Pioneer Researcher of Gait and Biomechanics

Gait Dr. Perry motions

Dr. Jacquelin Perry was a physician and researcher who shed light on the complexities of walking.  She was a leader in treating polio victims in the 1950s and again in the ’80s when the symptoms of some returned,  Dr. Perry died at age 94 on March 11, 2013 in Downey, California. Her death was announced by the Rancho Los Amigos National Rehabilitation Center, where she worked for more than 60 years.

Dr. Perry earned wide attention for her work in analyzing the human gait, which she broke down into eight motion patterns governed by 28 major muscles in each leg. Her 1992 book, “Gait Analysis: Normal and Pathological Function,” became a standard text for orthopedists, physical therapists and other rehabilitation professionals.

Her clinical observations and descriptions of “loading response” were clear and had implications for many biomechanists. To break walking, running, stair-climbing and other human ambulations into discrete components, illustrated with precise photographs, Dr. Perry used ultrasound studies, motion analysis and electromyography, which traces the nerve pathways through muscle using electric charges.

Dr. Perry was an active surgeon until a brain artery blockage forced her to stop operating. She then devoted much of her time to studying the biomechanics of walking. As part of her research, she investigated how muscles and joints behave when spinal-cord injury patients propel themselves in wheelchairs, and how below-the-knee amputees are able to walk with prosthetic feet.

http://www.nytimes.com/2013/03/24/health/dr-jacquelin-perry-who-aided-polio-victims-dies-at-94.html?_r=0

http://www.drpribut.com/wordpress/2013/03/24/jacquelin-perry-md-1918-2013-pioneer-of-gait-biomechanics-and-the-treatment-of-neurological-disorders/

The Biomechanics of Your Walking Gait

Gait Stance Phase Feet on Ground

Whether you are conscious of it or not, your feet move your body forward to where you want to go at the pace you want to take. They use the least amount of energy by moving in as straight a line as possible, and adjust their movement to avoid pain if you have a painful foot condition.  They act as shock absorbers for your body. And unless you are hopping, your feet alternate on the ground as you go forward with the lower one propelling the one in mid-air forward.

The alternating of your feet as you walk happens in two phases:

  • The ‘Stance phase’ is when the foot is on the ground. It comprises about 60% of the walking cycle. For part of the stance phase both feet will be on the ground for a period of time.
  • The ‘Swing phase’ occurs when one foot is on the ground and one in the air.

Even during the ‘Stance phase’ a single foot goes through five sub-stages:

  • Heel strike
  • Early flatfoot
  • Late flatfoot
  • Heel rise
  • Toe off.

The defining difference between walking and running is that during running there is a period of time when both feet are off the ground (the ‘Float’ phase).  Also, as running is associated with greater speeds, the forces that go through the foot when it lands can be substantially greater than during walking; it is often 4-5 times body-weight during running and even up to 6-7times body-weight during sprinting.

http://www.footeducation.com/biomechanics-of-walking-gait

Footwork Patterns in Dance: The Slow Waltz

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The Slow Waltz is famous for its ‘box step’. Dance partners create a square footwork pattern on the floor, counting ‘1,2,3’- ‘1,2,3’ as they move together, one going forward, one going backwards, to form the box. Once mastered, other graceful moves can be added.

Basic box steps for the man:

  1. Step forward with the left foot
  2. Right foot step sideways to the right
  3. Bring your left foot next to your right foot
  4. Step back with the right foot
  5. Step back sideways with the left foot
  6. Bring your right foot next to your left foot

Box steps for the lady:

  1. Step back with the right foot
  2. Left foot step sideways to the left
  3. Bring your right foot next to your left foot
  4. Step forward with the left foot
  5. Step forward sideways with the right foot
  6. Bring your left foot next to your right foot

At each step the dancers rise on their toes. They balance themselves by throwing body weight from one foot and then on the other. Despite the relatively slow tempo, The Slow Waltz is transformed into a dynamic dance by its turns, its step variations and its elegant poses.

Think Fred and Ginger.

 

http://en.wikipedia.org/wiki/Walking_Boston

http://en.wikipedia.org/wiki/Waltz_(International_Standard)

http://www.dancing4beginners.com/dance-steps-for-waltz.htm

Photo Source:

https://www.google.ca/images?hl=en-CA&q=waltz+images&gbv=2&sa=X&oi=image_result_group&ei=uB6bU4jwIsmlyASf6ILwCQ&ved=0CBMQsAQ

 

Footwork Patterns in Dance: The Twist

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The Twist is a rock and roll dance named after the smash-hit song “The Twist” by Chubby Checker. Super popular in the 1960s, it was the first major rock and roll dance style in which the couples did not have to touch each other while dancing.

Faced with explaining how to do the dance to the youthful audience of the era, a member of Checker’s entourage came up with the following description:

“It’s like putting out a cigarette with both feet, and wiping your bottom with a towel, to the beat of the music.”

http://www.the60sofficialsite.com/Dance_Crazes_of_the_60s.html 

Photo Source:

Footwork Patterns in Dance: The Moonwalk

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The Moonwalk is a dance move that presents the illusion of the dancer being pulled backwards while attempting to walk forward. A popping move, it became popular around the world after Michael Jackson’s Moonwalk footwork during a performance of “Billie Jean” on Motown 25: Yesterday, Today, Forever on March 25, 1983. The Moonwalk became his signature move.

