Which of the following statements is false?

The statement about the minimally detectable change (MDC) of the kyphotic index being 5 is considered false because the MDC represents the smallest amount of change that is considered significant and not due to measurement error in a clinical setting. Recent literature suggests that the MDC for the kyphotic index may differ based on various factors like population studied, methodology, and measurement techniques. In geriatric populations, precise MDC values are often carefully determined and may be lower or higher than the value stated, depending on the context and specific characteristics of the clinical study.

The other statements are based on established findings in the literature. Research has shown that flexible curve measurements are effective and validated for assessing kyphosis. Additionally, inter and intrarater reliability measures indicate that when using the flexible curve method in an erect posture, multiple testers can achieve consistent results. Finally, the formula for the kyphotic index, which involves height measurements, is indeed used to evaluate changes in kyphosis over time, a critical aspect for monitoring progression in elderly patients.