What Happens When a Dancer is Concussed?

The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe. - Michio Kaku

            My last article discussed concussions in dancers, and noted that although they are more common in other forms of physical activity like football, soccer and lacrosse, they still occur in dance. While concussions are more likely to be the result of a fall or being dropped during a lift, it is also worth noting that a dancer in a recent study reported developing concussion symptoms after “repeatedly whipping her head and neck in a choreographed movement.”

 

         Dancers who are concussed may report the following symptoms: headache, nausea, blurred vision, light sensitivity, noise sensitivity, feeling mentally foggy & concentration and memory problems.

         Although many people are now aware of the external symptoms of a concussion, few people are aware of what is actually happening inside the body.

         When a concussion occurs, the neuronal membranes, which are the outer layers that surround nerve cells, are damaged. As a result of this damage, potassium and an amino acid called glutamate leak out into the space between the cells. The body senses that there is a decrease in the amount of these substances in the nerve cells and sends more potassium into the cells to solve this problem. Since the potassium continues to leak out of the damaged cells, the body works harder to fix the issue and an imbalance is created.

         Because the body is doing all this extra work, it grows tired and an energy debt is created. An energy debt means that the body is working harder than normal and depleting all of its energy stores. This energy debt explains why a concussed individual craves carbohydrates; carbohydrates are the body’s preferred source for energy.

         It is for these reasons that rest is often prescribed for concussed athletes. In moderate to severe cases, concussed individuals may have to sit in dark rooms to rest the brain and limit the amount of input to which the brain must respond.

         Up until now, complete rest has been prescribed, followed by a gradual return to physical activity. Our next post will be a guest post written by a colleague of mine who has been conducting research on concussed individuals and will discuss the role that moderate aerobic exercise can play in the recovery process.

Concussions in Dance

           The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe. - Michio Kaku

           Concussions have become a topic of concern among the athletic community, but very little information is available about concussions in the dance community. Although the risk of concussion in dance is not as high as it is in others sports like football, basketball, and soccer, it still exists.

           

            A recent article published in the Journal of Dance Medicine and Science documented concussions that occurred in dancers over a 5 ½ year period. These injuries occurred in classes, rehearsals, and performances and seemed to be common among all types of dance. The documented cases included dancers who studied ballet, modern, acro, hip-hop, and musical theater dance.

            In most instances concussions are caused by a bump or a blow to the head. Almost all of the dancers reported hitting their heads while doing stunts, diving, flipping, or accidentally falling. It is interesting to note, however, that one dancer reported developing concussion symptoms after “repeatedly whipping her head and neck in a choreographed movement.”

            Although there is little information readily available that discusses concussions in dance, it is important for dancers, dance educators, and dance parents to know that they do occur and how to recognize the signs and symptoms.

            Fewer than 10% of people who sustain a concussion lose consciousness, and the symptoms may not show up right away. For some the symptoms may appear immediately, but for others it may take hours or days.

            Some symptoms that a concussed dancer may have:

·      Headache

·      Nausea or vomiting

·      Blurred vision

·      Light sensitivity

·      Noise sensitivity

·      Feeling mentally foggy

·      Concentration or memory problems

Listed below are the signs a teacher or parent should look for if a concussion is suspected:

·      Appears dazed

·      Cannot remember what happened before or after the injury

·      Seems confused

·      Forgets instructions

·      Moves clumsily

·      Answers questions slowly

·      Changes in personality or behavior

            If a concussion is suspected, the dancer should stop dancing immediately and be seen by a health care professional, who can evaluate the injury and determine when he or she can return to dance class. Returning to class too soon can result in a second concussion that can result in long-term problems like brain damage.

            My next post will discuss what happens in our bodies during a concussion and the treatment for those suffering from concussions.

            I would love to hear from you in the comments below if you or a dancer you know has sustained a concussion while dancing – is it more of a problem than we realize?

Dancers, Fatigue & Injuries

           "Fatigue makes fools of us all. It robs you of your skills and your judgment, and it blinds you to creative solutions. It's the best-conditioned athlete, not the most talented, who generally wins when the going gets tough." - Harvey Mackay


Participation in any type of physical activity bears the risk of injury.  Injuries occur in all types of sports programs and across all forms of dance.  With the increased availability of educational information about cross-training and caring for the body, Sports Medicine and Dance Medicine professionals are hoping to decrease the incidence rates, but it is interesting to look at when injuries are more apt to occur and why.

