Some Basic Tenets of Gait

Initial contact? Loading response? Mid stance? Terminal Stance? pre swing? Are these terms that are familiar to you? Hmmm. How about the wrong orthotic for someone with internal tibial torsion? Join us in this excerpt from a recent Gait and Needling seminar

 

https://vimeo.com/226733697

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So you want to do a Gait Analysis: Part 2

This is the second in a multi part series. If you missed part 1, click here.

We have been exploring the gait cycle, one step (literally) at a time. A quick review of the walking gait cycle components:

There are two phases of gait: stance and swing

Stance consists of:

  • Initial contact
  • Loading response
  • Midstance
  • Terminal stance
  • Pre-swing

Swing phase:

  • initial (early) swing
  • mid swing
  • terminal (late) swing

today, lets explore Loading Response

we remember that Loading response occurs when there is eight bearing on the loaded extremity from initial contact. This continues until the opposite foot is lifted for swing.

Lets look at what is happening here at the major anatomical areas:

Foot

  • Pronation begins: This is when the proverbial “rubber hits the road” occurs. Hopefully the coefficient of friction of the heel with the ground is great enough that pronation of the midfoot begins. As the calcaneus slows, the talus slides anteriorly and plantar flexes, adducts and everts, unlocking the subtalar joint and (hopefully) moving toward making its axis parallel with the calcaneo cuboid joint at midstance (more of that next time).
  • because of this motion, the calcaneus everts approximately 5°
  • both of these motions serve to lower the center of gravity of the leg, deepening the ankle mortise to provide more stability to the ankle
  • Both of these motions (especially adduction of the talus) initiate internal rotation of tibia and lower leg
  • these actions are attenuated by eccentric action of both the long flexors and extensors of the ankle, as well as the foot intrinsics

Ankle

  • The ankle plantar flexes 5-10 °. This motion is attenuated by eccentric action of the anterior compartment muscles of the lower leg
  • this serves to absorb shock (remember pronation is a shock absorber? if not, see here)
  • Ankle rocker occurs (click here for a review of the rockers of the foot)

Knee

  • Flexion to 20°. This is attenuated largely by the quadriceps, contracting eccentrically

Hip

  • The hip is at full flexion at loading response and now begins to extend. This is facilitated by a brief contraction of the gluteus maximus (which started at initial contact)

Starting to see what is happening? Can you understand why you need to know what is going on at each phase to be able to identify problems?

We are The Gait Guys. Two geeks spreading the word. WE appreciate your help doing the same.

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Hip Abduction moment?

This was a great question we received, so we thought we would make a post of it, so everyone could benefit.

“@GregLehman: @KineticRev @TheGaitGuys do you guys have a link to your thoughts on how an ER leg allows the quads to create a hip abductor moment? Thanks”

First of all, What IS a hip abduction moment?

In posts, we often refer to a “moment”, meaning almost literally, a few seconds where a certain motion occurs. When are watching someone from behind and see their heel adduct as they get to terminal stance and pre swing (just before they toe off), you are seeing an “adductory moment” of the heel, sometimes referred to as an “adductory twist”.

Now lets think about the hip. Have you ever seen a framing square used by a carpenter? It is an “L” shaped device to make sure things are square (like hanging a door). The hip is kind of like this. It is shaped like an “L” with the neck and head forming the shorter side of the “L” and the femoral shaft forming the longer side. If you imagine the short side of the square attached to the pelvis and now hinging that away from the body, you have abduction of the hip. Normally, this task is tended to (primarily) by the middle fibers of the gluteus medius and posterior fibers of the gluteus minimus, assisted by the quadratus lumborum on the opposite side.

How can the quad be involved?

We remember that the quadriceps has four parts, the vastus lateralis, vastus intermedius and vastis medialis (collectively called “the vasti’) and the rectus femoris.

The rectus femoris proximal attachments are at the anterior inferior iliac spine (this is called the straight or anterior head) and the superior lip of the acetabulum (called the reflected or posterior head) Please see the top of the 2nd picture above, you can see the 2 heads. The distal attachment, after blending with the vasti, is into the patellar tendon and ultimately the tibial tuberosity.

