Introduction

Quadriceps injuries represent a significant concern for elite soccer players, given the critical role of these muscles in performance and injury prevention. This study investigates the incidence and outcomes of quadriceps injuries in Major League Soccer (MLS) over a decade, with a specific focus on return-to-play (RTP) times, re-injury rates, and the impact on player performance metrics across different positions.

Methodology

This is a retrospective analysis using the MLS Injury Surveillance Database, identifying quadriceps injuries sustained by players between 2010 and 2021. Data on demographics, injury characteristics, RTP duration, and performance metrics post-injury were collected. Statistical analyses assessed trends over time, re-injury rates, and differences in RTP and performance outcomes across player positions.

Results

A total of 1,550 quadriceps injuries were recorded among 919 MLS players. The median absence from sport was 6.0 days. Notably, the median RTP time increased from 14.4 days in 2010-2015 to 23.0 days in 2016-2021, a statistically significant difference (p<0.001). Re-injuries accounted for 40.7% of all cases, with a slight decrease in the re-injury rate from 37.3% in 2010-2015 to 32.6% in 2016-2021 (p=0.05).

Weather conditions significantly influenced RTP duration, with shorter RTP observed in injuries occurring during rain or snow compared to sunny or clear conditions (10.9 days vs. 18.8 days, p<0.001). Performance analysis revealed that defenders showed a marked decrease in games played per season (21.11; 17.18, p=0.002), minutes played per season (1694.28; 1361.34, p=0.004), and goals per season (0.82; 0.43, p=0.008). In contrast, forward players, midfielders, and goalkeepers exhibited comparable post-injury outcomes to their pre-injury performance.

Conclusion

The study highlights a significant increase in RTP duration for MLS players with quadriceps injuries over the past decade, potentially reflecting more cautious rehabilitation practices. The median RTP following quadriceps injury in MLS players between 2010 and 2021 was 6 days, with a re-injury rate of 40%. A 60% increase in RTP duration was observed between the two periods, 2010-2015 and 2016-2021 (p<0.001). Despite a modest reduction (5%) in re-injury rates, the data suggests that longer rehabilitation may be justified. Defenders appear to be disproportionately affected by quadriceps injuries, experiencing significant declines in performance metrics post-injury, unlike forwards, midfielders, and goalkeepers. These findings highlight the need for position-specific rehabilitation strategies to optimize recovery and minimize long-term impacts on performance.