Development of finger force coordination in children
- 194 Downloads
Coordination is often observed as body parts moving together. However, when producing force with multiple fingers, the optimal coordination is not to produce similar forces with each finger, but rather for each finger to correct mistakes of other fingers. In this study, we aim to determine whether and how this skill develops in children aged 4–12 years. We measured this sort of coordination using the uncontrolled manifold hypothesis (UCM). We recorded finger forces produced by 60 typically developing children aged between 4 and 12 years in a finger-pressing task. The children controlled the height of an object on a screen by the total amount of force they produced on force sensors. We found that the synergy index, a measure of the relationship between “good” and “bad” variance, increased linearly as a function of age. This improvement was achieved by a selective reduction in “bad” variance rather than an increase in “good” variance. We did not observe differences between males and females, and the synergy index was not able to predict outcomes of upper limb behavioral tests after controlling for age. As children develop between the ages of 4 and 12 years, their ability to produce negative covariation between their finger forces improves, likely related to their improved ability to perform dexterous tasks.
KeywordsChildren Coordination Finger force Prehension Uncontrolled manifold
The study was partially supported by the Marguerite Stolz Research Fellowship Fund, Sackler Faculty of Medicine Tel Aviv University.
Compliance with ethical standards
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Informed assent was obtained from the child participants, and informed consent was obtained from their parents for all participants included in the study.
Conflict of interest
The authors declare that they have no conflict of interest.
- Aaron DH (2006) Pediatric hand therapy. In: Henderson A, Pehoski C (eds) Hand function in the child: foundations for remediation, 2nd edn. Elsevier Mosby, St Louis, pp 367–400Google Scholar
- Conners CK (1997) Technical manual for the Conners’ rating scales—revised. Multi-Health Systems, New YorkGoogle Scholar
- Connolly K, Elliott J (1972) The evolution and ontogeny of hand function. In: Blurton Jones N (ed) Ethological studies of child behaviour. University Press, CambridgeGoogle Scholar
- Friedman J (2014) Repeated measures (computer software). Zenodo. doi: 10.5281/zenodo.10438
- Friedman J (2017) 3D printable sensor base for four PCB 208C01 force sensors for finger pressing experiments. Figshare. doi: 10.6084/m9.figshare.4595326.v2
- Jeannerod M (1981) Intersegmental coordination during reaching at natural visual objects. In: Long J, Baddeley A (eds) Attention and performance IX. Lawrence Erlbaum Associates, New Jersey, pp 153–169Google Scholar
- Kilshaw D, Annett M (1983) Right- and left-hand skill I: effects of age, sex and hand preference showing superior skill in left-handers. Br J Psychol Lond Engl 1953 74(Pt 2):253–268Google Scholar