Quantitative assessment of tip-toe behavior in individuals with autism spectrum disorder and intellectual disability: A cross-sectional study.

The term "toe walking" describes walking on the toes with a lack of heel strike upon initiation of the stance phase of gait. In individuals with autism spectrum disorder (ASD), this phenomenon, or "tip-toe behavior" (TTB), can be present in a substantial proportion of subjects even during standing. In this study, we investigated TTB in 50 persons with ASD (age range 4-26 years). We evaluated TTB through an observational/report-based assessment protocol. Subsequently, we employed a new structured video-based coding protocol based on standardized video recordings, focusing on static and dynamic conditions. Finally, the findings of the two protocols were compared. Twenty-four subjects with TTB were identified and classified according to three functional groups: TTB1, present only during running (6 subjects); TTB2, present during walking and running (11 subjects); and TTB3, present during standing, walking, and running (7 subjects). Moreover, we found that TTB3 subjects exhibited a significantly higher quantity of TTB compared with subjects in the TTB1 and TTB2 groups during both standing and walking tests. Additionally, a high quantity of TTB in the static test was found to be related to a high quantity of TTB in the dynamic test. Variables such as age, autism severity, intellectual disability, and gender were not significantly associated with the mean percent of TTB both in static and dynamic tests in multivariate analysis. This structured video-based coding approach appears feasible and useful for assessing TTB in individuals with ASD and it has the potential to provide insights into TTB trajectories and aid in designing possible interventions.

Relationship between tip-toe behavior and soleus - gastrocnemius muscle lengths in individuals with autism spectrum disorders.

BACKGROUND: About 20% of individuals with autism spectrum disorders (ASD) showed tip-toe behavior (TTB). This behavior may be related to a decreased ankle joint range of motion (ROM) in dorsiflexion. Physiologically, gastrocnemius (GM) and soleus (SM) muscles influence ankle ROM independently. However, no studies investigated the relationship between the amount of time individuals with ASD spend in TTB and GM and SM muscle lengths. OBJECTIVE: To evaluate the relationship between three mutually exclusive clinical patterns of TTB i.e., during standing, walking and running (TTB Class 1), or during walking and running (TTB Class 2), or only when running (TTB Class 3), and GM and SM muscle lengths. METHODS: Sixty-nine individuals with ASD (average age: 14.1 ± 3.6 years, 56 males) were enrolled. In a clinical setting, SM and GM muscle lengths of both legs were assessed through a manual goniometer. Measurements were performed by two trained assessors blinded to TTB classifications. RESULTS: Individuals with ASD classified as TTB Class 1 demonstrated a shortening of both GM and SM compared with NO-TTB and TTB Class 3 individuals. CONCLUSIONS: Our results support the relationship between TTB severity and GM and SM shortening assessed by a decreased ankle joint ROM in dorsiflexion. Further studies are needed to determine the factors associated with TTB and decreased ankle ROM.

Assessment of presentation patterns, clinical severity, and sensorial mechanism of tip-toe behavior in severe ASD subjects with intellectual disability: A cohort observational study.

We assessed presentation patterns and characteristics of tip-toe behavior (TTB), more commonly known as toe walking, in a cohort of severe autism spectrum disorder (ASD) subjects with intellectual disability in two studies. The first study included 69 consecutive ASD subjects (57 males, mean age = 14 years-3.7 SD) under observation at our institute. A therapist assessed the presence of TTB during standing, walking, and running through direct observation and an interview with the subjects main caregiver. The prevalence of TTB was 32%. We found three clinical presentation patterns of TTB: (1) present when standing, walking and running (45.5%), (2) present when walking and running (18.4%), or (3) present only when running (36.4%). TTB subjects were more frequently nonverbal than those without TTB (72.7% vs. 44.6%-P = 0.03). On the other hand, no significant difference in ASD severity according to the ADOS scale was found between TTB and non-TTB subjects. In the second study, carried out in a subgroup of 14 ASD subjects (7 TTB and 7 non-TTB), we evidenced that a soft floor surface (foam mats) made a substantial difference in reducing the TTB phenomenon. TTB is frequently present in ASD individuals and may occur in three mutually exclusive modalities, which ultimately defines what is commonly known as toe walking. The presence of TTB seems correlated to the severity of language delay. Foot contact on soft surfaces reduces TTB both during static and/or dynamic tasks. Further evaluation is needed to clarify the potential pathophysiological implications of this phenomenon. Autism Res 2017, 10: 1547-1557. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.