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.

Ankle Sprains

          “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

         Last week’s post on the anatomy of the ankle explained how the two joints that comprise the ankle and the ligaments surrounding the ankle work.  When everything goes as planned, the ankle moves as it should and is prevented from moving in directions that could damage and/or compromise its stability.  Sometimes, however, there are factors that cause the ankle to move in dangerous ways and an injury occurs.

 

            Ankle sprains account for 15% of all athletic injuries, and an ankle sprain is the most common injury among all forms of dance.  A 2006 article published in Physical Medicine and Rehabilitation Clinics of North America reported that ankle injuries account for up to 62% of all dance injuries, up to 24% of all modern dance injuries, up to 95% of all ballet injuries and up to 45% of musical theatre dance injuries in professional dancers.  The same article reports that females are at a higher risk of injuring the ankle because of the amount of stress placed on the joint during pointe work.

            A sprain occurs when one or more of the ligaments surrounding the ankle joint are overstretched or possibly torn.  Since ligaments are designed to prevent movements from occurring, an overstretched or torn ligament allows for movement in a direction that the joint is not meant to go.

Lateral sprain

            The most common sprain among dancers is on the lateral, or outside, of the ankle.  This sprain occurs in the lateral collateral ligaments when the foot turns inward, or inverts, while the ankle rolls outward.  A less common sprain can occur on the medial, or inner side, of the ankle if the foot twists outward, or everts, while the ankle rolls inward.   Consequently, one or more of the deltoid ligaments and/or the calcaneonavicular ligament can be overstretched.  The least common type of sprain among dancers occurs at the top of the ankle and is called a high sprain.  It would involve the syndesmosis ligaments that connect the tibia to the fibula.

            Sprains can caused by either rolling over when on demi-pointe or pointe, landing a jump incorrectly, or dancing on poor surfaces like slippery floors.  Rolling over or a poor landing could be the result of poor alignment at the ankle joint.  If a dancer’s foot tends to pronate, or roll in, the ankle may become chronically misaligned.  Ankle misalignment can also occur if there are muscular imbalances in the leg, if turnout is forced, or if there are misalignments in other parts of the body.  Fatigue and/or a sudden increase in training or rehearsal time can also stress the body and cause it to respond to movement differently than expected.  Slippery floors limit the amount of control a dancer has when dancing and can cause unexpected movements or falls.

            When a sprain occurs, the dancer will experience immediate pain followed by swelling.  A mildly sprained ankle will be swollen, be tender and stiff, and cause a small amount of pain when walking.  When the swelling and tenderness are accompanied by bruising and extreme pain while walking, the sprain is classified as serious or moderate.  A severe sprain often results in an audible pop or snap and a feeling of tearing when it occurs.  The ankle will seem “wobbly”, and the dancer will be unable to walk on it.

            As with all injuries, the dancer should immediately stop dancing, ice the injured area, and elevate it.  The reasons for following these steps are reviewed in my post on caring for injuries.  Dancers should always be evaluated by a dance medicine specialist.  Depending upon the severity of the sprain, the injury can take anywhere from 6 weeks to 3 months to heal.  After the injury heals, it is important that the dancer work with a physical therapist to re-establish the strength of the ankle joint and to determine what may have caused the injury.  If the cause was misalignment and/or a muscular imbalance, a physical therapist can help the dancer retrain his/her body to keep another injury from occurring.

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Kadel, N. (2006). Foot and Ankle Injuries in Dance. Physical Medicine and

            Rehabilitation Clinics of North America, 17, 813-26.

O’Loughlin, P., Hodgkins, C., & Kennedy, J. (2008).  Ankle Sprains and Instability in

Dance.  Clinics in Sports Medicine, 27, 247-62.

Russell, J. (2010).  Acute Ankle Sprain in Dancers.  Journal of Dance Medicine and

            Science, 14(3), 89-96.

Learning About The Ankle

           “We will be in tune with our bodies only if we truly love and honor them. We can’t be in good communication with the enemy.”  -Harriet Lerner


          Dancers are athletes and, as such, their bodies endure many hours of physical activity.  The ankle joint is one that all types of dancers depend upon in order to perform.  The ankle needs to be strong enough to support the dancer and remain stable while being flexible enough to execute dance steps.

            The ankle is the site where most dance injuries occur, and it is helpful to both dancers and dance educators to understand the anatomy of this joint.

The ankle is home to two separate joints.  The actual ankle joint is formed where the tibia, the fibula, and the talus meet.   The tibia is the large bone of the lower leg that is located on the inside of the shin while the fibula is the narrow bone that is found on the outside of the shin.  The talus is the bone located on the top of the arch of the foot where the lower leg and foot meet.  This joint is a hinge joint that is responsible for the ability to plantar flex (point) and dorsiflex (flex) the foot.

