The Windmill Pitch: Fastpitch Softball. More proof that arm swing and opposite leg swing are powerfully coordinated and neurologically paired.

Step length and power can affect opposite arm power and speed.

You have heard us talk often about opposite arm and leg swing pairing and how important they are from a neurological coordination issue. We have also talked about energy conservation and transmission in prior blog posts when it comes to arm swing. Good arm swing will lead to energy conservation.  A reduction in arm swing leads to a poor gait economy.  Check out this study here and the statistics. 

Collins et al Proc Biol Sci, 2009, Oct 22 “Dynamic arm swinging in human walking.”

“normal arm swinging requires minimal shoulder torque, while volitionally holding the arms still requires 12 % more metabolic energy.  Among measures of gait mechanics, vertical ground reactive moments are most affected by arm swinging and increased by 63% without arm swing.”

* type in “arm swing” into our blog SEARCH box and you will see 14 articles we have written on arm swing in human locomotion.

Gait is in every sport, just about.  Here we see a beautiful depiction of the opposite arm and leg pairing neuro-biomechanically, albeit not gait here it is still in her movement.  The larger a first step , whether the pitcher is a overhead hardball thrower or underarm fastball pitcher, the concept remains preserved.  I was a pitcher for over 10 years in the Ontario Fastball league back in Canada when I was a youth and teenager.  I was not a big speed pitcher, but what I had troubles coming up with in speed I was able to make up in putting “junk” on the ball.  My first step was large, and the larger the left step length (as seen in this video here), the more pelvic obliquity that could be achieved, which in turn enabled an opposite “anti-phase” rotation of the shoulder girdle.  When you add increased shoulder girdle obliquity with full arm rotation speed losses can be contained and limited.  Hypothetically, ball speed in a smaller player with a large first step can be heightened to the point of a that of a larger stronger pitcher with a smaller step.

Here you can see a great demonstration of this large step length the video.  They are using the tilt board to facilitate a faster downward plantarflexion of the right foot to drive a larger faster left step. It is the same principle as if you stepped off a curb or into a hole unexpectedly, the body’s natural reaction is to step out quickly with the other limb to catch the body’s forward fall. The board is used to achieve the same result with control. This is why you will see pitchers dig out a trench immediately in front of the pitchers rubber, to create this same plantarflexion drop of the right foot (in this case, the right foot for a right handed pitcher).  The deeper the trench, the more aggressive that left step.

Shawn and Ivo………..digging deep trenches today…….. and finding gait theory everywhere, even in fastball.

http://youtu.be/QzojfAUcGEI

http://youtu.be/0OA6RfTre6M

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Well, you have heard it here before, the receptors drive the brain, and here is another study that backs this up. Remember that receptors, which include not only joint mechanoreceptors, but…

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Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Slow Your Gait & Shorten Your Stride and Your Brain May Slow

Well, you have heard it here before, the receptors drive the brain, and here is another study that backs this up. Remember that receptors, which include not only joint mechanoreceptors, but also muscle mechanoreceptors (muscle spindles and golgi tendon organs) and tactile receptors in the skin (Merkels discs, paccinian corpuscles, etc) feed into the brain cortex (via the dorsal column system) and the cerebellum (via the spino cerebellar system). This afferent (sensory information) input is important for proper coordination as well as cognition and learning.

Remember, your brain is always remodeling. Here, the old adage “if you don’t use it, you will lose it” applies. More input = more synapses = more neuronal growth. So less motion = less input=synaptic atrophy = fewer connections and thus slower brain function.

Increased speed and length of stride stretches receptors more; decreased speed and shorter stride lengths decrease receptor activation. So, take big steps quickly, or you may turn into a zombie ! There is a reason why they walk slowly !

In July 2012 at the Alzheimer’s Association International Conference in Vancouver, British Columbia Mayo Clinic researchers presented research indicating that walking problems such as a slow gait and short stride are associated with an increased risk of cognitive decline. Computer assessed gait parameters (stride length, cadence and velocity) in study participants at two or more visits roughly 15 months apart. They revealed that participants with lower cadence, velocity and length of stride experienced significantly larger declines in global cognition, memory and executive function.

references:

http://www.aansneurosurgeon.org/2012/08/02/slow-gait-short-stride-linked-to-increased-risk-of-cognitive-decline/

http://www.newswise.com/articles/view/591437/?sc=dwhn

Gait Pathomechanics: Walking in a Pencil Skirt.

If you want more on this topic, Drs Allen and Waerlop go on a fun and informative rant on fashion, pencil skirts and high heeled shoes on Podcast # S1-E3 (Season1-Episode3), a soon to be released podcast episode.

Who knows why this video is even on Youtube. It is 6 minutes of this gal walking back and forth, so do not watch  more than the first 60 seconds for anything exciting, trust us.  Read the blog post and then come back to the video and see what we talk about. There are some severe gait compromises in a skirt like this, let alone with the high heel shoes accompanying the gait.

