Summary of Patellofemoral Pain Syndrome
Patellofemoral Pain Syndrome (PFPS) is a condition that develops around the anterior aspect of the knee, and is experienced mostly by those who undergo repetitive stress activities. Runners, jumpers and other athletes such as cyclists or soccer players are also at risk for developing this condition. PFPS occurs mostly due to imbalances of the pulling forces imposed upon the patella during extension and flexion knee motions. Malalignment due to congenital abnormalities could also be to blame for occurence of PFPS. Among those with malalignment due to congenital abnormalities will be notable signs of leg length discrepancy, differences in dorsiflexion, genu varum and varus at the forefoot.1,3 Congenital malalignment aside, the malalignment may also occur because of a tight lateral quadriceps muscle or attached retinaculum, which can lead to an abnormal pulling of the patella, and therefore result in shearing forces which lead to cartilage breakdown within the patellofemoral joint.1 Abnormal tracking of the patella on the femur can cause a focal point of force to develop, and with a lack of even distribution of force, an acceleration of cartilage degeneration may occur, thereby leading to arthritis. Another name given to PFPS is Chondromalacia Patella. While the term “chondromalacia patella” is not synonymous with PFPS, the halmark feature of chondromalacia is the characteristic degeneration of the cartilaginous matrix within the retropatellar region, thereby causing pain associated with PFPS.2
Guide to PT Practice4
Pattern 4D: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Connective Tissue Dysfunction
Pattern 4E: Impaired Joint Mobility, Motor Function, Muscle Performance, and Range of Motion Associated With Localized Inflammation
Procedural Interventions / Therapeutic Exercise
Interventions
•Aerobic capacity/endurance conditioning or reconditioning
-aquatic programs
-gait and locomotor training
-increased workload over time
-walking and wheelchair propulsion programs
•Balance, coordination, and agility training
-developmental activities training
-motor function (motor control and motor learning) training or retraining
-neuromuscular education or reeducation
-perceptual training
-posture awareness training
-standardized, programmatic, complementary exercise approaches
-task-specific performance training
•Body mechanics and postural stabilization
-body mechanics training
-posture awareness training
-postural control training
-postural stabilization activities
•Flexibility exercises
-muscle lengthening
-range of motion
-stretching
•Gait and locomotion training
-developmental activities training
-gait training
-implement and device training
-perceptual training
-standardized, programmatic, complementary exercise approaches
-wheelchair training
•Relaxation
-breathing strategies
-movement strategies
-relaxation techniques
-standardized, programmatic, complementary exercise approaches
•Strength, power, and endurance training for head, neck, limb, pelvic-floor, trunk, and ventilatory muscles
-active assistive, active, and resistive exercises (including concentric, dynamic/isotonic, eccentric, isokinetic, isometric, and plyometric)
-aquatic programs
-standardized, programmatic, complementary exercise approaches
-task-specific performance training
Relieving Pain
With regard to pain relieving modalities, one review states that ice, e-stim and ultra sound are used in the conservative management of PFPS, as is the case with many musculoskeletal injuries.5 Patellar bracing and knee bracing have both been found to confer limited benefit as additional conservative options to treat the lateral patellar tracking in patients with PFPS.6 Foot orthoses are used as well to treat PFPS in those patients who present with a high degree of pronation with tibial and femoral rotation.5 Ancillary therapies such as acupuncture and biofeedback have been found to decrease pain. Quadriceps strengthening also seems to lead to reduction in pain levels in some studies. The use of a resistive brace, and the combination of exercises with patellar taping all also decrease pain. Soft foot orthotics in patients who present with overpronation appeared useful in decreasing pain as well.10
Increasing Strength
According to one systematic review, the current gold standard used to treat PFPS is quadriceps strength training exercise.6 Specifically, this same review stated that specific VMO training exercises are often currently used to restore balance within the quadriceps muscle complex. The VMO training is of particular importance because one of the objectives of treatment of PFPS is to achieve the restoration of proper quadriceps muscle balance. More to the point, the goal of VMO strength training is to restore the timing of the VMO firing with the firing of the vastus lateralis muscle and other associated lateral muscles of the thigh and hip, in order to achieve proper patellar alignment during tracking. Other recent evidence advocates the clinical usefulness of hip muscle retraining in order to address weakness in hip abductors and external rotators that seems to be prevalent in patients with PFPS.5 With respect to the use of weight-bearing versus non-weight-bearing exercises, the research indicates that neither method confers a greater benefit than the other in terms of reducing pain or increasing functional use of the knee with PFPS.5
A word on PNF…
PNF (Prioprioceptive neuromuscular facilitation) is useful for stretching or strengthening of the muscles of many individuals who are either healthy or who are afflicted with injury. However, according to one study, when PNF was tested against static knee splinting exercises over the course of 8 weeks, static knee splinting exercises resulted in a significantly greater decrease in both pain and increased strength, as evidenced by better VAS (Visual Analog Scale) pain scores and greater static maximum torque in both knee extensors and knee flexors.12
Improving Range of Motion
According to research, many therapists make the mistake of attempting to improve both strength and range of motion at the same time. This is counter-productive and an inefficient use of time. Full knee extension, and even hyperextension must be achieved before working on strength.7 Then the key is to restore knee flexion, that is, if a descrepancy was present in the first place. With anterior knee pain conditions such as PFPS, knee ROM assymmetry in flexion is often present. With respect to acquiring full extension, it is important to point out that full extension means reacquiring full terminal knee extension. Due to favoring of the involved knee, many patient acquire flexion contractures, and so it is for this reason that, at least initially, the acquisition of full terminal knee extension be the focus of rehabilitation of anterior knee pain. Another important point is that if full terminal knee extension is not restored, many functional activities such as standing, walking or climbing stairs, will be difficult.7 Therefore, the order is as such: first work on acquiring full terminal knee extension, then full knee flexion, then strength.
