The effects of ankle protectors on lower limb kinematics in male football players: a comparison to braced and unbraced ankles

Abstract

Football (soccer) players have a high risk of injuring the lower extremities. To reduce the risk of ankle inversion injuries ankle braces can be worn. To reduce the risk of ankle contusion injuries ankle protectors can be utilised. However, athletes can only wear one of these devices at a time. The effects of ankle braces on stance limb kinematics has been extensively researched, however ankle protectors have had little attention. Therefore, the current study aimed to investigate the effects of ankle protectors on lower extremity kinematics during the stance phase of jogging and compare them with braced and uncovered ankles. Twelve male participants ran at 3.4 m/s in three test conditions; ankle braces (BRACE), ankle protectors (PROTECTOR) and with uncovered ankles (WITHOUT). Stance phase kinematics were collected using an eight-camera motion capture system. Kinematic data between conditions were analysed using one-way repeated measures ANOVA. The results showed that BRACE (absolute range of motion (ROM) = 10.72° and relative ROM = 10.26°) significantly (P<0.05) restricted the ankle in the coronal plane when compared to PROTECTOR (absolute ROM=13.44° and relative ROM =12.82°) and WITHOUT (absolute ROM=13.64° and relative ROM=13.10°). It was also found that both BRACE (peak dorsiflexion=17.02° and absolute ROM=38.34°) and PROTECTOR (peak dorsiflexion =18.46° and absolute ROM =40.15°) significantly (P<0.05) reduced sagittal plane motion when compared to WITHOUT (peak dorsiflexion =19.20° and absolute ROM =42.66°). Ankle protectors’ effects on lower limb kinematics closely resemble that of an unbraced ankle. Therefore, ankle protectors should only be used as a means to reduce risk of ankle contusion injuries and not implemented as a method to reduce the risk of ankle inversion injuries. Furthermore, the reductions found in sagittal plane motion of the ankle could possibly increase the bodies energy demand needed for locomotion when ankle protectors are utilised.