Related Experiment Video
Updated: Jan 11, 2026
Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Have children's manual dexterity skills changed in the past 40 years? A cross-sectional observational norm comparison
Tami L Konieczny1, Nellie P Butler2, Lynne Allen-Taylor3
1Department of Occupational Therapy, Division of Rehabilitation, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Insights
Children
Area of Science:
- Pediatric medicine
- Neuroscience
- Occupational therapy
Background:
- Established norms for the Box and Block Test (BBT) in children were from 1985 and 2013.
- Evidence suggests potential changes in children's hand use over 40 years necessitate updated normative data.
Purpose of the Study:
- To compare current pediatric performance on the BBT against the 1985 normative data.
- To investigate potential declines in children's manual dexterity over time.
Main Methods:
- Secondary analysis of a cross-sectional observational study.
- Participants (N=181, ages 7-18) completed one trial of the BBT with each hand.
- Performance (blocks placed in 60 seconds) was compared to 1985 norms using one-sample t-tests.
Main Results:
- Children's mean BBT performance was statistically significantly lower than 1985 norms across all groups.
- The deficit ranged from 9.1 to 31.3 fewer blocks placed in 60 seconds.
- Nonoverlapping 95% confidence intervals and t-test results confirmed the decline.
Conclusions:
- Findings suggest a significant decline in children's manual dexterity over the past 40 years.
- The 1985 BBT norms may no longer be accurate for current pediatric populations.
- Clinicians should consider these findings when interpreting BBT results for children.
Background:
Norms for children aged 6-19 years were developed in 1985 for the Box and Block Test (BBT) and updated in 2013 for 3-10-year-olds. Evidence suggests that past normative data may need to be updated due to changes in children's hand use over the past 40 years.
Purpose:
To compare children's performance on the BBT with existing 1985 normative data.
Study Design:
Secondary analysis of a cross-sectional observational study to validate the Complete Minnesota Dexterity Test (CMDT) using the BBT.
Methods:
All were healthy volunteers, aged 7 to 18 years, with no known physical, cognitive, or emotional conditions. Participants completed study procedures in a pediatric hospital. During data collection we noted low performance on the BBT and hypothesized a decline compared to the 1985 norms. Participants completed one trial of the BBT with each hand. We compared our sample to the normative sample using mean number of blocks placed in 60 seconds and standard error of the means using two-tailed, one sample t-tests.
Results:
Of 816 children screened, 181 were eligible and consented to participate. A total of 98 females and 83 males participated. Each gender-by-age group-by-hand category ranged from 4-21 participants. In each group, means were statistically significantly lower than norms, indicated by nonoverlapping 95% confidence intervals and t-test results. The difference in blocks placed in 60 seconds ranged from 9.1 to 31.3 fewer blocks.
Discussion:
This study suggests that children's manual dexterity has declined over the past 40 years. Clinicians should consider this when using the BBT to evaluate performance. This study lacked enough subjects to establish new normative data but suggests the 1985 norms need to be updated.
Conclusions:
Our findings provide evidence of a decline in manual dexterity among children on the BBT since 1985.
