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Knee Pain and Function: Nonoperative Approaches to Managing Patellofemoral Pain Syndrome

Physical rehabilitation and osteopathic manipulative techniques can treat different aspects of “runner’s knee,” to alleviate tight muscles and tender points within the joint or muscle and increase range of motion.

Patellofemoral pain syndrome (PFPS) – runner’s knee – is a common condition, specifically identified as the most common injury sustained by runners.1 It is best understood as non-specific anterior knee pain resulting from dysfunction in the mechanical forces between the patella and the femur. The cause of the condition has not been conclusively determined, and there is a lack of consensus regarding the precise pathophysiology of PFPS.2

A variety of etiological and biomechanical factors leading to PFPS have been proposed and the condition most likely occurs due to a combination of several factors, including abnormalities in the anatomy or trauma.3-10 Females are more likely to experience PFPS than males, and it is commonly seen in those between the ages of 50 and 59 years old in the United States.5 However, a large number of active adolescents and adults may develop PFPS, particularly those who participate in jumping and sports that repeatedly bend the knee. Due to the symptoms of PFPS, limitation or complete cessation of such activities have been reported in about 74% of these patients.6

Women are more likely to develop runner's knee than men; patellofemoral pain syndrome commonly presents in women aged 50 to 59 years old. (Image: iStock)

It is, therefore, imperative to diagnose and treat PFPS early as it can lead to significant disability. Conservative management including rest and analgesics may provide relief. Other treatments involve physical rehabilitation and osteopathic manipulative treatment (OMT), both of which are effective nonoperative approaches in the management of PFPS.

Anatomy and Pathophysiology of Runner’s Knee

The patellofemoral joint consists of the patella articulating with the trochlea, which is the groove and distal surface of the femur.7 Normally, they are in alignment with this groove conforming to the contours of the patella during range of motion of the knee, such as bending and straightening. However, abnormalities of the trochlea, such as the shape and smoothness, may prevent the patella from moving normally in the trochlear groove, especially during flexion.7

Abnormalities of the patella can also result in PFPS, including malalignment and hypermobility. The patella may glide in different directions, or more to one side of the femur, ultimately resulting in pain or discomfort. This movement may be due to repeated trauma, which increases forces within the joint or adds to abnormal muscle imbalance. Delayed activity of the muscle may attribute to this abnormal muscle imbalance, as well. As described by Pal et al, the delayed activity of the vastus medialis, an extensor muscle within the quadriceps muscle group, can result in lateral misalignment of the patella.8

In addition to patellar malalignment, other biomechanical factors have been proposed as possible causes of runner’s knee as well. These include: lower extremity muscle weakness, especially of the quadriceps as well as hip abductors and external rotators, delayed activation of the vastus medialis, inflexibility of the lower extremity, and foot over-pronation.2,4

Another potential cause of PFPS involves the articular cartilage, which covers the distal femur and the trochlear groove. When healthy, this cartilage supports smooth and synchronized interrelated movement of the bones. Elevated cartilage stress, caused by joint posture and joint contact forces with the muscle, may result in pain. Females appear to exhibit greater cartilage stress, which may contribute to PFPS’ greater prevalence in this patient population.9  Direct trauma to the patella, such as dislocation or fracture, may also result in injury to the articular cartilage.10

Clinical Diagnosis of PFPS or Runner’s Knee

Patients with PFPS will commonly describe a gradual, dull pain above, below, underneath, or surrounding the patella, especially noticeable with activities such as running and squatting.11  This pain may occur with or without a history of trauma. Additionally, patients may describe that the knee feels like it is giving way or report joint instability.

Physical examination may reveal swelling, but there is no definitive clinical test in diagnosing PFPS.12 However, maneuvers may be done to check for patellar tracking, knee stability, or the alignment of the leg in relation to the knee. Range of motion (ROM) may be assessed to determine the severity of PFPS, where movement impairments can be identified to help with treatment.

Treatments for PFPS

Treatment for PFPS is typically conservative and includes rest, ice, and analgesics.13,14 Activity changes may be implemented, such as reduction or cessation of sports or activities involving the repeated use of the knee. In addition, low-impact activities will lessen the stress on the patellofemoral joint. NSAIDs can reduce swelling and pain.

Other approaches, such as strength training through physical rehabilitation and OMT, can also play a big part in treating those with PFPS, as described briefly below.

