Reduced match exposure in the previous 2 matches accounts for hamstring muscle injury

The upshot

Does playing fewer minutes in recent matches raise a professional footballer's risk of a hamstring injury?

In these two Spanish professional teams, players who had relatively less match exposure (less playing time, total distance, and high-speed running) in the 1 to 2 matches before a hamstring injury were at higher injury risk, the opposite of the expected overload pattern. The finding comes from a small observational study and should be seen as a signal rather than proof.

ChallengesRead paper

Primary study144 ParticipantsLimited evidence

Key points

Contrary to the overload hypothesis, players with reduced recent match exposure had higher hamstring injury risk.
The 1-match and 2-match windows before injury discriminated injured from uninjured players, but 3 and 4 matches before did not.
High-speed running in the match before injury was the single best marker (AUC 0.77).
Roughly 4 in 10 injuries occurred in players who had played 64 minutes or fewer in the prior match.
Authors suggest underloaded players may need individualized training to maintain match-equivalent loads.

How it was conducted

Design: Prospective, controlled, observational study (Level of Evidence 2b)
Setting: 2 Spanish 1st Division (LaLiga) teams over 3 seasons (2011/2012 to 2013/2014)
Participants: 144 outfield players (goalkeepers excluded); 37 noncontact hamstring injuries in 23 players, each matched 1:1 to an uninjured control by team and position
Exposure measures: Playing time, total running distance, and high-speed running (>24 km/h) via Mediacoach multicamera system, accumulated over the 4 matches before injury
Analysis: Generalized estimating equation models for relative risk; ROC/AUC and Youden index for diagnostic accuracy (acceptance AUC >0.70, J >0.30)

What they found

Injured players had less playing time in the match before injury than controls (65.4 +/- 37.2 min vs 88.5 +/- 13.2 min; RR 1.41, 95% CI 1.10-1.81; AUC 0.67, 95% CI 0.55-0.78).
Distance covered in the match before injury was lower in injured players (6.9 +/- 4.3 km vs 10.0 +/- 1.7 km; RR 1.41, 95% CI 1.13-1.74; AUC 0.72, 95% CI 0.60-0.82).
High-speed running in the match before injury was the strongest discriminator (318.0 +/- 244.5 m vs 509.3 +/- 180.1 m; RR 1.53, 95% CI 1.18-1.98; AUC 0.77, 95% CI 0.64-0.85).
Two-match-before thresholds remained associated with injury: playing time RR 14%, distance RR 14%, high-speed running RR 17%; associations at 3 and 4 matches before were not significant.
Best diagnostic thresholds from the match before injury: high-speed running <=328 m (sensitivity 64%, specificity 84%), playing time <=64 min (36%, 97%), running distance <=5.8 km (39%, 97%).
Injuries averaged 23 +/- 18 absence days; 86.4% occurred during matches and 13.6% during training; recurrence rate 10.8%.

Limitations

Only 2 teams and 37 injuries, limiting generalizability and statistical power.
No training load or internal (physiological) load data were collected, so total athlete load is incomplete.
Observational design with matched controls cannot establish that reduced exposure causes injury.
Variable recovery time between matches was not accounted for.

Why it matters

For patients: For a player returning after limited recent match minutes, this study hints that being underexposed to competitive load, not overloaded, may precede a hamstring strain.
For clinicians: Consider that players with reduced recent match exposure, especially low high-speed running in the prior match, may warrant individualized top-up training rather than load reduction.
For readers: This single small study challenges the simple overload model for hamstring injury and points to underexposure as a possible risk signal worth larger confirmation.

Source

doi:10.1177/19417381231158117

Read the original paper