Posterior Oblique Sling is another kind of anatomy sling. In the previous article, you read about Anterior Oblique Sling, and here you will read about the posterior oblique sling.
Evolution showed up that humans developed from quadrupedal into a bipedal creature. It opened up more ease and efficacy carrying tasks than we were doing before. It defines that body needs to adapt changes to cope with various stresses. As humans transformed into upright-functioning beings, the posterior structures of the body are experiencing changed demands, and thus have to be adapted accordingly.
Consider your major pelvic muscle, ‘gluteus maximus’ has evolved from a relatively small muscle to being the largest muscle in the body. This muscle has become an art of such a system, which is specialized and integral in supporting functional control in movements like gait – the posterior oblique muscle sling (POS).
Components of Posterior Oblique Sling
The posterior oblique slings system comprises the following components.
- Latissimus Dorsi (LD)
- Gluteus maximus (GM)
- Interconnecting thoracolumbar fascia (TLF)
Posterior Oblique Sling anatomical location
The Back Functional Line – another identity of the POS. It crosses approximately at the level of sarcolumbar junction.
The lower portion of the sling that contains the distal gluteus maximus fibers, passes underneath the iliotibial tract to attach to the posterolateral edge of the femur. Hence, this system sounds linked with a lateral sling. In these recent decades, the clinicians have started identifying that stability is a complex phenomenon, and ‘a system of assisting movement whilst stabilizing’ exist. For this method of functioning, they take the POS fundamental.
Role of the Posterior Oblique Sling
During the single support (stance) phase of gait, the role of the POS can be distinguished more. The ipsilateral hamstring muscle contraction initiates to prepare the limb for weight-bearing, before heel strike. During this, to prevent excessive anterior rotation of the ilium, the proximal hamstring stabilizes the ipsilateral pelvis against the activity of the quadriceps. Though once a heel strike occurs, GM undertakes the role of hamstring (limiting ilium movement) and hamstring activity diminishes. Here, the muscle is in a lengthened position, and the counter-rotation of the trunk begins simultaneously. In the process, the arm contralateral to the stance leg is ante-flexed, and undergo eccentric concentration of the LD to control the forward momentum of the limb, whilst considering the Latissimus dorsi also into a lengthened position.
The propulsive phase of gait, with both the Gluteus Maximus and contralateral Latissimus Dorsi concentric contraction. From a lengthened to shortened position, and results in extension of the with the opposite propelling leg.
When mechanisms of stance and propulsive phase of gait are coupled, GM contraction alongside its contralateral LD is observed. Due to it, the tension in the thoracolumbar fascia increases, eliciting the stabilization of the SIJ and lumbar spine. This theory credited the remark that the GM aspect of the POS weakness often results in hamstring dysfunction, due to the compensatory activity to stabilize the ilium.
Through thoracolumbar fascia, the system produces SIJ compressional stability. Some authors believe that this mechanism acts as a ‘smart spring’, using phasic contractions to release and store energy during gait. Vleeming theories explained that kinetic energy is built in the Gluteus Maximus and Latissimus Dorsi as they lengthen before and during heel strike, respectively. When muscles short immediately following the lengthening phase, kinetic energy releases. This same kind of response noted when a finger rapidly returns to a neutral position and is when released following passive full extension. Well, it is still debatable that which contains the stored energy, muscles, or TLF? Irrespective of this confusion, anatomist, physiologist, and other related professionals believe that this mechanism reduces energy expenditure of surrounding muscle of locomotion, thus reducing the metabolic cost of gait.
SIJ compressional stability
To stabilize the SIJ, in traditional exercise training, the focus is on ‘core’ units, often aim at isolating muscles to strengthen them. As discussed in the previous article ‘Anatomy Slings’, strengthening techniques should be incorporated into dynamic movements. So, to train the POS, the Gluteus Maximus and Latissimus Dorsi showed not be viewed in isolation, rather utilized in synergy with each other to promote efficient gait. One of the best exercises that physiotherapists can suggest for treating POS dysfunction is the reverse lunge. Once a patient achieved pain-free hip motion and static stability is also satisfactory, ten a therapist should utilize this. To facilitate efficient movement and for the prevention of injury, it is vital that the muscle slings of the body function in harmony with each other. For the AOS and the POS, it is especially applicable.
POSTERIOR OBLIQUE SLING TRAINING EXERCISE PROGRESSIONS
There are 4 steps in the progression exercise for the POS. Let’s consider throwing as an example;
- Energy produces in one region of the body (the legs).
- Energy goes through the hip/pelvis. Now it releases through the upper limb (hand) to provide a pitch that can be released at over 100mph. That is a lot of power that requires to generate and transfer effortlessly from one body region to another. That power transfer is where myofascial slings come in.
To Perform Exercise :
Start in the quadruped posture. Do hip extension, use the Gluteus on one side and shoulder extension on the other side employing the lat.
Now make a progression to a half-kneeling position. To maintain stability, considerate on driving your front heel into the ground.
Progress to work into a lunge position. Throughout the range of motion, you can hold the lunge position or work.
At last, incorporate a step up. Here, considerate on the end position. First, fully squeeze the glutes at the top. Then come to terminal hip extension while you extends your shoulder fully.
Enjoy this exercise progression and train the POS. Whether you are an athlete or a sportsman, it will work for you. Even the people with less physical activity can also train their POS to attain SIJ stability.