Anterior cruciate ligament (ACL) is the most commonly injured ligament. It has a great impact on athletes causing long absence from play and is linked with increased risks of osteoarthritis. Today, literature suggests that the knee braces may not completely reduce ACL injury mechanism risks. Ankle braces, on the other hand, have shown promising results in some of these aspects. Thus, the purpose of this research is to study the effectiveness of a knee-ankle brace restraint in reducing ACL injury risks by increasing knee flexion and reducing knee valgus angles. Eighteen healthy Asian male subjects performed a drop vertical jump maneuver from a 31cm platform. A motion analysis capture was carried out to measure the knee flexion and knee valgus angles. Results show that the effect of a knee-ankle brace restraint was insignificant in increasing knee flexion and in reducing knee valgus angles at initial contact and at peak vertical ground reaction force (VGRF). While the ankle brace showed some trends of increasing knee flexion angles at initial contact, the effect was insignificant. Similarly, the ankle brace did not show significant effects on knee flexion angles at peak VGRF and on knee valgus angles at both instances. The knee brace had little effect on knee flexion angles but showed significant effects on valgus angle increase. In conclusion, a knee-ankle brace restraint was not found to have an effect on reducing ACL injury risks during jump-landing. Ankle brace use did not adversely increase ACL injury risks but has shown weak effects in reducing the risks. The knee brace used in this study was not found to be suitable for reducing valgus angles. (C) 2013 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University