Influences Biomechanical Changes After Participation in an Anterior Cruciate Ligament
Injury Prevention Program
JA, Gatewood CT, Tran AA, Slider A, Shultz R, Delp DL, & Dragoo JL. Am J Sports Med. 2017; Online Ahead of
Print December 27, 2017.  
Take Home Message: Pre-adolescent female
soccer athletes had decreased knee valgus during a double leg landing task after
participating in an injury prevention program. 
Younger athletes seem to be ideal for prevention programming.
Previous posts have highlighted authors
who demonstrated that injury prevention programs are effective at reducing
anterior cruciate ligament (ACL) injuries in a variety of populations (see
below).  It remains unclear as to who may
benefit most from prevention programs; but, some researchers have suggested that younger athletes may benefit more than
older athletes.  Therefore, these authors
studied 51 pre-adolescents (10 to 12 years old) and 43 adolescent (14 to 18
years old) female soccer players to see if age influences the biomechanical
changes related to an injury prevention program.  The authors performed biomechanical testing
in 94 female soccer players. About half in each group completed an injury
prevention program and the other half served as controls.  The injury prevention program was performed about
2 times per week for approximately 8 weeks (25 min sessions). After completing
the program, the investigators repeated the biomechanical testing on all
participants.  The authors found that at
baseline, pre-adolescent athletes had higher initial contact and peak knee
valgus angles, as well as co-contraction during weight acceptance and landing
tasks in comparison to adolescent athletes. 
The injury prevention program improved pre-adolescent peak knee valgus
during a double leg landing task in comparison to pre-adolescent controls.  The authors observed no other differences
between participants who did or did not complete the prevention program.
Biomechanical improvements from an
injury prevention program are primarily observed in pre-adolescent female
soccer players.  This study emphasizes
the importance of trying to start prevention programming early in an athlete’s
motor development.  Pre-adolescent
athletes had poorer movement qualities than adolescent.  This also raises a question as to whether it
may be even more beneficial to introduce these programs even earlier than 10
years of age.  However, it remains
unknown how long these positive changes exist. 
It would be interesting to re-test these athletes a couple of months
after the cessation of the program to see if there are still benefits to the
program for landing and other biomechanical measures as we saw in earlier SMR posts.  There has been previous research that has shown that frequency and compliance can influence
the effectiveness, therefore it would be interesting to see if increasing the
frequency or monitoring the compliance of the injury prevention program further
aided in the improvements.  While these
authors excluded athletes with a previous knee injury, I think it would be very
valuable to see what type of an effect these programs can have on already
at-risk individuals.  Overall, this is
another study that shows injury prevention programs should be introduced early
in an athlete’s career. 
Questions for Discussion:  Are
you currently incorporating injury prevention programming?  How young do you think you would target injury
prevention programming?
by: Nicole Cattano
by: Jeffrey Driban