Genu varum is a condition resulting from the deformity of the varus around the knee whereby the lower leg is bowed inwardly causing the medial malleoli to touch, and as a result presents an appearance of the legs forming a bow shape. This condition could be caused by various factors ranging from leg infections to skeletal problems which hinders the proper formation of bones. Children are prone to such structural deviation from normal bone alignment from birth.
A likely treatment for this condition is the use of corrective leg braces.
People were not careful and wanted to take the selfie to show people that they did something cool. Mainly just to brag on the internet or feel righteous about themselves. Also by not taking the correct precautions