1. EXAMINING TRAINING PROGRAMS TO PREVENT ANTERIOR CRUCIATE LIGAMENT INJURY BY
BY IMPROVING PHYSIOLOGICAL CHARACTERISTICS
Lauren Aldred, Theodore O’Brien, Jason Melnyk, Chee Hoi Leong, and Kimberley Kostelis.
Central Connecticut State University, New Britain, CT
Participants: Participants (N=12) Strength and Conditioning prevention program,
(N=12) Proprioception prevention program were female premier soccer players
aged fifteen and sixteen.
Pre/Post Testing: Participants performed the following tests before and after the six
week prevention programs. “T” Agility test, “Z” Agility test, Broad Jump, Vertical
Jump, 1 Repetition Max (1RM) on Quadriceps and Hamstrings (See Figure 1),
Quadriceps to Hamstring ratio calculation (Dohoney et al., 2002), and MAXTRAQ
Video Analysis to calculate angular velocity of the knee when jumping and landing
when performing the vertical jump.
Six Week Prevention Training Programs: Implemented before the participants
training sessions, three times a week. 1) Strength and Conditioning, focusing on
muscular endurance and power. 2) Proprioception, focusing on balance and agility.
The following significant interactions occurred within subject repeated measures
of the pre to post testing: “Z” test scores F(1,17)=13.375, p<.05 (.002), Broad
jump scores F(1,17)= 7.317, p<.05 (.006), Vertical jump scores F(1,17)= 6.807,
p<.05 (.019), Jumping Vertical angle scores F(1,7)= 7.560, p<.05 (.033), 1 rep-
max quadriceps scores F(1,17)= 19.158, p<.05 (.000) and 1rep-max hamstring
scores F(1,17)= 39.203, p<.05 (.000). It can also be reported that the following
interactions within the repeated measures pre and post testing and the prevention
training group were significant for the following tests: “Z” test scores F(1,17)=
3.905, p<.05 (.006) and jumping vertical angle scores F(1,7)= 11.760, p<.05
(0/14).
There was no significant interactions between subject groups regarding pre to
post testing and which prevention training group was performed, all testing
scores between subjects showed significance of p>.05. However, all pre to post
testing scores increased, even if the results were not great enough to be
significant.
ABSTRACT METHODS RESULTS
Regardless of which prevention program is implemented, and even a
combination of both proprioception and strength and conditioning would be
beneficial to decrease the rate of ACL injury. Significant gains can be achieved
in a player’s agility, power and muscular strength, which are all huge factors in
performance in the sport of soccer. Seasonal prevention training would most
likely continue to increase the physiological characteristics associated with the
reduction of ACL injury to female soccer players.
SUMMARYAND CONCLUSION
ACKNOWLEDGEMENTS
I would like extend out gratitude to the Oakwood Soccer Club for their willingness
to participate in this study. They continue to implement ACL prevention programs
in their girls 13 to 18 teams.
Many of the youth today participate in soccer. In the USA alone, about 250,000
ACL injuries occur annually. ACL injuries in the female athlete predominantly
have a non-contact mechanism of injury and occur during cutting, decelerating,
or landing from a jump (Silvers & Mandelbaum, 2007). The current study was
designed to determine whether either of the two six-week ACL prevention
programs, Proprioception training and Strength and Conditioning, working to
improve strength, agility and power will decrease the incidence of ACL injury.
Figure 2
“T” test, “Z” test, Broad Jump, Vertical Jump, 1 RM Quadriceps and Hamstrings Diagrams.
REFERENCES
Dohoney P. D., Chromiak J. A., Lemire D., Abadie B. R., & Kovacs C. (2002).
Prediction of One Repetition Maximum (1-RM) Strength from a 4-6 RM and
a 7-10 RM Submaximal Strength Test in Healthy Young Adult Males.
Journal of Exercise Physiology online 5:54-59.
Silvers, H., & Mandelbaum, B. R. (2007). Prevention of Anterior Cruciate
Ligament Injury in the Female Athlete. British Journal of Sports Medicine,
41(1 Suppl), i52-i59.
INTRODUCTION
Purpose: The purpose of this study was to examine two training programs to
prevent (ACL) injury by improving physiological characterizes, such as
muscular strength, power and agility. Methods: Two prevention-training
programs were implemented in the spring season of the girls 15 and 16 Oakwood
Premier Soccer teams. One training program (n=12) included proprioception
movements through balance. The second training program (n=12) included
strength and conditioning. The teams were in season, training three times a week
and competition on weekends. Pretest data was collected in March, which
included the following tests: one repetition max (1 rep-max) quadriceps and
hamstrings, agility “T” and “Z” sprint tests, and broad and vertical jump tests.
The calculation of hamstring to quadriceps ratio was determined in regards to
force exertion, and angular velocity of the knee on jumping and landing through
MAXTRQ video analysis of the frontal plane when performing the vertical
jump. The same post testing was completed on the conclusion of the six-week
prevention trainings. Results: Significant differences between pretest to posttest
scores were found in Z test, broad jump, vertical jump, 1 rep-max quadriceps and
1 rep-max hamstring (p<0.05), but no interaction effect was found between the
prevention programs (p>0.05). Quadriceps to hamstring ratio were similar
between programs (p>0.05); eight players reported a ratio <80% pre test,
compared to only two players <80% posttest. Angular velocity of the knee on
landing and jumping angle was significant (p<0.05) from pre to posttest.
Conclusion: Both training programs were beneficial in terms of improving
physiological characteristics; however, it is unclear which one is more beneficial
than the other. Further research is needed to determine whether proprioception,
strength and conditioning exercises, or even a combination of both are most
beneficial to improving physiological characteristics. Coaches can apply these
findings to validate that a prevention training program implemented in the
warms up of trainings would be beneficial for ACL injury prevention.
Table 1
Descriptive Statistics for mean values of pre and post testing results.
Test Name
Strength/Conditioning Prevention
Group Mean Proprioception Prevention Group Mean
Pre Test Post Test Pre Test Post Test
TTEST (sec) 10.61± 0.70 10.54 ± 0.51 10.49 ± 0.60 10.38 ± 0.57
ZTEST (sec) 7.28 ± 0.44 7.21 ± 0.31 7.27 ± 0.61 7.05 ± 0.61
BROAD JUMP (inches) 83 ± 4.24 84.75 ± 2.71 80.2 ± 5.05 82.8 ± 2.53
VERTICAL JUMP (inches) 19 ± 1.49 19.38 ± 1.22 18.25 ± 1.70 18.65 ± 1.51
JUMPING ANGLE VERTICAL (degrees) 206.44 ± 11.92 192.05 ± 17.90 199.29 ± 13.35 200.88 ± 12.74
LANDING ANGLE VERTICAL (degrees) 199.67 ± 10.78 213.70 ± 16.58 188.41 ± 17.46 196.61 ± 29.96
1 RM QUAD (lbs.) 165.33 ± 13.84 181.30 ± 15.93 161.72 ± 17.49 171.46 ± 18.74
1 RM HAMSTRING (lbs.) 130.87 ± 8.31 156.46 ± 15.68 134.93 ± 9.24 151.02 ± 15.65
QUAD/HAM RATIO (%) 79.77 ± 9.37 86.41 ± 6.00 84 ± 7.41 88.28 ± 5.89
Figure 1
1 Repetition Maximum equation (Dohoney et al., 2002).
4-6RM: 82.07 + (0.76 x weight) + (5.66 x number of reps)
7-10RM: 95.0 + (0.65 x weight) + (8.52 x number of reps)