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1.
BMJ Open ; 10(1): e033230, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31900273

RESUMO

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.

2.
Inorg Chem ; 59(1): 705-716, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31860297

RESUMO

A series of seven molybdenum(III) complexes with the general formula of [Mo(diimine)Cl4]- were synthesized and characterized by X-ray diffraction, IR, cyclic voltammetry (CV), and UV-vis. The complexes were discovered to be highly solvatochromic, showing shifts in λmax between ∼120 and 170 nm in solvents ranging from water to acetone. Varying the substituents on the diimine ligand influenced the absorption energy such that electron-withdrawing groups induced a red shift while electron-donating groups exhibited the opposite effect. The complexes were surprisingly stable in both acidic and basic solutions, and in the case where carboxylic acid substituents were present, additional shifts in the absorption maxima were observed, corresponding to the state of protonation of these groups. Both the MoIV/III and MoIII/II redox couples were observed in CV experiments and were complemented with density functional theory (DFT) calculations.

3.
ACR Open Rheumatol ; 1(2): 104-112, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31763622

RESUMO

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.

4.
Ann Rheum Dis ; 78(10): 1412-1419, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31243017

RESUMO

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.

5.
Arthritis Care Res (Hoboken) ; 71(2): 198-206, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30238649

RESUMO

OBJECTIVE: The benefits of physical activity among persons with or at higher risk for knee osteoarthritis are well established. However, activity levels in this population are low, in part due to concern that activity will damage the knee joint. We hypothesized that sedentary and moderate-vigorous physical activity are each associated with greater risk of radiographic worsening of knee OA. METHODS: In Osteoarthritis Initiative participants with or at higher risk for knee OA enrolled in an accelerometer substudy at 48 months (study baseline), physical activity was measured by a uniaxial accelerometer (ActiGraph GT1M). Radiographic progression was defined as any 48 month to 96 month worsening of Kellgren/Lawrence (K/L) grade scores. All analyses were knee-level; we used multivariable logistic regression with generalized estimating equations, adjusting for key covariates. RESULTS: Of the 1,206 participants, 631 (52%) were female, the mean ± SD age was 64 ± 9 years, and mean ± SD body mass index (BMI) was 28 ± 5. The mean ± SD average daily sedentary activity was 602 ± 86 minutes, average daily light activity was 284 ± 75 minutes, and average daily moderate-vigorous activity was 20 ± 20 minutes. In 1,978 knees, 267 (14%) had worsening of K/L grade scores. In the multivariable model, age, sex, BMI, and pain, were associated with K/L grade worsening, but neither sedentary activity (adjusted odds ratio [OR] 0.99 [95% confidence interval (95% CI) 0.97-1.01]) nor moderate-vigorous activity (adjusted OR 1.00 [95% CI 0.91-1.09]) were associated with K/L grade worsening. CONCLUSION: In persons with or at higher risk for knee OA, age, sex, BMI, and pain, but not objectively measured average daily minutes of sedentary or moderate-vigorous activity, were associated with subsequent worsening of K/L grade. Whether findings differ in persons with more severe knee OA and/or engaged more frequently in moderate-vigorous activity should be examined in future studies.


Assuntos
Progressão da Doença , Exercício/fisiologia , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/fisiopatologia , Acelerometria/métodos , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
6.
J Orthop Sports Phys Ther ; 48(4): 343, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29607767

RESUMO

A 23-year-old woman was referred to physical therapy by her primary care physician for a 4-week history of right groin pain that had progressively worsened while training for a half-marathon. Before the physical therapy referral, the primary care physician ordered radiography of the right hip, which was unremarkable for fracture. Following examination, the physical therapist suspected osseous or soft tissue abnormality and requested that the primary care physician order magnetic resonance imaging without contrast, which revealed a femoral neck stress fracture. J Orthop Sports Phys Ther 2018;48(4):343. doi:10.2519/jospt.2018.7479.


