PEDIATRICS Vol. 99 No. 2 February 1997,
p. e3
Copyright ©1997 by the American Academy of Pediatrics
ELECTRONIC ARTICLE:
Osteogenesis Imperfecta in Childhood: Impairment and Disability
Received Feb 20, 1996; accepted Aug 7, 1996.
,
From the * Department of Pediatric Physical Therapy, University
Hospital for Children and Youth, "Wilhelmina Children's Hospital";
Department of Clinical Epidemiology, Utrecht University Hospital;
and § Clinical Genetics Center Utrecht, Utrecht, The Netherlands.
Objective. To determine clinical characteristics in children with osteogenesis imperfecta (OI) regarding impairment (range of joint motion and muscle strength) and disability (functional skills) in relation to the different types of the disease, and to study the correlation between characteristics of impairment and disability.
Methods. In a cross-sectional study 54 children with OI (OI type I: 24; OI type III: 15; OI type IV: 15), the range of joint motion, muscle strength, and functional ability were measured in a standardized way and analyzed statistically.
Results. The range of joint motion in almost all joints
differed significantly with respect to the different disease types. In
OI type I patients, generalized hypermobility of the joints was
present, without decrease in joint motion. In OI type III the
extremities were severely maligned, especially the lower limbs. In type
IV the upper and lower extremities were equally maligned. Muscle
strength differed significantly with respect to the different types of
OI. In type I patients, muscle strength was normal except for the
periarticular hip muscles. In type III, especially in the lower
extremities, muscle strength was severely decreased, with a muscular
imbalance around the hip joint. In type IV, muscle strength was mainly
decreased in the proximal muscles of the upper and lower extremities.
In children 
7.5 years of age, significant differences existed among
the different disease types in functional skills regarding mobility. No
significant difference was observed in self-care and social function,
although the most severely affected children showed a tendency to score
better with social function. Older children differed significantly
concerning mobility and self-care items. In children 7.5 years old, a
correlation was sometimes observed between impairment and disability
items, although in older children a moderate to good correlation was
always present (r > .6).
Conclusion. In OI, severity-related profiles exist, within the different subtypes of the disease, regarding range of joint motion, muscle strength, and functional skills. In younger children, impairment parameters do not sufficiently correlate for disability. Rehabilitation strategies in younger children should therefore focus on improvement of functional skills and not only on impairment parameters. osteogenesis imperfecta, pediatrics, muscle strength, range of joint motion, impairment, disability, functional outcome.
