Eyes-Closed Single-Limb Balance is Not Related to Hypermobility Status in Dancers

• Published in: Journal of dance medicine & science 2017-06, Vol.21 (2), p.70-75
• Main Authors: Marulli, Tiffany A., Harmon-Matthews, Lindsay E., Davis-Coen, J. Hope, Willigenburg, Nienke W., Hewett, Timothy E.
• Format: Article
• Language: English
• Subjects: Adolescent; Age Factors; Anniversaries; Ballet; Chi-Square Distribution; Dancers; Dancers & choreographers; Dancing - physiology; Equilibrium (Physiology); Female; Health aspects; Healthy Volunteers; Humans; Injuries; Joint instability; Joint Instability - diagnosis; Joint Instability - epidemiology; Male; Mobility; Physiological aspects; Postural Balance - physiology; Proprioception; Proprioception - physiology; Reference Values; Sampling Studies; Sex Factors; Statistics, Nonparametric; Vision, Ocular - physiology; Young Adult
• ISSN: 1089-313X; 2374-8060
• DOI: 10.12678/1089-313X.21.2.70

Hypermobility may be associated with decreased lower extremity proprioception, which in turn may increase injury risk. The prevalence of hypermobility in dancers varies across studies, but joint hypermobility appears to be more common in dancers than in the general population. The purpose of this study was to determine how hypermobility affects eyes-closed single-limb balance as an indirect measure of proprioception in dancers. The secondary aim was to compare hypermobility and balance across dancer affiliation groups. Data were collected from 45 professional dancers, 11 collegiate modern dancers, 227 student dancers, and 15 pre-professional dancers during routine dance screens. Dancer hypermobility status was assessed via an eight-point Beighton-Horan Laxity test. Single-limb balance time, in seconds, was assessed in parallel position with the eyes closed. Hypermobile (HM) and non-hypermobile (NHM) dancers showed very similar balance times (HM median: 36.5 seconds; NHM median: 33.0 seconds; p = 0.982). Hypermobility was not significantly different between dancer affiliation groups (p = 0.154): 47% in ballet academy students, 27% in collegiate modern dancers, 62% in pre-professional dancers, and 36% in professional dancers. The student, pre-professional, and professional ballet dancers all demonstrated longer balance times than the collegiate modern dancers; however, this difference was only significant between the professional ballet dancers and collegiate modern dancers (p = 0.026). Dancers demonstrated a higher prevalence of hypermobility than what has been reported for the general population. Joint hypermobility did not affect eyes-closed single-limb balance time. Future studies are needed to determine if joint hypermobility affects more sensitive measures of proprioception and risk of injury.