8 The effect of change of direction angle on knee mechanics – implications for ACL injury. (April 2019)

• Record Type: Journal Article
• Authors: Alhammad, Ayman; Herrington, Lee; Jones, Paul; Jones, Ritchard K
• Is Part Of: British journal of sports medicine. Volume 53(2019)Supplement 1
• Page Start: A3
• Page End: A3
• Publication Date: 2019-04
• Subjects: Sports medicine -- Periodicals; 617.1027
• DOI: 10.1136/bjsports-2019-scandinavianabs.8
• Languages: English
• ISSNs: 0306-3674

Abstract

Abstract : Introduction: Change of direction (COD) manoeuvres are important for many field sports, however they are unfortunately associated with non-contact ACL injuries. Although players frequently COD at >90° angles, limited knowledge is available on knee joint kinematics and kinetics during COD at 90° and 135° and whether limb preference impacts knee mechanics during COD at these angles, which formed the aims of this study. Methods: Healthy male recreational soccer players were recruited to take part in the study. 3D kinematics and kinetics were collected during COD manoeuvres at 90° and 135°. Running speed was controlled at 4±0.4 m/s and 3.5±0.3 m/s, respectively. To determine differences on variables associated with ACL risk; knee abduction angle and moment, across cutting angles and preferred legs, a paired sample t-test was conducted using a Holm method correction, α=(0.05/ (8 comparisons – rank +1). Results: 36 individuals took part in the study (24.25±6.21 years, 1.72±0.06 m and 66.41±10.83 kg). COD at 135° showed greater knee abduction angles and moments than at 90° but with similar peak VGRF. There were no differences between preferred and non-preferred legs, apart from the increased knee flexion angle during COD manoeuvres at 90° in the non-preferred leg. Conclusion: In male recreational soccer players, sharper cutting angles place the knee at more risk for ACL injuries with little asymmetry between preferred and non-preferred limbs. Sharper angles of examination should be utilized in the evaluation of individuals.