Table of Contents
For proper observation, the patient must be properly undressed so that the examiner can observe the posture of the spine, hips, knees, and ankles. The patient can be viewed from several different views: the anterior view, the lateral view and the posterior view in standing, then the anterior and lateral views in sitting.
Anterior view, standing
The examiner should note any malalignment of the knees, such as genu varum or genu valgum deformities. Malalignment here may work up or down the kinematic chain to cause malalignment elsewhere. Normally, the legs of an adult should be relatively straight. Swelling could indicate prepatellar bursitis. The position of the patella may be observed to see if they are “squinting” patella (tilting inward), “frog-eyed” patella (tilting outward), or “spinning” patella (rotated in or out). This may indicate patellofermoral instability. Normally, the patellae should face straight ahead with no lateral tilt or rotation.
Observe any apparent swelling, ecchymosis, bruising, discoloration, scarring, or signs of recent injury or surgery around the knees as well.
Lateral view, standing
The examiner should view both sides of the patient for comparison. Genu recurvatum, patella baja, patella alta or an inferior tilt of the patella should be noted. Normally, both legs should be equal and the plane of the patella and femoral condyles should be the same.
Posterior view, standing
Examining the patient from behind, the examiner should confirm what was seen from the anterior view. Abnormal swelling should be noted, which may indicate a popliteal cyst.
Anterior and lateral views, sitting
The patient should sit with the knee flexed to 90º and the examiner should observe anterior and both lateral views. Normally, the patella should face forward, resting on the distal end of the femur. Note for patella baja or patella alta, bony enlargements, abnormal swelling, or tibial torsion.
It is important to observe the patient’s gait while the patient is unaware of being observed, i.e. when first walking into your clinic or into the treatment room. The examiner should note any differences in stride length, walking speed, cadence, or linear and angular displacement. For example, if the patient has patellofemoral syndrome, the patient could show less knee flexion during the single-leg stance phase, combined with lateral femoral rotation during the swing phase. Furthermore, the examiner should watch for abnormal patellar movement, for patellar tracking problems, and abnormal motion of the tibia relative to the femur, for possible instability problems. Movement above and below the patellofemoral joint should also be observed, such as the hip, pelvis and ankle joints. For example, weak hip abductors (a positive Trendelenburg’s sign) combined with medial tibial rotation may lead to increased stress on the knee resulting in patellofemoral syndromes.
The examiner can palpate the patient’s knees in several different positions, such as in supine with knee extension, supine with knee flexion, prone with slight knee flexion, or with the foot of the test leg resting on the opposite knee.
In knee extension, the examiner should palpate the patella, patellar tendon, patellar retinaculum, medial and lateral epicondyle of the tibia and femur, bursa structures, plica, MCL, quadriceps, sartorius, pes anserine, IT band, and the tibial tubercle. In knee flexion, the examiner should palpate the tibiofemoral joint line, meniscal cysts, femoral condyles, and adductor muscles. With the patient prone with knees slightly flexed, the examiner should posteriorly palpate the soft tissues of the posterior knee, the popliteus corner (arcuate-popliteus complex, the lateral gastrocnemius, the biceps femoris, and lateral meniscus), the posteromedial corner (posterior oblique ligament, the semimembranosus, the medial gastrocnemius, and medial meniscus), and the hamstring and gastrocnemius muscles. Finally, with the patient’s test leg resting on the opposite knee, the examiner should palpate the LCL.
Range Of Motion
Normal range of motion for knee flexion is 135 degrees, which is measured with a goniometer. The patient position is supine with their lower extremity in anatomical position. The patient is instructed to slide their foot along the table toward their pelvis. The leg is then taken through the motion passively and held. The bony landmarks include the stationary arm of the goniometer at the lateral midline of the femur pointing toward the greater trochanter. The axis is the lateral epicondyle of the femur and the moving arm is the lateral midline of the fibula, which is in line with the fibular head and lateral malleolus. Remember to check the contralateral side.
