Sickling is a ballet term that is used to describe a dancer’s foot that is incorrectly placed or pointed, causing it to look curved inwards when looking at the front view of the leg. A dancer will often receive the correction of sickling many times thought out training and even into professional careers.
A sickled foot is somewhat common during training because the amount of flexibility in a person’s foot and ankle is generally greater on the inside of the foot. If a dancer thinks of simply “pointing your feet as hard as you possibly can!” the foot almost naturally goes into a sickled position.
So why is sickling considered a correction if it’s more natural?
The line a sickled foot creates for a dancer is generally thought as aesthetically unpleasing. Secondly, a dancer is more prone to injuries when sickling their feet because of the slanted alignment in their foot when releving or landing from a jump.
BalletHub has a very popular article to learn more about sickling in ballet.