Physical Rehabilitation

Physical therapy and rehabilitation can play an important role in the management of PFPS, as exercises can be recommended to strengthen and synchronize the actions of hip muscles, quadriceps, and hamstrings.14 Strength training builds muscle, while helping to improve tone and appearance. Improvement is especially seen in for patients with PFPS, where musculoskeletal pain may be attributed to muscle imbalances in the knee.15 Selection of exercises can be dependent on the movement impairments imposed by PFPS, and should include both hip and knee strengthening as well as movement retraining.16 These exercises can be performed with or without weights, and include straight leg raises, knee extensions, wall sits, and leg press.16

In addition to strength training, stretching is another major component of physical rehabilitation since patients with PFPS may have limited ROM of the hip, knee, and ankle. Therefore, stretching of the muscles, such as the quadriceps, hip flexors, hamstrings, and iliotibial band can be helpful in order to improve range of motion and decrease muscle restrictions.16

Patellofemoral taping, in conjunction with physical rehabilitation, can also help reduce pain. More specifically, patellofemoral taping can help with the malalignment of the patella in the patellofemoral groove.16,17 Therefore, patients may be able to perform their physical rehabilitation exercises without pain.16 Due to conflicting evidence regarding efficacy, taping should ideally be used in addition to physical rehabilitation, and not as a stand-alone treatment.16 If taping is used, clinicians should assess the patient pre- and post-taping, specifically for the severity of the patient’s PFPS pain.16

Osteopathic Manipulative Treatment (OMT)

OMT offers a nonoperative approach in treating patients with PFPS. Before treatment, it is very important to do a thorough careful exam of the knee, hip, foot, and ankle, assess ROM, and identify somatic dysfunction.18 After doing so, certain techniques, such as myofascial release, strain-counterstrain, and muscle energy, may be performed to improve ROM and restore patella alignment. While a full review of possible OMT for PFPS exceeds the scope of this article, three techniques often associated with improvement of PFPS symptoms are:

  • myofascial release
  • strain–counterstrain
  • muscle energy

Myofascial release is one of the many hands-on techniques performed by various clinicians, including physicians trained in OMT, physical therapists, and bodyworkers in general. Benefits of myofascial release treatment are that the treatment is gentle, unlikely to flare pain, and allows for reduction of tension and restrictions by targeting the fascia, the main connective tissue in the body. MR of the popliteal fossa specifically, the shallow space located posteriorly of the knee joint, engages fascial restrictions that may contribute to decreased lymphatic drainage,18 a common clinical finding associated with inflammation surrounding the knee joint. Myofascial release can also support healing of fibrotic tissues surrounding the patella.19

The strain­–counterstrain can be performed to provide pain relief in. For this technique, specific tender points in the muscle, tendon, or joint are identified. The patient is then passively positioned by the clinician in a position where the pain associated with the tender point is significantly reduced. Positioning the patient in this manner allows those areas to be relaxed, targeting muscle spindles, Golgi tendon organs, and other structures to aid in proper function of the neuromusculoskeletal system. This position of comfort is then held for 90 seconds, allowing the muscle to relax and relieve tension, and the clinician then returns the patient passively to neutral position. Following a successful treatment, the tender point’s intensity should be reduced by 70% or more. In patients with PFPS, common tender points include the patellar tendon, and medial or lateral patellar surfaces.18

Muscle energy technique targets specific muscles to ultimately reduce contractility and restore full range of motion of muscles and joints utilizing sequential active isometric contractions of that muscle by the patient followed by post-isometric relaxation and repositioning. This cycle of contraction and relaxation, with passive repositioning of the patient to the point of movement that engages the connective tissue dysfunction, results in the initiation of a reflexive relaxation by Golgi tendon organs and reflexive reciprocal neural inhibition of the antagonist muscles.20  Muscles that can be evaluated and treated to help patients with PFPS include gastrocnemius, hamstring, and quadriceps muscles to improve range of motion in the knee joint.19

Practical Takeaways for Treating PFPS

Nonoperative approaches in the management of PFPS beyond analgesics, rest, immobilization, and other conservative treatments include physical rehabilitation and OMT. Physical rehabilitation can help to alleviate pain by strengthening lower extremity muscles that may be contributing to the malalignment of the patella. Stretching these muscles and patellofemoral taping can also keep the patellar within the patellofemoral groove. Various osteopathic manipulative techniques can be utilized in treating different aspects of PFPS, such as fascial restrictions, tight muscles, tender points within the joint or muscle, and limited range of motion.

No matter the approach to management, the goals behind treating patellofemoral pain syndrome in runners is to reestablishing proper synchronicity and function of musculoskeletal, fascial, and other structures to reduce pain and improve function.

Last updated on: June 1, 2021
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