Patellar Femoral Syndrome - Part I

“When there is alignment and understanding, it is much easier to navigate forward together, ” - Karen Kimsey-House


          The knee is one of the most relied upon joints of the human body and is subjected to a great deal of force every day. During a simple activity like walking, the amount of force placed upon this joint is equal to anywhere from one-third to one-half an individual's body weight. When a person is climbing stairs the force placed upon the joint is equivalent to 3 times the individual's body weight, and when squatting, the knee must manage a force equal to 7 times the individual's body weight. When considering these facts, it is easy to understand that there must be a great amount of stress placed upon the knee in all kinds of dance. When the knee joint is functioning correctly, it is usually able to cope with this stress, however, when something is misaligned, and the knee joint is not functioning efficiently, the stress can be detrimental.

        Patellar femoral syndrome is a chronic condition in which the patella, or knee cap, is not correctly aligned. The patella is a triangular shaped bone that lies on top of the femur, or thigh bone. There is a groove in the femur which allows the patella to slide back and forth as the knee bends and extends. When the patella is not in alignment, it does not fit well into this groove, and the friction of the patella against the femur begins to wear away the cartilage found in the joint.

          
          When the knee joint is at rest, the patella is held in place by the capsule surrounding the joint, the ligaments on either side of the patella (the retinaculum), and the patellofemoral ligament, which connects the femur to the patella.

When the knee is actively bending or extending, the joint's stability is provided by the quadriceps (the four muscles located on the front of the thigh), the vastus medialis (which is a muscle that is found on the inner side of the thigh), the vastus lateralis (which is a muscle that runs along the outside of the thigh), and the iliotibial band, which runs from the gluteal muscle of the buttocks down the outside of the thigh.

          Dancers with patellar femoral syndrome will experience pain behind and around the kneecap during activities that require the knee to bend like squatting, jumping or climbing stairs. Occasionally, the dancer will also experience the knee buckling, or "giving way" when walking and may also complain of stiffness in the knee after sitting for a while.

          Any dancer experiencing these symptoms should rest the joint and use ice and anti-inflammatories to control the discomfort. The dancer should also contact a sports or dance medicine doctor to get a complete diagnosis. In most cases, once the cause is determined, physical therapy can help alleviate the symptoms and help realign the kneecap.

          Since an ounce of prevention is worth a pound of cure, my next post will focus upon the causes of patellar femoral syndrome and how to prevent this condition from occurring.

Chronic Conditions of the Knee

         "There are three steps you have to complete to become a professional dancer: learn to dance, learn to perform, and learn how to cope with injuries." -D. Gere

         

      The knee is the largest joint in the body and is constantly supporting the body’s weight.  Dancers depend upon their knees to support their bodies while turning, jumping, and performing extensions.  Since the knee joint is found between sets of muscles that dancers use repeatedly, and dancers often have muscular imbalances in the leg that cause misalignments, it is not surprising that knee injuries account for 14-20% of complaints among dancers.

            This week’s post will discuss some chronic dance injuries that affect dancers.  These injuries develop over time and increase in severity until the cause is determined and eliminated.

            A condition that occurs in children and adolescents who are involved in activities like dance that involve quick turns or jumping is Osgood Schlatter’s Disease.  One in five adolescent athletes is diagnosed with this condition, and it occurs when quick movement demands are placed upon the body during the growth spurt.  During the growth spurt, bones grow quicker than muscles placing a strain on the body.  When this strain is exacerbated by activities that stress the body, this condition develops.  It manifests itself as a painful lump on the leg right below the kneecap.  Dancers may experience swelling, tenderness around the knee, tightness in the quadriceps and/or hamstrings, and/or pain with exercise.  It can involve inflammation of bone, cartilage, the patellar tendon, or any combination of the three.  It should be treated using the PRICE method (protection, rest, ice, compression, elevation) and anti-inflammatories.  It usually resolves itself in 12-24 months when the growth spurt is completed.  A physical therapist can help the dancer find ways to navigate through classes and rehearsals.  In extreme cases, a dancer may be forced to take a break from dance until the pain begins to subside.

            Patellar femoral syndrome occurs due to a misalignment in the leg.  Muscular imbalances or forcing the body into unnatural positions that are unhealthy for the body, like forcing turnout from the knee, can cause the patella, or kneecap, out of position.  Instead of sliding back and forth in the groove on the femur, or thighbone, the kneecap is “derailed”.

          As the back of the kneecap rubs against the femur, the cartilage under the kneecap wears away causing chondromalacia.  It is characterized by pain around the kneecap during jumps, during pliés, and after sitting for a long period of time.  The dancer may also experience some swelling around the knee and/or hear a “crunching” sound when moving it.  Rest and ice may help, and a physical therapist should be consulted to determine the underlying cause.  The dancer’s technique can be examined to determine what alignment issues may be present, and the dancer can be evaluated for muscular imbalances that may be the cause.  A physical therapist who works with dancers will be able to help correct technical problems and/or provide strengthening and stretching exercises to fix any imbalances that are present.

