Screening the lumbopelvic muscles for a relationship to injury of the quadriceps, hamstrings, and adductor muscles among elite Australian football league players.

Hides JA, Brown CT, Penfold L, & Stanton WR (2011). The Journal of Orthopaedic and Sports Physical Therapy, 41 (10), 767-75 PMID: 21891873

The transition from
offseason to preseason training for many sports carries a substantial risk of
thigh muscle strain injury (quadriceps, hamstrings, and adductors).  Due to the contribution of the lumbopelvic
region (core stability) to lower extremity function it is thought that the size
and asymmetry of lumbopelvic stabilizers may play a role in these injuries. To assess
this theory, Hides et al assessed the relationships between thigh muscle strain
and lumbopelvic muscle (i.e., psoas major, quadratus lumborum, and multifidus
muscles) size and asymmetry as well as transverse abdominis ability to contract
and draw in the abdominal wall. Prior to
the preseason training period 34 elite Australian football players had the
cross-sectional area of each lumbopelvic muscle quantified with magnetic
resonance imaging (47 players were initially screened but 13 were lost to
follow-up).  At the end of the 3 to 4
month training season 12 thigh muscle strains occurred: 2 hamstring strains, 4 quadriceps
strains, and 6 adductor strains. 
Severity was determined by number of days lost of activity: 23 no
injuries (0 days lost), 5 mild injuries (1 to 3 days lost), and 6 severe injuries
(greater than 4 days lost).  Mean cross-sectional
areas of the multifidus muscles were significantly smaller among athletes with
a severe thigh muscle strain compared to athletes with no injuries.  Muscle size or asymmetry of the psoas major or
quadratus lumborum, as well as ability to contract the transverse abdominis were
not related to thigh muscle strain occurrence or asymmetry.  Multifidus mean cross sectional area at L5 spinal
level predicted severe thigh muscle strain with 96.4% specificity (correctly
predicting a player not getting a severe strain) and 83.3% sensitivity (correctly
predicting a severe strain)

This study provides
further evidence that local stabilizing muscles of the lumbar spine may play a
role in lower extremity injury.  The
multifidi are important stabilizers, sense lumbar spine position (because they
are dense with muscle spindles), and hold lordosis; all of which has implications
for pelvic position and thus functional implications for the musculature that
attaches on the pelvis (e.g., quadriceps and hamstring). The lack of
association between thigh muscle strains and the psoas major, transverse
abdominis, and quadratus lumborum is thought to be due to several possible
factors: 1) these muscles are less involved in lumbopelvic stability compared
to the multifidus, 2) the ability to draw in the abdominal wall may not be
relevant among elite athletes that can perform the task well, and 3) low sample
size.  The addition of measuring the
multifidus cross-sectional area to current injury screening tools (physical
exam, functional movement screening, landing kinematics) maybe a worthwhile
venture for assessing injury risk. Ultrasound imaging could be an efficient
method to do these measures since it is 
validated and maybe more accessible and cost effective to
clinicians.  This would allow us to
target the often time consuming and clinician intensive interventions to
improve multifidus activation to those with deficits (ultrasound imaging may
even have a role as a biofeedback tool). Has anyone incorporated core training
(or more specifically multifidus activation exercises) into their injury
prevention programs? If so, what are your experiences with these interventions?

Written by: Dustin
Reviewed by: Jeffrey
Driban, Jimmy Onate 

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