Assuntos
Artralgia/diagnóstico por imagem , Terapia por Exercício/métodos , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/reabilitação , Fraturas de Estresse/diagnóstico por imagem , Fraturas de Estresse/reabilitação , Imagem por Ressonância Magnética/métodos , Corrida/lesões , Competência Clínica , Diagnóstico Diferencial , Feminino , Humanos , Adulto Jovem
7.
Semin Arthritis Rheum ; 47(5): 683-688, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29103557

RESUMO

INTRODUCTION: While OA literature indicates greater pain is related to less time being physically active, it is not known if time curtailment occurs primarily for moderate intensity activities or for light activities or in both. We examine the cross-sectional association of knee pain with physical activity using data from 1874 Osteoarthritis Initiative participants. METHODS: Knee pain characteristics of constant and intermittent pain were each scored by the Intermittent and Constant Osteoarthritis Pain instrument and categorized into four pain levels (no pain, intermittent pain below and above median level, and constant pain). The relationships between knee pain levels and objectively measured physical activity (average weekly moderate or light intensity minutes) were assessed by quantile regression adjusted for socio-demographics and health factors. RESULTS: Knee pain levels had a strong negative relationship with moderate intensity physical activities (p-value for trend =0.029). Compared to the no pain group, persons with more severe knee pain, particularly those reporting higher intermittent or constant pain spent less time in moderate activity. In contrast, there was no notable trend related to pain with time spent in light intensity activity. These patterns remained when restricted to persons with clinical evidence (symptoms and/or radiographic) of knee OA and among persons not using medications for knee symptoms. CONCLUSION: Greater knee pain levels were strongly related to less moderate intensity activity time, but not time spent in light intensity physical activity. This relationship suggests that light activity may be a more acceptable way to increase physical activity than moderate activity for people with symptomatic knee pain.


Assuntos
Exercício/fisiologia , Articulação do Joelho/fisiopatologia , Osteoartrite do Joelho/fisiopatologia , Dor/diagnóstico , Atividades Cotidianas , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/fisiopatologia , Medição da Dor
8.
J Orthop Res ; 36(1): 397-404, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28742277

RESUMO

The peak external knee adduction moment (pKAM), KAM impulse, and peak knee flexion moment (pKFM) during gait are important loading variables in medial tibiofemoral osteoarthritis. We evaluated the effects of gait modification, using real-time pKAM visual feedback, on pKAM, KAM impulse, and pKFM; and whether participants could maintain the KAM-reducing gait after feedback removal. Eleven healthy individuals performed a series of walking trials on a split-belt instrumented treadmill under four conditions of Baseline, Feedback, No Feedback Early, and No Feedback Late. Guided by real-time feedback of pKAM, they modified their gait patterns to lower pKAM by 20%. Three-dimensional joint kinematics/kinetics during each walking condition were recorded by a 12-camera motion capture system and the instrumented treadmill. Change in each knee loading parameter from baseline across conditions was assessed using one-way repeated-measures analysis-of-variances. In the feedback limb, successful 20% reductions from baseline in pKAM and KAM impulse were achieved across all three conditions. There was a trend for concomitant pKFM increases, partially attenuating the beneficial effects of pKAM reduction. A carry-over effect of KAM reduction in the non-feedback limb was noted. The altered gait patterns were participant-specific and multi-modal; each participant reported a combination of two to three gait modification strategies used for pKAM reduction. Toe-in and medial foot contact were the most reported strategies. The findings support the real-time pKAM visual feedback as a tool for individualized gait modification to reduce knee load. Future studies to evaluate its effectiveness in persons with or at risk for medial knee osteoarthritis is warranted. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:397-404, 2018.


Assuntos
Marcha/fisiologia , Articulação do Joelho/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Osteoartrite do Joelho/fisiopatologia , Suporte de Carga
9.
Arthritis Rheumatol ; 69(11): 2136-2143, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28772066

RESUMO

OBJECTIVE: To determine if varus thrust, a bowing out of the knee during gait (i.e., the first appearance or worsening of varus alignment during stance), is associated with incident and progressive knee osteoarthritis (OA), we undertook an Osteoarthritis Initiative ancillary study. We further considered hypothesized associations adjusted for static alignment, anticipating some attenuation. METHODS: Gait was observed for the presence of thrust by 1 of 2-3 examiners per study site at 4 sites. In eligible knees, incident OA was defined as subsequent incident Kellgren/Lawrence grade ≥2, whole- and partial-grade medial joint space narrowing (JSN), and annualized loss of joint space width (JSW); progression was defined as medial JSN and JSW loss. Outcome measures were assessed for up to 7 years of follow-up. Analyses were knee-level, using multivariable logistic and linear regression with generalized estimating equations to account for between-limb correlation. RESULTS: The incident OA sample included 4,187 knees (2,610 persons); the progression sample included 3,421 knees (2,284 persons). In knees with OA, thrust was associated with progression as assessed by each outcome measure, with adjustment for age, sex, body mass index, and pain on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. In knees without OA, varus thrust was not associated with incident OA or other outcomes. After adjustment for alignment, the thrust-progression association was attenuated, but an independent association persisted for partial-grade JSN and JSW loss outcome models. WOMAC pain and alignment were consistently associated with all outcome measures. Within the stratum of varus knees, thrust was associated with an increased risk of progression. CONCLUSION: Varus thrust visualized during gait is associated with knee OA progression and should be a target of intervention development.


