Subtle clues often provide the answers.

We like yoga as much as anyone else. We saw this picture on the latest cover and couldn’t resist making a few comments on this pose.

Yoga has many benefits. Our understanding is that in addition to the cognitive and spiritual effects of yoga, is that it helps to build your core.

 At first look you may say that this woman has a few issues:

• she has a right pelvic shift and a left body lean
• She has slight head rotation to the right and a slight left head tilt
• you may have noticed that she appears to have more tone in the musculature on the right side of her face than on the left.   Just look at the nasolabial fold as well as the corner of her mouth any area of wrinkling underneath her left orbit.
•  You may have also noticed the subtle flexion and lack of external rotation of the right hip.

 You may go on and think that she has a week right gluteus medius as well as an overactive quadratus lumborum on the left-hand side which may be causing the pelvic shift. The head tilt may be in compensation for the right side gluteus medius weakness and the subtle rotation may be an attempt to engage a tonic neck response. ( a tonic neck response is  ipsilateral extension of the upper and lower extremity to the side of head rotation with contralateral flexion of the same counterparts.

 You may have also noticed that the toes of the right foot are not dorsiflexed and that her hair appears to be flowing on the right side, and this is not the case at all, but rather she is either standing on a sloped surface or on the downward phase of a jump. According to the magazine it is the latter.  If you caught this at first then congratulations: you are sharper than most. If not remember to always look for subtle clues.

 Like Sir Topham Hat says in Thomas the Train: “  You didn’t get the whole story. What really happened is what really matters.

So why the mild facial ptosis on the left side? She could have had an old Bells palsy, or other form of facial paresis. Note that mostly the lower portions of the (left) face are affected (ie, below the eye). We remember that the upper portions of the face receive bilateral innervation but lower portions of the face unilateral innervation, from the contra lateral facial motor nucleus; this is why it could be a mild upper motor neuron lesion (micro infact, lack of cortical afferent input) and not an lower motor neuron lesion (like Bells Palsy). Why is this germane? Or is it not?

Stand in front of a mirror. Jump up in the air trying to assume the same pose as this woman does and what do you see.  Make sure that you jump up from both legs and then bring one leg over and your hands in front of you in the "praying position”. You may want to have a friend take a snapshot of you performing this. You will notice that you have contralateral head rotation,  a pelvic hike on the side opposite the leg that’s extended and a head tilt to the side that is flexed.  You are attempting to stabilize your core as you’re going up and coming down.

What we are witnessing is a normal neurological phenomena.  This gal merely seems to have some limited external rotation of her left hip. Now perform the same maneuver again but this time don’t externally rotate your leg as far as this woman does and what do you see. You should’ve seen an increase in the aforementioned body postures.

Subtle clues are often the key. Keep your eyes and ears open. 

The Gait Guys. Helping the subtle to become everyday for you, with each and every post.

So you want to do a gait analysis? Part 1

From casual observation to a computer driven model, before you can know what may be wrong with a gait, you need to know what is right. Knowing what is happening at each phase of the gait cycle is essential. This series will explore just that and provide you with an overview of what should be happening.

Let’s begin with a typical walking gait cycle. There are two phases: stance and swing. It comprises approximately 62 percent of the gait cycle.¹ Jaqueline Perry^2,3 uses this descriptive classification to describe stance phase:

• Initial contact: When the foot first touches the floor.
• Loading response: Weight bearing on the loaded extremity from initial contact and continues until the opposite foot is lifted for swing.
• Midstance: The first half of single-limb support, beginning when the opposite foot is lifted until weight is over the forefoot.
• Terminal stance: Begins with heel rise and continues until the opposite foot strikes the ground.
• Pre-swing: When initial contact of the opposite extremity begins and toe-off ends.

Swing phase is divided into 3 parts

• initial (early) swing: when the extremity is being accelerated just after pre swing; this action initiates supination in the opposite, stance phase leg
• mid swing: largely passive
• terminal (late) swing: when the extremity is being actively decelerated, largely through eccentric action of the muscles

How about we start with initial contact, commonly called “heel strike”.

Heel strike, a traumatic deceleration event with the transfer of weight from one extremity to the other, creates shock, which must be attenuated. This is accomplished by four distinct mechanisms:

• Ankle plantar flexion: At heel strike, followed by eccentric contraction of the pretibial muscles to decelerate foot fall.
• Subtalar pronation: As the coefficient of friction between the calcaneus and the ground increases, the talus slides anterior on the calcaneus while plantar flexing, adducting and everting. This motion causes concomitant internal rotation of the lower leg. Both these actions cause a time delay, allowing force to be absorbed over a longer period of time.
• Knee flexion: This is a reaction to the heel rocker, forward motion of the tibia, and passive tension in the posterior compartment. It is slowed by eccentric contraction of the quadriceps, with the abdominals acting as a primary anchor.
• Contralateral pelvic drop: This is decelerated by the ipsilateral hip abductors (primarily gluteus medius) and lateral chain, as defined by Myers.⁴ It occurs as weight is suddenly dropped on the contralateral limb.

What is happening biomechanically? Lets look at the major anatomical areas:

•  Foot

the foot should be supinated at this point, as it should be from preswing. It is dorsiflexed, inverted and adducted. 

• Ankle

The ankle should be neutral or slightly dorsiflexed

• Knee

the knee is usually neutral or slightly flexed and the thigh and leg externally rotated approximately 4-6 degrees

• Hip

The heel strike hip should be flexed 20-30° and the lumbar spine neutral; the opposite hip should be extended 20-30° and equal to the amount of flexion present in the initial contact hip.

Today, look for aberrances at initial contact in your clients and patients. Knowing what is normal is the 1st step toward knowing what isn’t. Got it?

Next post in this series (not necessarily our next post) will cover loading response.

Ivo and Shawn

1. Root MC, Orion WP, Weed JH. Normal and Abnormal Function of the Foot. Los Angeles: Clinical Biomechanics, 1977.
2. Perry J. Gait Analysis: Normal and Pathological Function. Thorofare, NJ: Slack 1992.
3. The Pathokinesiology Service and the Physical Therapy Department. Observational Gait Analysis. Rancho Los Amigos National Rehabilitation Center, Downey, CA, 2001.
4. Myers TW. Anatomy Trains: Myofascial Meridians for Manual and Movement Therapists. Elsevier: 2001.