Small Multifidus Size
Predicts Football Injuries.

JA, Stanton WR, Mendis MD, Franettovich MM, and Sexton MJ. Orthopaedic
Journal of Sports Medicine June 2014 2: 2325967114537588, first published on
June 16, 2014 doi:10.1177/2325967114537588

Take Home Message: Smaller
lumbar multifidus size during preseason and the competitive season was
associated with lower extremity injury in Australian Football. Additionally,
lumbar multifidus asymmetry, limb kicking dominance and a history of low back
pain were also associated with increased lower extremity injury.

injuries to the lower extremity are common during preseason and in-season
competitions. If we could identify modifiable factors associated with these
injuries then it may allow us to develop injury prevention programs.
Stabilizing muscles of the lumbo-pelvic region may contribute to lower
extremity injury risk but this needs to be verified in larger studies across
both preseason and competitive seasons. The authors assessed ~260 Australian
Football League players to determine whether the size, asymmetry, and ability
to contract the lumbar multifidus were related to new lower extremity injuries
during preseason and competitive season. They also attempted to establish combinations
of factors to best predict injury. Participants from six Australian Football
League teams provided demographic and sport history details and received
ultrasound imaging of the lumbar multifidus at the start of both preseason and
competitive seasons. Bilateral cross-sectional area (CSA), and muscle thickness
at rest and during voluntary isometric contraction were recorded for all
individuals along with histories of injury and low back pain. The team medical
staff diagnosed injuries during the preseason or playing season as any
sport-related injury that prevented a player from completing a practice or
game. Lower extremity injury occurred in 38% (105 athletes) and 70% (191
athletes) athletes during the preseason and competitive seasons, respectively. The
authors found that an athlete with a smaller lumbar multifidus CSA is more
likely to have a lower extremity injury during the preseason and competitive
season. Furthermore, an athlete with a smaller muscle thickness on the
preferred kicking leg compared with the opposite limb was more likely to suffer
a lower extremity injury. The authors identified two key injury prediction
models: 1) decreased lumbar multifidus CSA, and history of low back pain
increased the risk of lower extremity injuries during the preseason; and 2) decreased
CSA, changes in lumbar multifidus size, and kicking limb were associated with
lower extremity injuries during the competitive season. Athletes with a
preferred kicking limb and reduced lumbar multifidus sizes were at increased
risk for injury, while those who use both limbs equally and increased muscle
size had a decreased risk of lower extremity injury. The two models identified
61% and 92% of the athletes that sustained an injury in the preseason and
competitive season respectively, while identifying 85% and 46% of those that
did not sustain an injury.

findings may indicate that increased lumbar multifidus size and symmetry may
reduce the risk of lower extremity injury during preseason training and the
competitive season. Interestingly, the ability to maintain lumbar multifidus
size throughout the season or increase size following an injury reduced the
risk of lower extremity injury across the competitive season. A smaller lumbar
multifidus may indicate reduced neuromuscular control, which could  lead to instability and improper transferring
of forces between the lower extremity and spine. Specific lumbar multifidus
training throughout the offseason and regular season may reduce the number of
lower extremity injuries sustained by athletes during competition. However, the
current study only identified a relationship between lumbar multifidus size and
lower extremity injury and does not indicate causality between the two
variables. Additional research should focus on lumbar multifidus exercise
training programs and lower extremity injury prevention. The current findings
support the incorporation of lumbar multifidus exercise as part of an injury
prevention program since the risk associated with exercise training in minimal.

Questions for Discussion: Why
do you think limb dominance and bilateral muscle imbalance influence injury in
sports that require bilateral limb skill contributions? Do you assess lumbar
multifidus size and muscle function? Do you do prevention exercises that target
the multifidus with your athletes?

by: Mark A. Sutherlin
by: Jeffrey Driban


Hides JA
and Stanton WR. Can motor control training lower the risk of injury for professional football players?
Med Sci Sports Exerc. 2014;46(4):762-8.

Hides, J., Stanton, W., Mendis, M., Franettovich Smith, M., & Sexton, M. (2014). Small Multifidus Muscle Size Predicts Football Injuries Orthopaedic Journal of Sports Medicine, 2 (6) DOI: 10.1177/2325967114537588