/or function improvement after a 12-week exercise intervention in participants with knee osteoarthritis (OA). METHODS: We performed a secondary analysis of a randomized, single-blind comparative effectiveness trial showing similar treatment effects between Tai Chi mind-body exercise and standard physical therapy intervention for knee OA. Baseline PA was assessed by Community Healthy Activities Model Program for Seniors (CHAMPS) Questionnaire and, in a subsample, by tri-axial accelerometers. OMERACT-OARSI dichotomous responder criteria was used for clinically meaningful improvement at follow-up. Associations between baseline self-reported PA by CHAMPS and outcomes of responders vs. non-responders (reference group) were assessed using logistic regressions, adjusting for demographic covariates. We compared objectively-measured PA by accelerometry between responders vs. non-responders using Wilcoxon tests. RESULTS: Our sample consisted of 166 participants with knee OA who completed both baseline and 12-week post-intervention evaluations: mean age 60.7 year (SD 10.5), BMI 32.4 kg/m2 (6.9), 119 (72%) women, and 138 (83%) OMERACT-OARSI responders. Neither time spent in total PA (OR 1.00; 95% CI 0.96, 1.03) nor time in moderate-to-vigorous (MV) PA (OR 1.01; 95% CI 0.93, 1.09) at pre-intervention were associated with being a responder. Similar findings were observed in 42 accelerometry sub-cohort participants. CONCLUSION: Pre-intervention PA level (subjective report or objective measurement) was not associated with whether an individual will achieve favorable treatment outcomes after a 12-week exercise intervention, suggesting that regardless of pre-intervention PA level, individuals will likely benefit from structured exercise interventions.

Development and validation of risk stratification trees for incident slow gait speed in persons at high risk for knee osteoarthritis.

OBJECTIVES: Disability prevention strategies are more achievable before osteoarthritis disease drives impairment. It is critical to identify high-risk groups, for strategy implementation and trial eligibility. An established measure, gait speed is associated with disability and mortality. We sought to develop and validate risk stratification trees for incident slow gait in persons at high risk for knee osteoarthritis, feasible in community and clinical settings. METHODS: Osteoarthritis Initiative (derivation cohort) and Multicenter Osteoarthritis Study (validation cohort) participants at high risk for knee osteoarthritis were included. Outcome was incident slow gait over up to 10-year follow-up. Derivation cohort classification and regression tree analysis identified predictors from easily assessed variables and developed risk stratification models, then applied to the validation cohort. Logistic regression compared risk group predictive values; area under the receiver operating characteristic curves (AUCs) summarised discrimination ability. RESULTS: 1870 (derivation) and 1279 (validation) persons were included. The most parsimonious tree identified three risk groups, from stratification based on age and WOMAC Function. A 7-risk-group tree also included education, strenuous sport/recreational activity, obesity and depressive symptoms; outcome occurred in 11%, varying 0%-29 % (derivation) and 2%-23 % (validation) depending on risk group. AUCs were comparable in the two cohorts (7-risk-group tree, 0.75, 95% CI 0.72 to 0.78 (derivation); 0.72, 95% CI 0.68 to 0.76 (validation)). CONCLUSIONS: In persons at high risk for knee osteoarthritis, easily acquired data can be used to identify those at high risk of incident functional impairment. Outcome risk varied greatly depending on tree-based risk group membership. These trees can inform individual awareness of risk for impaired function and define eligibility for prevention trials.