Reversal of handedness effects on bimanual coordination in adults with Down syndrome.
Right-handed adults with Down syndrome may lead with the left hand during two-hand tasks, so check motor dominance before you design bimanual interventions.
01Research in Context
What this study did
Researchers asked adults with Down syndrome to move both hands together in a steady rhythm. They watched which hand led the motion and how stable the pattern stayed.
They compared right-handed adults with DS to non-right-handed peers and to typical adults. The goal was to see if handedness works the same way in DS as it does in everyone else.
What they found
Right-handed adults with DS surprised the team. Their left hand took the lead during the task, the opposite of what happens in typical right-handers.
The reversed lead made their coordination less steady. Non-right-handed adults with DS looked more like the control group.
How this fits with other research
Shoji et al. (2009) saw a similar flip in the ears. Teens with DS showed a left-ear edge on a listening task, again the reverse of typical kids. Together the studies hint that the DS brain may wire dominance differently across both sound and movement.
Rigoldi et al. (2011) and Diemer et al. (2023) also found shaky motor control in DS, but they looked at quiet standing and stair climbing. The new paper adds the fresh twist that the trouble can start with which hand the brain picks as leader.
Perry et al. (2024) extends the story into real life. They showed that DS adults who dance have tighter postural sway, almost matching typical levels. So reversed hand lead is not a fixed limit; practice can still sharpen motor output.
Why it matters
Before you write a bimanual program, test hand preference with a quick lead task. If the left hand jumps ahead in a self-declared right-hander, adjust your prompts and cues. Build in extra practice trials and celebrate small stability gains. The brain in DS may route dominance its own way, but data from dance and balance studies say training still helps.
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02At a glance
03Original abstract
BACKGROUND: Research on unimanual tasks suggested that motor asymmetries between hands may be reduced in people with Down syndrome. Our study examined handedness (as assessed by hand performance) and perceptual-motor integration effects on bimanual coordination. METHODS: Adults with Down syndrome (13 non-right-handed, 22 right-handed), along with comparison groups of adults (16 non-right-handed, 21 right-handed) and children (15 non-right-handed, 22 right-handed) without Down syndrome, drummed with auditory, verbal and visual instructions. RESULTS: In contrast to handedness effects in the children and adults without Down syndrome, right-handed participants with Down syndrome led more with the left hand, and had lower coordination stability than non-right-handed participants with Down syndrome. CONCLUSIONS: The reversed handedness effect during bimanual coordination suggests a complex relationship between handedness and task requirements in adults with Down syndrome.
Journal of intellectual disability research : JIDR, 2011 · doi:10.1111/j.1365-2788.2011.01457.x