Related Experiment Video
Updated: Jun 13, 2026

Block Building Task Identifies Distinct Groups of Left/Right-hand Choice Patterns After Unilateral Peripheral Nerve Injury
Published on: March 21, 2025
Automatic determination of left- and right-hand bone age in the First Zurich Longitudinal Study
David D Martin1, Julia Neuhof, Oskar G Jenni
1University Children's Hospital, Tübingen, Germany.
Background/Aims:
A more advanced bone age (BA) has been reported for the left hand relative to the right hand, while another study has found no such effect. The aim was to study the average difference of automated BoneXpert BA determination (left- vs. right-hand) for normal children, examine the precision of automatic BA and provide a BA reference for normal Caucasian children.
Methods:
Radiographs of both hands (age range: 2-20 years) were digitised and analysed automatically to determine Greulich-Pyle BA, producing analysis results for 3,374 left-hand and 2,752 right-hand images.
Results:
Comparison of left- and right-hand BA showed no average difference (<0.07 years, 95% confidence). The SD of the differences between left and right sides was 0.25 years for boys as well as girls, implying the precision of automated Greulich-Pyle BA determination was 0.18 years or better. Greulich-Pyle BA for boys and girls were on average 0.10 and 0.21 years below the chronological age.
Conclusion:
The left and right hand give the same BA on average and the SD between the sides is 0.25 years, indicating an excellent precision of the automated method.
Related Concept Videos
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a short...
Bones of the Upper Limb: Ulna
Bones of the Upper Limb: Humerus

