At what age does Sever's disease commonly occur in females?

Sever's disease, also known as calcaneal apophysitis, typically occurs in children and adolescents experiencing rapid growth, particularly during periods of increased physical activity. The disease is most common in those aged around 8 to 14 years, coinciding with the growth spurts associated with puberty.

Focusing on the correct response of 9 years, this age falls well within the typical range where Sever's disease can manifest, particularly in females, who generally experience growth spurts earlier than males. It is also a common age for participation in sports, which can increase the risk of overuse injuries like Sever's disease due to repetitive stress on the heel.

The other choices fall outside the most typical age range for the onset of this condition, either being too young or too old. An age of 7 years is on the younger side and may not yet coincide with the significant physical activity levels that contribute to the development of such issues. Similarly, ages 11 and 13 indicate a later onset, where the prevalence of such a condition would be expected to decrease as the individual progresses further in their physical maturity. Hence, 9 years is the age most closely associated with the onset of Sever's disease in females, aligning with peak growth and