Flexible backs are a highly popular asset for dancers. Check any social media site and you can find extreme positions of that back extension. Many dance moves (port de bras/cambres, arabesques, needles, scorpions, and more acrobatic type poses like chin stands and elbow stands) require extreme ranges of motion in the lumbar spine.
Repetitive and constant hyperextension in combination with rotation (occurring in dance with one leg front and one leg back) of the lumbar spine can lead to weakening of the pars interarticularis, which is part of the facet joints of the vertebrae. Genetics and bone structure may also increase the probability of injury as some people have thinner shaped bones.
Spondylolysis is the term that describes when a fracture occurs in pars interarticularis of the facet joints (connecting hinge-like joints) of the vertebrae. It can occur on one side of the vertebrae or both sides.
Spondylolisthesis can occur if spondyloysis (occurring on both sides of the vertebrea) is left untreated. Spondylolisthesis is when the fracture separates allowing the vertebrae to shift forward.
With spondylolysis, some people do not experience any pain or symptoms or will only experience pain when going into that hyperextended position. Some people experience pain in the low back and/or radiating symptoms to the buttock or thigh. With spondylolisthesis, dancers may experience muscle spasms, tight hamstrings, or difficulty walking. More serious, or high level spondylolisthesis, may involve numbness and tingling and/or weakness which is due to the nerve root being compressed by the shifted vertebrae.
*It’s important to note that no pain does not equal no problem. It’s also important to note that there are many other potential causes of pain, radiating pain, and weakness besides fracture.
Typically, treatment involves resting to allow the fracture to heal, physical therapy for strengthening and flexibility, then slowly returning to regular activities. If the injury is very serious, it may require surgery.
The best way to treat a spondylolysis or spondylolisthesis would be to prevent it all together or to at least prevent re-occurrence. The best option would be to work with a healthcare professional who has experience with dancers. It’s important work on gaining and maintaining good core, back, and hip strength; improving mobility of upper back and the hips in order to make sure flexibility is not only occurring at the low back to hit those positions but along the entire body; and checking or correcting technique in order to make sure it will not be a contributing factor.