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Complexity of force output during static exercise in individuals with Down syndrome
Kevin S Heffernan1, Jacob J Sosnoff, Edward Ofori
1Department of Kinesiology and Community Health, University of Illinois at Urbana, Champaign, Champaign, Ilinois 61820, USA. kheffer2@uiuc.edu
Journal of Applied Physiology (Bethesda, Md. : 1985)
|January 24, 2009
Summary
Individuals with Down syndrome (DS) exhibit greater force variability and altered temporal structure, similar to older adults. This suggests a potential link between premature aging and impaired force control in DS.
Area of Science:
- Neurology
- Human Physiology
- Biomedical Engineering
Background:
- Force variability is elevated in individuals with Down syndrome (DS), mirroring patterns observed in normal aging.
- Understanding the structural differences in force output variability is crucial for characterizing motor control deficits in DS.
Purpose of the Study:
- To analyze the time and frequency domain structure of force output variability in individuals with DS.
- To compare force control deficits in DS with those in healthy young and older adults.
Main Methods:
- An isometric handgrip task at 30% maximal voluntary contraction was performed by individuals with DS, young controls, and older controls.
- Analysis included statistical measures (SD, CV) and advanced techniques like spectral analysis and approximate entropy (ApEn).
Main Results:
- Individuals with DS showed greater force variability (SD, CV) compared to both young and older controls.
- The DS group exhibited a higher proportion of low-frequency power (0-4 Hz) and lower ApEn values than young controls, indicating less complex force output.
- Force output variability structure in DS was comparable to that of older adults.
Conclusions:
- Young individuals with DS display enhanced temporal structure and increased low-frequency oscillations in force output, differing from their non-DS peers.
- The findings suggest that force control in DS shares similarities with age-related decline, pointing towards a potential premature aging phenotype.
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