From Southern California Orthopedic Institute

            The other joint that is responsible for ankle movement is the subtalar joint.  This joint is formed where the talus and the bone located beneath it, the calcaneus meet.  When these two bones glide over each other, the foot can be moved from side to side.

            The ankle is held together by a series of ligaments.  Ligaments are responsible for connecting bone to bone and for preventing certain movements that could dislocate and/or compromise the joint.

            The inside, or medial, side of the ankle is home to the deltoid ligaments and the calcaneonavicular ligament.  These ligaments connect the tibia to the talus and the calcaneus.  They are responsible for stabilizing the inside arch of the foot, holding the talus in place, and keeping the ankle from collapsing inward.

            The lateral collateral ligaments are found on the outside, or lateral side of the ankle.  The syndesmosis ligaments connect the tibia to the fibula and provide stability at the top of the ankle.  The strongest lateral ligament is the posterior talofibular ligament.  It connects the fibula to the talus and prevents the talus from slipping backwards and externally rotating.  The calcaneofibular ligament connects the fibula to the calcaneus and prevents the foot from twisting too far away from the body, or everting.  The anterior talofibular ligament connects the fibula to the talus, stabilizes the talus, and prevents the foot from twisting too far toward the body, or inverting.  This ligament tends to be the weakest lateral ligament of the ankle.

From Foot Doc

              Next week’s post will discuss ankle sprains, the frequency at which they occur in dancers, their causes, and treatment.

Dancers and Cocaine Use

            "Dancing appears glamorous, easy, delightful. But the path to paradise of the achievement is not easier than any other." - Martha Graham

          Dancers – they accomplish supernatural feats with their bodies, they have an extremely strong work ethic, and audiences applaud their efforts.  However, those supernatural feats take their toll on the body, the strong work ethic leads to hours and hours of class and rehearsals, and when the applause dies down, the performance high fades along with it.

            Dance is a difficult pursuit, and the stress of it can lead to eating disorders, which I have written about at length here, or substance abuse.   Cocaine abuse has been a problem within the dance community since the 1980’s.  Ballerina Gelsey Kirkland wrote candidly about it in her autobiography, Dancing On My Grave, and American Ballet Theater dancer, Patrick Bissell died of a cocaine overdose in 1987.

            Originally used as a painkiller, cocaine is made from coca leaves and usually mixed with cornstarch, talcum powder, sugar, or other drugs.  It is normally either snorted in through the nose or smoked.

            Cocaine creates a hyper vigilant state that increases alertness, creates high energy levels, decreases appetite, and creates a euphoric state.  All of these effects would seem to be advantageous for dancers.  Being alert means learning combinations quickly, lots of energy means the ability to dance at peak levels for a longer time, appetite suppression means that the dancers can control their weight without thinking so much about it, and the euphoric state replicates the high created during a performance and prevents feelings of post-performance letdown.

            Unfortunately, like most substances, cocaine also has a downside.  All of these “benefits” occur because cocaine blocks neurotransmitters from being absorbed.  Neurotransmitters are substances that line the pathways between different nerves so that impulses, or messages, can travel from the body to the brain and back again.  When absorption is blocked, a chemical build-up occurs in the body, and the neurotransmitters norepinephrine, serotonin and dopamine accumulate. 

            Norepinephrine and serotonin increase heart rate and constrict blood vessels.  The increased heart rate causes breathing to increase and puts a strain on both the heart muscle and the lungs.  The constricted blood vessels increase blood pressure and limit the amount of blood that can flow to the heart, brain and digestive system.  The lack of blood flow to the heart can lead to heart attacks or irregular heartbeats, the lack of blood flow to the brain can cause a stroke, and low blood flow to the digestive system can cause ulcers.

            Additionally, cocaine use causes a breakdown in muscle tissue that is released into the bloodstream and breaks down into a substance that causes kidney damage.  If cocaine is snorted, there will be sinus tissue damage, and it if is smoked, it can result in lung tissue irritation and/or damage.

            Cocaine is a highly addictive drug and is a definite problem in the dance community.  Dance educators, directors, and dancers need to acknowledge this issue and help dancers find help if they are using it and raise awareness to prevent other dancers from following this path.

            A new short film, Ballon, seeks to do just that.  It follows a ballerina through a cocaine addiction and her journey to become healthy once again.  More information on this film can be found here.

            Any effort to keep dancers healthy needs to start with awareness and education.  By arming dancers with the knowledge of what cocaine does physiologically, we can hopefully help decrease the problem and keep them dancing longer, stronger and healthier.