I have read a number of articles on PTontheNET.com that refer to the posterior oblique system and sub system, and they ask you to ensure that your client has proper glute firing procedure.
I know the posterior oblique system is concerned with the pulling of the glutes, lats and TVA in different directions. I also know this decreases the pressure on the lumbar discs. But can you give me any more information on this system please, and what is the posterior oblique sub-system?
Also how do you assess proper firing sequence of the glute musculature?
Research has shown that the muscles of the body can be grouped functionally into main groups. The "Inner Unit" (or "Local Muscular System") otherwise known as the CORE, and the "Outer Unit" (or Global Muscular System). The outer unit can be further divided into 4 groups of muscles (LS-Lateral System, DLS-Deep Longitudinal System, POS-Posterior Oblique System, AOS-Anterior Oblique System), all functioning interdependently with one another. These groups have been called SYSTEMS, SUB-SYSTEMS, or SLINGS; and are all referring to the same subject matter. The group you're referring to, the "POSTERIOR OBLIQUE SYSTEM" (POS), is detailed below... (DIAGRAM 1)
To answer your second question regarding muscular sequencing in hip extension I've drawn the following exerpt directly from "Integrated Training for the New Millennium" by Clark pg. 68-69.
An individual with altered hip extension is characterized by increased lumbar lordosis (increased arch in the low back), externally rotated lower extremity (foot turned out), and noticeable groove in the IT-Band. This created from the tightness in the psoas, erector spinae, and hamstrings, with concomitant weakness/inhibition in the gluteus maximus and deep stabilization mechanism. During gait analysis the individual demonstrates decreased hip extension, increased lumbar extension, and toeing out. These individuals usually complain of low back pain, knee pain, or lower extremity pain with functional activities. During normal hip extension the prime mover is the gluteus maximus. If the client is prone (lying on their stomach), the normal firing order to extend their hip (lift their leg off from the ground while keeping the knee straight) consists of the gluteus maximus, the contralateral erector spinae (opposite side), and the IPS lateral (same side) hamstring and erector spinae, respectively. Health and fitness professionals can test this by palpating the gluteus maximus, hamstring, and erector spinae (DIAGRAM 2). An individual with poor posture and muscle imbalances will demonstrate abnormal muscle firing patterns during the hip extension test. If your client demonstrates this dysfunction, it is important to improve the flexibility of their hip flexors (psoas, sartorius, rectus femoris, TFL), hamstrings, and hip external rotators. It is also important to strengthen and facilitate their gluteus maximus and deep abdominal stabilization mechanism (inner unit/CORE) prior to initiating an aggressive integrated training program.
Diagram 1. The Posterior Oblique System
- POS MUSCLES/TISSUES INVOLVEDM
- Gluteus Maximus
- Latissimus Dorsi
- TLF (Thoracolumbar Fascia)
- Works hand in had with the DLS (Deep Longitudinal System, consisting of the erector spinae, TLF, sacrotuberous Ligament, and biceps femoris).
- Because the muscle fiber alignment runs perpendicular the SI joint, this provides TRANSVERSE PLANE stability to this area as well as distributing transverse plan forces created through rotational movements (the movements of life!).
- PRIOR TO HEEL STRIKE: The contralateral latissimus dorsi and gluteus maximus are eccentrically loaded.
- AT HEEL STRIKE: Both of these muscles concentrically accelerates the upper/lower limbs creating a tension in the TLF.
NOTE: This diagram was referenced from "Optimum Performance Training for the Performance Enhancement Specialist," pg. 33, by Clark and Russell.
Diagram 2. Muscle Sequencing test for Hip Extension
NOTE: This diagram was referenced from "Integrated Training for the New Millennium," pg. 69, by Clark.