Current research is leading to the conclusion that many of the overuse conditions of the knee are not really conditions of the knee at all. Anterior knee pain may in fact be more of a symptom than a diagnosis. Two of the three conditions mentioned in the opening sentence ( chondromalacia and patella- femoral syndrome) may in fact be more related to issues at the hip but present as knee pain. (Powers, 2003) The analogy we have frequently used to describe why this occurs is what I refer to as the "band analogy". If I put a band loosely around your neck, stood in front of you, and pulled on it you would tell me that the back of your neck hurt. If I simply stopped pulling on the band your neck pain would disappear. The fact of the matter is that nothing was ever really wrong with your neck. The neck was simply the endpoint at which you felt the pull. This is very similar to the effect of the glute medius and glute max pulling on the IT band and resulting in pain at the knee. The IT band transmits forces from the glute medius area to the patella tendon or the patella femoral joint. The patella area feels pain much like the back of the neck feels the pull from the rope.
Another potential cause of anterior knee pain may be an unintentional loss of ankle mobility. The zeal of athletic trainers to stabilize the ankle with shoes, tape and braces has led to many athletes playing with ankle joints that function as if they were fused. The reality is that in the sport of basketball (a leading sport for anterior knee pain) serious ankle sprains are less frequent but patella-femoral pain has reached near epidemic levels. You can see in the video how losing ankle mobility effects shock absorption on landing. Logically, this transfers pain up the chain.
The desire to over-stabilize the ankle joint has also led to a phenomenon we now call the "high ankle sprain" and to an epidemic of patella tendon issues. The high ankle sprain was virtually unknown twenty years ago and may also be a by-product of over-stabilizing the ankle. Interestingly enough soccer has few ankle or patella-femoral problems yet, soccer players use a low cut, lightweight shoe on grass. Training with less artificial stability at the ankle joint probably protects both the ankle and the knee.
Over the past decade, Anterior Knee Pain has been blamed on poor VMO development, poor "patella tracking" and numerous other causes. Most treatments have centered on trying to reduce the pain at the pain site with various treatments ( ice, taping, ultrasound etc.) The reality is that an aggressive strengthening program aimed from the hip down, particularly the eccentric control of knee flexion, hip adduction and hip internal rotation may in fact be more effective. The Ireland study ( Ireland et al. 2003) states clearly that "females presenting with patella-femoral pain demonstrate significant hip abduction and external rotation weakness when compared to non-symptomatic age matched controls". Lower extremity strengthening done with emphasis on hip control in combination with a program of progressive single leg plyometric training to address the eccentric and neural stability components may allow many trainees to experience long-term relief.
Recently I listened to Professor Jill Cook on Jake Tuura's Jacked Athlete Podcast and Dr Cook's word's strengthened my views as they relate to anterior knee pain. However Dr Cook drew a clear line between patella femoral issues ( very prevalent across the board) and true patella tendonitis, a condition she said effects almost exclusively young, jumping males. The distinction here is that 90 percent or more of the anterior knee pain we see will not be tendonitis but rather patella-femoral. Why does this matter? Because the treatments are entirely different. Non-tendonitis patella femoral pain will be solved with a Does It Hurt rehab approach. This means that you must go to any and all costs to avoid pain in the rehab process. This also means that we must look at both the feet and the hip as potential sources or contributors.
Two of the best ways to avoid problems are
1- With painful knees think vertical tibia. There is a big "knees over toes" push these day. If you have young athletes with knee issues, ignore the "knees over toes" folks and really work on vertical tibia. We will use what we call a "bench block" to teach athletes to keep the tibia vertical. One thing we have seem is that athletes with knee issues are naturally "knees over toes" and that vertical tibia is the solution, not the problem.
2- Avoid "Extensive Plyometrics". This is another phenomenon that has recently become trendy. Extensive plyometrics basically means a high volume of lower intensity jumps. This is just an accident waiting to happen. For my plyo thoughts read here ( Plyometric Training)
Research has validated what began as an empirical feeling. All athletes presenting with knee pain in our facility would be evaluated for hip pain (palpation of glute medius/ miniumus area) when complaining of anterior knee pain. We found nearly a 100% correlation between Anterior Knee Pain and lateral glute tenderness. All of our athletes with anterior knee pain had direct point tenderness in the glute medius of the hip on the effected side. Soft tissue work to the glute medius ( foam roll, tennis ball, massage) caused a significant reduction in the pain at the patella in almost every case.
Most athletes also had marked weakness in manual muscle testing for the glute medius. The conclusion is obvious. Weak or underactive hip stabilizers cause a lack of control of knee and hip flexion with an additional component of adduction and internal rotation. These control issues result in a painful condition in the patella-femoral joint that may or may not effect the patella tendon.
Further study (Summer 2006) has caused us to look at the adductors, another hip stabilizer in the lateral sub-system. In 2006 in addition to looking at lateral hip structures as a potential causative factor in knee pain we also began to look at the strength and over-activity of the adductors. Upon further investigation we found weakness in the adductor muscle group, with a preference to substitute hip flexors for adductors, as well as obvious tender trigger points in the adductors.
The key from a both a cause and a solution standpoint lie in understanding and rejecting the sagittal plane and bilateral dominant strength training so prevalent in the American system. Our American strength training system is classically sagittal plane dominant as well as double leg oriented. It seems clear that the key to solving anterior knee pain lies in control of hip, knee and foot movement in the frontal plane and that single leg exercises must be employed in both strength training and power training to address these issues.
