Article Text

Download PDFPDF

101 Biomechanical risks of knee injury in mixed martial arts: a video-based notation analysis
  1. Kam Ming Mok1,3,
  2. Ivan YH Lau1,
  3. Lobo Louie2,
  4. Patrick Shu Hang Yung1
  1. 1Department of Orthopaedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, Hong Kong (China)
  2. 2The Department of Sport and Physical Education, Hong Kong Baptist University, Hong Kong, Hong Kong (China)
  3. 3Office of Student Affairs, Lingnan University, Hong Kong, Hong Kong (China)


Background Incidence rate of knee injury in mixed martial arts (MMA) is high. MMA is a high-intensity sport that requires constant angle and level change. A majority of the combined movements overlap with biomechanics that have been suggested to be associated with increased risk of knee injury.

Objective To identify the frequency of occurrence of the high-risk movements, i.e. dynamic valgus, during MMA competitions.

Design Video-based notation analysis.

Setting The analysed movements have been separated into two categories, Gross Biomechanical Risks and Detailed Biomechanical Risks. High-intensity movements were analysed in slow motion to ensure accuracy. Three fights were re-watched after all 29 fights as quality control to access the reliability of measurement.

Patients (or Participants) 29 MMA fights.

Interventions (or Assessment of Risk Factors) Documenting all visible high-risk knee injury movements occurred in the fights.

Main Outcome Measurements The frequency of occurrence of the high-risk movements, i.e. dynamic valgus, during MMA competitions. In addition, other gross biomechanics were recorded.

Results On average, an MMA athlete experienced 31 times of knee valgus motion with explosive force drag during a match. The side affected was highly subjective to the stance of the fighter. The rear leg was most likely to go through knee valgus motion.

Conclusions The result showed high-risk knee motions are common in MMA. Based on the data, knee valgus on the rear leg is of interest for future injury prevention focus. The data collected in this study can be used as the backbone for further investigation on the possible ways for knee injury prevention.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.