Effect of Ankle Braces on Lower Extremity Joint Energetics in Single-Leg Landings

GARDNER, JACOB K.1; MCCAW, STEVEN T.2; LAUDNER, KEVIN G.2; SMITH, PETER J.2; STAFFORD, LINDSAY N.2

Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e318240d564
Applied Sciences
Abstract

Purpose: Ankle sprains are one of the most common injuries in competitive and recreational athletics. Studies have shown that the use of prophylactic ankle braces effectively reduces the frequency of ankle sprains in athletes. However, although it is generally accepted that the ankle braces are effective at reducing frontal plane motion, some researchers report that the design of the brace may also reduce ankle sagittal plane motion. The purpose of this study was to quantify lower extremity joint contributions to energy absorption during single-legged drop landings in three ankle brace conditions (no brace, boot brace, and hinged brace).

Methods: Eleven physically active females experienced in landing and free of lower extremity injury (age = 22.3 ± 1.7 yr, height = 1.66 ± 0.04 m, mass = 58.43 ± 5.83 kg) performed 10 single-leg drop landings in three conditions (one unbraced, two braced) from a 0.33-m height. Measurements taken were hip, knee, and ankle joint impulse; hip, knee, ankle, and total work; and hip, knee, and ankle joint relative work.

Results: Total energy absorption remained consistent across the braced conditions (P = 0.057). Wearing the boot brace reduced relative ankle work (P = 0.04, Cohen d = 0.43) but did not change relative knee (P = 0.08, Cohen d = 0.32) or hip (P = 0.14, Cohen d = 0.20) work compared with the no-brace condition.

Conclusions: In an ankle-braced condition, ankle, knee, and hip energetics may be altered depending on the design of the brace.

Author Information

1Department of Kinesiology, Recreation, and Sport Studies, The University of Tennessee, Knoxville, TN; and 2School of Kinesiology and Recreation, Illinois State University, Normal, IL

Address for correspondence: Jacob K. Gardner, M.S., Department of Kinesiology, Recreation, and Sport Studies, 1914 Andy Holt Ave., 322 HPER Bldg., The University of Tennessee, Knoxville, TN 37996-2700; E-mail: jgardn25@utk.edu.

Submitted for publication March 2011.

Accepted for publication October 2011.

©2012The American College of Sports Medicine