To increase full extension of the knee, a combination of exercises may be used. Prone hangs, heel prop (Fig. 1), towel extension exercises (Fig. 2), and gait and posture training." According to research, the best way to achieve full knee extension is to instruct patients to weight bear on the involved extremity and consciously be mindful of their stance, lock out the involved knee through contracting their quadriceps muscle.8 While it has been stated that neither weight-bearing nor non-weight-bearing activities are associated with functional improvements to patients with PFPS5, the focus of the aforementioned ROM instruction seems to be on acquiring full knee extension through neuromuscular reeducation. The goal is to consciously fire the quads and become aware of how the sensation feels, in order to teach the quads to function in such as way that favors full extension of the involved knee.
Once extension is achieved, active and passive flexion exercises such as supine wall slides, heel slides in sitting, and the use of stationary bike while progressively decreasing the height of the seat may be employeed to increase knee flexion.9
With respect to mobilizations, research has stated that a regimen that involved patellar mobilization, stretching and patellar taping to decrease pain, enhance vastus medialis oblique muscle activation and to improve patellar tracking yielded good-to-excellent" results.11
Fig. 1: Image borrowed from http://sportsmedinfo.net/images/knee-rehab-prop.jpg
Fig. 2: Image borrowed from http://www.daily-health.org/wp-content/uploads/2010/02/29125062.jpg
Decreasing Swelling
Research states that ice is a reasonable modality to use to treat inflammation or soreness associated with anterior knee pain conditions. If this does not work, over-the-counter NSAIDs may be used to control inflammation and pain. Lastly, cortisone injections may be administered by a Physician to achieve pain relief that does not occur with simple ice and NSAID treatment.7
Functional Activities/Home Exercise13
Multi-Joint Exercises:
40° Knee Flexion Squats: A barbell or weighted stick is placed in Olympic Sytle back squat position. Starting position is hips externally rotated 30 to 45 deg (10 o'clock and 2 o'clock) and feet apart so that the medial malleolus is in line with the greater trochanter of the femur. During the descent of the squat, care is taken to maintain external rotation of the hip so that the knees do not endure a valgus stress and limit flexion of the hip to attempt to keep the vertebral column close to perpendicular to the platform. The descent phase of the squat is to 1/3 to 1/2 of a full parallel Olympic Style Back Squat (around 40 degrees of knee flexion). Care should be taken to keep the entire sole of the foot in contact with the platform during the entire exercise The ascent phase of the squat is to between 0 to 5 degrees of knee flexion with care taken to keep the hips externally rotated and the vertebral column as close to perpendicular to the platform. The knee should not be in hyperextension at the culmination of the repetition. Start at 3 sets of 8 reps and progress to 4 sets of 8 reps.
60° Knee Flexion Leg Press: Starting position is hips externally rotated 30 to 45 deg (10 o’clock and 2 o’clock) and feet apart so that the medial malleolus is in line with the greater trochanter of the femur. During the descent of the leg press, care is taken to maintain external rotation of the hip so that the knees do not endure a valgus stress. The descent phase of the leg press is to 60 deg of knee flexion. The ascent phase of the leg press is to between 0 to 5 deg of knee flexion to keep from entering hyperextension. Care should be taken to keep the medial epicondyle of the knee aligned with the medial malleolus by maintaining external rotation of the hips and keeping the entire sole of the foot in contact with the platform during the entire exercise. Start at 3 sets of 8 and progress to 4 sets of 8 reps.
Isolation Exercises:
Back Extension: Athlete uses back extension apparatus with ventral surface of hands placed behind the region of the C1 vertebrae, but not touching. Athlete starts at 0 deg of hip flexion and maintains isometrically contracted abdominals. Athlete descends to 45 deg of hip flexion. Athlete ascends to 0 deg of hip flexion utilizing the hamstrings and gluteus maximus as prime movers. Start at 3 sets of 8 reps and progress to 4 sets of 8 reps.
