Background and aims 

Twenty-thirty percent of individuals with autism walk on their tiptoes[1]. Studies about quantitative assessment of Tip-toe behavior (TTB) are scarce. In a previous study we described three mutually exclusive clinical functional classes of TTB of increasing severity using a qualitative assessment: TTB only during running (TTB1), TTB only during walking and running (TTB2) and TTB during standing, walking and running (TTB3)[2]. The aims of this cross-sectional cohort study are: 1) to quantify TTB during both a static and a dynamic test in an ASD sample; 2) to compare the intensity of TTB in the three TTB clinical functional classes and in a NO-TTB group. 

Methods 

45 ASD subjects (mean age 13,15 years, 40 males) diagnosed according to the DSM V criteria were assessed for the presence/absence of TTB during standing, walking and running using standardized protocol[2]. The quantitative tests were conducted using a standardized video recordings. The quantity of TTB during static and dynamic tests was calculated as percentage of time spent on the tip toes and as the percentage of toe steps. 

Results 

According to the qualitative assessment, 25 ASD subjects resulted not TTB, 3 resulted in TTB class 1, 10 in TTB class 2 and 7 in TTB class 3. During the static quantitative test, the TTB time percentage values was 0.25% in NO-TTB group vs 1.82% in TTB1+2 vs 32,34% in TTB3 (p 

Conclusions

We quantified TTB using a new structured static and dynamic assessment test in our ASD sample. We found significant difference between NO-TTB and the 2 TTB subgroups. The TTB quantity in the static test is correlated with TTB quantity in the dynamic test. 

Notes:

1 Autism Research Unit, Villa Santa Maria Foundation, Tavernerio (Como), Italy;
2 University of Genoa; (3) School of Medicine and Surgery, University of Milano Bicocca, Milan, Italy