Pediatric Rheumatology Online Journal → June 2003 → Rehabilitation→ Abstract #69
ASSESMENT OF LOWER LEG STRENGTH IN YOUNG GIRLS WITH JUVENILE IDIOPATHIC ARTHRITIS
E. Brostrom,1 M. M. Nordlund,2 A. G. Cresswell.2
1Women and Child Health, Karolinska Institute; 2Neuroscience, Karolinska Institute, Stockholm, Sweden
Introduction Muscle atrophy of the lower leg is characteristic of children with juvenile idiopathic arthritis (JIA). A reduction in functional strength of the plantar- and dorsiflexors may well be useful in tracking the development of the disease. The aim of this study was to investigate isometric and dynamic plantar- and dorsiflexor strength in young girls with JIA and compare their strength to healthy controls.
Methods Ten girls diagnosed with JIA (8-12 yrs), and 10 healthy girls participated in the study. All underwent an examination of plantar- and dorsiflexor strength using a isokinetic dynamometer. Initially subjects performed three maximal isometric plantar- and dorsiflexor actions at an ankle angle of 90[deg>. Thereafter, lengthening and shortening plantar and dorsiflexor maximal efforts were performed at an ankle angular velocity of 15°
s-1 through a 30° range of motion, commencing from ankle angles of either 75° or 105°
.
Results Maximal isometric plantar- and dorsiflexor torques were significantly lower (48% and 38%) for the children with JIA compared to the controls. For shortening plantar flexions, the JIA group produced significantly lower torques compared to controls (52%). Maximal lengthening plantar flexor torques were not significantly different between the two groups. Controls were significantly stronger than the JIA group for both shortening and lengthening dorsiflexor actions (52% and 37%). Comparisons between action types in children with JIA showed significantly larger lengthening torques than isometric or shortening and significantly higher isometric torques than those during shortening. All plantar flexor torques were approximately four to five times greater than dorsiflexor torques.
Discussion Apart from lengthening plantar flexions, young girls with JIA exerted less maximal voluntary torque for all strength measures than the healthy controls. We believe that strength assessment of major functional muscle groups needs to be continuously made to asses the progress of the disease and the efficacy of treatments.