Decreasing Knee Injury Risk Factors With Neuromuscular Training
| Status: | Completed |
|---|---|
| Conditions: | Hospital, Orthopedic |
| Therapuetic Areas: | Orthopedics / Podiatry, Other |
| Healthy: | No |
| Age Range: | 18 - 20 |
| Updated: | 4/2/2016 |
| Start Date: | September 2011 |
| End Date: | June 2012 |
| Contact: | Brian G Ragan, Ph.D. |
| Email: | ragan@ohio.edu |
| Phone: | 7405971876 |
The Effectiveness of Neuromuscular Training on Modifiable Anterior Cruciate Ligament Injury Risk Factors
Anterior cruciate ligament (ACL) tears are disabling injuries that place a significant
burden on the athlete. Roughly 80% of these injuries are linked to a noncontact mechanism,
with more than 70% of them occurring while landing from a jump. Female athletes are at
higher risk of sustaining a noncontact ACL injury due to the higher number of risk factors
that they possess compared to their male counterparts. Due to this statistic, ACL prevention
programs have been developed over the past 15 years in attempt to reduce this risk among the
female athletic population. These programs have been shown to reduce the rate of noncontact
ACL injuries in females by correcting the risk factors associated with them. However, it
remains unclear as to whether these positive results are solely due to the program or a
higher exercise workload in its participants. The purpose of this study is to evaluate the
effectiveness that an ACL prevention program has on modifying at-risk landing mechanics
(associated with noncontact ACL injury) compared to a resistance training program of equal
workload.
burden on the athlete. Roughly 80% of these injuries are linked to a noncontact mechanism,
with more than 70% of them occurring while landing from a jump. Female athletes are at
higher risk of sustaining a noncontact ACL injury due to the higher number of risk factors
that they possess compared to their male counterparts. Due to this statistic, ACL prevention
programs have been developed over the past 15 years in attempt to reduce this risk among the
female athletic population. These programs have been shown to reduce the rate of noncontact
ACL injuries in females by correcting the risk factors associated with them. However, it
remains unclear as to whether these positive results are solely due to the program or a
higher exercise workload in its participants. The purpose of this study is to evaluate the
effectiveness that an ACL prevention program has on modifying at-risk landing mechanics
(associated with noncontact ACL injury) compared to a resistance training program of equal
workload.
Injury Background Anterior cruciate ligament (ACL) tears are disabling injuries that place a
significant burden on the athlete. The average cost for ACL reconstruction is estimated to
be approximately $17,000 per patient and full recovery commonly takes around 6 months to
achieve. It has been estimated that 1 in every 3000 people in the United States suffer an
ACL rupture each year. Roughly 80% of these injuries are linked to a noncontact mechanism,
with more than 70% of them occurring while landing from a jump.
Injury Mechanism Upon landing, the lower body falls into what is referred to as the
"position-of-no-return" (PNR). The landing kinematics involved with the PNR places a high
amount of stress on the ACL and can ultimately lead to a complete rupture.
Injury Imbalance Female athletes who participate in sports that involve jumping and cutting
activities suffer 4-to-6 times more ACL injuries than males who participate in the same
sports. This is attributed to the higher number of risk factors that females possess during
and after puberty. In particular, upon maturation, males exhibit a neuromuscular spurt, with
increases in power, strength, and coordination, whereas females do not. Other risk factors
that females demonstrate are quadriceps dominance and ligament dominance. Both of these
dominances are linked to the landing kinematics of the knee when placed in the PNR.
Quadriceps dominance is characterized by the extended knee posture that is displayed in the
PNR when landing from a jump. When landing on an extended knee, the tibia is translated
anteriorly to the femur, causing the ACL to become taunt. In order to prevent the ACL from
rupturing, the hamstrings must activate to flex the knee and translate the tibia
posteriorly. In response to anterior tibial translation, females are found to utilize a
different muscle recruitment pattern than males by contracting their quadriceps before their
hamstrings, whereas males follow the opposite pattern. By contracting the quadriceps first,
the hamstrings are overpowered, which allows for further anterior tibial translation to
occur during landing.
Ligament dominance is evidenced by the increased knee valgus that displayed in the PNR when
landing and cutting. During these maneuvers, females rely on their knee ligaments rather
than lower extremity musculature to absorb ground reaction forces. This tendency places a
high amount of stress on the ACL, which in turn, increases the probability of it rupturing.
