Muscle function assessment in children.

Assessment of muscle function has a range of applications, including appraisal of the presence and severity of muscle weakness and fatigability, examination of the effectiveness of intervention programmes and development and monitoring of training programmes. Muscle function assessment is routinely performed in rehabilitation, physical education, coaching and research. Procedures have been extensively examined in adults, but not in children. The aim of this review is to bring to the forefront the issue of paediatric muscle function assessment. Objective methods of muscle function assessment are critically analysed with specific attention to the issues of applicability, validity and reliability. Each of the methods reviewed (isokinetic dynamometry, hand-held dynamometry, field tests, and standard weights equipment) has its limitations. All procedures have been occasionally studied for validity and reliability and optimal procedures have yet to be identified. Methodological limits can be generalized to the type and speed of activation, standardization of procedures, subject familiarization, gravity and size and psychological influences. It is important for administrators of muscle function tests to be aware of the various factors that can both influence and confound interpretation. It was concluded that muscle function assessment in children requires significant further investigation. Although there is a wide range of procedures available, there is limited and equivocal research proving validity and reliability. Widespread use of the most valid and reliable methods is encouraged. Future research directions are also considered.