Assuntos
Marcha/fisiologia , Genu Varum/epidemiologia , Osteoartrite do Joelho/epidemiologia , Idoso , Fenômenos Biomecânicos , Progressão da Doença , Feminino , Genu Varum/fisiopatologia , Humanos , Incidência , Articulação do Joelho/diagnóstico por imagem , Modelos Lineares , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Osteoartrite do Joelho/diagnóstico por imagem , Estudos Prospectivos , Radiografia
10.
Clin J Sport Med ; 27(5): 438-443, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28036322

RESUMO

OBJECTIVE: To investigate the effects of femoral rotational taping on task performance, dynamic postural control, and pain during the Star Excursion Balance Test (SEBT) in patients with patellofemoral pain (PFP) compared to healthy controls. DESIGN: Case-control study, pretest-posttest. SETTING: Laboratory. PARTICIPANTS: Twenty-four female participants (16 with PFP, 8 controls). INTERVENTIONS: Participants in both the PFP and control groups performed SEBT with no taping, sham taping, and femoral rotational taping. MAIN OUTCOME MEASURES: The maximum anterior excursion distance, 3-dimensional hip and knee kinematics of the stance leg, and pain score (VAS) during SEBT were recorded. The coefficients of variance (CV) of kinematic data gathered from electromagnetic sensors on pelvis and femur were calculated to represent segmental stability. RESULTS: When performing the SEBT in the anterior direction, application of femoral rotational taping increased maximum excursion distance (65.57% vs 66.15% leg length, P = 0.027), decreased hip adduction excursion (47.6 vs 32.1 degrees, P = 0.010), and pain (3.34 vs 2.38, P = 0.040) in the PFP group. Femoral rotational taping also improved the medial-lateral (7.1 vs 4.6, P = 0.015) and proximal-distal stability (7.5 vs 4.5, P = 0.020) of the pelvis, and medial-lateral stability (7.2 vs 6.1, P = 0.009) of the femur. CONCLUSIONS: The results support the use of femoral rotational taping for improving dynamic postural control and reducing pain during SEBT. CLINICAL RELEVANCE: Femoral rotational taping could be used in the management of young female patients with PFP.


Assuntos
Fita Atlética , Articulação do Joelho/fisiopatologia , Síndrome da Dor Patelofemoral/terapia , Equilíbrio Postural , Adulto , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Fêmur , Humanos , Adulto Jovem
11.
Arthritis Care Res (Hoboken) ; 67(8): 1095-102, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25732594

RESUMO

OBJECTIVE: Manifestations of instability in knee osteoarthritis (OA) include low overall knee confidence, low confidence that the knees will not buckle, buckling, and excessive motion during gait. Confidence and buckling may particularly influence activity choices, contributing to events leading to disability. Buckling is more likely to affect advanced than basic functional tasks. In this prospective longitudinal study, we tested the hypothesis that overall knee confidence, buckling confidence, buckling, and frontal plane motion during gait are associated with advanced 2-year function outcomes in persons with knee OA. METHODS: Persons with knee OA were queried about overall knee confidence (higher score = worse confidence), buckling confidence, and knee buckling, and underwent quantitative gait analysis to quantify varus-valgus excursion and angular velocity. Physical function was assessed using the Late-Life Function and Disability Instrument Basic and Advanced Lower Extremity Domain scores. Logistic regression was used to evaluate the relationship between baseline instability measures and baseline-to-2-year function outcome, adjusting for potential confounders. RESULTS: The sample was comprised of 212 persons (mean age 64.6 years, 76.9% women). Buckling was significantly associated with poor advanced function outcome (adjusted odds ratio [OR] 2.08, 95% confidence interval [95% CI] 1.03-4.20) but not basic function outcome. Overall knee confidence was significantly associated with advanced outcome (adjusted OR 1.65, 95% CI 1.01-2.70), while associations between buckling confidence and both outcomes approached significance. Neither varus-valgus excursion nor angular velocity during gait was associated with either outcome. CONCLUSION: Knee buckling and low knee confidence were each associated with poor 2-year advanced function outcomes. Current treatment does not address these modifiable factors; interventions to address them may improve outcome in knee OA.


