Functional Biomechanics of the Yoga Vinyasa Jump Through
Question: Sometimes from down dog they will say jump through to sitting, sometimes even with the legs straight. Though I have seen this done many times, I have never had anyone explain how to do it. I have been doing yoga for many years and I am quite advanced in my practice, but I still can’t get this straight legged jump though. Do you have any pose explanations on how to do this. (Or if not, maybe you can explain it to me.)
Answer: The classic, straight leg jump through in Vinyasa/Ashtanga flows requires a combination of specific strength engagement techniques along with ample range of motion in the back lines of the body. With this foundation of strength and flexibility, you then need to be able to coordinate these physical elements in order to systematically flow the legs through to sitting.
Let’s look first at the strength/muscular engagement elements using the image provided as a visual guide.
Taking flight! The jump through requires a lifting of the upper body followed by the kinetic chain elevation of the lower body. This initial ‘lift’ mimics a pressing up into a handstand so the pelvis is almost in a vertical line with shoulders and hands. This initial lift should not be solely driven by power jumping up with the legs. The back, arm and shoulder musculature (ie back extensors, triceps and anterior deltoids) need to fully engaged and have enough strength to virtually be able to hold the body up in this vertical line for a moment. This upper body strength is required to hold the body in the air to facilitate the cascading chain of lower body movements to come.
As the back line musculature draws the body up and into the air in this vertical line, the serratus anterior (muscles between the shoulder blade and ribs) must engage along with the anterior shoulders and triceps muscles (back of the arm). The serratus anterior is your power center for shoulder girdle stability. This engagement of the serratus anterior with the anterior shoulder generates the sensation that you are lifting out of the hands and creating a sensation of your body weight rising off the arm bones.
Now, with your hips up in the air, you move into the flexibility component. As you can see from the image (descending phase), you need optimal ‘clearance’ for the legs. As the back extensors, shoulders, arms, and serratus anterior briefly hold the body up in the air, the hip flexors and abdominal muscles engage to flex the hips and bring the body into a ‘piked’ position. The quadriceps (thigh muscles) fully contract to continuously extend/straighten the legs. The ankles dorsi-flex to draw the toes towards the shins. You can visualize your body forming a variation of Paschimottasana (seated two leg forward bend) as you close the body enough to provide clearance for the heels to thread throw the hands. Without this closed, piked position, the legs will not be able to slide through even with ample upper body engagement.
So, you are now taking flight with the hips vertically over the shoulders. You begin to flex at the hips and pike the legs into the torso. You will begin to thread the legs through with a controlled landing. The same upper body muscles remain engaged and now transition into an eccentric contraction phase (contracting as the muscles resist and elongate). Your back extensors and anterior shoulders still remain powerful so you can slowly lower the upper body. Your hip flexors and abdominal muscles also stay powerfully engaged holding you up in the piked alignment. The serratus anterior muscles shift in their application now.
The serratus anterior muscles move the shoulder blades further into protraction (sliding forward over the ribs) and lateral rotation (moving away from the midline/spine). This is similar to the chest/triceps dips exercise on a parallel bar that you would see in a gym. This enhanced ‘pressing’ motion is shown in the image where the shoulder blade region is rounded. This sustains the lift the torso as you swivel at the shoulder joint and bring the legs through. During this descent and swivelling at the shoulders, the chest muscles contribute in the pressing motion moving from the upper, middle, and then finally the lower pectoralis muscle fiber lines. Through the very last portion of the descent, the lower trapezius muscles draw the shoulder blades down the back (called shoulder blade depression which lifts the rib cage upwards so the body does not collapse down into the shoulder girdle).
Therefore, besides requiring a great deal of dynamic flexibility in the back lines (lower back, hamstrings, and calf muscles), a great deal of strength and body awareness is required by the back extensors, arms, shoulders and serratus anterior muscles. The serratus anterior and hip flexors are the fundamental power centers at play that involve the manipulation and control of the shoulder girdle and core. It is from these power center manipulations that the legs take on a more fluid, and almost automatic gliding sensation into sitting.
Throughout this entire process, there are other fine detailed aspects like body awareness, coordination, hand placement/integrity. These elements come with practice. But the overall foundation of flexibility and strength throughout the above-mentioned joints and muscles is required before attempting the development of fine details.