According to wikipedia:
The slim, narrow shape of a pencil skirt can restrict the movement of the wearer so pencil skirts often have a slit at the back, or less commonly at the sides. Sometimes a pleat, which exposes less skin, is used instead of a slit. The classic shoes for wearing with a pencil skirt are high heels,[3] with sheer stockings or tights. The predecessor to the pencil skirt is the hobble skirt, a pre-WWI fad inspired by the Russian Ballet. This full-length skirt with a narrow hem seriously impeded walking. The French designer Christian Dior introduced the classic modern pencil skirt in the late 1940s. The pencil skirt feels different from looser skirts, and can take some adjustment by the wearer in terms of movement and posture in order to manage it successfully. Walking needs to be done in short strides; entering and leaving a car gracefully takes practice; and when sitting the legs are held close together which some find restrictive (though others like the feeling of their legs being “hugged” by the skirt). Activities such as climbing ladders and riding bicycles can be very difficult in a pencil skirt. The pencil skirt is warmer due to the reduced ventilation, and is less likely to be blown up by gusts of wind.

The Gait Guys dialogue on pencil skirts :
Tie a rope or theraband around your knees, you will suddenly experience the short cute steps that this gals does devoid of almost all hip flexion and hip extension, both serious gait cycle restrictions.
Without hip flexion-extension the entire timing of the swing phase is off. No longer can there be adequate use of the obliquity of the pelvis and thus abdominals or contralateral leg swing to initiate supination and toe off.
Step and stride lengths are dictated by the tightness of the roap, and in this case the diameter and give of the bottom of the skirt.  Not to mention the bloody complication added by the high heels !
– There is an unnatural oscillation of the pelvis due to the restrictions mentioned above.

The Pencil skirt:  Never again will you be able to wear one and not notice its gait impairments. Nor will men be able to just watch the ladies in the skirts for the appreciation of beauty and style. Men, you will have much more to study now, you just may hate us for your undying need to evaluate the biomechanics in skirt wearers forevermore ! Just be sure you do not abuse this new evaluation superpower as an excuse to your spouse to watch girls walk by.  We are not responsible for abuses of acquired superpowers.  And although we many have actually just become your new heros, just remember, with great powers come great responsibilities.

Once the website launches you will find our new product, “pencil skirt training noose” on our online store.  $50 for the finest of roap loops

There is so much more on this topic in Podcast #3 . Be sure not to miss it. We will launch it here on the blog and on our Facebook page and in iTunes once we get permissioned by Apple.

Shawn and Ivo, your new superheros of gait. Gait Fashonistas, perhaps we have a purpose and calling in the fashion industry !

This week we will focus on the basics of gait and the gait cycle in our attempt to assist in gait literacy

Gait Cycle Basics: Part 1

Steps and strides….

What does the gait cycle that have to do with therapy or rehabilitation? Well, most people walk at some point in the day, and most have walked into your office. If people can’t carry the changes you made on the table and incorporate it into walking, then what you do will have limited effectiveness. Thus, the need for understanding the gait cycle as it relates to rehabilitation or how it can give you clues to the biomechanical faults present. An example is a loss of functional hip extension and chronic LBP/ SI dysfunction. This could be due to a myriad of reasons, from weak glutes, loss of ankle dorsiflexion, or even a dysfunctional shoulder. Understanding how these seemingly unrelated body parts integrate into the kinetic chain, especially while moving upright through the gravitational plane.

 

One gait cycle consists of the events from heel strike to heel strike on one side. A step length is the distance traveled from one heel strike to the next (on the opposite side). Comparing right to left step lengths can give the evaluator insight into the symmetry of the gait.  Differences in step length, on the simplest level, should cause the individual to deviate consistently from a straight line (technically it should cause the individual to eventually walk in a large circle!).  Often, compensations occur functionally in the lower kinetic chain to compensate for the differences in step length to ensure that you walk in a straight line.  It is these longstanding complex compensations that are the generators of many of our patient’s complaints.

 

A stride length is the distance from heel strike to heel strike on the ipsilateral side (the distance covered in one gait cycle.  Step width, or base of gait, is the lateral distance between the heel centers of two consecutive foot contacts (this typically measures 6-10 cm).  Foot progression angle is the angle of deviation of the long axis of the foot from the line of progression (typically 7-10 degrees). Çhanges in the progression angle can be due to both congenital (torsions, versions) as well as developmental reasons.

Next time we will take a closer look at the gait cycle itself. Yup, we are still…The Gait Guys

special thanks to Dr. Tom Michaud, who has allowed us to use these images in our book

“while no significant changes were found in all the gait variables in the sham group, the experimental group had significant increases in the gait speed, step length, as well as in several components of the joint angles and moments.”

Immediate effects of acupuncture on gait patterns in patients with knee osteoarthritis.