Assuntos
Instabilidade Articular/fisiopatologia , Instabilidade Articular/psicologia , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/psicologia , Idoso , Feminino , Marcha/fisiologia , Humanos , Instabilidade Articular/complicações , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações , Estudos Prospectivos
12.
J Sci Med Sport ; 18(4): 388-93, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25127530

RESUMO

OBJECTIVES: To explore the hip and knee joint kinematics as well as muscle activation between participants with patellofemoral pain syndrome (PFPS) and controls, and to investigate the immediate effect of proximal femoral rotational taping on pain, joint kinematics, and muscle activation during single-leg squat (SLS). DESIGN: Cross-sectional study. METHODS: Sixteen female participants with PFPS, and eight healthy female controls participated. Three-dimensional hip and patellar kinematics measured by electromagnetic tracking system, hip (gluteus maximus and gluteus medius) and thigh (rectus femoris) muscle activation measured by EMG, and subjective report of pain were recorded during SLS in three randomized conditions of no tape, sham taping, and femoral rotational taping with kinesiotape. RESULTS: Without taping, compared with controls, PFPS group had increased hip adduction angle (23.5±11.3° vs. 15.8±7.3°) during SLS. Additionally, PFPS group exhibited lesser rectus femoris activity during the initial 0-15° of SLS. Application of both femoral rotational and sham tapes reduced pain for PFPS group. Compared with no tape or sham tape, femoral rotational tape significantly shifted the patella into more posterior (1.59±0.83cm in no tape vs. 1.54±0.87cm in sham tape vs. 1.32±0.72cm in femoral rotational tape) and distal (-2.49±0.95cm vs. -2.64±0.80cm vs. -3.11±0.77cm) positions in the PFPS group. CONCLUSIONS: Femoral rotational taping could alter patellofemoral kinematics and decrease pain in treatment of young female participants with PFPS.


Assuntos
Articulação do Quadril/fisiopatologia , Articulação do Joelho/fisiopatologia , Síndrome da Dor Patelofemoral/fisiopatologia , Síndrome da Dor Patelofemoral/terapia , Modalidades de Fisioterapia , Adulto , Fita Atlética , Fenômenos Biomecânicos , Estudos de Casos e Controles , Estudos Transversais , Teste de Esforço , Feminino , Humanos , Extremidade Inferior/fisiopatologia , Contração Muscular , Medição da Dor , Músculo Quadríceps/fisiopatologia , Adulto Jovem
13.
Arthritis Care Res (Hoboken) ; 66(12): 1828-35, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25047144

RESUMO

OBJECTIVE: Few strategies to improve pain outcome in knee osteoarthritis (OA) exist in part because how best to evaluate pain over the long term is unclear. Our objectives were to determine the frequency of a good pain experience outcome based on previously formulated OA pain stages and test the hypothesis that less depression and pain catastrophizing and greater self-efficacy and social support are each associated with greater likelihood of a good outcome. METHODS: Study participants, all with knee OA, reported pain stage at baseline and 2 years. Baseline assessments utilized the Geriatric Depression Scale, Pain Catastrophizing Scale, Arthritis Self-Efficacy Scale, and Medical Outcomes Study social support survey. Using pain experience stages, good outcome was defined as persistence in or movement to no pain or stage 1 (predictable pain, known trigger) at 2 years. A multivariable logistic regression model was developed to identify independent predictors of a good outcome. RESULTS: Of 212 participants, 136 (64%) had a good pain outcome and 76 (36%) a poor pain outcome. In multivariable analysis, higher self-efficacy was associated with a significantly higher likelihood of good outcome (adjusted odds ratio [OR] 1.14 [95% confidence interval (95% CI) 1.04-1.24]); higher pain catastrophizing was associated with a significantly lower likelihood of good outcome (adjusted OR 0.88 [95% CI 0.83-0.94]). CONCLUSION: This stage-based measure provides a meaningful and interpretable means to assess pain outcome in knee OA. The odds of a good 2-year outcome in knee OA were lower in persons with greater pain catastrophizing and higher in persons with greater self-efficacy. Targeting these factors may help to improve pain outcome in knee OA.


