The primary aim of the study was to measure the intra-rater and inter-rater reliability of MyotonPRO in measuring postural muscle tone and mechanical properties in individuals with spinal muscular atrophy (SMA). The secondary aim is to question the existence of a relationship between the functional levels of individuals with SMA and their muscle tone and biomechanical properties. It is assumed that the outputs to be obtained from this research will form the norm data for moyotonometer evaluation in children with SMA.

It seems to be important to examine peripheral changes in the pathogenesis of SMA. Although it shows that the target center in SMA is alpha motor neurons located in the anterior horn of the spinal cord, considering the interaction network of interneurons, cerebellum, neuromuscular junction, gamma-alpha motor neuron pool, descending and ascending pathways, and reflex arc, it has potential to be investigated in individuals with SMA. This suggests that it may have important consequences for peripheral mechanisms. It may be important to examine muscle mechanical properties to reveal any potential correlations between SMA types and disease progression. In addition, moyotonometer results can be a key evaluation method in examining treatment efficacy, diagnosis and disease course. However, in order for these activities to be observed with myotonometer, first of all, the reliability of its use in individuals with SMA should be questioned.

Inclusion Criteria:

• Between 0-4 years old
• Diagnosed with spinal muscular atrophy (SMA)
• Children who continue their medical treatment at home and are not in intensive care
• Children of families who agreed to participate in the study and approved the informed consent form.

Exclusion Criteria:

• Children of families who disagreed to participate in the study

The study was to be conducted with children with a diagnosis of Spinal Muscular Atrophy (SMA) followed in the Pediatric Chest Diseases Outpatient Clinic at Bağcılar Medipol Mega University Hospital and Istanbul Medipol Hospital, and with their families meeting the inclusion criteria of the study.