Single Leg Control

Single Leg Control and the Tri-planer Essence of Gait.

Carve your turns with every step, there’s a ride in every stride.

Can you stand with integrity on one leg?

Believe it or not, every step is a journey akin to carving while downhill skiing, where you actually arc and dive toward one leg… the feeling is much like watching a dolphin breeching and diving back in to the water at a slight angle…it’s delicious.

This article / video will attempt a rather simplistic, though semi-lengthy, description of controlling your torso over your base of support while on leg.

Single Leg Standing, or single sided stability is a hugely complex and difficult to comprehend concept.  This view is at the heart of Postural Restoration, and if you understand the message presented here, you’ll see one of its major goals more clearly.

The idea is to learn to move in a subtle tri-planer (all three planes of movement) way at the level of the diaphragm to control the weight in the torso over the anchored limb.  The movement is akin to banking a turn as you dive in an airplane or carving on skis, and the generators of the movement are essentially the muscles of the deep abdominal wall.

In gait, or any single leg activity, you must anchor your center of gravity and control the mass of your torso, head and pelvis over the stabilizing limb, or you will simply fall toward the side of the leg you remove from the ground.  Achieving this begins with positioning the bones of the pelvis and ribcage in a stable relationship on one side while opening them up for mobility on the other. 

It all starts here as these two big pieces contain more then half of the weight of the entire body, especially the liquid weight, which as it shifts, drags the remainder of you with it (think walking with a large bucket full of water). 

When an individual goes to stand on one limb and lift the other, they must move the mass of the body over the standing limb and maintain it there throughout the gait cycle on that side or they will be pulled off of the standing leg prematurely causing torsion and strain throughout the body as it attempts to compensate and keep you on top of that limb until the other foot hits the ground.  Backs, hips, knees, ankles, feet, toes… all pay a huge price.

Much of the information that addresses this single leg need, focus’s on the muscles of glute medius, which anchors the pelvis down to the femur (hip to leg) and prevents your pelvis from falling to the side of the leg you’re lifting (Trendelenburg Sign for the PT’s in the room).  You’re most likely familiar with an exercise called the ‘clam shell’, where you lay on your side opening your knees to strengthen the side of your buttocks, progressing to opening your legs with straight knees.  While there’s no denying that glute med is a key player in single leg standing (though not in the open chain of the clam shell, on the standing leg at least…but that’s another topic entirely), focusing on the muscles of the torso which control the majority of the weight is absolutely critical to achieving single leg control.

‘Banking a dive’…’carving your turn’  is the simple key to controlling the weight over one limb in single side loading activities such as gait.  It’s as subtle as it is monumental.  This movement happens at the level of the diaphragm, right above the navel.

I want you to imagine, right below your sternum (breast bone), resting right in the sternal notch, is the cockpit of an airplane facing the same direction as you are.  The wings of this plane extend out of your sides at the level of your lower ribs.  When this plane banks a turn to the Left (left leg standing) it will dive, tip and spin (this is tri-planer movement: flexion/sagittal, sidebending/frontal and rotation/transverse) bringing the Right wing (ribcage) up and around toward the left front pocket, and the left wing down toward the left back pocket.  This takes the entire contents of the torso and gently tips and shifts and spills them toward the Left, stabilizing limb.

At the hub of this task is the deep abdominal wall, especially the Internal Oblique and Transversus Abdominals.  I’ve focused on the ‘SAFE’ position in previous articles and it’s vital here.  Visualize the letter ‘A’ with it’s top at your sternal notch and the legs reaching out toward your outer pelvis (hips), and a ‘V’ angling up from your pubic bone up to your lower outer ribs.  The SAFE position teaches you to draw these pieces together to anchor and control the anterior (front) ribs and pelvis.

This ‘banking a dive’ is a unilateral effort that requires you being SAFE on one side.  In fact the “A/V’ muscles of the deep abdominal wall on one side will actually pull you over to that side if you ‘carve’ your step correctly. This will expel the excess air, secure the torso for loading without strain and spill the abdominal contents toward the anchored side.  This abdominal action will also tip the pelvis backwards on that side, locking the pelvis for standing and turning the sacrum and spine to orient in the direction of the loaded leg.

The beauty is that not only do the muscles align the bones and joints for their respective tasks as well as shifting the abdominal contents over the base of support, but they also displace the air by compressing and deflating the lung on that side which allows for the space for the fluid and viscera to shift into.  The now open, un-muscularly contracted side with the fluid and viscera contents sliding away, creates space for inhalation, which will bias toward this mobile / empty side.  And as the unloaded side fills with air, this pneumatic pressure will literally ‘push’ you to the opposite side and directly over your base of support. 

Perfection… use of structural (both force and form), hydraulic (in even more ways then described here) and pneumatic forces to maintain your center of gravity over your base of support in single leg activities.

In a nutshell, every step you take requires tri-planer control and subtle movement at the level of the diaphragm for ideal physiological function.  Carve your turn…bank your dive.   Beyond the structural integrity that it provides, the circulatory, digestive, neurological, endocrine and limbic benefits cannot be over stated.

Once understood, the movement is quite subtle and simple, and it needs to become a central aspect of your consciousness during gait, respiration and all other single leg activities.  When you get it, it feels amazing…like skiing with every step.

I’ve added a video in attempt to give a quick demo and explanation, because I know, it sounds like a lot…but it’s critical.  Good luck, and enjoy the ride.