Coach Alicia Fong

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Health tip for week Feb 21st

Open and Closed Kinetic Chain Exercises

This week’s health tip is about learning to choose exercises.

The selection of exercise should be based on movement patterns rather than individual muscles or muscle groups.  Movement patterns or exercises can be classified as occurring in an open or closed chain kinetic chain.

What is open and closed chain exercises?

Open Chain Exercises:

  1. Distal segment moves in space.
  2. Independent joint movement; no predictable joint motion in adjacent joints.
  3. Movement of body segments only distal to the moving joint.
  4. Muscle activation occurs predominantly in the prime mover and is isolated to muscles of the moving joint.
  5. Typically performed in non weight-bearing positions.
  6. Resistance is applied to the moving distal segment.
  7. Use to external rotary loading.
  8. External stabilization (manually or with equipment) usually required.

Closed Chain Exercises:

  1. Distal segment remains stationary (fixed in place)
  2. Interdependent joint movement; relatively predictable movement patterns in adjacent joints
  3. Movement of body segments may occur distal and/or proximal to the moving point
  4. Muscle activation occurs in multiple muscle groups, both distal and proximal to the moving joint
  5. Muscle activation occurs in weight-bearing positions
  6. Resistance is applied simultaneously to multiple moving segments
  7. Use of axel loading
  8. Internal stabilization by means of muscle action, joint compression, and congruency and postural control

For example, looking at the photo below.  The movement is the same but the left picture (a squat) is closed chain and the right picture (leg press) is open chain.

All movements can be open or closed chain.  The key is to train what is functional to you.

Let’s bring back the example above.  The squat is more functional because most individuals will be doing this movement everyday.  You sit down.  You pick something up from the floor.  Every time you go to the bathroom, you squat first to sit on the toilet.

And now let’s examine the leg press. How does the leg press exercise carry to real life situation and how often?  Perhaps, sitting down and pushing an object away.  This will probably happen once a week.

In this example, you will want to pick the squat as part of your exercise routine.

Most upper body movement will be open chain exercises and lower body will be closed chain exercises due to functionality.   Therefore, pick exercises based on movement patterns and make sure they are functional.

If you are still confused about open and closed chain exercises, come to our “Strength Training Integration” seminar this coming weekend Feb 26th and 27th at AF Performance Center.  We will be discussing in detail the kinetic chain, practicing all of the exercises you can think of, and going over exercise programming.

To sign up, go to http://www.evo-performance.com/seminars.htm or call at (310) 895-5385.

 

February 21, 2011 Posted by | Uncategorized | , , , , , , , , | Leave a comment

Health tip for week Oct. 19th

  • Avoid doing leg press because it’s dangerous.

Doing leg press machine is not only really bad for you but also not functional.  The leg press is when you sit on the machine at a 45 degree with your back against a pad and your feet on a platform.  You push the platform until your legs are straight and lower the platform by bending your knees again.

leg_pressWhy is bad?

  1. It is dangerous on your lower back.  We need mobility in certain areas of our bodies and we don’t need that in our lower back.  We need stable lower back.  If the hips do not move properly, our low back eventually will hurt.  Dr. Stuart McGill, a low back specialist, states that “any flexion or extension will create a disc to blow.”  It might not happen the 1st, 2nd, or 50th time you perform this exercise, but eventually your low back will “hurt”.  A physiologist, Dr. Michael Yessis, also concurs that the potential danger in this exercise is seen when you, in an attempt to get a greater range of motion, bring the knees in close to the chest on the lowering phase. This, in turn, rounds the lumbar spine and because of the heavy weights typically used, the pressure acting on the spinal discs increases greatly. The high compression forces can cause disc rupture or other low back injury.
  2. The exercise is a completely nonfunctional movement.  Where in real life do you have to push out with your feet to move a heavy object and your back is locked at a 45 degree?  It’s more likely that we are standing on the ground lifting a heavy object, pushing ourselves off the floor (in other words, jumping off the floor), and/or squatting and carrying a heavy object.  There are many other situations but not one leg press movement will imitate any movements that are actually useful in real life.
  3. It causes knee pain and increase injuries in the future.  When you are in a sitting position and pushing heavy weights with your leg, you are strengthening lower body muscles but not teaching certain muscles to stabilize your body.  Muscles have more than one function.  In this situation, your gluteus (butt or glutes) muscle, for instance, will shut down.  There is no way you will fire up those glutes while sitting down.  One big function of the glutes is to stabilize the hip and the hip stabilizes your knees.   So, the leg press causes a neurological dysfunction in your lower body.  Also, the fix position you are forced to be when doing the leg press will cause degeneration and weariness in your knees.  Every time you do a rep in the leg press machine, you are in a fixed range of motion.  The machine fixes you and forces you to do the same exact mechanics/movements in your knees all of the time; therefore, degenerating and wearing out your knees.  While doing squats, the knees always bent slightly different every time and move accordingly to how your body is built.

Recommendation: Do squat instead of leg press.  First, doing leg press is easy.  People love to load up the machine with lots of plate and then say they lifted heavy.  If any of these people could squat even half of what they use in the machine, I would be impressed.  “You get to lift a whole lot of weight without actually accomplishing anything here”, a friend told me this once and it applies here for leg press.  A squat offers all the benefits but a fraction of the dangers.  If you have existing lower-back problems, customize your squat. There are so many different types of squats, find the one that is appropriate and functional to you.  Ask a trainer if you don’t know which ones to do.  The body is meant to function in a certain way so let’s train it the way it needs to be trained.

October 20, 2009 Posted by | Uncategorized | , , , | Leave a comment