Assessment of quadriceps
strength. The examiner places his hands over the distal leg and asks the patient
to try to straighten out their leg.
Quadriceps:
The quadriceps muscles are a group of muscles on the anterior of the thigh
(vastus lateralis, rectus femoris, vastus intermedius, vastus medialis, vastus
medialis obliquus, vastus lateralis obliquus and genu articularis)which primarily
function to extend the leg. The quadriceps muscles act by pulling through
the quadriceps tendon-patella-patellar tendon complex. This complex is in
turn attached to the tibial tubercle and, through this attachment, it extends
the leg. Quadriceps muscle strength is very important to the functioning
of the knee, especially for the patellofemoral joint.
Assessment of hamstring strength. The examiner places
their hand over the posterior distal leg and asks the patient to pull their
leg toward the bed.
For patients with suspected proximal hamstring tears,
the same test may be performed in the prone position to both assess strength
and to observe (or palpate) for any balling up of the proximal hamstring on
exertion.
Hamstrings:
The hamstrings are a group of muscles
on the posterior aspect of the thigh whose primary function is to flex the
knee. The hamstring muscles (long head of the biceps femoris, short head of
the biceps femoris, semimembranosus, semitendinosus, and in some respects
the gracilis and sartorius) attach at various locations on the tibia to exert
a flexion moment which serves to flex the knee. Properly rehabilitated hamstring
muscles are extremely important in prevent anterior tibial translation in
the ACL deficient knee. Overall strength levels can be assessed by functional
testing or testing to fatigue on calibrated machines.
