Strategy adoption and locomotor adjustment in obstacle clearance of newly walking toddlers with down syndrome after different treadmill interventions

Abstract

This study investigated how newly walking toddlers with Down syndrome (DS), after different treadmill interventions, adopted clearance strategies and modified anticipatory locomotor adjustment patterns to negotiate an obstacle in their travel path. Thirty infants with DS (about 10 months of age) were recruited and randomly assigned to either a lower-intensity, generalized (LG) treadmill training group, or a higher-intensity, individualized (HI) treadmill training group. Thirteen in each group completed a one-year-gait follow-up after the treadmill intervention. Initially, both groups chose to either crawl or walk over an obstacle. However, walking over the obstacle became their preferred clearance strategy over the course of the gait follow-up even though the height of the obstacle increased from visit to visit. The HI group used the strategy of walking over the obstacle at a considerably higher percentage than the LG group within 6 months after the training. When approaching the obstacle, both groups started to show consistent anticipatory locomotor adjustments about 6 months after the training. Both groups decreased velocity, cadence and step length, and increased step width at the last three pre-obstacle steps. It was concluded that the retention of the HI training effects led the HI group to predominantly walk over an obstacle earlier than the LG group within 6 months after treadmill intervention, and the two groups produced similar anticipatory locomotor adjustments in the last three steps before negotiating the obstacle.

Time and frequency analysis of the static balance in young adults with Down syndrome

“…People with DS exhibit a number of anatomical and physiological characteristics that differentiate them from people without DS. For example, the brains of individuals with trisomy 21 are smaller and lighter than those of normal individuals [2] and exhibit a lower neuronal density; they also show synaptic irregularities due to the reduction of neurotransmitters [3] and anomalies in myelination processes [4]. Individuals with DS also show alterations in sensory modalities.…”

Effect of Treadmill Training and Supramalleolar Orthosis Use on Motor Skill Development in Infants With Down Syndrome: A Randomized Clinical Trial

“…8,16 The higherintensity, individualized training also has been reported to have a positive impact on adaptive gait and physical activity. 17,18 This study is an extension of the previous treadmill training research involving infants with DS. The intent was to incorporate orthosis use into the lower-intensity treadmill training protocol of Ulrich and colleagues 13 to provide improved biomechanical alignment during stepping practice.…”

Gait and Balance

“…Other randomized clinical trials have been applied in infants with Down syndrome and revealed an earlier onset of independent sitting (Ulrich et al 2001) and walking (Ulrich et al 2001;Wu et al 2007;Wu et al 2008), and longer stride length . Furthermore, infants with ID responded better to a high compared to a low-intensity treadmill program, by increasing walking speed, cadence, by decreasing double support duration and by being able to walk over an obstacle at higher rates within a 6-month training period .…”

“…More particularly, the selected strategy to cross the obstacle varies from trial to trial (Virji-Babul and Brown 2004) and there is often hesitation prior to obstacle crossing. Furthermore, they need more time to anticipate the obstacle (Smith and Ulrich 2008;Sparrow et al 1998;Wu et al 2008) and therefore, as early as three steps before the obstacle, they may increase the base of stance width and reduce walking speed, cadence, and step length . Regarding the distance of the foot from the obstacle Smith and Ulrich (2008) reported a decrease in people with Down syndrome which makes obstacle crossing more dangerous for tripping.…”

“…The available randomized clinical trials include people with Down syndrome, treated to improve gait and balance with treadmill training protocols (Angulo- Carmeli et al 2002c;Ulrich et al 2001;Wu et al 2007;Wu et al 2008). Carmeli et al (2002c) have shown that TUG test performance, as well as knee flexion and extension strength, improved significantly for the experimental group of adults (57-65 years old) with ID after 6 months of training.…”