Injury Prevention Due to the high rate of noncontact ACL injuries seen in female athletes,
neuromuscular training (NMT) programs have been developed in an attempt to prevent or reduce
the risk of injury. These programs are administered as either an off-season regimen or
in-season warm-up routine, and they incorporate a combination of plyometric, proprioceptive,
and strength training exercises, with particular focus being placed on correct technique. By
modifying neuromuscular risk factors, NMT programs have been able to significantly reduce
the rate of noncontact ACL injury.
Specific Aim 1:
To evaluate the effectiveness that an ACL prevention program has on modifying at-risk
landing mechanics (associated with noncontact ACL injury) compared to a resistance training
program of equal workload.
Specific Aim 2:
To evaluate the effectiveness that an ACL prevention program has on improving max vertical
jump height compared to a resistance training program of equal workload.
significant burden on the athlete. The average cost for ACL reconstruction is estimated to
be approximately $17,000 per patient and full recovery commonly takes around 6 months to
achieve. It has been estimated that 1 in every 3000 people in the United States suffer an
ACL rupture each year. Roughly 80% of these injuries are linked to a noncontact mechanism,
with more than 70% of them occurring while landing from a jump.
Injury Mechanism Upon landing, the lower body falls into what is referred to as the
"position-of-no-return" (PNR). The landing kinematics involved with the PNR places a high
amount of stress on the ACL and can ultimately lead to a complete rupture.
Injury Imbalance Female athletes who participate in sports that involve jumping and cutting
activities suffer 4-to-6 times more ACL injuries than males who participate in the same
sports. This is attributed to the higher number of risk factors that females possess during
and after puberty. In particular, upon maturation, males exhibit a neuromuscular spurt, with
increases in power, strength, and coordination, whereas females do not. Other risk factors
that females demonstrate are quadriceps dominance and ligament dominance. Both of these
dominances are linked to the landing kinematics of the knee when placed in the PNR.
Quadriceps dominance is characterized by the extended knee posture that is displayed in the
PNR when landing from a jump. When landing on an extended knee, the tibia is translated
anteriorly to the femur, causing the ACL to become taunt. In order to prevent the ACL from
rupturing, the hamstrings must activate to flex the knee and translate the tibia
posteriorly. In response to anterior tibial translation, females are found to utilize a
different muscle recruitment pattern than males by contracting their quadriceps before their
hamstrings, whereas males follow the opposite pattern. By contracting the quadriceps first,
the hamstrings are overpowered, which allows for further anterior tibial translation to
occur during landing.
Ligament dominance is evidenced by the increased knee valgus that displayed in the PNR when
landing and cutting. During these maneuvers, females rely on their knee ligaments rather
than lower extremity musculature to absorb ground reaction forces. This tendency places a
high amount of stress on the ACL, which in turn, increases the probability of it rupturing.
Injury Prevention Due to the high rate of noncontact ACL injuries seen in female athletes,
neuromuscular training (NMT) programs have been developed in an attempt to prevent or reduce
the risk of injury. These programs are administered as either an off-season regimen or
in-season warm-up routine, and they incorporate a combination of plyometric, proprioceptive,
and strength training exercises, with particular focus being placed on correct technique. By
modifying neuromuscular risk factors, NMT programs have been able to significantly reduce
the rate of noncontact ACL injury.
Specific Aim 1:
To evaluate the effectiveness that an ACL prevention program has on modifying at-risk
landing mechanics (associated with noncontact ACL injury) compared to a resistance training
program of equal workload.
Specific Aim 2:
To evaluate the effectiveness that an ACL prevention program has on improving max vertical
jump height compared to a resistance training program of equal workload.
Inclusion Criteria:
- Female college underclassman (ages 18-20)
- Body Mass Index (BM) between 18.5 - 25 (normal range)
- Blood pressure below 140/90 (below hypertension)
- History of participation in high school athletics
- Signed Informed Consent form
Exclusion Criteria:
- History of ACL injury
- Current/ongoing knee condition
- History of surgical intervention within one year (not including facial)
- Current/ongoing musculoskeletal injury
- History of previous ACL prevention training
- Currently involved in intercollegiate athletics
- Currently Pregnant
We found this trial at
1
site
