Prevalence and Biomechanical Analysis of Knee Valgus and Knee Flexion Angle during Hop Test and Step-down Test among Badminton Players

BACKGROUND: The knee joint plays a crucial role in various badminton-related functional movements for both stability and mobility. Specifically, an optimal flexion and valgus angle upon landing tasks ensures less injury risk. AIMS: Thus, the study aimed to investigate the prevalence and biomechanical analysis of knee joint flexion and valgus angle among badminton athletes. METHODS: Sixty players were included in this study. The study conducted a two-dimensional biomechanical analysis using the Kinovea software to measure the knee flexion and valgus angle while hop and step-down tests, respectively. RESULTS: The study found that for the 13-17 age group, the mean knee flexion angle is 109.8° ± 8.0° (right) and 112.9° ± 8.7° (left), whereas for the 18-25-year age group, it is 110.4° ± 10.1° (right) and 111.7° ± 9.6° (left). The knee valgus angle for 13-17 years is 11.0° ± 5.5° (right) and 11.1° ± 5.7° (left), and for 18-25 years, it is 12.6° ± 6.1° (right) and 11.9° ± 4.0° (left). The difference in knee flexion and valgus angle between legs or the age groups did not find statistically different (P > 0.05). CONCLUSION: The findings conclude that there was a high prevalence of increased valgus angle among badminton players. However, the flexion angle was found to be optimal. There was no meaningful differences in the knee joint alignments neither between both the legs and the age groups. The study findings can underscore the potential mechanisms and necessary training modifications by emphasising certain neuromuscular control trainings and optimal landing mechanics to ensure a safe and effective badminton-related mechanics, thereby reducing injury risks.