Each author certifies that his or her institution has approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. H. M. Molenaar ( & ), R. W. Selles, S. E. R. Hovius Department of Plastic and Reconstructive Surgery and Hand Surgery, Erasmus MC, University Medical Center, Room Ee 1591, PO Box 2040, 3000 CA Rotterdam, The Netherlands e-mail: [email protected] H. M. Molenaar, R. W. Selles, H. J. Stam Department of Rehabilitation Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands S. P. Willemsen Department of Biomedical Statistics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands 123 Clin Orthop Relat Res (2011) 469:868–876 DOI 10.1007/s11999-010-1638-4
hypoplastic thumb after applying a specific tendon transfer to this thumb may provide more specific information than when measuring grip strength. The Rotterdam Intrinsic Hand Myometer (RIHM) [ 11 , 14 , 17 ] can measure the strength of the individual fingers or thumb at a specific joint. Although grip and pinch measurements provide more general information, the RIHM reliably [ 11 , 15 , 18 ] measures individual finger and thumb strength more directly [ 16 , 18 ]. Generally, when treating children whose hand function is affected, accurately monitoring their hand strength development with time provides insight regarding whether the treat- ment is effective. At present, no normative values for the strength measurement of the individual fingers and thumb have been presented for children. Because normative values presented in a classic table format are difficult to use, an alternative would be to use a growth diagram in which strength is plotted against age. This approach to reference values in children would allow for easier dis- crimination between the effects of growth, neuromuscular maturation, and the intervention. Using growth diagrams where an increase or decrease of strength can be plotted easily with time facilitates an intuitive and easily inter- pretable way of using reference values, whereas variation in strength can be accounted for using the correct per- centiles. Similar growth diagrams for length and weight are widely used at infant welfare centers across the world [ 4 – 6 ]. We recently developed these same diagrams for grip strength [ 12 ]. These strength development diagrams provide an immediate indication of the strength that can be expected at the child’s age using a continuous age scale, in contrast to reference tables with 1-year or 2-year intervals. We therefore (1) present reference values of individual finger and thumb strengths and (2) present them in the form of growth diagrams, providing an easy way to distinguish between the effects of growth and intervention on strength development.
- Spring '17
- H. M. Molenaar PhD