How to (and how not to) do a single leg squat, CORRECTLY !

Here Dr. Allen has one of his elite marathon and triathletes demonstrate how to correctly and incorrectly do a single leg squat. The single leg squat can show many of the pathologic movement patterns that occur in a lunge. The single leg squat is more difficult however because it requires balance and more strength. Many people do not do the single leg squat correctly as you will see in this video. Many drop the opposite hip which means that there is an inability to control the frontal plane pelvis via the stance leg gluteus medius and the entire orchestrated abdominal core. Most folks will drop the suspended hip and pelvis and thus collapse the stance phase knee medially. This can lead to medial knee pain (tracking disorder in the beginning) , a driving of the foot arch into collapse and impingement at the hip labrum. We know that when the knee moves medially that the foot arch is under duress. This problem is often the subliminal cause of all things foot arch collapse in nature, such as plantar fascitis to name a common one. Remember, optimal gluteus medius is necessary here. And the gluteus maximus is working to eccentrically lower the pelvis through hip flexion. So, if you do not consider the gluteus maximus a hip flexor then you are mistaken. Everyone thinks of it as a powerful hip extensor and external rotator. But do not be mistaken, in the closed chain it is a powerful eccentric controller of hip flexion and internal hip rotation.

Tomorrow we will look at this same case and look at her feet and discuss those as a problem, predictor and limiting factor to long term optimal function.

We are The Gait Guys,

Shawn and Ivo (visit our blog daily at www.thegaitguys.tumblr.com)

what we think we look like  when we run is not always the case.  Pictures are worth a thousand words !

More on Gait Forensics. Soon to be in airports ? not yet→

Trust us, this will be something we will see in time.  This brief newsflash talked about foot plantar pressure representations, but as Ivo and I know…… there is so much more to the overall gait patterning. We know, we look at it everyday.

According to the brief article, “Researchers at the University of Liverpool analyzed more than 100,000 pressure points people’s feet create when they walk and came up with about 70 patterns said to be unique to any one individual, The Daily Telegraph reported.

The researchers said the findings could add another type of "biometric” identification in addition to retinal scanning and fingerprints at airports and in other security settings.“

Read more: http://www.upi.com/Science_News/2011/10/10/Study-How-you-walk-can-identify-you/UPI-96891318285793/#ixzz1axvvfVAO

Gait Forensics labs……. you might want to look at our body of work…… we kinda know what we are doing. 

Shawn and Ivo, quite possibly, future experts in Gait Forensics.

speachless……. brilliant

worlds oldest Marathoner

Check this guy out! we hoipe we are still running when we are his age…

http://local.stv.tv/edinburgh/news/268592-worlds-oldest-marathon-runner-prepares-to-take-on-eighth-race-aged-101/

http://bcove.me/0xexeqxu

Hope you are enjoying the weekend!

Ivo and Shawn

Shawn & Ivo…… The Gait Guys……. maybe just a little crazy ourselves. Hoping we are changing the way you, and everyone else, look at gait. We miss you Steve.

Training Tip: Ditch the Flip Flops. Our mention in Triathlete magazine.→

Our brief mention in  Sept 16th issue of Triathlete magazine

link is above….. Jene Shaw the editor did a nice job on a touchy subject.

Training Tip: Ditch The Flip-Flops

 
Published: Sep 16th 2011 3:09 PM UTC by Jené Shaw

Although they date back to King Tut and Cleopatra, your favorite thong-style sandal may be bad for your running health according to biomechanical experts The Gait Guys (Thegaitguys.com), Dr. Shawn Allen and Dr. Ivo Waerlop.

In 2008 Auburn University researchers found that wearing flip-flops alters your gait, which can result in biomechanical issues from your foot to your spine. “In flip-flops the kinetic chain is essentially asked to function differently,” Allen says. “They can force changes in step and stride length, reduce function of the glutes, and compromise lower leg and foot intrinsic muscles, to name a few.”

When wearing flip-flops, use of the foot intrinsic and toe extensor muscles is reduced in the stance phase of gait. What’s important about this is that the toe extensors, found in the lower leg, are synergists for ankle dorsiflexion (the upward movement of the foot), which is key in running. Without ample function of these muscles, the toe flexors, calf and Achilles shorten and tighten, which impairs optimal ankle and foot joint function.

3 strikes against flip-flops:

• Without sufficient strength in the anterior tibial compartment (the front of your lower leg) you are at risk for several problems, including shin splints.

