Muscle Thickness in Lower Extremity and Locomotor Functions in Children With Down Syndrome and Typical Developing Peers.
Ultrasound shows kids with Down syndrome have thinner front-shin muscles that directly shorten their steps—so target dorsiflexor strength early.
01Research in Context
What this study did
The team used a small ultrasound wand to measure lower-leg muscle thickness in 48 kids. Half had Down syndrome, half were typical peers .
Each child also walked and ran while cameras tracked step length, speed, and balance.
What they found
Kids with Down syndrome had thinner calf and shin muscles. Their steps were shorter and they walked slower.
One muscle—the tibialis anterior in front of the shin—was the best predictor. Thinner muscle meant shorter steps.
How this fits with other research
Lancioni et al. (2009) reviewed 26 studies where treadmills or walker-plus-microswitch setups helped kids with Down syndrome take more steps. Esra’s new data explain why that works: weak dorsiflexors limit step length, so strengthening them should boost gains from treadmill training.
Mulder et al. (2020) showed kids with Down syndrome chew less efficiently. Together with Esra’s leg-muscle findings, a pattern emerges: both oral and leg muscles are under-developed, suggesting body-wide hypotonia targets.
Gandhi et al. (2022) found adults with intellectual disability meet exercise guidelines at only half the rate of typical adults. Esra’s study flags one root—thinner lower-leg muscles start in childhood and likely snowball into low adult activity.
Why it matters
You now have a quick, portable screen: a 30-second ultrasound of the tibialis anterior tells you if a child is at high risk for short, slow gait. Pair that with treadmill training and dorsiflexor strengthening games—think towel-scrunches or marble-pickups—to lengthen steps and maybe prevent the low activity levels seen later.
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02At a glance
03Original abstract
OBJECTIVES: Children with Down syndrome (DS) have deficits in motor skills that lead to stereotypical changes in the characteristics and adaptations of their movement. The aim of the study was to investigate locomotor characteristics and muscle thickness of the selected muscles in the lower extremity and the relationship between muscle thickness and locomotor parameters in children with DS and typically developing peers. METHODS: Children with DS (n = 18; age: 5.36 ± 0.60) and typically developing (TD) (n = 30; age: 5.62 ± 0.60) aged 4-7 years participated. Lower limb muscle thickness was assessed through B-mode ultrasound. The GAITRite system evaluated gait and running spatiotemporal parameters, using linear regression to determine the strength of the relationship between muscle thickness and these parameters. RESULTS: Compared to the TD group, the DS group had significantly less lower limb muscle thickness and differed significantly in gait and running parameters (p < 0.05), except for gait stance and swing percentages. Tibialis anterior muscle thickness predicted step length in TD (1.546 ± 0.081) and DS (1.501 ± 0.148), respectively, explaining 16.3% and 31.4% of gait, and in DS, 26.8% of running. CONCLUSIONS: Muscle thickness may serve as an indicator of muscle strength and coordination, contributing to the understanding of their impact on locomotor performance in DS children, particularly with regard to the tibialis anterior muscle, which is essential for dorsiflexion and foot placement control. The prioritisation of stability for gait and running is essential due to reduced velocity, increased step width and shorter step length in DS children.
Journal of intellectual disability research : JIDR, 2026 · doi:10.1111/jir.70083