Dale A. Ulrich*, Beverly D. Ulrich*, Rosa M. Angulo-Kinzler*, & Joonkoo Yun‡ * Division of Kinesiology, University of Michigan, Ann Arbor, Michigan; and the ‡ Department of Exercise and Sport Science, Oregon State University, Corvallis, Oregon.
Objective. On average, infants with Down syndrome (DS) learn to walk about 1 year later than nondisabled (ND) infants. The purpose of this study was to determine if practice stepping on a motorized treadmill could help reduce the delay in walking onset normally experienced by these infants.
Methods. Thirty families of infants with DS were randomly assigned to the intervention or control group. All infants were karyotyped trisomy 21 and began participation in the study when they could sit alone for 30 seconds (Bayley Scales of Infant Development, Second Edition 1993, item 34). Infants received traditional physical therapy at least every other week. In addition, intervention infants received practice stepping on a small, motorized treadmill, 5 days per week, for 8 minutes a day, in their own homes. Parents were trained to support their infants on these specially engineered miniature treadmills. Every 2 weeks research staff went into the homes and tested infants' overall motor progress by administering the Bayley Scales of Infant Development, Second Edition, monitored growth status via a battery of 11 anthropometric measures, and checked parents' compliance with physical therapy and treadmill intervention. The primary measures of the intervention's effectiveness were comparisons between the groups on the length of time elapsed between sitting for 30 seconds (entry into the study) and 1) raising self to stand; 2) walking with help; and 3) walking independently.
Results. The experimental group learned to walk with help and to walk independently significantly faster (73.8 days and 101 days, respectively) than the control group, both of which also produced large effect size statistics for the group differences. The groups were not statistically different for rate of learning to raise self to stand but there was a moderate effect size statistic suggesting that the groups were meaningfully different in favor of the experimental group.
Conclusions. These results provide evidence that, with training and support, parents can use these treadmills in their homes to help their infants with DS learn to walk earlier than they normally would. Current research is aimed at 1) improving the protocol to maximize outcome; 2) determining the impact of treadmill practice on walking gait patterns; 3) testing the application to other populations with a history of delays in walking; and 4) determining the long-term benefits that may accrue from this form of activity.
Phys Ther75: 14-23 (1995)
Ulrich BD, Ulrich DA, Collier DH, Cole EL Background and Purpose. In this study, we used a dynamic systems strategy to examine longitudinally the ability of infants with Down syndrome to produce alternating steps when supported on a motorized treadmill. Subjects. Seven infants participated, ranging in age from 8 to 11 months at entry into the study and 13 to 29 months at their final session. Methods. Data were collected in the infants' homes on a monthly basis. Testing continued until each subject produced consistent alternating step patterns during three consecutive test sessions. Results. All infants responded by producing alternating steps, on average, 13.3 months before they walked independently, but they initiated this response at a wide range of chronological ages and significantly later than reported previously for nondisabled infants. Similar developmental variables (control parameters) marked the shift into responsiveness to the treadmill context for all infants with Down syndrome, but these variables differed from those identified for nondisabled infants. Conclusion and Discussion. With age, alternating treadmill stepping became a more stable response, although the relative timing of interlimb coordination (phase lag) of the step cycles remained quite variable across ages. We discuss our results relative to the usefulness of dynamic systems theory in understanding delayed development and the possibilities of pursuing the treadmill paradigm as an intervention approach.
Am J Ment Defic90 (3): 313-318 (1985 Nov)
Motor skill acquisition by individuals with Down syndrome
Kerr R, Blais C Motor skill acquisition of subjects with Down syndrome on a pursuit tracking task was assessed in comparison to groups of mentally retarded subjects without Down syndrome and nonretarded subjects matched for functional age and chronological age (CA). Thirty-seven male subjects performed eight trials on a subject-paced pursuit tracking task. The main finding was that subjects with Down syndrome did not respond to directional probability in the same manner shown by the retarded or the nonretarded subjects matched for CA or functional age. This difference in strategy was also reflected in their greater emphasis on accuracy rather than speed. Finally, these effects were consistent across the subjects with Down syndrome despite the large intersubject variability seen in their performance.
Am J Ment Defic85 (4): 416-424 (1981 Jan)
Performance of Down syndrome and other retarded children on the Cratty Gross-Motor Test
Henderson SE, Morris J, Ray S The Cratty Test of Gross-Motor Performance was administered to 18 Down syndrome and 18 other mentally retarded children between the ages of 7 and 14 years. Subjects were individually matched on both MA and CA. Examination of their test profiles showed that the Down syndrome children had consistently lower scores that did the matched control children, but only two of the differences were significant. The findings, therefore, provide tentative support for the notion that Down syndrome children suffer a specific deficit in some areas of motor coordination. A number of criticisms of the internal consistency of the test were discussed in terms of their theoretical and practical implications.