• Lack of adequate function of the toe extensors can lead to toe flexor dominance (look to see if your toes have a gentle curl to them at rest; if so, you are in that group!) which has implications with general weakness of the foot muscles responsible for arch strength and general foot health.

• In order to keep a flip-flop on our foot, we tend to grip with our flexors, which forces us deeper into this scenario.

If you are going to wear sandals and you want healthier feet, The Gait Guys recommend wearing sandals that have straps that fasten to your heel or lower leg.

We don’t dig the music, but lots of shoes and entertainment factor here!

Have a great Friday!

Ivo and Shawn

This is a nice study looking at lateral gastroc activity and changing firing patterns with speed of movement. It also melds nicely with yesterdays Neuromechanics post…

Those darn Ia afferents….

You remember them, large diameter afferent (sensory) fibers coming from muscle spindles and appraising the nervous system of vital information like length and rate of change of length of muscle fibers, so we can be coordinated. They act like volume controls for muscle sensitivity. Turn them up and the muscle becomes more sensitive to ANY input, especially stretch (so they become touchy…maybe like you get if you are hungry and tired and someone asks you to do something); turn them down and they become less or unresponsive.

Their excitability is governed by the sum total (excitatory and inhibitory) of all neurons (like interneuron’s) acting on them (their cell bodies reside in the anterior horn of the spinal cord).

If we slow things down, the rate of change of length slows as well and excitability decreases, like we see in this study (3-6% slower). We also notice that the length of contraction increases; hmmm, why doesn’t it decrease?

Remember these folks are on a treadmill. The treadmill is constantly moving, opposite the direction of travel. With the foot on the ground, this provides a constant rate of change of length of the gastroc/soleus (ie, it is putting it through a slow stretch); so , once the muscle is activated, it contracts for a longer period of time because of the treadmill putting a slow stretch on the gastroc (and soleus).

This article also talks about people with upper motor neuron lesions. An important set of inhibitory neurons come from higher centers of the brain, in the motor cortex. These tend to attenuate the signals affecting the Ia afferents, and keep us stable. When we have an upper motor neuron lesion (like a brain lesion or stroke), we lose this “attenuation” and the stretch reflexes (and muscle tone) becomes much more active (actually hyperactive), making the muscle more sensitive to stretch. This loss of attenuation, along with differing firing patterns of the gastroc are important to remember in gait rehab.

The soleus and medial gastroc begin firing in the first 10% of the gait cycle (at the beginning of loading response) and fire continuously until pre swing (peaking just after midstance). The lateral head begins firing at midstance; both leads (along with soleus) decelerate the forward momentum of the tibia, flex the knee at midstance, and the medial head assists in adducting the calcaneus to assist in supination.

We remain, inexplicably….The Gait Guys

Effects of treadmill walking speed on lateral gastrocnemius muscle firing.

by Edward A Clancy, Kevin D Cairns, Patrick O Riley, Melvin Meister, D Casey Kerrigan

American journal of physical medicine rehabilitation Association of Academic Physiatrists (2004) Volume: 83, Issue: 7, Pages: 507-51 PubMed: 15213474

Abstract

OBJECTIVE: To study the electromyographic profile-including ON, OFF, and peak timing locations-of the lateral gastrocnemius muscle over a wide range of walking speeds (0.5-2.1 m/sec) in healthy young adults. DESIGN: We studied gastrocnemius muscle-firing patterns using an electromyographic surface electrode in 15 healthy subjects ambulating on a treadmill at their normal walking speed and at three paced walking speeds (0.5, 1.8, and 2.1 m/sec). Initial heel contact was determined from a force-sensitive switch secured to the skin over the calcaneous. RESULTS: For all speeds, the gastrocnemius firing pattern was characterized by a main peak, occurring 40-45% into the gait cycle, that increased in amplitude with walking speed. Speeds of > or =1.3 m/sec produced a common electromyographic timing profile, when the profile is expressed relative to the stride duration. However, at 0.5 m/sec (a speed typical of individuals with upper-motor neuron lesions), the onset of gastrocnemius firing was significantly delayed by 3-6% of the gait cycle and was prolonged by 8-11% of the gait cycle. CONCLUSION: Many patients with upper motor neuron lesions (e.g., stroke and traumatic brain injury) walk at speeds much slower than those commonly described in the literature for normal gait. At the slow walking speed of 0.5 m/sec, we have measured noticeable changes in the electromyographic timing profile of the gastrocnemius muscle. Given the importance of appropriate plantar flexor firing patterns to maximize walking efficiency, understanding the speed-related changes in gastrocnemius firing patterns may be essential to gait restoration.