The Technique

A Moonwalk dancer creates the appearance of gliding backwards. Initially, his front foot is held flat on the ground, while his back foot is in a tiptoe position. His flat front foot remains on the ground but he slides it lightly and smoothly backward past his tip-toe back foot. He lowers what is now his front foot and raises his back foot into a tiptoe position.  He repeats these steps creating the illusion that he is being pulled backwards by an unseen force while still trying to move forward.

http://en.wikipedia.org/wiki/Moonwalk_(dance)

Photo Source:

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Footwork Patterns in Dance: The Foxtrot

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The Foxtrot is a smooth dance characterized by continuous, flowing movements across the dance floor, usually to the sounds of big band music. Similar in its look to the Waltz, (though the rhythm is in a 4/4 time not 3/4), the Foxtrot reached its height of popularity in the 1930s.

The basic elements of the Foxtrot are walking steps and side steps. The long walking movements also involve a rise & fall action, more subtly than the Waltz. The Foxtrot has a slow, slow, quick, quick rhythm. The slow steps use two beats of music and the quick steps use one. 

Instructions:

Partners stand upright with your feet together. Face each other, lady puts her right hand in man’s left. His right hand is on her left shoulder blade; her left hand is on his right arm. 

Basic Steps – Gentleman

  1. Step forward with your left foot (slow step)
  2. Step forward with your right foot (slow step)
  3. Sidestep to the left with your left foot (quick step)
  4. Move your right foot to your left foot (quick step)
  5. Step backward with your left foot (slow step)
  6. Step backward with your right foot (slow step)
  7. Sidestep to the left with your left foot (quick step)
  8. Move your right foot to your left foot (quick step) 

Basic Steps – Lady

  1. Step backward with your right foot (slow step)
  2. Step backward with your left foot (slow step)
  3. Sidestep to the right with your right foot (quick step)
  4. Move your left foot to your right foot (quick step)
  5. Step forward with your right foot (slow step)
  6. Step forward with your left foot (slow step)
  7. Sidestep to the right with your right foot (quick step)
  8. Move your left foot to your right foot (quick step)

 

http://www.dancing4beginners.com/foxtrot-dance-steps.htm

Photo Source:

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Footwork Patterns in Dance: The Cha-Cha-Cha

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Originating in Cuba, the Cha-Cha-Cha is a lively and versatile Latin dance.  It is characterized by its captivating rhythm – one, two, cha, cha, cha or step, step, cha, cha, cha. The footwork is simple, focusing on shifting weight from one foot to another. 

You dance the Cha-Cha-Cha to music in 4/4 time. Your steps follow the music – two slow steps, then two quick steps, followed by one slow step. So the count would be: Slow, slow, quick, quick, slow. Slow, slow, quick, quick, slow… 

Instructions:

Partners face each other in a basic ballroom hold. Gentleman starts with left foot; lady starts with right foot.

Basic Steps for Men

  1.   Step forward with your left foot
  2.   Right foot in place, weight shifts to it
  3.   Sidestep to the left with your left foot
  4.   Move your right foot to your left foot
  5.   Sidestep to the left with your left foot
  6.   Step backward & left with your right foot
  7.   Left foot in place, weight shifts to it
  8.   Step forward & right with your right foot
  9.   Move your left foot to your right foot
  10.   Sidestep to the right with your right foot

Basic Steps for Women

  1.   Step back with your right foot
  2.   Left foot in place, weight shifts to it
  3.   Sidestep to the right with your right foot
  4.   Move your left foot to your right foot
  5.   Sidestep to the right with your right foot
  6.   Step forward & right with your left foot
  7.   Right foot in place, weight shifts to it
  8.   Step backward & left with your left foot
  9.   Move your right foot to your left foot
  10.   Sidestep to the left with your left foot

 

http://www.dancing4beginners.com/cha-cha-steps.htm 

Photo Source:

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Famous Foot Gaffe – In the Watergate Scandal

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It was dubbed the “Rose Mary Stretch”, and it became an iconic image of truth-stretching in the Watergate era.  Arched awkwardly backward to answer the phone, the ever-loyal Richard Nixon secretary Rose Mary Woods demonstrated to prosecutors how her foot errantly tapped the record button, causing part of a crucial 18 ½-minute gap in an Oval Office tape. 

“I am most dreadfully sorry,” she said. Her epic bend of back and logic made her a national punch-line, and helped push her boss to early retirement less than a year later.  Ms. Woods died in 2005 at 87.  But her infamous Pilates move lives on.  There is an annual award for “worst performance in open government” in her honour, and a play called Stretch (A Fantasia).

Quoting:  Barrie McKenna   ‘A Moment in Time: Nov. 26, 1973’ — “Rose Mary Woods Explains the Tape Gap.”  The Globe and Mail, November 26, 2010

 

 

 

Photo source:

https://www.google.ca/search?q=Rose+Mary+Woods+AP+photo&tbm=isch&tbo=u&source=univ&sa=X&ei=n_gQU82RB6Pp2QWkjIEg&ved=0CCYQsAQ&biw=1366&bih=566

Jogging Your Memory

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Perhaps this expression is more literal than we thought –

       Here’s what it means:

Being in motion makes us smarter, and being smarter allows us to move more efficiently.

       Here’s the scientific hypothesis:

Jogging after prey helped to drive human brain evolution.  A million years ago, we could out-run and out-walk most other mammals over long distances. Our brains were shaped and sharpened by movement. We continue to require regular physical activity in order for our brains to function optimally.

      There are many studies.

http://well.blogs.nytimes.com/2012/12/26/exercise-and-the-ever-smarter-human-brain/?_php=true&_type=blogs&_r=0 

       Here’s a finding:

Regular exercise, even walking, leads to more robust mental abilities, beginning in childhood and continuing into old age.

 

Picture source:  http://www.123rf.com/stock-photo/jogger.html