Single-Leg Hop Performance and Limb Symmetry in Athletes With and Without a History of ACL Injury: The Role of Leg Dominance
Salmela, Kalle (2025)
2025
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2025051612783
https://urn.fi/URN:NBN:fi:amk-2025051612783
Tiivistelmä
Anterior cruciate ligament (ACL) injuries are among the most common and challenging injuries in sports involving cutting, jumping, and rapid changes of direction. This study examined whether athletes with a his- tory of ACL injury perform differently in the single-leg hop for distance (SLHD) test compared to athletes with no history of knee injury. The study also explored whether leg dominance or limb differences had an impact on performance outcomes.
From an initial pool of 51 athletes, 24 competitive athletes were selected — 12 with a verified history of ACL injury and 12 non-injured controls. Each participant completed the SLHD test on both legs under natural cueing conditions. Hop performance was analyzed using independent and paired t-tests as well as two- way ANOVA to assess group-level and within-subject differences.
No statistically significant difference in hop distance was found between the ACL group (M = 165.7 cm, SD = 24.9) and the control group (M = 159.4 cm, SD = 27.5), t(22) = 0.57, p = .574. Similarly, no significant main effect of leg dominance (F(1, 42) = 0.71, p = .404) or interaction between dominance and injury status (F(1, 42) = 0.05, p = .832) was observed. A non-significant trend favoring the dominant leg emerged in the con- trol group (p = .089).
Limb Symmetry Index (LSI) values exceeded the commonly used 90% return-to-sport (RTS) threshold at the group level. However, 25% of the ACL group and 16.7% of the control group failed to meet this benchmark individually. These findings suggest that functional asymmetries can persist even when group averages ap- pear acceptable. The results support using hop performance and LSI in RTS evaluations, but also highlight the importance of individual-level assessment in capturing subtle deficits that may affect performance or re-injury risk.
From an initial pool of 51 athletes, 24 competitive athletes were selected — 12 with a verified history of ACL injury and 12 non-injured controls. Each participant completed the SLHD test on both legs under natural cueing conditions. Hop performance was analyzed using independent and paired t-tests as well as two- way ANOVA to assess group-level and within-subject differences.
No statistically significant difference in hop distance was found between the ACL group (M = 165.7 cm, SD = 24.9) and the control group (M = 159.4 cm, SD = 27.5), t(22) = 0.57, p = .574. Similarly, no significant main effect of leg dominance (F(1, 42) = 0.71, p = .404) or interaction between dominance and injury status (F(1, 42) = 0.05, p = .832) was observed. A non-significant trend favoring the dominant leg emerged in the con- trol group (p = .089).
Limb Symmetry Index (LSI) values exceeded the commonly used 90% return-to-sport (RTS) threshold at the group level. However, 25% of the ACL group and 16.7% of the control group failed to meet this benchmark individually. These findings suggest that functional asymmetries can persist even when group averages ap- pear acceptable. The results support using hop performance and LSI in RTS evaluations, but also highlight the importance of individual-level assessment in capturing subtle deficits that may affect performance or re-injury risk.