This week on Neuromechanics, Dr Waerlop discusses muscle spindles and their importance in determining muscle tone. Think about this clinical applications with gait, in light of our most recent posts

More Lactate:   

Before we talk about determining blood lactate levels, we need a deeper understanding of the energy producing systems at play, as well as some commonly used terminology.

There are 2 main systems for producing energy in the body, the aerobic system and anaerobic system. There is a 3rd system, the Creatine Phosphate system, which provides energy for very short bursts of a few seconds, or until your creatine phosphate stores are depleted. we will concentrate on the 2 main ones.

The aerobic system or aerobic metabolism, utilizes oxygen, using predominately fats & some carbohydrates for energy along with recycled lactate which is produced at low levels and metabolized efficiently. This is your endurance energy system. You may still have recurring nightmares about this from freshman biology, also known as the Krebs (or Citric Acid) Cycle

Your lactate threshold (LT) is a highly aerobic point where lactate levels in the blood are still low but just starting to reach steady state levels. Your LT is the most efficient effort level that you can sustain for long periods of time without going in to your energy reserves (i.e. glycogen). Beyond this point, you are exceeding your ability to recycle lactic acid back into the Citric Acid Cycle and lactate levels begin to rise; changing local blood pH and affecting local chemical reactions. 

The anaerobic system does not utilize oxygen, using predominantly carbohydrates for energy. An efficient anaerobic system will produce a lot of lactic acid as its by-product. As you know, in large amounts, this causes the burn and fatigue you often feel when working hard.  Thus, your anaerobic threshold (AT) is much more stressful and is therefore only sustainable for shorter periods of time.

What does this mean?

For the endurance athlete, the BALANCE of these two systems must be developed optimally for their chosen event. Performing a lactate test (to be discussed in another post) will help determine the relative contribution of each system. In general, the well-developed endurance athlete will produce very little lactate even at high speeds. Endurance sport athletes, such as cyclists, Ironman athletes, triathletes and top marathon runners need to be highly aerobic, which means that very little lactate is produced even at peak speeds and testing reveals a very flat lactate curve. Most of their energy comes from aerobic sources.

Optimizing lactate threshold development is the main goal of endurance training, and racing at or near LT proves the most efficient route to a solid race day performance.

So, how can you use this information for training? Watch for an upcoming post on Lactate testing.

Yup, we know a thing or two about gait AND training. 

The Gait Guys: Ivo and Shawn

The Ankle-Foot Orthosis : Another option for foot drop.

Do you have a client who suffers from some foot drop ? Do they have a classical AFO but it drives them nuts ? Foot drop occurs when the anterior compartment of the lower leg (mostly tibialis anterior and/or long toe extensors) gets compromised neurologically leaving a persons gait compromised during the swing phase and early half of stance phase.  Early to mid stance phase of gait requires that the anterior compartment muscles slowly (eccentrically) lowers the foot to the ground in a controlled manner.  When this is compromised the foot quickly, and without strategy, slaps to the ground thus rushing the persons gait onto the forefoot.  This often occurs in an uncontrolled fashion and renders some balance and weight transfer complications. Then, during late stance phase, when the foot comes off of the ground merely by forward body progression, these clients leave the foot in the pointed plantarflexed position leaving the toes without proper clearance. This often leads to tripping and stumbling.

Always looking out for newer and better solutions, we came across this variation on the AFO (ankle-foot orthosis) strategy. It seems like it could have some advantages from a logistical side. Whereas the typical AFO comes under the foot and maintains the foot in a 90 degree ankle rocker (dorsiflexion) position this one has a bit of a dynamic effect. The bungee cord-like device should slowly lower the foot to the ground as well as help to spring the foot back into dorsiflexion for swing phase clearance so that the toes are not catching on the ground.  Seems so simple we have to wonder.  We might give this one a try on a few patients who have varying degrees of footdrop and report back.

Regardless, we wanted to share……. we love outside the box thinking. Especially when it is so simple !

bravo !

shawn and ivo…………. toss in a side of orthopedics and a main course of neurology, sprinkle a little biomechanics on that and you have a well rounded meal.  We are …… The Gait Guys

Parkour Running: Taking gait and running to another level.

Nike Commercial: How to outrun a chicken .

