vendex and Arthritis--Juvenile

This study assessed the magnitude of changes in isokinetic muscle strength in children with juvenile idiopathic arthritis (JIA) before and after treatment with intra-articular corticosteroid injection and assessed the feasibility of a larger study of the same effect. Isokinetic dynamometry was used to measure peak knee extension and flexion torque in 12 children before and after treatment for unilateral knee arthritis. Extensor and flexor strength was reduced on the affected side before treatment (-0.56 Nm/kg, p = .004 and -0.24 Nm/kg, p = .02 respectively). Increases in extensor strength were observed at two weeks (p = .01) and twelve weeks postinjection (p = .03). Improvements at 6 weeks approached but did not reach statistical significance (p = .17). Improvements in flexor strength were not observed until 12 weeks postinjection (p = .03). Despite significant improvements in extensor strength, low peak knee extensor torque continued to be observed at 12 weeks (p = .01). Knee extensor and flexor strength is reduced in children with JIA with active arthritis and improves following intra-articular corticosteroid injection. Significant improvements in knee extensor and flexor strength were seen postinjection; however deficits in extensor strength were still evident at three months. Isokinetic dynamometry was safe and well tolerated in our sample of children with JIA with active arthritis.

Topics: Adolescent; Adrenal Cortex Hormones; Arthritis, Juvenile; Child; Feasibility Studies; Female; Humans; Injections, Intra-Articular; Knee Joint; Longitudinal Studies; Male; Muscle Strength; Muscle Strength Dynamometer; Muscle, Skeletal; Organ Size; Range of Motion, Articular; Thigh; Time Factors; Torque

Juvenile idiopathic arthritis (JIA) is a chronic illness with a high risk of developing long-term disability. Disease activity is currently being monitored and quantified by ACR core set. Here, joint inflammation is determined; however joint function is the crucial component for developing disability. The aim of this study was to quantify and compare dynamic joint function in healthy and arthritic knee joints and to evaluate response to improvement.. A single center cohort study of consecutive children presenting to the rheumatology outpatient clinic was performed to measure dynamic knee joint function. Serial measures were performed if possible. Splint fixed electrogoniometers were used to measure dynamic knee joint function including ROM and flexion and extension torque.. A total of 54 children were tested including 44 with JIA, of whom eight had to be excluded for non-JIA-related knee problems. The study included 36 JIA patients of whom eight had strictly unilateral knee arthritis, and nine controls. Dynamic joint function ROM and torque depended on age and bodyweight, as demonstrated in healthy joints. ROM and torques were significant lower in arthritic compared to unaffected knee joints in children with unilateral arthritis and across the cohort. Importantly, extension torque was the most sensitive marker of impaired joint function. Follow up measurements detected responsiveness to change in disease activity.. Measuring dynamic joint function with electrogoniometers is feasible and objective. Active ROM and torque during flexion and extension of arthritic knee joints were significant lower compared to unaffected. In dynamic joint measurement extension torque is a sensitive marker for disease activity.

Topics: Adolescent; Age Factors; Arthritis, Juvenile; Arthrometry, Articular; Body Weight; Case-Control Studies; Child; Child, Preschool; Cohort Studies; Feasibility Studies; Female; Humans; Knee Joint; Male; Range of Motion, Articular; Severity of Illness Index; Torque; Young Adult

Moment-angle relationship (dynamic joint stiffness)--the relationship between changes in joint moment and changes in joint angle--is useful for demonstrating interaction of kinematics and kinetics during gait. However, the individual contributors of dynamic joint stiffness are not well studied and understood, which has thus far limited its clinical application. In this study, ankle dynamic joint stiffness was analyzed and decomposed into three components in thirty able-bodied children during the stance phase of the gait. To verify the accuracy of the decomposition, the sum of decomposed components was compared to stiffness computed from experimental data, and good to very good agreement was found. Component 1, the term associated with changes in ground reaction force moment, was the dominant contribution to ankle dynamic joint stiffness. Retrospective data from eight children with juvenile idiopathic arthritis and idiopathic toe-walking was examined to explore the potential utility of analytical decomposition in pathological gait. Compared to controls, component 1 was the source of highest deviation in both pathological groups. Specifically, ankle dynamic joint stiffness differences can be further identified via two sub-components of component 1 which are based on magnitudes and rates of change of the ground reaction force and of its moment arm, and differences between the two patient groups and controls were most evident and interpretable here. Findings of the current study indicate that analytical decomposition can help identify the individual contributors to joint stiffness and clarify the sources of differences in patient groups.

