rehabilitation exercise：
Lift the thigh and draw a circle.
one foot standing,
The other leg lifts the thigh (the calf naturally hangs down),
With the knee joint (knee bone) as the center,
at the front of the body - draw a circle.
The following images are quoted from
health.businessweekly.com.tw/AArticle.aspx?ID=ARTL000026523&p=2
