Generalized flexibility or joint hypermobility is highly valued among professional dancers and widely sought by dance students, but Dutch researchers have found that the more flexible dancers from the Amsterdam School of Arts Academy for dance and theater were also at greatest risk for injury.
Mark C. Scheper, PhD, from the Education of Physiotherapy, Amsterdam School of Health Professions, University of Applied Sciences, Amsterdam, and the Department of Rehabilitation, Academic Medical Center, University of Amsterdam, the Netherlands, and colleagues report in an article published in the April issue of Rheumatology that dancers with generalized joint hypermobility (GJH) were less physically fit, experienced more fatigue, and reported more psychological distress than dancers without GJH or control subjects.
"Dancers with GJH seem more vulnerable to musculoskeletal and psychological complaints. In addition, GJH was also associated with lower physical fitness, despite training. Caregivers for professional dancers should monitor closely the physical capabilities and the amount of psychological strain," the authors conclude.
"What was surprising is that GJH was an independent factor indicating increased vulnerability," Dr. Scheper told Medscape Medical News. "Until now, this had only been described in symptomatic forms of GJH (Ehlers Danlos and hypermobility syndrome). However, in 'healthy' nonsymptomatic individuals, the same findings as in the symptomatic forms of GJH were present. This indicates that these problems are the result of the structural integrity of connective tissue rather than being the result of deconditioning. Another surprising aspect was...the magnitude of the effect of GJH, which was quite large."
The researchers compared 36 professionals with control participants (mean age, 20.1 years) to study the effect of GJH in professional dancers on physical fitness, musculoskeletal complaints, and psychological distress. Joint hypermobility was quantified using the Beighton score without a warm-up phase.
Multivariate analysis showed that dancers have higher levels of physical fitness, measured by the 6-minute walk test and by estimated peak oxygen uptake, but this advantage disappeared when GJH was taken into account. Dancers also had significantly higher levels of fatigue and psychological distress (anxiety and depression) compared with control participants, and the effect was exaggerated in dancers with GJH.
The researchers suspect that the increased fatigue reported by hypermobile dancers is in part a result of the additional effort required to stabilize hypermobile joints. Dr. Scheper said that inflammation caused by cartilage damage might also be a factor. The researchers speculate that the association between hypermobility and psychological distress in dancers might be a result of a common genetic origin.
Dr. Scheper advised clinicians caring for dancers to check on physical and psychological status at least twice a year and to consider yearly psychological consults for those at risk.
An accompanying editorial by Howard A. Bird, MD, from the Department of Sports Science, University College, London, and Elaine C. Foley, from Trinity Laban Conservatoire for Music and Dance, London, United Kingdom, also took up the question of how to monitor health in dancers. The authors argue that the hypermobility criteria used in this study are inadequate for judging the health and fitness of dancers and that new criteria that include factors relevant to particular dance styles are needed. "There is a need for both the dance and medical professions to move away from scoring systems that simply count joints," they write.
Professor Rodney Grahame, MD, who coauthored a landmark article on hypermobility in dancers in 1972, told Medscape Medical News, "There is nothing new in this study. Pat Klemp et al. in the 1980s in Cape Town showed that hypermobility was a risk factor for injury in professional ballet dancers, and I note that their study does not figure in the present paper's list of references. What is disappointing in the Scheper paper is that no attempt was made to establish a definitive diagnosis, either by applying the Brighton Criteria for Joint Hypermobility Syndrome (JHS) or the Villefranche Criteria for Ehlers-Danlos–hypermobility type (EDS/HM). It is universally agreed that the Beighton Score alone is inadequate to identify either JHS or EDS/HM, as may have been the prevailing view in the 1980s and 1990s. Our understanding of hypermobility and its implications has moved on since then." Dr. Grahame, who was not involved in the study, is professor of clinical rheumatology and runs the hypermobility clinic at University College London Hospitals.
The authors, editorialists, and Dr. Grahame have disclosed no relevant financial relationships.
Rheumatology. 2013;52:585-58, 651-658. Article abstract, Editorial extract
Janis C. Kelly • Medscape Medical News © 2013 WebMD, LLC