Normal range of motion for knee extension is 0 degrees which is measured with a goniometer. The patient position is supine with their lower extremity in anatomical position. The patient is instructed to push their knee into the table with the lower limb held out straight. The leg is then taken through the motion passively and held. The bony landmarks include the stationary arm of the goniometer at the lateral midline of femur pointing toward the greater trochanter. The axis the lateral epicondyle of the femur and the moving arm is the lateral midline of the fibula, which is in line with the fibular head and lateral malleolus. Remember to check the contralateral side
Clearing the joints
The examiner should clear above and below the knee joint to ensure that pain or abnormal issues are not being referred from another joint. The joints that need to be cleared are the hip, SIJ, and the knee. In any point of the exam, if the passive ROM brings on pain, no overpressure should be applied and/or the examiner should not provoke the patient’s pain any further with an increase in the position of aggravation. Before clearing specific joints, the examiner could assess multiple joints by asking the patient, while standing, to stand on one leg, hop on one leg and squat.
Clearing the hip
With the patient in supine, the examiner should bring the hip into end-range hip flexion and apply overpressure. Then examiner should bring the flexed hip into internal rotation. Next, the examiner should test hip flexion with adduction and apply overpressure. The last position to clear the hip would be a combination of hip flexion, adduction and internal rotation with overpressure.
Clearing the SIJ
With the patient in supine, the examiner should find the ASIS and apply strong distraction and compression for thirty seconds, or until pain is elicited.
Clearing the knee
With the patient in supine, the examiner should take the knee to end range flexion with overpressure and into end range extension with overpressure (the force is applied below the knee joint).
Clearing the ankle
With the patient in prone, the examiner should take the ankle joint to end-range dorsiflexion and apply a flick, to end-range plantar flexion and apply a flick, and to end-range inversion.
Manual Muscle Test
The patient is positioned prone with limbs straight. The examiner is standing next to the tested limb with one hand giving resistance on the posterior surface just proximal to the ankle joint. The other hand is palpating the hamstring tendons to feel for contraction. The patient is first instructed to go through available range of motion actively then taken through passively by the examiner. The patient is then instructed to flex the knee while resisting the force given by the examiner. The graded muscle tests include a grade 5 if the patient is able to withstand maximal resistance and the end knee flexion position cannot be broken. A grade 4 is when end knee flexion position is held against strong to moderate resistance and a grade 3 is given if the patient can hold end range position but cannot tolerate any resistance. If the patient cannot perform the motion against gravity then they must be put in side-lying. A grade 2 is given if the patient can complete the available range of motion of knee flexion in a gravity eliminating position with the leg held by the examiner. A grade 1 is given with the patient in prone and the knee is partially flexed and held by the examiner and there is a visible or palpable muscle contraction of the hamstrings. Remember to check the contralateral side.
The patient is short sitting with knees bent. The examiner is positioned to stand next to the limb tested with one hand over the anterior surface of the distal leg just above the ankle joint. The patient is first instructed to go through available range of motion actively then taken through passively by the examiner. The patient is then instructed to straighten the knee while resisting the force given by the examiner. The graded muscle tests are a grade 5 if the patient is able to withstand maximal resistance and the end of knee extension position cannot be broken. A grade 4 is when end knee extension position is held against strong to moderate resistance and a grade 3 is given if the patient can hold end range position but cannot tolerate any resistance. If the patient cannot perform the motion against gravity then they must be put in side-lying. A grade 2 is given if the patient can complete the available range of motion of knee extension in gravity eliminating position with the leg held by the examiner. A grade 1 is given with the patient in supine and the examiner palpates the quadriceps muscle to feel a contraction. Remember to check the contralateral side.
The patella tendon is innervated by L2, L3 and predominately by L4. The knee jerk is a deep tendon reflex that is performed by the examiner with a reflex hammer striking the patella ligament with the patient in short sitting. If the patient kicks his knee upon a hammer strike then their neurological reflex is intact. Lack of a knee jerk is a positive sign for a lower motor neuron problem. Remember to check the contralateral side.
