In response to Paolo de Leva's posting concerning the term "contact" forces
I would like to make the following comments:
If you accept that contact means zero distance then there is no contact
between bone surfaces because simply that distance is not zero in joints!
That implies however that there is no bone-on-bone forces since there is
no actual bone contact!
I use the term "contact" accepting that the interface between tibia and femur
in the knee for example is through ligaments, synovial fluid and other
joint supporting structures. The forces exerted or absorbed by these
structures therefore can be termed tibio-femoral contact forces.
The patellar tendon is NOT part of this tibio-femoral interface and
therefore the muscular force is not part of the contact forces.


Vasilis Baltzopoulos
University of Liverpool, U.K.