Assuntos
Catastrofização/psicologia , Osteoartrite do Joelho/psicologia , Dor/psicologia , Autoeficácia , Apoio Social , Idoso , Analgésicos/uso terapêutico , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações , Osteoartrite do Joelho/tratamento farmacológico , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor , Índice de Gravidade de Doença , Resultado do Tratamento
14.
Med Sci Sports Exerc ; 46(7): 1400-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24389517

RESUMO

PURPOSE: Pivoting neuromuscular control and proprioceptive acuity may play an important role in anterior cruciate ligament injuries. The goal of this study was to investigate whether pivoting off-axis intensity adjustable neuromuscular control training (POINT) could improve pivoting neuromuscular control, proprioceptive acuity, and functional performance. METHODS: Among 41 subjects, 21 subjects participated in 18 sessions of POINT (three sessions per week for 6 wk), and 20 subjects served as controls who did their regular workout. Both groups received pre-, mid-, and postintervention evaluations. Propensity score analysis with multivariable regression adjustment was used to investigate the effect of training on pivoting neuromuscular control (pivoting instability, leg pivoting stiffness, maximum internal, and external pivoting angles), proprioceptive acuity, and functional performance in both groups. RESULTS: Compared with the control group, the training group significantly improved pivoting neuromuscular control as reduced pivoting instability, reduced maximum internal and external pivoting angles, increased leg pivoting stiffness, and decreased entropy of time to peak EMG in the gluteus maximus and lateral gastrocnemius under pivoting perturbations. Furthermore, the training group enhanced weight-bearing proprioceptive acuity and improved the single leg hop distance. CONCLUSION: Improvement of pivoting neuromuscular control in functional weight-bearing activities and task performances after POINT may help develop lower limb injury prevention and rehabilitation methods to reduce anterior cruciate ligament and other musculoskeletal injuries associated with pivoting sports.


Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos do Joelho/prevenção & controle , Destreza Motora/fisiologia , Músculo Esquelético/fisiologia , Educação Física e Treinamento/métodos , Propriocepção/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , Masculino , Músculo Esquelético/inervação , Suporte de Carga , Adulto Jovem
15.
J Biomech ; 47(2): 360-6, 2014 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-24321442

RESUMO

Impaired proprioception and poor muscular stabilization in the frontal plane may lead to knee instability during functional activities, a common complaint in persons with knee osteoarthritis (KOA). Understanding these frontal plane neuromechanical properties in KOA will help elucidate the factors contributing to knee instability and aid in the development of targeted intervention strategies. The objectives of the study were to compare knee varus-valgus proprioception, isometric muscle strength, and active muscular contribution to stability between persons with medial KOA and healthy controls. We evaluated knee frontal plane neuromechanical parameters in 14 participants with medial KOA and 14 age- and gender-matched controls, using a joint driving device (JDD) with a customized motor and a 6-axis force sensor. Analysis of covariance with BMI as a covariate was used to test the differences in varus-valgus neuromechanical parameters between these two groups. The KOA group had impaired varus proprioception acuity (1.08±0.59° vs. 0.69±0.49°, p<0.05), decreased normalized varus muscle strength (1.31±0.75% vs. 1.79±0.84% body weight, p<0.05), a trend toward decreased valgus strength (1.29±0.67% vs. 1.88±0.99%, p=0.054), and impaired ability to actively stabilize the knee in the frontal plane during external perturbation (4.67±2.86 vs. 8.26±5.95 Nm/degree, p<0.05). The knee frontal plane sensorimotor control system is compromised in persons with medial KOA. Our findings suggest varus-valgus control deficits in both the afferent input (proprioceptive acuity) and muscular effectors (muscle strength and capacity to stabilize the joint).


