Force Attenuation Properties of Padded Dance Support Socks

Abstract

Background: Foot injuries occur frequently in dancers, and researchers have investigated different protective measures to reduce their incidence. Research has primarily focused on ballet, but foot injuries also are common in modern and contemporary dance where footwear is not worn. While padded dance socks are a potential solution, the extent to which they provide force reduction for the feet is unknown.<br/> Purpose: This study investigates the extent to which padded dance support socks can reduce force on the foot during a dance sequence and when landing from a sauté jump.<br/> Methods: Twenty-one injury-free dancers (2 M, 19 F; age: 21.5 ± 6.7 years; height: 165.5 ± 6.1 cm; mass: 68.6 ± 15.0 kg) volunteered for this randomized, cross-over design study. Participants per- formed a 40-second modern dance sequence and a sauté jump landing under two conditions: wearing Apolla Performance Shock™ dance socks (DS) and with bare feet (BF). During these activities, 1.0 cm diameter circular force transducers were affixed under the first metatarsophalangeal joint and under the center of the heel. The sensors wirelessly recorded peak toe force, peak heel force, mean toe force, and mean heel force during dancing. A force platform measured vertical ground reaction force (VGRF) and time to peak VGRF, while the foot sensors measured peak toe force and peak heel force, during the jump landings. A Noraxon MR3.12 biomechanics system synchronized and recorded the data. All force data were normalized to body weight (BW). Dependent samples t-tests were used to assess pairwise differences in these measures between the DS and BF conditions. Alpha was set at p < 0.05.<br/> Results: Mean and peak heel forces/BW when dancing with DS were significantly lower than during BF dancing (mean: p = 0.015; peak: p = 0.0004). Peak VGRF/BW when landing from the sauté jump with DS was significantly lower compared with landing in BF (p = 0.035). All other variables were not significantly different between conditions, but all DS force values were lower than BF.<br/> Conclusions: We offer evidence that padded dance socks may reduce foot forces dancers commonly encounter during modern dance. The trends we recorded require further study to assess the extent to which the socks exhibit beneficial effects when considering both the many hours dancers train and the cumulative effects of impacts sustained by their feet.