With
slight distal traction on the leg, a valgus and internal rotation force
is applied to the extended knee
With
maintenance of the forces noted above, the knee is then flexed past 30°.
Pivot
shift test in an ACL deficient knee. In the intitial stages of knee flexion,
the tibia will be anterolaterally subluxed on the distal femur with application
of a valgus and internal rotation force at the knee.
With
further flexion of the knee (past approximately 30° ), the iliotibial band goes
from an extendor to a flexor of the knee and the tibial anterolateral subluxation
reduces (shifts) back into place.