Performance on a Single-Legged Drop-Jump Landing Test Is Related to Increased Risk of Lateral Ankle Sprains Among Male Elite Soccer Players: A 3-Year Prospective Cohort Study

Abstract

Background: Soccer has a high injury rate, with lateral ankle sprains being a common injury. Therefore, an approach to prevent or at least reduce the occurrence is warranted. Injury prevention can be improved by identifying specific risk factors and individuals at risk.

Purpose: To assess drop-jump landing performance as a potential predictor of lateral ankle sprain within 3-year follow-up.

Study design: Case-control study; Level of evidence, 3.

Methods: Single-legged drop-jump landing tests were performed by 190 elite soccer players. Based on ground-reaction forces, 6 outcome measures were calculated that aim to reflect the impact and stabilization phase. Lateral ankle sprains were registered during up to 3 years of follow-up. Following a z score correction for age, a multivariate regression analysis was performed.

Results: During follow-up, 45 players (23.7%) suffered a primary lateral ankle sprain. Of those, 34 were regarded as severe (absence >7 days). Performance was related to increased risk of ankle sprain ( P = .005 for all sprains and P = .001 for severe sprains). Low mediolateral stability for the first 0.4 seconds after landing (a larger value indicates more force exerted in the mediolateral direction, resulting in rapid lateral stabilization) and high horizontal ground-reaction force between 3.0 and 5.0 seconds (a smaller value indicates less sway in the stabilization phase) were identified as risk factors. A player that scored 2 SD below average for both risk factors had a 4.4-times-higher chance of sustaining an ankle sprain than a player who scored average.

Conclusion: The current study showed that following a single-legged drop-jump landing, mediolateral force over 0 to 0.4 seconds and/or mean resultant horizontal ground-reaction force over 3 to 5 seconds has predictive value with regard to the occurrence of an ankle sprain among male elite soccer players within 3 years.

Keywords: balance; football; injury; motor control; proprioception.

Figure 1.

Stills from video registration (Appendix Video, available in the online version of this article). The images show a player just before impact on the force plate.

Figure 2.

Illustration of the 6 selected outcome measures based on the ground-reaction forces (GRFs) (y-axis) and time series (x-axis): (A) peak force V and TTS VRAW 1.5, (B) Hor GRF dyn and Hor GRF late dyn, and (C) RMS ML 0.4 and peak force AP. See Outcome Measures section for definitions. BW, body weight.

Figure 3.

Scatterplot of all players regarding follow-up length and z score of RMS ML 0.4. The multicolored dots represent the corresponding RMS ML 0.4 z score (y-axis) for those players who sustained an ankle sprain at a certain moment in time (x-axis). The black dots signify the z scores at end of follow-up for the players who did not sustain an ankle sprain (hence, the vertical lines of dots at 1, 2, and 3 years). See Outcome Measures section for definitions.

Figure 4.

Risk chart with regard to (A) all ankle sprains and (B) the severe sprains; z scores of 0 for RMS ML 0.4 and Hor GRF late dyn mirror no change in risk (1.000). See Outcome Measures section for definitions.