In case you missed it, the poll for this week’s Journal Club article was a three-way tie! The winning article is Comparing Lumbar Lordosis in Functional Dance Positions in Collegiate Dancers With and Without Low Back Pain by Skallerud et al. The article investigated the relationship between lumbar lordosis in dance positions, while comparing hip range of motion and core muscle endurance in collegiate dancers with and without low back pain.
Before we dive in, let’s get on the same page about what lumbar lordosis is. The spine consists of 33 vertebrae, making up the cervical spine (neck), thoracic spine (mid-back), lumbar spine (low back), sacrum, and coccyx (tailbone). In a normal spine, the stacked vertebrae provide our trunk with an S-shaped posture including lordotic curves and kyphotic curves. Both our cervical and lumbar spine have natural lordotic curves, also known as cervical lordosis or lumbar lordosis. On the other hand, our thoracic spine, sacrum, and coccyx have a kyphotic curve — you may have heard of thoracic kyphosis. In fact, having lumbar lordosis is completely normal and is actually preferred in a healthy spine, but having an increase or decrease in the angle of our natural lordotic or kyphotic spine curves can present musculoskeletal problems in life. This article from the Cleveland Clinic is a great resource if you’d like to read more about the spine.
As I imagine you know, dance is incredibly physical, requiring dancers to access extreme ranges of motion of the spine while simultaneously actively stabilizing. To make matters worse, dancers frequently experience a high volume of movement repetition during class and rehearsals. Given these insights, I wasn’t surprised when the article mentioned that 60% of dancers experience low back pain each month. The study consisted of 27 dancers from dance programs at the University of Michigan, Oakland University, and Wayne State University. Researchers from the physical therapy department at Wayne State University collected information on each participating dancer’s passive hip range of motion, lumbar lordosis measurements in varying positions using sensors, core endurance tests, and a weekly questionnaire on low back pain. The questionnaire collected information on whether or not the dancer has back pain. If so, the dancers were asked to identify the location and intensity of the pain. They were also asked to describe the onset of the pain if it was related to a specific event. To measure lumbar lordosis, two ViMove wearable motion sensors were placed on the spine at vertebral levels S2 and T12-L1. The sensors captured the degree of motion between the two spaces while dancers held the following positions:
- Standing with feet parallel, hip-width apart
- Standing in first position
- The bottom of a second position grand plié
- Cambré with both arms in fifth while standing in first position
- Retiré from fifth position, arms in first
- At the peak of developpé á la seconde
- First arabesque
Core endurance testing was completed with the dancers maintaining three different positions: plank on elbows, double leg bridge, and single leg bridge. The dancers held the positions as long as they could with proper form while the researchers timed them. Data was collected over a four-month semester. Afterward, data analysis was completed to investigate the relationship between lumbar lordosis, hip range of motion, core endurance, low back pain, and different dance positions.
Results
- 59.3% of the participating dancers reported an incidence of low back pain during the semester
- Dancers in this study averaged 39˚ of lumbar lordosis when standing parallel. Lumbar lordosis in the general population ranges between 20˚ and 45˚, so this is on the higher end
- Dancers who reported pain exhibited increased lumbar lordosis, especially during right retiré and right developpé positions
- Dancers demonstrated similar hip range of motion and core endurance test results regardless of reported low back pain
- Dancers experiencing low back pain reported the highest pain ratings during right retiré, right developpé, and in first arabesque to the right side
Overall, the study showed that there is a relationship between low back pain and increased lumbar lordosis in collegiate dancers.
Thoughts
As a dance medicine physical therapist, I often work with individuals experiencing low back pain in and outside of the studio setting. Many dancers don’t come to see me until the back pain is limiting their ability to participate in class or rehearsal — I wish they would seek me out sooner…
A common trend I have observed is the quantity of pain episodes increasing with a high training volume, as well as mechanical training errors such as forcing turn-out using the friction of the floor or anteriorly tilting the pelvis. While low back pain episodes can stem from various factors, another common trend I have seen is a dancer preferring an anterior pelvic tilt position when standing, sitting, and dancing. One of the first lessons (of many) I teach a dancer experiencing low back pain is how to find their “neutral pelvis” in the clinical setting and then we explore how that carries over to dance-specific movements. While that may sound incredibly simple, dancers I work with are often surprised by the amount of re-teaching we have to do for their neuromuscular system. It is easy to establish bad habits, especially if that means creating more aesthetic movements (and receiving praise from peers!) but it’s not so easy to break those habits. For this reason, I loved that the authors reported that “increasing lumbar lordosis is one of the most common technical errors to compensate for limited hip range of motion and can indicate a possible lack of neuromuscular control in the spine, which could increase the risks of low back pain”.
I also appreciated how the authors measured hip range of motion and core endurance. Often what I experience in the clinic is that dancers with chronic low back pain (spanning multiple years) have decreased core muscle endurance when I ask them to complete core endurance tests. In this study, all of the participants were able to maintain the endurance tests for longer than the proposed cut-off scores. I was surprised by this at first, but then I read that dancers who had experienced low back pain within two weeks prior to the study starting were excluded from participating, which eliminates any dancers with chronic low back pain from participating in data collection. I am curious if the results would be any different if they didn’t have that exclusion criteria and rather categorized the “pain” groups into chronic versus acute. I wonder if there may be a different relationship between lumbar lordosis and core endurance with the “chronic” low back pain dancers… My guess is yes.
A limitation of this study is the small sample size of 27 participants. The study is also primarily exclusive to ballet and modern collegiate dancers, and may not be reflective of other dance genres or ages. The lumbar lordosis measurements were also taken with the dancers maintaining the static position rather than having the dancers move through the positions. In all, I can definitely see how the data shows a relationship between lumbar lordosis and low back pain in dancers.
If you are a dancer experiencing low back pain, please consult a licensed physical therapist or your healthcare provider. Bonus points if they are familiar with dance!
Discussion
- What are your thoughts on the study?
- Are there any dance positions that you would like to see included in the lumbar lordosis measurements?