Does balance impairment underlie motor development delay? This study investigates the motor skills of preschool children and the role of balance in motor performance. The aim is to identify those at-risk for motor-delay and test if balance is an underlying mechanism that explains sub-par performance. Children with poor motor skills abound in pre-schools (Valentini, & Rudisill, 2004). To best address their needs, motor skill assessment and focusing on balance mechanisms may establish avenues for early intervention.
Gross motor skills of young subjects (5-7 years; N= 28) from Lubbock, Texas (Parkway Elementary School) were assessed via the Test of Gross Motor Development 2 (TGMD2, Ulrich, 2000) involving locomotor (LOC: galloping, hopping, running, jumping, leaping, sliding) and, object manipulation skills (OBJ: rolling, dribbling, ball-striking, throwing, catching, and kicking). Balance was tested via the Sensory Organization Test (SOT) protocol, where the task was to maintain upright stance under six conditions: C1) control-unperturbed, C2) vision-absent, C3) vision sway-referenced, C4) platform sway-referenced, C5) vision-absent + platform sway-referenced, and C6) platform- and vision- sway-referenced.
Results indicate that means for TGMD2 scores, whether based on overall percentile rank (M= 54.6; SD= 23.9) or percentiles specific to either LOC (M= 60.9; SD=20.6) or OBJ (M= 46.9, SD= 27.3) reflect a largely heterogeneous group (note the large SD's). Subjects were then stratified into three sub-groups: 1) at-risk for motor delay (MD: °Ü 35 th percentile, N= 8), 2) typically developing (TD) group (50th ¨C 58th percentile, N=5), and 3) advanced (ADV) group (°Ý 79th percentile, N=7). To conduct further analyses, subjects whose percentile ranks fall between the grouping criteria were not included in the Analyses of Variance (smaller N=20). Overall TGMD2 percentile means for these sub-groups were as follows: MD group = 26.5, TD group = 54.8 and ADV= 86.5, while SOT (composite score) means were 61, 60 and 66 respectively.
Analyses of composite SOT scores (sub-groups) as well as specific C1 to C6 scores indicated non-significant group differences. Subsequent analyses of the relationship between (unperturbed) balance (C1 score) and motor performance revealed a moderate correlation using either overall TGMD2 (r= 0.47) or LOC percentile (r= 0.55) scores. When the correlation analyses were repeated using the total subject pool (N=28) the correlation between C1 and either overall TGMD2 (r= 0.48 ) or LOC percentile (r=0.38) yielded similar low-to-moderate results. The small sample size likely contributed to these results; the need to understand mechanisms underlying motor delays warrants further investigation.