            Studies within the dance community have indicated injury rates as high as 95% in professional ballet dancers and 82% in professional contemporary dancers.  Injury rates in dance are comparable to those in other professional sports.

            Research has shown that 67% of dance injuries occur late in the day and that 75% of all injuries occur during preparation for performances when bodies are tired and/or overworked.   The lack of time and resources for tissue repair, additional hours of rehearsal, and constant repetitive movements when rehearsing specific phrases from dance pieces have all been cited as causes. 

            Dancers are known for diets that are low in nutritional value.  They are constantly going to extremes to avoid foods that may cause them to gain weight or diminish the aimed for aesthetic in the dance community.  Performance and rehearsal schedules allow little time for careful meal planning and food consumption, and it is difficult for dancers to consume enough calories to equal the amount of calories burned during an intensive performance season.

             Additionally, a large percentage of female professional dancers are amenorrheic, or do not have regular menstrual cycles.  The absence of a monthly period results in abnormal estrogen levels which reduce the amount of calcium that the body can absorb and use for repair. 

            Although most athletes’ bodies are able to use protein to recover quickly from minor muscle tears, this is not the case for dancers.  Without a proper diet filled with additional calories for tissue repair, the body is placed under stress during normal situations.  Once the intense performance season begins, the body is unable to care for itself efficiently.

            When this nutrition deficit is combined with a rehearsal/performance schedule that allows little time for rest and recovery, dancers are placed at a high risk for injuries.  While a minor breakdown in body tissue can be sufficiently repaired during an interval of rest, in dancers, who do not have sufficient rest time, the breakdown of tissue becomes greater than the body’s ability to repair, or remodel. 

            When the same muscle groups are used repeatedly during long hours of rehearsal and performance, they grow tired and use up their energy reserves.  When the central nervous system (CNS) receives the message that a muscle is fatiguing and having difficulty holding a contraction, it either tries to get the muscle to work harder, or activates surrounding muscles (synergists) to help.

            Muscular fatigue is only one piece of the puzzle.  Long work hours also stress the central nervous system.  The CNS uses sensory input to determine where the body is in space.  Messages communicated through visual clues and proprioceptive clues help the CNS determine which muscles need to contract and to determine the force that must be used to keep the body moving safely.  Although the body is engineered so that the CNS will protect the tired muscles by directing adjustments in the body, when the CNS is stressed, its ability to direct these adaptations slows down.  The delayed response affects motor control and coordination.  Landings from jumps and the body’s ability to slow down after leaps or turns are affected.  As a result, the way the body normally distributes the stress over the bones and joints is also compromised.

            The change in stress distribution and the lag time in reorganizing the muscular response set the body up for injuries.  All of these factors explain why most dance injuries occur late in the day or during an intense performance season.  Since dancers have a very high pain tolerance, when they get injured, they often do not realize it immediately.  Moreover, injured dancers tend to “dance through” the pain so they do not lose roles or jobs.

            In an ideal world, major rehearsals could be scheduled early in the day before the body is fatigued, and schedules could be designed to accommodate rest periods for dancers to allow for ample recovery time.  Unfortunately, rehearsal space is not always available at ideal times, and dancers need to be able to accommodate the schedules of theater personnel, musicians, and stage, sound, and lighting crews.  Additionally, audiences are only available after the traditional workday ends – in the evening.

            Educating dancers to listen to their bodies, eat properly, cross-train, and using periodization training can be helpful.  Rather than “dancing through” pain, dancers should be encouraged to care for injuries before they become chronic or more serious.  While eating properly has always been a challenge for dancers, a bit of knowledge about healthy foods and the convenience of food today make it easier.  Cross-training will strengthen all of the muscles in the body so that when some muscles fatigue, the synergistic, or helper muscles, will be prepared to start working, and periodization training can help prepare the dancer for performance season and alleviate some of the stress on the body.

