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Updated: May 6, 2026
An Objective and Child-friendly Assessment of Arm Function by Using a 3-D Sensor
Published on: February 12, 2018
Assessing shoulder motion in children: age limitations to Mallet and ABC Loops
Michael L Pearl1, Fabian van de Bunt, Michaela Pearl
1Department of Orthopedic Surgery, Kaiser Permanente Medical Center Los Angeles, Los Angeles, CA, USA.
Background:
Shoulder ROM and function of the shoulder are difficult to evaluate in young children. There has been no determination of the age at which children can comply with the current assessment tools in use, but doing so would be important, because it gives us more accurate insight into the development and assessment of shoulder functional ROM in young children.
Questions/Purposes:
We (1) determined whether age would limit the use of two different observational scales used to assess shoulder ROM and function in young children (the Mallet scale and the ABC Loops protocol); and (2) compared the two scales in terms of intra- and interobserver reliabilities.
Methods:
Sixty-five able-bodied children (32 boys, 33 girls; mean age, 3.9 years; range, 0.5-7.0 years) were recruited from local preschools and evaluated using the Mallet scale and ABC Loops protocol. Children were assessed on their ability to complete the examinations and time to completion for each measurement protocol. Intra- and interobserver reliability was tested by percentage agreement. Forty-eight children (mean age, 4.4 years; SD, 1.3 years) were able to complete the Mallet and ABC Loops measurement protocols; 17 children (mean age, 2.3 years; SD, 1.1 years) failed to complete either test.
Results:
Younger children had more difficulty completing the examinations; there was a strong negative correlation between age and failure: probability of failure increased with decreasing age (Pearson r = -0.601, p < 0.001). Children who were able to complete one test were able to complete the other. Interobserver and intraobserver agreement was very high for both scales (in excess of 95% for all comparisons), and with the numbers available, there were no differences between the scales.
Conclusions:
The Mallet scale and ABC Loops protocol have high reliability metrics in children younger than 6 years, but very young children (those younger than 3 years) generally will not be able to complete the examinations. The ABC Loops test took longer to perform than the Mallet scale but may more comprehensively evaluate a child's functional capabilities. We therefore state that both assessment tools can be reliably used in children older than 3 years; we believe the ABC Loops gives a more accurate assessment of shoulder ROM.
