injury rate in professional football is higher in matches played within 5 days
since the previous match: a 14-year prospective study with more than 130 000
match observations.

Bengtsson H, Ekstrand J, Waldén M,
Hägglund M. Br J Sports Med. 2018 Sep;52(17):1116-1122. doi:
10.1136/bjsports-2016-097399. Epub 2017 Nov 3.
Take Home Message: A professional athlete with 6 or 7 days rest
between soccer matches may be less likely to have a muscular injury during a
match than a player with 3 or fewer days between matches.

Numerous investigators have studied the possible
relationship of the time between matches and injury rates in professional
football (soccer).  For example, prior
researchers showed that if a team plays 2 matches within 4 days compared to 6
or more days they are more likely to have greater muscular injury rates. However,
prior studies have small sample sizes or study teams instead of individuals,
which can make interpreting the findings challenging. Hence, the authors
analyzed the associations between match congestion and match injury rates at an
individual player level in a large population of professional soccer players.  The authors used data gathered through a
prospective cohort study known as the UEFA Elite Club Injury Study.  This study included data from 14 consecutive
seasons of 57 professional European teams from 16 countries for a total of
2,672 players.  A member of the technical
staff recorded individual exposure for each match and all time-loss injuries,
including information on the occurrence and diagnosis.  The authors defined short-term match
congestion as the number of days since the player’s last recorded match
exposure.  Long-term match congestion was
defined as the total hours of match play that a player was exposed to during the
prior 30 days.  Injury rate was defined
as number of injuries per 1000 hours of match exposure.  This study included a total of 133,170
individual match observations, adding up to a total of 166,433 match
hours.  The authors found no relationship
between total injury rates and short-term match congestion.  However, when the authors looked specifically
at muscular injuries they found that muscle injury rates were 21% lower with 6
days rest and 19% lower with 7-10 days, compared to <3 days between
matches.  Players with 4 or 5 days of
rest had a similar risk of injury as those with had 3 or less days of rest. There
was no consistent evidence of an association between long-term match congestion
and overall or muscular injury rates.

Using a large sample size and individual
player data, the authors found that short-term match congestion may be related
to muscular injuries.  This is important
as more leagues are becoming aware of and making changes regarding
training/playing load, with the goal of preventing injuries.  A recent rule change has been suggested to
allow at least 4 days to recover between matches.  The authors note that from their findings,
this rule change would have limited benefit since there was no difference
between muscle injury rates among players with 3 to 5 days off.  The authors acknowledge that overall, the
individual player is still unlikely to suffer an injury in a congested match
schedule.  Even though this is true, untimely
and possibly preventable injuries, can make a difference in a championship run
for a team.  The authors discuss planned
player rotation strategies as a way to prevent injuries, but there are still
limitations to the amount of substitutions available for each team.  This is relevant to the debate on the need
for substitution rule changes to allow for proper medical evaluation during
injuries, such as with concussion, that don’t penalize teams for proper medical
care.  This study, although done in
European soccer players, is also probably relevant to the discussion in the National
Football League (American football) regarding player safety with adding more
weekday games (such as Thursday Night Football).  In conclusion, medical staff should advocate
for strategies to promote longer rest intervals between matches to help reduce
the risk of muscular injuries.
Questions for Discussion: What are your thoughts on how teams can
balance competition, player safety, and increased financial incentives from
more games?  Should new substitution rules
be allowed?
Written by: Kris
Fayock, MD
Reviewed by: Jeffrey Driban

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