Ultrasound (US) is a well-established and validated diagnostic imaging method in the evaluation of patients with suspected muscle disorders [10]. It is a relatively cheap and easily applicable method, allowing the visualisation of striated muscle with a high temporal resolution (>0.1 mm). The major advantage of US is the lack of any radiation exposure, which makes it the perfect imaging method for the evaluation of children. It even allows dynamic imaging of contracting muscles and can visualise pathological muscle activity such as fasciculation [11–13].