            Another knee problem that can be caused by alignment issues and/or muscular imbalances is patellar tendonitis.  In this condition, the patellar tendon, which connects the quadriceps to the kneecap, becomes inflamed.  When the tendon is pulled on excessively due to tight quadriceps muscles, it becomes swollen and painful.  Rest, ice, and anti-inflammatories will help alleviate swelling and pain, and a physical therapist can provide exercises to eliminate the tightness in the quadriceps.

            Prepatellar bursitis is a condition found mostly in modern and jazz dancers because of the knee work involved in these techniques.  Bursae are tiny fluid-filled sacs found in the joints of the body that act as cushioning.  When repeated friction occurs in a joint, the bursae become inflamed and painful.  When executing knee work, the constant friction between the knee and the floor becomes a source of irritation.  Rest, ice, anti-inflammatories, compression, and physical therapy can alleviate the swelling.  In more severe cases, cortisone shots or surgery may be necessary.

            My next post will cover acute knee injuries that are the direct result of trauma and tend to be more serious in nature.

Learning About the Knee

            The knee is the largest joint in the body and one that everyone uses daily.  It is a hinge joint, which means it is only capable of flexing, or bending, and extending, yet dancers rely on it for almost every movement they execute and should, therefore, have a thorough understanding of it and how it works.

             

From Sci-eng.net

             The knee is made up of three bones – the tibia, which is the larger of the two shinbones; the femur, or thighbone; and the patella, or kneecap.  The joint is formed when the tibia and the femur meet to unite the upper leg with the lower leg.  The patella is a triangular shaped bone that covers and protects the surface of the joint so that we can kneel down without sacrificing the joint’s integrity.

            In between the tibia and the femur are two C-shaped pads of cartilage called the lateral meniscus and the medial meniscus.  Their job is to provide cushioning between the two bones and to absorb the shock that comes from the bones hitting against each other while walking, running, and jumping.

            The knee joint is surrounded by ligaments that provide stability and prevent unwanted movement that could harm the joint.  The collateral ligaments connect the tibia to the femur on the outside of the knee (the lateral collateral ligament) and on the inside of the knee (the medial collateral ligament).  These ligaments prevent sideways movement of the femur.  The anterior collateral ligament, or ACL, crosses the center of the joint, connects the tibia to the femur, and prevents the tibia from sliding forward during movement.  The posterior collateral ligament, or PCL, runs directly behind the ACL and prevents the tibia from sliding backward.

From web md

            The patella slides along a groove on the front of the femur and is held in place above by the quadriceps tendon which connects the thigh muscles to the joint and below by the patellar tendon which connects the patella to the tibia.

            The knee contains many fluid-filled sacs called bursae that help cushion the joint and keep the bones moving smoothly against each other.

            The four quadriceps muscles found on the front of the thigh – the rectus femoris, the vastus intermedius, the vastus lateralis, and the vastus medialis are responsible for extending the knee.

            The hamstring muscles which are found on the back of the thigh as well as the gastrocnemius, which is the major calf muscle, and the popliteus, which runs across the back of the knee, are responsible for bending, or flexing the knee.

            Next week’s post will focus on common knee injuries and concerns that dancers may have and how to prevent and care for them.

Alignment: Developing a Strong Foundation

"When you find that your life is out of alignment with your grandest idea of yourself, seek to change it." -Neale Donald Walsch

         A contractor would never try to build on an unstable infrastructure, yet each day dancers attempt multiple pirouettes and complicated combinations upon misaligned bodies that provide a shaky foundation.

         Correct body alignment allows for efficient muscle use, encourages a less bound and more relaxed approach to movement, reduces the risk of injury, and contributes to ease of movement.

         Whenever a dancer has difficulty with balance or executing a step, which he or she should be strong enough to do, it is important to first observe his or her body alignment.  Just as a building will weaken if there is a crack in the foundation, the body is weakened by misalignment.

         Before each class a dancer needs to re-establish a strong base by being certain that all five toes are flat on the floor.  Body weight should be equally distributed on each foot in a triangular pattern formed by the base of the big toe, the heel, and the base of the pinky toe.  The ankle should be lifted so that the base of the tibia is not rolling forward and causing the foot to pronate, or roll inward.  Subsequently, the knee joint should be centered over the ankle, and the hip joint should be centered over the knee.  The base of the ribcage should be in line with the pelvis while the sternum is lifted and the shoulders rest on the body, similar to how frosting rests upon a cake.  The neck should be lengthened with the head lifting as if it were a helium-filled balloon.

         Dancers are often told to “pull up their centers” which often causes a disconnect between the upper and lower halves and the front and back halves of the body. When a dancer “pulls up” the stomach, the tendency is to “sit” or relax into the back of the hips and open the ribcage, resulting in a swayed back.  Dancers engage their abdominal muscles, tuck the pelvis, and hyperextend their legs and believe they are properly aligned.

         This ideology results in gripping muscles instead of lengthening them, stressing ligaments instead of strengthening muscles, and skeletal misalignment.

