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Rehabilitation and CORE musculature in the Treatment of Patellofemoral pain
371
Treatment focus
Prior to having the patient engage in closed
kinetic chain (CKC) lower extremity
strengthening exercises, adequate recruitment
of lower extremity musculature in an open
kinetic chain (OKC) condition must be demons
trated, specifically strength and endurance of
the gluteus maximus and medius musculature.
OKC activity of the quadriceps muscle may
impose high joint forces across a relatively
small contact surface area, aggravating the pain
cycle. For this reason, any quadriceps
strengthening, in particular OKC exercises,
should be approached cautiously with high
vigilance to pain.
Some possible exercise suggestions for
strengthening individual muscles groups before
engaging in strengthening thru co-ordinated
body movement patterns are:
• Isometric quadriceps presses in deeper angles
of knee flexion, when the patella is fully
engaged in the trochlear groove. (Caution: the
patient should not have a cartilage lesion that
contributes to pain with increased patella on
trochlea contact).
• Quadriceps strengthening at a single angle in
the knee arc motion has proven to have
beneficial effects for quadriceps strength
across all knee angles [15]. With more
exaggerated quad shutdown and dysfunction,
CKC activities often bypass the quad with a
kinetic task seemingly performed without
appropriate quad activation. Specific isolated
quadriceps strengthening may need to be
performed to activate the muscle prior to a
progression into more complex, coordinated
or loaded strengthening activities. To this
end, terminal knee extension (TKE) quadri
ceps activities, often prohibited in PF
exercises, may be employed cautiously with
the end goal of the patient being able to
execute terminal extension without a lag.
Resistance is not employed with this activity;
only the weight of the limb against gravity is
used. With such an activity, heavy consi
deration must be given for reported pain,
observed effusion response, and stress on any
surgically influenced structures. Once
adequate muscle strength to achieve active
TKE is restored, transitioning to CKC
quadriceps strengthening is recommended to
minimize potentially deleterious loading of
the PF joint.
• A good alternative to OKC quadriceps
exercises in early rehabilitative phases would
be load-reduced CKC activities, such as leg
press or leg press simulation into a stabilized
exercise ball through the terminal degrees of
knee extension/early degrees of knee flexion.
Once proficiency with coordinated quadriceps
control of this early range of motion is
demonstrated, the patient will better tolerate
the transition to CKC activities with body
weight and/or external resistance.
Physical Performance Tests for PF
issues
Physical performance testing of the lower
extremity is a method of assessing knee
function & movement coordination impair
ments. These tests typically establish the
“norm” as the patient’s contra lateral limb and
thus compute a side-to-side difference in lower
extremity function (Limb Symmetry Index –
LSI). Such testing is common in the recovery
of function after a ligamentous knee injury and
surgery, most commonly employed in theACL-
deficient and ACL-reconstructed population
[16, 17]. In dealing with the patellofemoral
joint, this method can be challenging or less
useful as often these patients demonstrate
bilateral abnormalities and/or symptoms; using
the opposite limb as “normal” has to be viewed
with some skepticism.
Strength tests around the knee involve:
- Testing of individual muscle groups.
Isokinetic testing of knee flexion and exten
sion is a common tool to establish objective
strength parameters about the knee. Proximal
lower extremity muscle testing may be
performed through standardized manual
muscle testing methods or with the use of
hand-held or isokinetic dynamometry when
such equipment is available.
- Testing of functional (co-ordinated) knee
activity: (e.g.) hop tests, balance reach tests.
- CORE testing (proximal limb control afforded