            We are given one body to last our entire life.  It is up to us to learn as much as we can about how to dance in a way that preserves its health to the best of our ability.

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       Liederbach, M. Schanfein, L. & Kremenic, I. What is known about the effect of fatigue on injury occurrence among dancers? Journal of Dance Medicine and Science. 2013;17(3):101-8.

       Murgia, C. Overuse, tissue fatigue, and injuries. Journal of Dance Medicine and Science. 2013;17(3):92-100.

      Shah, S., Weiss, D. & Burchette, R.  Injuries in professional modern dancers: incidence, risk factors and management.  Journal of Dance Medicine and Science. 2012;16(1):17-25.

      Tajet-Foxell, B. & Rose, F. D. Pain and pain tolerance in professional ballet dancers.  British Journal of Sports Medicine. 1995:29:31-4.

Labral Tears of the Hip

            "To keep the body in good health is a duty... " - Buddha

               The joints in our bodies are protected by two types of cartilage.  Hyaline cartilage covers the surface of the bones and protects them from the friction damage that would occur if the bony surfaces rubbed against each other.  White fibrous cartilage can be found in joints that are subjected to frequent stress.  This type of cartilage helps keep joints intact and acts as a shock absorber.

            Movements that are repeated over and over again will gradually start to wear away cartilage just as a stream will erode the surface of a rock over time.  When joints are placed in unnatural positions, such as a turned out position, the body’s weight cannot be distributed normally over the joint, and undue stress is placed upon it.  Unnatural joint positions also occur when the dancer's body is misaligned or the dancer has a muscular imbalance.  When this stress is combined with repetitive movements, tiny tears begin to occur in the cartilage.  After a while these tears increase and result in bigger tears.  Additionally, jumps, leaps, pivots, and turns create enough force to cause cartilage damage on their own.  It is not surprising then that those who participate in ice hockey, soccer, football, golf, and ballet are at a greater risk for developing tears in the cartilage of the hip joint.

From arthroscopichipsurgeon.com

           
The labrum is a ring of white fibrous cartilage that can be found along the edge of the acetabulum, or the socket in the pelvis where the femur sits.  Its job is to hold the femoral head in place by increasing the depth of the hip socket. 

            The labrum often tears away from the acetabulum due to overuse and small injuries that may occur during twisting or pivoting movements and accumulate over time.  Dancers who experience a labral tear may complain of pain in the front of the hip, feel a “catch” in the joint when moving, experience stiffness in the hip, and/or have a limited range of motion at the joint.  These feelings may get worse after a long walk, or after staying in one position for a long time.  As the tear grows, the pain may radiate down the leg, to the side of the hip, or toward the lower back, and may become constant enough and severe enough to cause the dancer to avoid certain exercises and/or lessen the amount of time spent in class or rehearsals.

            If left untreated, a torn labrum can cause a shift in the way the femoral head sits in the acetabulum and increase the stress on the joint, predisposing the dancer to arthritis.

From arthroscopichipsurgeon.com

            Labral tears are diagnosed through an MRI scan of the hip.  More and more frequently, medical professionals are trying to avoid surgery and work instead with physical therapists to help dancers with this injury.  Anti-inflammatories will help with pain management, and physical therapists can work with dancers to eliminate any muscular imbalances they may have and to strengthen the muscles of the hip.  If the pain continues, cortisone shots can also help.  Because the inner side of the labral cartilage has no blood vessels, it has no way to repair and/or heal itself as do other soft tissues like muscles and tendons.

            If physical therapy does not work, or if the tear is too severe, surgery may be required.  During the surgery, any pieces of cartilage that have completely torn off can be removed, and the surgeon will trim the torn edge of the labrum and re-attach it to the edge of the acetabulum.  The recovery time for this type of surgery is a long one – 4-6 months with physical therapy for rehabilitation.

            The good news is that, although labral tears have been very common among ballet dancers, dance medicine specialists believe that education can play a key role in decreasing the risk.  Providing both dance educators and dancers with information about proper anatomical training, the dangers of muscular imbalances, the dangers of fatigue and overuse of the body, and the benefits of cross-training can help produce healthier dancers who can dance longer, stronger and happier without this type of injury.