Leg pain/locking up knee?

Is sitting with crossed legs (ankle-on-knee) detrimental for the bone structure of your leg?

• Specifically, is sitting with the ankle of one leg resting on the knee of the other leg detrimental to the bone structure of your twisted knee (i.e. the knee of the leg of which the ankle is resting on the knee of the other leg)? Photo: Author: Andreas Praefcke (2009) License: Creative Commons Attribution 3.0 Unported (http://creativecommons.org/licenses/by/3.0/deed.en). URL: http://commons.wikimedia.org/wiki/File:Passau_Dialog_Mensch_Fisch_Sinnender.jpg#filelinks

• Answer:

  In short, probably not!  The musculoskeletal system is pretty robust and it is unlikely that sitting in the position described above would cause damage to the structure of your leg.  Prolonged inactivity or maintenance of a single posture can cause discomfort for a variety of reasons (blood pressure, nerve pinching, muscular strain, etc), but your body will generally cause you to shift position from discomfort, thus alleviating these problems.  However, it is possible for certain postures to cause permanent changes to your musculoskeletal system if they are habitually practices from a young age, for long periods of time, and continued through-out life.  The most common one seen is habitual squatting, which can alter the shape of the tibia, fibula, and foot bones.  I am unsure if there have been any studies looking into the cross legged position described above though!