Quadriceps:
Bridges: Athlete lies supine on two benches separated so the scapula and calcaneus are in contact with separate benches. A light weight can be centrally placed over the pelvis resting on the bony prominence of the Anterior Superior Iliac Spine (ASIS) bilaterally. The rectus abdominus is contracted isometrically to support the lumbar spine. One leg is externally rotated at the hip to between 30 and 45 deg of flexion (10 o’clock and 2 o’clock). The same leg is raised using hip flexion, knee extension, and dorsiflexion of the ankle for a period of time. The raised leg is lowered to rest on the bench. The alternate leg is then raised in the same position for the same amount of time. Start at 3 sets of 30s (15s each leg) and progress to 4 sets of 50s (25s each leg).
Closed Kinetic Chain Terminal Knee Extension: Starting position is hips externally rotated 30 to 45 deg (10 o’clock and 2 o’clock) and feet apart so that the medial malleolus is in line with the greater trochanter of the femur. One end of physical therapy band is securely attached to a fixed piece of equipment or wall mount, while the other end is securely attached around the knee joint. The knee is flexed to 30 deg and then returned to between 0 to 5 deg flexion. Start at 3 sets of 8 reps and progress to 4 sets of 8 reps.
Hip abductors/adductors:
Manual Resistance (MR) or Thera-band Hip Abductor/ Adductor: Athlete lies in decubitus position if manual resistance or stands if using physical therapy band. Athlete performs set of resisted hip abduction through full ROM with pressure applied from a partner or physical therapy band at the region of the lateral epicondyle. Athlete performs a set of resisted hip adduction through full ROM with pressure applied from a partner or physical therapy band at the region of the medial epicondyle. Start at 3 sets of 8 reps and progress to 4 sets of 8 reps.
Stretches:
Thomas Test Stretch/ Single Leg Sprinter Stretch: Athlete lies supine with one leg in hip/knee extension with ankle dorsiflexed. The other leg is in hip/knee flexion with ankle dorsiflexed. The partner or athlete pushes/pulls in the region of the tibial tubercle to create greater hip flexion. The athlete attempts gain greatest ROM in hip flexion, while keeping the opposite leg firmly on the ground. A partner can apply a force in region of the tibial plateau of the flexed leg towards the chest, while applying a downward force to the distal 1/3 of the anterior thigh to keep hip flexion from occurring. Start at 1 set of 30s and progress to 1 set of 60s.
Supine AIS Gastrocnemius Stretch: The athlete sits supine with hips flexed and knees in extension. The tibialis anterior muscle in contracted causing active dorsiflexion to maximum dynamic ROM. Either a partner or a stretching band is then used to assist in increasing the ROM of the ankle, while maintaining the knee in extension. This point of maximal dorsiflexion is held for 2 seconds. The ankle is then plantarflexed passively. Another repetition is performed with the same ankle. At the culmination of the set, the alternate ankle should be stretched. Start at 1 set of 6 reps and progress to 1 set of 10 reps.
Supine AIS Dorsiflexion Hamstring Stretch: The athlete lies supine with hips and knees in extension. Ankle is dorsiflexed. The athlete should bilaterally keep the hips on the floor throughout the stretch and keep the other leg in hip and knee extension with dorsiflexion on the floor. The athlete contracts the quadriceps muscle group to maximally dynamically flex the hip. Either a partner or a stretching band is then used to assist in increasing the flexion angle of the hip while maintaining the knee in extension and the ankle in dorsiflexion. This point of maximal hip flexion is held for 2 seconds. The knee and hip are then flexed passively. Another repetition is performed with the same leg. At the culmination of the set, the alternate leg should be stretched. Start at 1 set of 6 reps and progress to 1 set of 10 reps.
Lying IT Band Stretch: The athlete lies supine with one leg and knee in extension with dorsiflexion. The other leg is in adducted in hip and knee flexion. The athlete pushes on the lateral epicondyle of knee of the leg to be stretched. The stretch is held in maximum static ROM. Start at 1 set of 30s and progress to 1 set of 60s.
AIS= Active isolated stretch
Modalities14,15
A systematic review14 pointed out that the evidence supporting the use of modalities to treat symptoms of patellofemoral pain syndrome is limited. In fact, this review found that taping and knee sleeves are likely not to result in helping to alleviate symptoms of PFPS in the short term. This study also found that positive long term results for the use of acupuncture and positive short term results for nandrolone, patella mobilization and soft foot orthotics were limited. NSAIDS, EMG biofeedback and low-level laser reported neutral results.
Another systematic review15 was constructed to determine the overall effectiveness of therapeutic modalities for patients presenting with PFPS. Specifically, the review investigated whether cold, ultrasound, phonophoresis, iontophoresis, neuromuscular electrical stimulation, electrical stimulation for pain control, electromyographic biofeedback, and laser were effective in treating symptoms of PFPS. While many of the studies examined were of either low to moderate quality, results indicated that some therapeutic modalities, if combined with additional treatments, could potentially confer some therapeutic benefit to patients with PFPS. Overall, none of the modalities by themselves that were examined were of therapeutic use to the clinician when treating symptoms of PFPS. The take home message was this: if any therapeutic modalities were to be used, they must be used to combination with each other, and only to supplement traditional physical therapy. Traditional physical therapy is defined as using a manually based approach in the treatment of PFPS.
Bibliography
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