Dance floor force reduction influences ankle loads in dancers during drop landings. Issue 4 (July 2015)

• Record Type: Journal Article
• Authors: Hopper, Luke S.; Alderson, Jacqueline A.; Elliott, Bruce C.; Ackland, Timothy R.
• Is Part Of: Journal of science and medicine in sport. Volume 18:Issue 4(2015:Jul.)
• Page Start: 480
• Page End: 485
• Publication Date: 2015-07
• Subjects: Sports sciences -- Periodicals; Sports medicine -- Periodicals; Exercise -- Physiological aspects -- Periodicals; Sports -- physiology -- Periodicals; Sports Medicine -- Periodicals; Sportgeneeskunde; 617.102705
• DOI: 10.1016/j.jsams.2014.07.001
• Languages: English
• ISSNs: 1440-2440

Abstract

<abstract abstract-type="author" id="abs0005"> <title id="sect0005">Abstract</title> <sec> <title id="sect0010">Objectives</title> <p id="spar0005">Dance floor mechanical properties have the potential to influence the high frequency of ankle injuries in dancers. However, biomechanical risk factors for injury during human movement on hard, low force reduction floors have not been established. The aim of this study was to examine the ankle joint mechanics of dancers performing drop landings on dance floors with varied levels of force reduction.</p> </sec> <sec> <title id="sect0015">Design</title> <p id="spar0010">Repeated measures cross sectional study.</p> </sec> <sec> <title id="sect0020">Methods</title> <p id="spar0015">Fourteen dancers performed drop landings on five custom built dance floors. Ankle joint mechanics were calculated using a three dimensional kinematic model and inverse dynamics approach.</p> </sec> <sec> <title id="sect0025">Results</title> <p id="spar0020">Ankle joint kinematic (dorsiflexion; range of motion, peak angular velocity and acceleration) and kinetic (plantar flexion; peak joint moments and power) variables significantly increased with a decrease in floor force reduction. Many of the observed changes occurred within a latency of <0.1 s post-contact with the floor and were associated with increased vertical ground reaction forces and decreased floor vertical deformation.</p> </sec> <sec> <title id="sect0030">Conclusions</title> <p id="spar0025">The observed mechanical changes are interpreted as an increase in the load experienced by the energy absorbing structures that cross the ankle. The short latency of the changes represents a high intensity movement at the ankle during a period of limited cognitive neuromuscular control. It is suggested that these observations may have injury risk implications for dancers that are related to joint stabilization. These findings may be of benefit for further investigation of dance injury prevention and support the notion that bespoke force reduction standards for dance floors are necessary.</p> </sec> </abstract>