Previous experiments involving discrete unimanual tasks have shown that individuals with Down syndrome (DS) have auditory/verbal-motor deficits. The present study investigated unimanual and bimanual continuous perceptual-motor actions in adults with DS. Ten adults with DS, 10 typical adults, and 10 children drew continuous circles at increasing periods bimanually and unimanually with each hand. Movement was paced by either a visual or an auditory metronome. The results revealed that for circle shape and coordination measures, children and adults were more accurate with the visual metronome, whereas adults with DS were more accurate with the auditory metronome. In the unimanual tasks, adults with DS displayed hand asymmetries on spatial measures. In the bimanual task, however, adults with DS adopted an in-phase coordination pattern and stability more similar to adults than children. These results suggest that bimanual coordination in adults with DS is functioning effectively despite hand asymmetries evident in unimanual performance.
Shannon D. Ringenbach, Romeo Chua, Brian K. V. Maraj, James C. Kao, and Daniel J. Weeks
Stamatis Agiovlasitis, Robert W. Motl, John T. Foley, and Bo Fernhall
This study examined the relationship between energy expenditure and wrist accelerometer output during walking in persons with and without Down syndrome (DS). Energy expenditure in metabolic equivalent units (METs) and activity-count rate were respectively measured with portable spirometry and a uniaxial wrist accelerometer in 17 persons with DS (age: 24.7 ± 6.9 years; 9 women) and 21 persons without DS (age: 26.3 ± 5.2 years; 12 women) during six over-ground walking trials. Combined groups regression showed that the relationship between METs and activity-count rate differed between groups (p < .001). Separate models for each group included activity-count rate and squared activity-count rate as significant predictors of METs (p ≤ .005). Prediction of METs appeared accurate based on Bland-Altman plots and the lack of between-group difference in mean absolute prediction error (DS: 17.07%; Non-DS: 18.74%). Although persons with DS show altered METs to activity-count rate relationship during walking, prediction of their energy expenditure from wrist accelerometry appears feasible.
Chih-Chia (JJ) Chen, Shannon D.R. Ringenbach, Nathaniel E. Arnold, and Kahyun Nam
Down syndrome (DS) is a genetic alteration that occurs in fetus formation. Due to chromosomal abnormality, individuals with DS are characterized by limited intellectual functioning, hypotonia, obesity, and musculoskeletal, balance, heart, and perception problems that contribute to significant
Janet L. Hauck, Isabella T. Felzer-Kim, and Kathryn L. Gwizdala
The persistent motor delays present in infants with Down syndrome (DS) can become constraints to safety, quality of life, and family convenience. Such delays prolong the time when an infant is physically dependent on caregivers. For instance, an infant who cannot independently roll must be
Amanda Young, Seán Healy, Lisa Silliman-French, and Ali Brian
Down syndrome (DS), a genetic syndrome caused by a chromosomal anomaly, is the most prevalent cause of intellectual disability (ID) in the United States ( American Psychiatric Association, 2013 ; van Gameren-Oosterom et al., 2011 ). According to the Centers for Disease Control and Prevention
Kerri L. Staples, E. Andrew Pitchford, and Dale A. Ulrich
cannot be directly inferred upon populations with disabilities, it is critical to address aspects of reliability and validity, including instructional sensitivity, in both children with and without disabilities. This study includes a sample of children with Down syndrome to examine the instructional
Stamatis Agiovlasitis, Jooyeon Jin, and Joonkoo Yun
.S. population of individuals with ID includes about 250,000 persons with Down syndrome (DS) ( Presson et al., 2013 )—a condition caused by a chromosome 21 abnormality ( Roizen & Patterson, 2003 ). Individuals with ID and DS experience disparities in health compared with the general population ( Krahn & Fox
Nicolas Vuillerme, Ludovic Marin, and Bettina Debû
This study evaluated stance control in 24 teenagers with and without Down syndrome (DS) by (a) assessing center of foot pressure variables under different conditions of availability of visual and somatosensory inputs and (b) analyzing postural perturbation and adaptation following abrupt changes in visual information. Results showed no gender-related differences in either group. Group comparison revealed similar strategies in adolescents with and without DS, although quantitative differences may exist in the ability to integrate sensory inputs to control stance. Adaptation to changing environmental conditions varied greatly from one individual to another in the two groups. Finally, comparison of the two experiments suggests that the increased postural oscillations reported for the sample with DS on long lasting recordings could be related to insufficient allocation of cognitive resources in stable environments.
Geert J.P. Savelsbergh, John van der Kamp, and Walter E. Davis
Twenty-one children with Down syndrome (DS) and 20 without disability, ages 3 to 11 years, completed the experiment in which they were asked to grasp and lift cardboard cubes of different sizes (2.2 to 16.2 cm in width). Three conditions were used: (a) increasing the size from the smallest to the largest cube, (b) decreasing the size from the largest to the smallest, and (c) a random order of sizes. Children with DS were found to have smaller hand sizes in comparison to age-matched children without DS. In addition, the shift from one-handed to two-handed grasping appeared at a smaller cube size for children with DS than for children without DS. However, when the dimensionless ratio between object size and hand size was considered, the differences between groups disappeared, indicating that the differences in grasping patterns between children with and without DS can be attributed to differences in body size.
Shannon D. Ringenbach and Dawn A. Lantero
This study examined the influences of intention on continuous bimanual circle drawing performed by adults with Down syndrome (DS) and mental age (MA) and chronological age (CA) matched comparison groups. The task was performed with preferred and instructed coordination patterns paced by a 500 ms metronome. While all participants adopted an in-phase coordination mode in the preferred conditions, only the adults with DS were unable to perform in-phase coordination when instructed to do so. We suggest that intention to perform specific coordination patterns taxes the attentional resources available, and mental age may be a precipitating factor to appropriate attention directing when performing multiple tasks. Results are discussed with respect to the developmental differences in attentional resources.