Dermatones of the lower extremity should be examined upon suspicions of neurological involvement. They should be done specifically if there are complaints of numbness and tingling down the leg. The examiner should use a pointy object and press on the distal portion of the dermatone on both legs and ask the patient if one side feels different then the other side.
Myotomes of the lower extremity should be examined upon suspicions of neurological involvement. They should be done when there are complaints of shooting pain, numbness or tingling or complaints of weakness. The examiner should test for hip flexion (L2), knee extension (L3), ankle dorsiflexion (L4), ankle plantar flexion (S1), big toe extension (L5) and toe flexion (S2). These tests are conducted by having the examiner apply resistance to the muscle and instruct the patient to hold and not let the examiner move them.
Femoral Nerve Stretch
The purpose of the femoral nerve tension test is to determine if there are any adhesions blocking the femoral nerve. This test is performed with the patient lying prone and the involved leg is bent towards the patient's hips for about 30 seconds. A positive test is pain, their comparable sign or a difference with the contralateral leg.
The purpose of this test is to evaluate patella subluxation or dislocation. The patella is moved laterally by the examiner with the patient lying in supine with legs in a neutral position. A positive test is pain or a feeling of the patella about to "give-way".
The purpose of this test is to evaluate the quality of patella articulating surfaces. The patient is supine with legs in neutral. The examiner pushes the patella distally and asks the patient to contract quadriceps muscle. The patella should glide smoothly cephalid. A positive sign yields pain and crepitation.
The purpose of this test is to evaluate for the presence of patellafemoral pain syndrome. The patient lies supine with legs in neutral. The examiner applies downward pressure and moves the patella longitudinally. A positive sign is pain or crepitus.
This test occurs with the patient in standing. The examiner observes the height of the patella. A positive sign for patella alta is if the patella is higher than normal due possibly due to tight quadriceps. A positive sign for patella baja is if the patella is lower than normal possibly due to a tight patellar ligament or scar tissue from surgery.
Synovial Pinch Test aka Perkin's Pinch Test
The purpose of this test is to determine if there is inflammation of the plica in the knee cap. The patient lies supine with legs in neutral. The examiner stands on the side of the knee being tested with one hand on the patella and the other hand on the lateral side of the patella. The examiner moves the patella laterally and pinches the skin with the other hand. A positive sign is pain.
The purpose of this test is to determine if the patient has a tight IT band. The patient is side-lying with the lower leg bent for stability. The examiner then takes the top leg, which is the leg being tested, and extends it back forcing hip extension with the knee flexed to about 90 degrees. The examiner then lets go of the leg and lets it fall. A postivie sign is when the leg stays above the plinth.
Patellar rotation, tilt, glide
With the patient in supine, the examiner can test patellar rotation, tilt and glide. The patient’s quadriceps muscle should be relaxed and the examiner should keep the femur in neutral rotation. In patellar rotation, the superior and inferior poles of the patella should be examined to see if the patella is rotated. For patellar tilt, the examiner should look for a patellar tilt towards the medial or lateral pole of the patella. This can be better seen if a flat object, such as a goniometer, is placed on top of the patella. A lateral tilt could indicate a tight lateral retinaculum or IT band. Next thing to assess is patellar glide. If the patella is sitting normally, the examiner should feel the femoral condyles at about the same time. The examiner can also move the patella medially and laterally, taking care to not dislocate the patella. A positive sign could be a tightening of the quadriceps in apprehension of dislocation.
The patient is sitting and extends his/her knee. The examiner should observe the tracking of the patella as the patient goes from knee flexion to knee extension. If the patella tracks medially at terminal knee extension, then this is indicative of patellar maltracking and is called a “reverse” J-sign. It could be caused by a tight medial retinaculum. Normally, the patella should track laterally in an upside-down J-sign during the movement from knee flexion to extension.
With the patient sitting, the examiner applies force while the knees of the patient are held in an isometric quadriceps contraction at 120º, 90º, 60º, 30º, and 0º. If pain is produced during any of the angles, the examiner should push the patella medially and maintain that position while force is applied again at the painful angle. A decrease in pain indicates a patellofemoral issue.