As
discussed in our blogs on the Lateral
Subsystem and the Deep
Longitudinal Subsystem, muscles rarely work in isolation. Instead they are recruited by
the nervous system in groups or synergies.
Today’s
blog is on the Posterior Oblique Subsystem, one of the four common muscle
synergies. Resembling a cross, with two slings reaching from each shoulder to
the opposite hip, it is formed of the gluteus maximus and latissimus dorsi,
which both attach to the thoracolumbar fascia.
The
origination and insertion of the Posterior
Oblique Subsystem
Gluteus
maximus – origination:
posterior of the sacrum, illium and coccyx; inserts: gluteal tuberosity of the
femur and iliotibial tract.
Latissimus
dorsi – origination: spinous processes of T7-T12, iliac crest, thoracolumbar fascia,
inferior angle of the scapula and inferior three or four ribs; insertion: floor
of the intertubercular humerus.
Thoracolumbar fascia – origination: the spinous processes of the thoracic and the lumbar vertebrae; insertion: median crest of the sacrum and muscle fascias such as the quadrus lumborum, erector spinae and latissimus dorsi.
The action and basic functional movement of the Posterior Oblique Subsystem
Working
alongside the Deep Longitudinal Subsystem, the Posterior Oblique Subsystem
distributes transverse plane forces when the core and back are rotated. This is
particularly useful for throwing or hitting a ball and for twisting movements,
for example in sports such as golf, tennis, baseball and boxing.
This
system is also employed when we walk or run, transferring forces from the
transverse plane into propulsion in the sagittal plan, and it provides
stability for the lower spine and sacroiliac joint (SIJ).
Problems
associated with the Posterior Oblique
Subsystem
If
the Posterior Oblique Subsystem fails to support the spine and SIJ, this can
result in muscle tightness and pain in the lower back, SIJ syndrome
(inflammation and pain in the joints) or piriformis syndrome (muscle spasm
causing pain in the buttocks).
Other
issues with a weak or injured Posterior Oblique Subsystem can include hamstring
strain caused by increased tension in this muscle.
If
a personal trainer or fitness instructor, notices that a client has rounded
shoulders, internally rotated hips or long reaction times when accelerating and
decelerating, this may suggest work is needed on their Posterior Oblique
Subsystem.
Exercises to strengthen the Posterior
Oblique Subsystem
The
best exercises for the Posterior Oblique Subsystem are rotational activities
performed in the transverse plane, with particular focus on the gluteus maximus
and contralateral latissimus dorsi.
Examples
include:
- One arm, single leg cobra
- Bird dog exercise
- Single leg deadlift with dumbbell or cable
- Split squat or rear foot elevated split squat with dumbbell or
cable
- Squat to row (advance to unstable squat with unilateral row)
- Reverse lunge with opposite arm overhead press
- Curtsy lunge
- Step up with cable
- Medicine ball reverse lunge and shot put