         Instead, dancers need to think of the ankle being lifted by the patella, or kneecap, and the leg being lengthened by the pelvis lifting and lengthening the quadriceps and hamstrings.  Dancers also need to remember to lengthen the back of the torso as well as the front as if the entire upper body were being sucked up through a straw.  Additionally, it is important for dancers to lengthen through the front and back of the neck equally to avoid the turtling of the head that often occurs.

         Simply thinking about dance posture differently will help align the body, engage the muscles in a different way, and produce a lengthening of the body which will increase the efficiency of movement, improve mechanics and balance, and lead to healthy dancing.

        

Working With Hyperextended Knees

            "More is not always better."

        The knee is a hinge joint, which means it is capable of flexing and extending.  It is a joint that is primarily held together by ligaments.  Some people are born with tight ligaments, and some are born with loose ligaments that allow for an increased range of motion.  Research has shown that most dancers have looser ligaments than the average person but has also concluded that dance does not result in loose ligaments.  This laxity appears to be genetic, and researchers have concluded that those who dance choose to because they have this expanded range of motion.

            A result of this increased range of motion is less control.  Loose knee ligaments allow that joint to go beyond extension into a state of hyperextension that results in the legs curving backwards.  This backward curve misaligns the leg and puts pressure on the anterior cruciate ligament (ACL) whose job it is to prevent the joint from overextending.  Continual pressure stretches out the ACL further and contributes to instability of the knees, which must support the weight of the body on a daily basis. For these reasons, it is important that dancers be taught how to straighten their legs without hyperextending them. 

            When dancers with loose ligaments are told to straighten their legs, they tend to lock the knees in the hyperextended position that causes them to stand in a first position with space between their heels.  Instead of asking them to straighten their legs, educators should ask them to lengthen their legs.  Hyperextended dancers should bend their knees slightly and shift their weight forward while using the quadriceps muscles to lengthen the front of the thigh to lift the patella, or kneecap, up toward the pelvis.  This action will eventually strengthen the muscles around the knee, limit the hyperextension, stabilize the joint and enable the heels to touch in first position.

            The long line of a hyperextended leg looks beautiful in a non-weight bearing position of a tendu, degagé or arabesque, but rather than locking or hyperextending the knee, dancers should constantly be thinking about lengthening the back of the leg.

            It is extremely important that dancers with hyperextended knees learn to avoid locking the knees and to work correctly before beginning pointe work.  When dancing on pointe, correct alignment is the key to avoiding unnecessary strain on the body. 

            All dancers should avoid stretches which put unnecessary pressure on the ACL and place the knee in a hyperextended position such as a split stretch with the front ankle up on a chair while seated on the floor or sitting with the legs straight out in front while flexing the feet until the back of the knees touch the floor.

            Dancers who learn to respect and work effectively with the bodies they have will be able to dance longer, stronger, happier and healthier. 

Muscles, Tendons & Ligaments

“It is a dancer’s responsibility to know the parts of her instrument and study how they work in unison to create a beautiful work of art.”

            Understanding the different parts of the body and how they work is an essential part of dance training.  Physical activities, like dance, require a thorough knowledge of the instrument in order to produce the best possible performance.

         Skeletal bones are the body’s foundation, but they require muscles to hold them securely together and to allow for movement.  Muscles are organs that are composed of thousands of individual fibers.  These fibers have four important qualities:  excitability, contractility, extensibility and elasticity.  Excitability means that muscles are able to receive stimuli, or messages, from the nervous system and react to them through movement.  When a muscle receives a signal to move, it contracts, or shortens, to pull on the bone to which it is attached.  The abilities to shorten and exert a force and to release afterward are contractility and extensibility.  Muscles are also capable of being stretched.  Elasticity is the quality that allows the muscle to return to its original length after being stretched.

            In order for muscles to move the skeleton, they must be connected to the bones by tendons.  Tendons are thick bands of tissue that can be stretched and, like muscles, are elastic and will return to their original length.  Studies have shown that tendons respond to forces like muscles do, and when they are used repeatedly, they will also grow stronger.  A recent study published by The Proceedings of the Royal Society in March 2012, showed that, in addition to connecting muscles to bones, tendons act as shock absorbers.  When a dancer lands a jump, it is the tendon that absorbs the primary shock and not the actual muscle.  Resultantly, the tendon is also thought to act as a spring and provide recoil strength after landing.

            While tendons connect muscles to bones, ligaments connect bones to each other.  The main purpose of a ligament is to limit or prevent certain movements.  The knee joint is one joint in the body where ligaments predominate.  The medial (inside) and lateral (outside) collateral ligaments limit sideways motion of the patella, or kneecap, while the posterior cruciate ligament prevents the knee from bending backwards.  Ligaments do not possess the same amount of elasticity that muscles and tendons do.  Once a ligament is stretched forcibly or for an extended period of time, it will not return to its original length and may require surgery.  It is for this reason that a bone dislocation should be cared for as soon as possible to prevent permanent ligamental damage.  Some people are born with extremely loose ligaments and are incorrectly labeled “double-jointed”.

            Knowing the body and how each part functions helps dancers to understand how to get the most from their training, understand how to care for injuries if they happen and learn how to optimize their performance.