Closed Kinematic Chain Leg Extension; Hip/Knee Extension; Knee Tracking; Range Of Motion - CYBEX VR2 Owner's And Service Manual

Closed Kinematic Chain Leg Extension

• Hip/Knee Extension - The quadriceps are
responsible for extension of the knee joint. The
gluteus maximus and hamstring are responsible
for hip extension. The hip-knee relationship in
closed kinematic chain extension represents an
indirect proportion. An increase in hip motion
will increase hip extensor work and proportion-
ally decrease knee extensor work, and vice
versa.
• Knee Tracking - Functioning as a hinge, it is
imperative that the knee be directed toward the
toes when eccentrically flexing or concentrically
extending during closed chain movements.
Exactly which toe(s) the knee is to be directed
towards is dependent upon the anatomical
structure of the user. It is commonly suggested
that the knee track between the big and second
toes. However, if a marked Q-angle is noted,
tracking is recommended more toward the fifth
(little) toe. Comfort is also a factor in the decision.
Ultimately, once the proper tracking has been
determined, it must be monitored and
maintained throughout each repetition.
• Range of Motion - The range of motion is limited by spinal alignment during eccentric
flexion and at full knee extension concentrically. Hyperextension of the knee is to be
avoided in closed chain leg work.
• Associated Muscles - Hip adductor involvement varies with foot placement. As the feet are
placed wider and the knees track accordingly, hip adduction is increased.
Exercise
Page 3-2
CYBEX VR2 Owner's Manual
MUSCLES TRAINED