Are age-specific differences in the scapulo-humeral coordination negligible when examining patients?

Abstract

s / Gait & Posture 42S (2015) S1–S27 S11 free walking and walking performing a mental dual task (DT). For all the participants and each condition 30 strides were analyzed [3]: turns were excluded from the analysis. The following methods for quantifying gait stability were applied: stride time variability, Poincare plots, harmonic ratio, short term Lyapunov exponents, maximum Floquet multipliers, recurrence quantification analysis andmultiscale entropy [2]. An unpaired t-test (level of significance of5%)wasperformedon the twogroups for eachmethod: t-testwas rightor left-tailed hypothesizing higher stability in the NotGrown group. Results: t-Test results showed no differences between the two groups for stride time variability, Poincare plots, harmonic ratio, short termLyapunov exponents andmaximumFloquetmultipliers. Recurrence quantification analysis andmultiscale entropy showed statistically significant results for the two groups in the DT condition when applied on the AP axis and indicated correctly the NotGrown as more stable than the Grown. Discussion: Preliminary results suggested that during normal walking no stability indices could discern between Grown and NotGrown adolescents. In DT condition, recurrence quantification analysis and multiscale entropy identified the Grown group as less stable than the NotGrown, suggesting that a focused attention to the task make the two groups not discernible, while, during DT, some manifestations of low coordination appeared. Moreover, the AP direction seemed to be the most sensitive to the differences between the two groups: further studies are needed in order to understand if this result is indicative of a focused direction of the motor control during gait. Present results are preliminary and are based on two different groups of adolescents, who declared whether they recently grew or not. More detailed and significant results will be obtained through the longitudinal study on the 280 adolescents included.