Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement.

Unlabelled: Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P < .05). Not only was PF of the talocrural joint significantly less than the other 2 measurements (P < .001), PF from the goniometric method applied to the x-rays was significantly less than PF obtained from clinical goniometry (P < .05). These data provide insight into the extreme ankle and foot motion, particularly PF, required in female ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers.

Level Of Evidence: Diagnostic, Level I.