Topics: Adolescent; Ankle Joint; Arthritis, Juvenile; Child; Computer Simulation; Elastic Modulus; Female; Humans; Male; Models, Biological; Muscle Contraction; Muscle, Skeletal; Range of Motion, Articular; Torque; Walking

To compare lower-leg strength of young girls with polyarticular juvenile idiopathic arthritis (JIA) with that of healthy, age-matched controls.. Isometric and isokinetic strength tests of the plantar- and dorsiflexors. All strength measures were made at an ankle angle of 90 degrees. Isokinetic plantar- and dorsiflexor measures were made at 15 degrees/s during shortening (concentric) and lengthening (eccentric) actions.. Strength testing laboratory.. Ten prepubertal girls diagnosed with JIA and 10 healthy girls.. Not applicable.. Isometric and isokinetic plantar- and dorsiflexor strength.. Isometric plantar- and dorsiflexion torques were significantly lower (48% and 38% respectively; P<.05) for the children with JIA than for the controls. The JIA group also produced lower shortening plantarflexion torques (52%, P<.05). Lengthening plantarflexor torques did not differ significantly between the 2 groups (P<.05). Controls were stronger than the JIA group for both shortening and lengthening maximal dorsiflexor actions (P<.05). All children were 4 to 5 times stronger in plantarflexion than in dorsiflexion.. Girls with JIA had significantly less plantar- and dorsiflexor strength than age-matched, healthy peers. The reduced strength of children with JIA is likely to affect function in daily activities and probably contributes to reduced levels of physical activity.

Topics: Activities of Daily Living; Age Factors; Ankle; Arthritis, Juvenile; Body Height; Body Mass Index; Case-Control Studies; Child; Disease Progression; Female; Foot; Humans; Isometric Contraction; Isotonic Contraction; Muscle Weakness; Physical Therapy Modalities; Range of Motion, Articular; Sex Characteristics; Torque

To determine the intratester reliability of joint torque testing with a hand-held dynamometer (HHD) during contractions of four major lower extremity muscles in children with juvenile chronic arthritis (JCA) and to compare results for children with JCA to results for children without disability.. Eleven children with JCA and 14 children with normal musculoskeletal function were tested with a HHD using isometric muscle contractions of the right quadriceps, hamstrings, tibialis anterior and triceps surae.. Intratester reliability values exceeded the 0.92 level, regardless of the number of trials, for all motions tested. Statistically lower joint torque values were found in a subgroup of children with JCA for contractions of the tibialis anterior (p=0.003) and triceps surae (p=0.05) muscles.. HHD offers a reliable means of testing the joint torque generated with contraction of these lower extremity muscles in children with JCA. Findings in children with JCA compared to children without disability agree with previous reports concerning quadriceps muscle function, but also point to concerns for muscles associated with generating ankle joint torque.

Topics: Adolescent; Arthritis, Juvenile; Child; Child, Preschool; Female; Humans; Isometric Contraction; Knee Joint; Leg; Male; Muscle, Skeletal; Reproducibility of Results; Torque

To examine the reliability of testing strength in children with juvenile arthritis (JA), and to determine the relationship between strength and function.. Children with JA were tested for grip and pinch strength (n = 32). Isometric force produced by hip abductors and knee extensors was tested with a hand-held dynamometer (n = 29). Two therapists both performed each of the tests twice so that intrarater and interrater reliability could be examined. Function was measured by means of the Childhood Health Assessment Questionnaire (CHAQ) and performance on a 50-meter run. Reliability was examined with intraclass correlations (ICC). The relationships of strength and function were determined with Pearson and Spearman correlations.. All measures demonstrated good intrarater (ICC = 0.92-0.97) and interrater (ICC = 0.80-0.95) reliability. Grip strength and pinch were correlated with the CHAQ (r = -0.45 and -0.33, respectively), while hip abduction and knee extension torque were correlated with rankings on the 50-meter run (rho = -0.34 and -0.38, respectively).. Isometric strength can be reliably measured in children with arthritis in a clinical setting.

Topics: Activities of Daily Living; Adolescent; Arthritis, Juvenile; Child; Disability Evaluation; Female; Hand Strength; Humans; Isometric Contraction; Leg; Male; Nursing Assessment; Observer Variation; Range of Motion, Articular; Reproducibility of Results; Surveys and Questionnaires; Torque