Assuntos
Articulação do Joelho/fisiologia , Osteoartrite do Joelho/fisiopatologia , Propriocepção/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Instabilidade Articular/fisiopatologia , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Amplitude de Movimento Articular/fisiologia
16.
Arthritis Rheum ; 64(5): 1437-46, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22135125

RESUMO

OBJECTIVE: To evaluate whether low knee confidence at baseline is associated with poor baseline-to-3-year physical function outcome in the Osteoarthritis Initiative. METHODS: Knee confidence was assessed using an item from the Knee Injury and Osteoarthritis Outcome Score instrument. Physical function was assessed using self-report measures (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] function score and Short Form 12 physical component scale) and performance-based measures (20-meter walk and chair stand test). Poor function outcome was defined as moving into a worse function group or remaining in the 2 worst function groups between baseline and 3 years. Logistic regression was used to evaluate the relationship between baseline knee confidence level and poor baseline-to-3-year function outcome, adjusting for potential confounders. RESULTS: The sample included 3,975 men and women with or at high risk of developing osteoarthritis of the knee, of whom 37-53% had poor baseline-to-3-year function outcome. For both self-report measures, increasingly worse knee confidence was associated with a greater risk of poor function outcome, and trend tests supported a graded response (e.g., the adjusted odds ratios [95% confidence intervals] for the WOMAC function score for worsening confidence categories were 1.26 [1.07-1.49], 1.43 [1.16-1.77], and 2.05 [1.49-2.82], P for trend <0.0001). Similar associations between confidence and performance-based function outcome were observed, but statistical significance did not persist in adjusted analyses. Factors independently associated with poor function outcome for all 4 outcome measures were depressive symptoms, comorbidity, body mass index, and joint space narrowing. CONCLUSION: These findings indicate that worse knee confidence at baseline is independently associated with greater risk of poor function outcome by self-report measures, with evidence of a graded response; the relationship with performance measures is not significant in fully adjusted models.


Assuntos
Articulação do Joelho/fisiopatologia , Limitação da Mobilidade , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/psicologia , Caminhada/psicologia , Acidentes por Quedas , Atividades Cotidianas , Idoso , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/diagnóstico por imagem , Medição da Dor , Equilíbrio Postural/fisiologia , Estudos Prospectivos , Qualidade de Vida , Radiografia , Inquéritos e Questionários , Caminhada/fisiologia
17.
Arthritis Rheum ; 63(4): 1002-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21225680

RESUMO

OBJECTIVE: Varus-valgus alignment has been linked to subsequent progression of osteoarthritis (OA) within the mechanically stressed (medial for varus, lateral for valgus) tibiofemoral compartment. Cartilage data from the off-loaded compartment are sparse. The purpose of this study was to examine our hypotheses that neutral and valgus (versus varus) knees each have reduced odds of cartilage loss in the medial subregions and that neutral and varus (versus valgus) knees each have reduced odds of cartilage loss in the lateral subregions. METHODS: Patients with knee OA underwent knee magnetic resonance imaging at baseline and 2 years. The mean cartilage thickness was quantified within 5 tibial and 3 femoral subregions. We used logistic regression with generalized estimating equations to analyze the relationship between baseline alignment and subregional cartilage loss at 2 years, adjusting for age, sex, body mass index, and disease severity. RESULTS: A reduced risk of cartilage loss in the medial subregions was associated with neutral (versus varus) alignment (external tibial, central femoral, external femoral) and with valgus (versus varus) alignment (central tibial, external tibial, central femoral, external femoral). A reduced risk of cartilage loss in the lateral subregions was associated with neutral (versus valgus) alignment (central tibial, internal tibial, posterior tibial) and with varus (versus valgus) alignment (central tibial, external tibial, posterior tibial, external femoral). CONCLUSION: Neutral and valgus alignment were each associated with a reduction in the risk of subsequent cartilage loss in certain medial subregions and neutral and varus alignment with a reduction in the risk of cartilage loss in certain lateral subregions. These results support load redistribution as an in vivo mechanism of the long-term alignment effects on cartilage loss in knee OA.


Assuntos
Mau Alinhamento Ósseo/complicações , Cartilagem Articular/fisiopatologia , Articulação do Joelho/fisiopatologia , Osteoartrite do Joelho/epidemiologia , Osteoartrite do Joelho/prevenção & controle , Idoso , Fenômenos Biomecânicos/fisiologia , Cartilagem Articular/patologia , Feminino , Humanos , Articulação do Joelho/patologia , Estudos Longitudinais , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/fisiopatologia , Análise de Regressão , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Suporte de Carga/fisiologia
18.
Ann Rheum Dis ; 70(1): 74-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20705634