J Ment Defic Res30 (4): 317-330 (1986 Dec)
Walking patterns in Down's syndrome
Parker AW, Bronks R, Snyder CW Jr. Cinematographic analysis techniques were used to evaluate the walking patterns of 10 5-year-old Down's syndrome (DS) children (trisomy 21). Comparison with similar analyses of non-handicapped children revealed a wide developmental variability in the walking of DS children and retardation in some temporal components. The DS children adopted a more flexed posture of the hip and knee joints, and increased fluctuation of ankle movement during the walking cycle. The data suggest a wide continuum of locomotor development which may be a function of the degree of impairment of associated neuromuscular mechanisms.
Phys Ther59 (12): 1489-1494 (1979 Dec)
Assessment of the quality of sitting and gait patterns in children with Down's syndrome
Lydic JS, Steele C. Clinical work with children with Down's syndrome resulted in a suggestion of a relationship between the external rotation and abduction of their hips, their excessive hip mobility in sitting, and their wide-based gait. This relationship was examined using data from 104 questionnaires completed by the parents of children with Down's syndrome. The clinical and demographic findings consistently documented the unusual sitting patterns of these children. How children were placed in the sitting position significantly influenced subsequent come-to-sit patterns but did not appear to influence subsequent walking patterns. Longitudinal studies of sitting patterns, hip mobility and gait are recommended. Therapeutic implications are that body rotation should be incorporated into motor intervention programs for children with Down's syndrome.
J Ment Defic Res75 (3): 207-218 (1985 Sep)
Age changes in the flexibility of Down's syndrome children
Parker AW, James B. The association between Down's syndrome (DS) and joint hyperflexibility is well documented. However, objective information concerning developmental expectations for flexibility in DS children is lacking. This investigation used goniometric techniques to examine the changes in flexibility with growth and maturation in 30 DS children aged 5, 10 and 15 years and compared them with 30 normal controls. Flexibility declined consistently with age in the DS children and in the controls, and although the DS children were more flexible than their control counterparts at each age, the magnitude of change over the whole age range was parallel in both groups of children suggesting some similarity in mechanisms controlling the maturation of joint tissues. The greatest reduction in flexibility occurred in the hip and ankle joints, and in the elbow and knee hyperextension. A trend was evident for the largest reduction in measurements to occur between 5 and 10 years in the DS children compared with a consistent or later reduction in the controls. It is postulated that this may be attributable to the improvement in generalized muscular hypotonia expected during this age period, or to differences in the rate of maturation of joint structures in the early years, caused by the effects of the syndrome on the intrinsic mechanisms regulating the growth of joints.
Phys Ther65 (11): 1658-1661 (1985 Nov)
Relationship of ankle strength and hypermobility to squatting skills of children with Down syndrome
MacNeill-Shea SH, Mezzomo JM. We used ankle goniometric and force measures to determine the relative contribution of hypermobility and strength to heels-down squatting (HDS) in four groups: eight children with Down syndrome, eight hypermobile children, six retarded children, and seven children with normal development. Analysis of variance and across group correlations revealed force as a major but not sole contributor to HDS; hypermobility was found not to have significant influence. Heels-down squatting may be a compensatory mechanism resulting from underdeveloped balance or irregular activation of agonist-antagonist relations around the ankle joint.
American Journal on Mental Retardation106 (5): 470-478 (19XX)
Analysis of Ankle Kinetics During Walking in Individuals With Down Syndrome
Matteo Cioni, Anna Cocilovo, Fabio Rossi, Domenico Paci, Maria Stella Valle Department of Experimental and Clinical Pharmacology, University of Catania, V.le A. Doria 6, 95125, Catania, Italy.
The biomechanical characteristics of the ankle during gait of 17 participants with Down syndrome, ages 8 to 36 years, were investigated. Ten volunteers without disabilities of comparable anthropometric parameters were the control group. A 3-dimensional gait analysis was performed using an optoelectronic system equipped with a force platform. Participants with Down syndrome showed significant decreases of plantar-flexor moments and of A1 and A2 joint powers. Furthermore, correlation between kinetic and temporal spatial parameters was markedly reduced or weak in comparison to the control group. These results point out a hypofunctioning of ankle, probably due to hypotonia and ligament laxity.