Assessing Side-to-Side Injury Risk and Reliability of the Modified Landing Error Scoring System (LESS–M) in Youth Basketball Athlete

Objective To explore the risk of non-contact anterior cruciate ligament (ACL) injury in basketball players, with a specific focus on comparing dominant (DL) and non-dominant limbs (NDL) assessed with the LESS–M and tested the LESS–M reliability. Design Observational study Setting Field-based testing Participants Thirty-six youth basketball players (31 males, 5 females; average BMI 21.35 ± 1.98 kg/m 2 ) Main Outcome Measures LESS–M total scores of DL and NDL, and intraclass correlation coefficient ICC (2,1) and ICC (2,k) reliability. Results The LESS–M total scores were no statistically significant side-to-side difference (p=0.327) between DL (4.11 ± 1.16) and NDL (4.28 ± 1.36). The LESS–M demonstrated good intra- and inter-rater reliability, with ICC (2,1) = 0.789 and ICC (2,k) = 0.803, respectively. Conclusion The risk of non-contact ACL injury assessed using the LESS–M was similar between the DL and NDL in basketball players. The LESS–M demonstrated good reliability and may be a practical screening tool for movement assessment in basketball athletes. Future prospective studies are needed to establish cut-off values and explore its application in injured populations.