Physical therapy techniques can be helpful in both diagnosing and treating chronic knee pain. In a review of common contributing factors such as iliotibial band syndrome and patellofemoral syndrome, this author offers anatomical insights, diagnostic pointers and treatment recommendations.

Knee pain is a common condition seen by healthcare professionals. Patients with knee problems accounted for approximately 19 million visits to physician offices in 2003 and approximately 25 percent of older Americans report suffering from chronic knee pain.1,2 Many of these patients seek medical attention after recurrent pains have gone unaddressed or after suffering an insidious, gradual decline in their functional mobility. It is chronic cases like these that pose a great diagnostic challenge to most clinicians, especially if the origin of the knee pain is unknown.

At first glance, the knee looks mechanically simple: a hinged joint easily accessed between two long lever arms (the femur and the tibia). Anatomically, however, the knee is particularly susceptible to injury.3 Furthermore, there are numerous structures within and around the knee that may be implicated when it comes to identifying the site and source of a patient’s chronic knee pain.

The patellofemoral grind test is a quick way to screen if the patellofemoral joint is involved. A positive test would reproduce pain and crepitus.

Examining these patients is not always easy and there is not always a clear mechanism of injury. Accordingly, one must have a strong knowledge of the structures of the knee and how they function in order to conduct a thorough assessment (see “A Pertinent Overview Of Knee Anatomy And Biomechanics” on page 25). Often, making a referral to physical therapy is a realistic and appropriate treatment option for these patients.

Essential Insights For Detecting Patellofemoral Joint Pain
Once one has determined there is a musculoskeletal cause behind a patient’s knee pain, clinicians should proceed to identify the structures causing the pain. While it is beyond the scope of this article to discuss a full orthopedic evaluation of the knee, here are some simple and quick tests that can help the clinician identify structures causing knee problems.

Anterior knee pain is common and this pain often comes from the patellofemoral joint. Performing a quick patellofemoral grind test can help you determine if the patellofemoral joint is inflamed. With the patient supine and the knee extended, the clinician pushes the patella distally with the web space between the thumb and index finger. While maintaining this position, the patent actively flexes the quadriceps. Pain and/or crepitus may indicate patellofemoral dysfunction.

Limited patellar mobility may indicate a tracking problem. To assess the amount of patellar mobility, passively glide the patella medially and laterally, with the leg fully extended and in 25 to 30 degrees of knee flexion. The patella should glide approximately 25 percent of its width in each direction.

The distal attachment of the vastus medialis is the medial border of the patella. The vastus medialis muscle helps prevent lateral tracking of the patella. To see if there is vastus medialis atrophy, have the patient actively tighten the quadriceps with the leg extended. Compare the muscle definition to the other side. Sometimes, there is an obvious difference between the painful knee and the uninvolved side. Clinicians can also place the knee in approximately 60 degrees of flexion and have the patient resist extension in order to assess the oblique orientation of this muscle.8 One should note any difference in size or definition as it can be an indicator of vastus medialis atrophy and, accordingly, a potential source of the pain.

Keys To Assessing The ITB And The Quadriceps
The iliotibial band (ITB) is often a major contributing factor in chronic knee pain, especially when it comes to patellofemoral syndrome (PFS). To assess tightness of this structure, the late Florence P. Kendall, PT, FAPTA, recommended performing the modified Ober Test.9

Have the patient lie on the uninvolved side while maintaining his or her pelvis in a neutral position. The clinician stabilizes the pelvis at the iliac crest to prevent a tilt. Proceed to extend the patient’s knee and hip so the entire lower extremity is even with the trunk. Then allow the leg to drop into adduction toward the table. Normal length of the ITB is indicated by the leg dropping 10 degrees below a horizontal line passing through the hip joint.

To assess quadriceps length, one should have the patient in a prone position and passively flex the heel of the involved leg toward the buttock. Normally, there will be approximately 140 degrees of knee flexion.9 To assess hamstring length, have the patient in a supine position and passively raise the straightened leg off the table. Normal hamstring length is considered 80 degrees.9

Normal patellar mobility is 25 percent of the width of the patella. This test can be performed in extension or 25 degrees of flexion with the leg relaxed.

When palpating the knee structures, the goal is to reproduce tenderness and identify areas of swelling or taut, palpable bands.

Have the patient in a supine position with a pillow under the knee. Start at the prepatellar bursa by compressing it into the patella. Proceed to palpate the border around the patella. Go to the inferior pole of the patella, palpate the patellar ligament and then move just lateral to palpate the fat pad.

Clinicians can then palpate the quadriceps muscle. Frequently, one will note point tenderness and taut bands in this muscle as well as in the ITB along the lateral border of the thigh. By reaching behind the thigh, clinicians can palpate the hamstrings by compressing them into the underlying femur. One would palpate the medial collateral ligament (MCL) and lateral collateral ligament (LCL) at the medial and lateral joint lines respectively.

What You Should Know About Patellofemoral Syndrome
Patellofemoral syndrome is actually a generic term to describe anterior knee pain associated with crepitus. The symptoms of PFS often increase with activities such as squatting, stair negotiation and rising from a seated position.

Keep in mind that PFS can have multiple sources. Wilk, et. al., describes a classification system of PFS that divides this condition into eight groups.10 These groups include patellar compression syndromes, patellar instability, biomechanical dysfunction, direct patellar trauma, soft tissue lesions, overuse syndromes, osteochondritis dissecans and neurological diseases.