The rectus is an accessory hip flexor and knee extensor, though it not normally a prime mover for either of these motions. It’s amount of action depends on the position of both the knee and hip.  When the knee is flexed, the rectus has less mechanical advantage, because it is placed in a lengthened position; same goes if the hip is extended.  It will be shortened if the hip is flexed and if the knee is extended at the same time, will have a mechanical disadvantage.

Now think about the direction of travel of each of the heads.

The “straight” head actually runs more obliquely from lateral to medial from its proximal attachment (AIIS) to the distal attachment (blending with vasti and patellar tendon); the refelected head runs a similar course, but not as oblique. If you were to externally rotate the thigh (remember, some folks may have an externally rotated foot due to external tibial torsion), it would actually give these heads more mechanical advantage (when the knee is relatively extended, such as at heel strike/ initial contact and toe off/ preswing) as abductors (remember to think from the ground up, closed chain, so the distal attachments are acting more like the origin); thus, the abductor moment we have talked about.

 

There you have it @Greglehman. Thanks for the great question.

 

The Gait Guys. Uber Gait Aficionado’s Extraordinaire. Come and learn with us. Watch us on Youtube; follow us on Facebook and Twitter, see many of our downloads on our payloadz site by clicking here.

 

All material copyright 2013 the Gait guys/ The Homunculus Group. All rights reserved; don’t make us call Lee.

Gait, Running and Sound. Are you listening to your body ?

A few months ago we tried something new.  We tested your gait auditory skills while listening to a video of a runner on a treadmill. We queued you to listen to the foot falls listening for the one foot to slap or impact harder than the other at foot strike. Most of you got it right, we  got plenty of positive feedback on that piece. Here is that piece (link).

This is something we do during the initial evaluation for each and every patient that comes to see us, no matter what their issue. We ask them to walk. We ask them do they notice anything. The answer is almost always, “no”.  This is because they are accustomed to their walking habit.  The first queue we notice much of the time is that there is either a bilateral heavy heel strike (because heel strike is normal in walking) or it is  heavier on one side. We ask them to hear and feel that heavier strike once we point it out to them. Not only can they feel it, they can hear it. It is something they have rarely been aware of until that moment.  We then do the same for forefoot loading. If the anterior compartment is a little weaker on one side or if they departed abruptly off the opposite leg for some reason (decreased hip extension, tight calf, loss of ankle rocker etc), a heavier forefoot loading response will be felt and heard as well (opposite side of the mentioned issues).  These are great initial gait queues that anyone can use to gain diagnostic information.  It also draws the client into greater body awareness of their habitual patterns of movement. We then draw out the numbers and forces for them so they understand what several thousand cycles of this event can cause into their body and their clinical problems they are presenting with.  This is typically a new skill they will develop and always be aware of and be able to report to you as they progress through their care with you.  Sound and feeling are key biofeedback tools.

Just remember, they are feeling and hearing what they are doing, not what is wrong ! It is your job to take this information and figure out the “Why” it is happening, and the “how” to fix it.  This is the hard part.

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Gait Cycle Basics: Part 2

Gait Cycle components

Let’s begin today with a typical walking gait cycle.

There are 2 phases: stance and swing. It comprises approximately 62% of the gait cycle. Inman and Scranton use the following classification:

 

Heel strike: when the heel hits the ground

Full forefoot load: weight is transferred anteriorly to the forefoot

Heel lift: when the heel begins lifting off the ground

Toe off: the beginning of propulsion

 

They further divide this into a contact period (heel strike to full forefoot load), a midstance period (from full forefoot load to heel lift) and a propulsive period (from heel lift through toe off)

 

Jaqueline Perry, the Matriarch of gait, uses a slightly more descriptive classification which we prefer:

 

Initial contact: when the foot 1st 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 1st ½ 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 toes off ends

She also describes 3 tasks to be performed during a gait cycle: weight acceptance (the limb is able to bear weight), single limb support (when weight is supported by one limb with the other in swing phase), and swing limb advancement (moving the opposite limb through space to become the next stance phase leg.

The question is, how do we adequately progress over the stance phase leg? Stay tuned to our next post for a primer on the 3 rockers….

The Gait Guys…Promoting gait literacy and understanding for the clinician and the consumer.