Background: Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder. Mounting evidence show that persons with ASD may present sensorimotor deficits. Tiptoe behavior (TTB) is a possible finding during standing and/or walking and/or running assessment of individuals with ASD [1]. TTB persistence may lead to Gastrocnemius (GM) and Soleus (SM) muscles length shortening [1]. Their assessment can be done measuring ankle dorsiflexion range of movement (ROM) with knee extended (GM) and knee 90° flexed (SM)[1]. Traditionally, ROM has been assessed using visual estimation or long-arm goniometer technique. Recently, photography-based goniometry has been validated as instrument to measure joint ROM [2,3]. This non-invasive tool could be useful when measuring GM and SM length in individuals with ASD, where tactile hypersensitivity can be often found.

Objectives: The aim of this study was to investigate the feasibility of measure GM and SM lengths in subjects with ASD through use a photography-based goniometry (“Dr. Goniometer” app).
Methods: We assessed SM and GM length values in a sample of ten subject with ASD (5 with TTB and 5 without TTB), diagnosed following the DSM-5 criteria. Moreover, the ASD severity was assessed using the Autism Diagnostic Observation Schedule (ver. 2) calibrated severity score.
To assess TTB presence or absence we applied a standardized qualitative assessment previously described [1]. Photography-based goniometry measurement was conducted following the methodology previously described from Wang et al. [4] (see Fig.1).

Results: The mean age of the study sample was 14.48 yrs (SD 3.4) (age range: 8.9-20.3 yrs; 10 males). The participants presented moderate to high ASD severity (mean ADOS CSS: 7.89 - SD 1.36; range: 6-10). We were able to assess measure of GM and SM lengths using “Dr.Goniometer” tool in 9/10 subjects (90%). Details about demographic characteristic of study sample and GM and SM length values are summarized in table 1.

Conclusion: Photography-based goniometry seems to be a feasible tool for assessing GM and SM muscle lengths in ASD individuals both with and without TTB.

Notes:

1 Autism Research Unit, Villa Santa Maria Foundation, Tavernerio (CO), Italy
2 School of Medicine and Surgery, University of Milano-Bicocca, Milano, Italy 3 Institution, City, Country