When it comes to patellar compression syndromes, one common scenario involves a tight ITB and a weak VMO. This length-strength imbalance in the thigh causes the patella to track laterally and compresses it into the lateral femoral condyle. This results in inflammation and knee pain.11

When there is resistance of knee extension at approximately 60 degrees, the clinician can observe the oblique orientation of the vastus medialis.

Physical therapy rehabilitation goals for PFS are restoring normal patellar mobility, improving strength and flexibility, and returning to activities of daily living (ADLs) or sport.

Physical therapy treatment for PFS includes: mobilizing the patella; soft tissue mobilization of the lateral thigh musculature and ITB; and stretching and strengthening the lower extremity and hip musculature with particular attention to strengthening the VMO. Patellar taping is also an option to prevent the patella from tracking laterally.

Can Physical Therapy Be Beneficial For Those With OA In The Knee?
Osteoarthritis (OA) is the most common form of knee arthritis.12 Symptoms include pain, stiffness and limited range of motion (ROM). Common causes of OA include joint injury, intraarticular fractures, overuse of joints and previous surgery, obesity, and genetic predisposition.13-15 In OA, the underlying problem is a breakdown of articular cartilage. This causes narrowing of the joint space and the collateral ligaments to become lax, further exacerbating the problem.13

Since OA is a structural change, the goal of physical therapy rehabilitation is minimizing stress at this joint. Some research indicates that increased physical activity does not lead to an increased risk of OA.16 Clinicians can help patients reduce joint stress by improving lower extremity flexibility and strength, and gradually returning the patient to functional activities. Flexibility exercises typically include stretching the quadriceps, hamstrings, gastrocnemius and ITB. A strengthening program may include quadriceps setting exercises in which one pushes the back of a straightened knee into the floor by tightening the quadriceps. Another exercise involves wall squats, which one can perform by standing against a wall and squatting halfway down. Lunges and bicycle riding are other good sources of strengthening the quadriceps.11

Physical therapists will experiment with different exercises because the occurrence of pain, swelling and stiffness would indicate that the exercise program is too intense or needs modification.11 One may assess the patient’s shoes as insoles may be indicated. When it comes to treating advanced stages of OA, one may need to consider bracing and assistive devices in order to help facilitate safe ambulation.

A Closer Look At Pes Anserine Bursitis
The pes anserine is the attachment of the sartorius, gracillis and semitendinosis tendons to the anteromedial aspect of the proximal tibia (see “A Pertinent Overview Of Knee Anatomy And Biomechanics” on page 25). Clinicians commonly refer to the pain in this area as pes anserine bursitis. Signs and symptoms include localized pain, tenderness and possibly swelling.

Here one can see a normal modified Ober test. As you can see, the lower extremity drops at least 10 degrees below the horizontal line.

However, not unlike many other loosely defined diagnoses, “pes anserine bursitis” is a bit of a misnomer in that this pain can be attributable not only to a bursitis (inflamed bursa) but also to a tendonopathy (inflamed tendon or tendon sheath), a fascitis (inflamed fascia) or a panniculitis (inflamed fat pad).17

This condition is most common in obese, middle-age women and in patients with OA of the knee.18 Common causes of pes anserine bursitis are acute injury to the medial knee, athletic overuse, OA, pes planus and sporting injuries requiring lateral movements.15

Physical therapy treatment of pes anserine bursitis incorporates stretching, strengthening and correcting biomechanics in order to minimize abnormal forces. Modalities can include ultrasound, infrared light and various forms of electric stimulation. Correcting foot biomechanics, usually with a stability shoe or orthotics, may be beneficial by reducing stress at the knee. In my experience, I have found that a myofascial release in this area is particularly effective. This technique utilizes a gentle, long duration stretch to improve tissue mobility.19

The positive modified Ober test occurs when the lower extremity does not drop below the horizontal line. Note that the examiner is stabilizing the pelvis to prevent a tilt, and that the lower extremity is kept in extension and is not allowed to internally rotate.

A Guide To Treatment For Iliotibial Band Syndrome
The primary symptom of ITB syndrome is diffuse lateral knee pain. This painful, inflammatory condition is caused by friction of the distal ITB over the lateral femoral condyle that occurs with repetitive flexion and extension of the knee. This condition is common in long distance runners and cyclists.20,21 This is often aggravated after or during running/cycling. Those with advanced stages of ITB syndrome may also experience these symptoms at rest.

When patients have this history of symptoms, there are clinical tests to assess for an ITB syndrome. These tests include the aforementioned positive modified Ober Test and the presence of point tenderness to the ITB just above the lateral joint line.

Physical therapy treatment typically includes modalities, such as ultrasound or electric stimulation, soft tissue mobilization to the ITB, stretching of the hip flexors, quadriceps, hamstrings and the ITB, and gluteus medius strengthening.

Clinicians should emphasize a gradual return to sport, encouraging patients to start slowly on level surfaces and gradually increase the speed and intensity of activity as tolerated.

In Conclusion
Chronic knee pain is fairly common and has many potential sources. While clinicians often employ medications and injections to treat chronic knee pain, these options do not address the underlying structural problems that frequently accompany patients’ pain. Physical therapy can be very effective in these cases as clinicians can more thoroughly assess and address strength, flexibility and biomechanical deficits as well as movement abnormalities. Indeed, utilizing physical therapy techniques may help provide more lasting relief for those who suffer from chronic knee pain.