Sebastian Fouucan vs. David Belle

Pants around your thighs.  We have this gangster gait on our list of things to do.

The Gait Guys indirect link to Sidney Crosby of the NHL and his head trauma.

So, how did the Gait Guys get so smart ? Both Dr. Allen and Dr. Ivo studied in the field of chiropractic neurology. Dr. Ivo had the wonderful opportunity to study directly under Dr. Carrick for several years. Dr.Carrick is the leader in the field of functional neurology. Dr Ivo studied under the best out there. Dr. Ivo is a diplomate of the chiropractic neurology board, one of the most challenging diplomates to attain.

Most recently Dr. Carrick was asked to evaluate and treat Sidney Crosby arguably the best player in the NHL.  EVeryone was failing on helping Sidney, until Dr. Carrick was begged to come into the picture to help. 

Here is an awesome press conference with Dr. Carrick’s talk starting at 7:40 into the press conference. Enjoy

The Gait Guys, ……. Ivo and Shawn……. not your average doctors.

Reebok International Ltd has agreed to pay $25 million to settle charges that it made unsupported claims

what we were saying all along about these types of shoes and MBT’s…….

____________________________

By Diane Bartz in Washington and Nivedita Bhattacharjee in Bangalore | Reuters

WASHINGTON (Reuters) - Reebok International Ltd has agreed to pay $25 million to settle charges that it made unsupported claims that its “toning shoes” provide extra muscle strength, the U.S. Federal Trade Commission said on Wednesday.

The money will go toward consumer refunds.

Reebok advertisements said the shoes strengthened hamstrings and calves by up to 11 percent more than regular sneakers, and toned the buttocks by up to 28 percent more, the FTC said.

read the rest here…… link below

http://shine.yahoo.com/channel/health/reebok-paying-to-settle-charges-over-shoe-claims-2571097/

Life’s the same, except for the shoes….

Ric Ocasec

Happy Friday

Ivo and Shawn

Gait Forensics: Gait Recognition Software.→

Imagine you are a wanted criminal or terrorist. You know that in the soon-to-be police state that America is leaning towards, there will be cameras on every corner, in every building, on every public transportation service. Heck, it is in many of these places already.  So, what is a criminal to do ?  Hiding their identity was once the way but it is coming to an end because of the improving facial recognition computer programs currently being used. A once simple process of growing some facial hair, wearing sunglasses, changing haircut or color, wear hats is coming to an end.  Still, there are so many other ways criminals can hide amongst us and from the pending camera-happy America that we are soon becoming.  So, what is America’s next step to stay ahead of all this ?

Yup, why not begin a database of gait traits that can be identified; sort of like an AFIS for feet? After all, people do have different foot types, and combining that with gait patterns provides unique clues to an what makes us unique.

In the above article , “A team of New York University researchers has honed in on motion capture as a particularly promising approach to analysis. Associate computer science professor Chris Bregler is studying whether potential security threats can be identified via unique patterns of movement. How might someone walk if he was carrying a bomb in his backpack?” “A person’s body moves differently when it must compensate for some unnatural burden, such as a heavy backpack or even high-heeled shoes, says Bregler.”

“Bregler and his team have identified certain movement signatures with the help of the same motion-capture technology used for special effects in the Lord of the Rings and Harry Potter movies.”

In present day America, one unfamiliar with suicide bombers, we feel safe most of the time.  But as these guys are investigating, carrying excess weight that one is not typically accustomed to, could generate some traceable gait characteristics that a camera could pick up on. But the problem, as we see it, is that if the terrorists know what we are looking for, they can train themselves to adapt to the added weight.

It took a decade or more for facial recognition software to become perfected by the government.  It is so simple now that Facebook has thrust it upon all of our photo galleries.  So who knows, in another decade or so, all of our gait patterns could be mapped and logged for the government and the “next Facebook” phenomenon. 

Hopefully these companies will come calling on the guys of gait……. the experts.

Shawn and Ivo…….The Gait Guys

in the infamous words of Steven Tyler, …..“walk this way”……. or

the immortal words of James Taylor…..“there’s something in the way she moves …..”

want more from the article ?  here is the link below

http://www.pbs.org/newshour

In this weeks Neuromechanics, Dr Waerlop discusses the importance and significance of the “Central Integrated State” of the Nervous system; What is is, and what influences it. Many thanks to Dr Ted Carrick, who hammered this into Dr Ivo’s head while completeing his diplomate in neurology.

Enjoy!