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Muscle function in juvenile chronic arthritis
1Department of Pediatrics, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
Insights
Children with juvenile chronic arthritis (JCA) experience reduced muscle strength and thickness. This impairment is most severe in muscles located near inflamed joints, impacting overall muscle function.
Area of Science:
- Pediatric Rheumatology
- Musculoskeletal Health
- Arthritis Research
Background:
- Juvenile chronic arthritis (JCA) is a condition affecting children, potentially impacting musculoskeletal development and function.
- Understanding the specific effects of JCA on muscle strength and thickness is crucial for effective management and rehabilitation.
Purpose of the Study:
- To investigate and quantify the impact of juvenile chronic arthritis (JCA) on muscle strength and thickness in affected children.
- To compare muscle function in children with JCA to healthy controls and assess the influence of joint inflammation proximity.
Main Methods:
- Evaluated voluntary isometric, isokinetic, and nonvoluntary isometric muscle strength in 20 children with JCA.
- Measured quadriceps muscle thickness using ultrasound and compared results with reference values from healthy children and a matched control group.
Main Results:
- Children with JCA exhibited reduced isometric muscle strength in knee extensors, elbow flexors, and wrist dorsiflexors.
- Muscle strength deficits were more pronounced (45-65% of expected) near inflamed joints compared to muscles without adjacent arthritis (80-90% of expected).
- Quadriceps muscle thickness was reduced in children with JCA, regardless of knee joint involvement.
Conclusions:
- Children diagnosed with JCA demonstrate significant reductions in both muscle strength and thickness.
- The degree of muscle impairment in JCA is closely correlated with the proximity of muscles to inflamed joints.
Objective:
Muscle strength and thickness were studied in children with juvenile chronic arthritis (JCA) to evaluate their muscle function.
Methods:
We studied voluntary isometric, isokinetic, and nonvoluntary isometric muscle strength, as well as muscle thickness, in 20 children with JCA. Thickness of the quadriceps muscle was measured by ultrasound. Results were compared with reference values for healthy children and a matched control group.
Results:
Isometric muscle strength in knee extensors, elbow flexors, and wrist dorsiflexors was reduced in children with JCA. In muscles near an inflamed joint, the strength was 45-65% of expected value. In muscles without adjacent arthritis, the strength was slightly decreased (80-90% of expected value). Isometric and isokinetic strength in ankle dorsiflexors was reduced only in children with ankle arthritis. Nonvoluntary muscle strength in thumb adductors during electrical stimulation of the ulnar nerve was reduced in children with arthritis in the hand. Thickness of the quadriceps muscle was reduced both in children with and without knee arthritis (75 and 90% of expected).
Conclusion:
Children with JCA have reduced muscle strength and thickness, which is most pronounced in muscles near an inflamed joint.
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