Locking/Unlocking

Question 1

Locking into CPP

-Sitting->standing

Answer 1

• Fem condyles roll ant from Tib Plateau over tibial condyles
• They then glide post over tib condyles to prevent FCs from rolling right off of TCs
• Approaching extension, movement stops at shorter lat fem condyle first while longer/thinner med fem condyle continues with femur rotating medially around fixed lat condyle until it locks in

Question 2

Unlocking to OPP

• Standing->sitting
• Initiated by Popliteus which lat rotates femur on fixed tibia

Answer 2

• Femur rotates laterally on tibia

- Fem condyles then roll posteriorly on tib condyles and glide ant on TCs to stop FCs rolling off of TCs