The 30s-STS test has not been formally validated specifically for myositis patients, despite its frequent utilization in studies. Unlike in Parkinson’s disease where posture is a key concern, myositis primarily affects muscle strength rather than posture control. This difference in disease manifestation may impact the test’s validity and interpretation for myositis patients

• Compare to the patient’s own baseline rather than population norms
• Consider the status of comorbid conditions that may impact performance
• Use in conjunction with other clinical measures and laboratory tests