Aims
In Asia and the Middle-East, people often flex their knees deeply
in order to perform activities of daily living. The purpose of this
study was to investigate the 3D kinematics of normal knees during
high-flexion activities. Our hypothesis was that the femorotibial
rotation, varus-valgus angle, translations, and kinematic pathway
of normal knees during high-flexion activities, varied according
to activity.
Materials and Methods
We investigated the in vivo kinematics of eight
normal knees in four male volunteers (mean age 41.8 years; 37 to
53) using 2D and 3D registration technique, and modelled the knees
with a computer aided design program. Each subject squatted, kneeled,
and sat cross-legged. We evaluated the femoral rotation and varus-valgus
angle relative to the tibia and anteroposterior translation of the
medial and lateral side, using the transepicodylar axis as our femoral
reference relative to the perpendicular projection on to the tibial
plateau. This method evaluates the femur medially from what has
elsewhere been described as the extension facet centre, and differs
from the method classically applied.