In addition the single leg strength training must center around what we have termed single leg unsupported exercises like one leg squats and one leg deadlift variations. Knee dominant single leg exercises like split squats and rear-foot elevated split squats (sometimes referred to as Bulgarian squats from Spassov's work) may provide adequate stress in the sagittal plane but do not provide adequate stress to the hip structures in the frontal or transverse planes. The athlete must be standing on one foot with the opposite foot having no contact with either the floor or any other object. In essence the act of standing on one foot and performing a single leg squat becomes a tri-planar exercise even though the athlete is moving in only the sagittal plane. Having only one foot in contact with the ground forces the hip structures ( abductors and external rotators) to stabilize against movement into both the frontal and transverse planes. In these single leg unsupported exercises we will allow less than full ROM to develop hip control. This is a major exception in our system of training as we have always used full range of motion exercises. The objective is always to get to a full pain free range with bodyweight before the addition of any external resistance.
The exception will be the addition of five pound dumbbells to allow weight shift toward the heel. We have dubbed this concept progressive range of motion exercise. The progression is in range versus load to cause the progressive control of hip motion.
The following treatment program is suggested for patella-femoral pain syndromes:
Step 1- Soft tissue work to glute medius with tennis ball and foam roll or by a qualified therapist, trainer etc. if available.
Step 2- use of Reactive Neuromuscular Training for the hip abductors in conjunction with a strengthening program for the knee and hip extensors focusing on single leg unsupported exercises and progressive range of motion if necessary.
The term Reactive Neuromuscular Training can be confusing as the same term has been used by two well-respected physical therapists to describe two entirely different thought processes. Mike Clark of the National Academy of Sports Medicine uses the term Reactive Neuromuscular Training for all intents and purposes in place of the term plyometrics. Physical Therapist Gray Cook on the other hand uses the term Reactive Neuromuscular Training to apply to an entirely different thought process. Cook's concept of Reactive Neuromuscular Training involves applying a stress to a joint in opposition to the action of the muscles. In other words to effectively target the hip abductors a band is placed around the knee and the leg is pulled with an adduction force. The addition of the adduction force will in effect "turn on" the abductors.
Single Leg Unsupported with Progressive Range of Motion Increases and RNT Emphasis is a mouthful. The key is that the athlete is standing on one foot. In a therapy or personal training situation the adduction force can be provided by the therapist or trainer with Superband,Theraband etc.
Single Leg Unsupported 1 Leg Squatting
RNT to Glute Medius ( RNT starts a 10 sec mark)
Another possibility is to create the RNT effect by driving internal rotation of the pelvis on the femur with what we would refer to as "cross body reach". The intent here is to create great glute involvement by driving the pelvis on the femur
Step 3- Hip Extension Strengthening- strengthening the hip extensors must include three distinctly different patterns. Pattern one is a straight leg pattern as in the one leg straight leg deadlift ( actually a misnomer as the knee is intentionally bent to twenty degrees.)
Pattern two is a bent leg pattern that incorporates the mechanics learned in the bridging exercises from core training. Pattern 3 is a leg curl pattern incorporating the hip extensor function of the glutes.
Pattern 1- 1 Leg SLDL, Low Pulley Anterior Reach ( 20 degree knee flexion, flat back)
Pattern 2- Bridge and Single Leg Bridge Variations. These exercises target the glutes and decrease the length tension effect of the hamstring.
Pattern 3- Slideboard leg curl variations. The key with the slideboard leg curl is that the glutes function isometrically to maintain hip extension while the hamstrings act to flex and extend the knee. Any flexion of the hip negates the effectiveness of this class of exercises. Even one degree of motion at the hip negates the glute function. The best teaching progression is to begin in a bridge with glutes and abs contracted and eccentrically lower into an extended position.
Step 4- Concentric training of Hip Abductors -- although many would argue that isolated single joint training is not functional it is still necessary to train the concentric action of the hip abductors. This can be done with simple side leg lifts or with standing abduction on a Pilates Reformer or MVP Shuttle.
Additional Points of Emphasis
Calf Training- variations of both standing and seated calf raises have also been shown to be beneficial in dealing with patella -femoral pain.
Core Training- Core training should always be included in any sound program but, with patellafemoral pain both quadruped and bridge variations should be used for emphasis on glute max and glute med function.
Conditioning/ Muscle Endurance-
Retro walking is another excellent exercise for the athlete or client with patella femoral pain. Backward walking provides less stress to the patella-femoral joint and is in fact a series of closed chain terminal knee extensions. Backward walking can begin with a treadmill program of intervals at progressively higher inclines and progress to walking backward with a weighted sled.
( great Ben Bruno cameo here!)
Eccentric strength work should focus on single leg plyometrics with emphasis on landing skills, hops should be forward as well as medial and lateral. In addition the MVP Shuttle can be used to develop landing skills for athletes returning from injury or athletes with poor strength to bodyweight ratios. This is the more advanced rehab stage once strength work has been successful
The key to battling patella femoral pain is adopt a well rounded approach that works on the source of the pain versus the site of the pain and takes into account all of the functions of the lower extremity. Remember to read Does It Hurt and when your done, read it again!
How's this for a Throwback
Powers, Christopher ,The Influence of Altered Lower Extremity Kinematics on Patella Femoral Joint Dysfunction, Journal of Orthopedic and Sports Physical Therapy, 2003;33: 639-646 Ireland et al Hip Strength in Females with and without Patella-Femoral Pain. Journal of Orthopedic and Sports Physical Therapy, 2003;33:671-676