1. Ballet shoes: Each dancer was tested using his/her personal ballet shoes.
2. Barefoot: The dancers were tested standing barefoot on the AMEDA device.
3. Textured insoles: We used rubber insoles with four nodules (3 mm high and 1 mm diameter) per square centimeter, similar to the textured rubber compound described previously by Waddington and Adams (2000, 2003). The rubber was cut-to-fit for each dancer and was inserted into the dancer's own ballet shoe (Fig. 2).
4. Smooth insoles: 3mm PVC Vinyl upholstery “Expanded e Slate” insole. The smooth insoles were cut to fit for each dancer and were inserted into the dancer's own ballet shoe.