RESUMO

OBJECTIVES: Meniscal tears have been linked to knee osteoarthritis progression, presumably by impaired load attenuation. How meniscal tears affect osteoarthritis is unclear; subregional examination may help to elucidate whether the impact is local. This study examined the association between a tear within a specific meniscal segment and subsequent 2-year cartilage loss in subregions that the torn segment overlies. METHODS: Participants with knee osteoarthritis underwent bilateral knee MRI at baseline and 2 years. Mean cartilage thickness within each subregion was quantified. Logistic regression with generalised estimating equations were used to analyse the relationship between baseline meniscal tear in each segment and baseline to 2-year cartilage loss in each subregion, adjusting for age, gender, body mass index, tear in the other two segments and extrusion. RESULTS: 261 knees were studied in 159 individuals. Medial meniscal body tear was associated with cartilage loss in external subregions and in central and anterior tibial subregions, and posterior horn tear specifically with posterior tibial subregion loss; these relationships were independent of tears in the other segments and persisted in tibial subregions after adjustment for extrusion. Lateral meniscal body and posterior horn tear were also associated with cartilage loss in underlying subregions but not after adjustment for extrusion. Cartilage loss in the internal subregions, not covered by the menisci, was not associated with meniscal tear in any segment. CONCLUSION: These results suggest that the detrimental effect of meniscal tears is not spatially uniform across the tibial and femoral cartilage surfaces and that some of the effect is experienced locally.


Assuntos
Cartilagem Articular/patologia , Traumatismos do Joelho/patologia , Osteoartrite do Joelho/patologia , Lesões do Menisco Tibial , Idoso , Progressão da Doença , Feminino , Seguimentos , Humanos , Traumatismos do Joelho/complicações , Imagem por Ressonância Magnética/métodos , Masculino , Meniscos Tibiais/patologia , Pessoa de Meia-Idade , Osteoartrite do Joelho/complicações , Suporte de Carga/fisiologia
19.
Conf Proc IEEE Eng Med Biol Soc ; 2011: 2081-4, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22254747

RESUMO

The goal of this study was to use an offaxis robotic elliptical trainer to improve off-axis neuromuscular control in people with knee injuries. Thirteen individuals with knee injuries participated in the study. Among them, 8 individuals participated in 18 sessions of pivoting offaxis intensity-adjustable neuromuscular control training (POINT) (3 sessions/week for 6 weeks including 3 evaluation sessions) to improve offaxis neuromuscular control, specifically dynamic lower limb stability in pivoting. 5 individuals served as controls who only participated in the three evaluations. Following POINT patients in the training group reduced pivoting instability (p=0.024), while the control group did not (p=0.118). Individuals in the training group were able to hop farther in a single leg hop for distance task, take shorter in 12 m hop time for time task, and reported reduced knee pain. The results suggest that subject-specific POINT utilizing the novel robotic elliptical trainer can be implemented as a rehabilitation protocol for patients with knee injuries to improve their lower limb functions and reduce knee symptoms.


Assuntos
Terapia por Exercício/instrumentação , Instabilidade Articular/reabilitação , Traumatismos do Joelho/reabilitação , Robótica/instrumentação , Terapia Assistida por Computador/instrumentação , Adulto , Idoso , Humanos , Instabilidade Articular/fisiopatologia , Traumatismos do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Terapia Assistida por Computador/métodos , Resultado do Tratamento
20.
Conf Proc IEEE Eng Med Biol Soc ; 2010: 4846-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21096648

RESUMO

The goal of this study was to investigate the efficacy of off-axis neuromuscular control training using a pivoting elliptical machine. Although knee motion is mainly in flexion/extension, injuries to the knee are usually associated with excessive off-axis movement (tibial axial rotation and valgus/varus). A pivoting elliptical training system was developed to improve neuromuscular control about the off-axes. Six week training was conducted in nine healthy individuals and seven healthy individuals served as control and only participated in evaluation sessions. Our results showed that following the pivoting elliptical training, individuals were able to reduce pivoting instability across different phases of the elliptical cycle (p〈0.01) and also mediolateral instability at mid and terminal swing phase (p〈0.05). A trend of reduced response time and phase dependent changes in EMG patterns were also observed. The results showed that the pivoting elliptical training is effective to improve off-axis neuromuscular control in healthy individuals and such training protocol can potentially be implemented to prevent knee injury.


Assuntos
Ciclismo , Terapia por Exercício/instrumentação , Traumatismos do Joelho/prevenção & controle , Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Aptidão Física/fisiologia , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Traumatismos do Joelho/fisiopatologia , Amplitude de Movimento Articular/fisiologia
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