Monday, May 14, 2007

The link between core stability, strength, endurance, flexibility and posture

The link between core stability, strength, endurance, flexibility and posture -
From Rowing & Regatta Magazine, Jan 2006, pp 26-27
If you took time to sketch a good body-position at the finish of a rowing or sculling stroke it is likely that it will have a perfectly straight back, and can pivot from the hips. Yet rowers in real life are more complicated than this; they have a pelvis that tilts, and a spine that bends!

Whether rowing or coaching, you need to be aware of the movements of the pelvis and spine, particularly the lower back (lumber spine). The degree of bend and development of bend at the lower back vs the pivot of the hips is known as the lumbo-pelvic rhythm.

When looking out for rowing technique, it can help to think of rowers as being like the slightly more complex stick man pictured;

Good body position at the finish
The back is straight and in a strong position. The pelvis and lumber spine are lined up with each other. There is no slumping.

Poor body position at the finish
In this example, the rower is slumped at the finish. Their pelvis is rotated backwards and is not in line with their lumber spine. They will be sitting on the fleshy part of their bottom. They are also bending (flexing) their lumber spine.

Look out for movement in a rower’s lumber spine and pelvis; is their pelvis slumped? Is their lumber spine flexed? Does this happen as they get more tired?

Rowers have muscles!
Unlike stick men, rowers have muscles. They can be big or small, active or inactive, strong or weak, have high or low endurance, be involved in moving or in stabilizing, and be stronger or weaker than opposing muscles. That’s a lot of complexity! When writing a training program coaches often focus on developing muscles strength and endurance rather than considering other ways to training muscles.

For example you need to train your core trunk muscles to be active and to develop their strength and endurance. This involves training both the deep stabilizing muscles and the other abdominal muscles; to better balance your trunk strength and endurance with your back strength and endurance.

Muscular imbalance and weakness affect flexibility, rowing posture and technique. Good examples of this are the hamstring muscles and hip flexors. If rowers neglect to develop the muscles that stabilize the pelvis, the hamstrings and hip flexors will take up the role of stabilizers and be more active which over time, can lead to them shortening. Many rowers have short hamstrings and hip flexors. Freeing these muscles from overwork (by activating and training the stabilizing muscles) means they can stretch and lengthen, which will allow the postures required for good rowing technique to be achieved and maintained. You must train stability, strength and endurance to allow the muscles to be stretched.

What do the hamstrings do?
The hamstrings shorten to extend the thigh and flex the knee, and help to extend the hips so the opposite movements to these can be used as stretches.

What will stretch hamstrings?

Develop core stability, strength and endurance first!
The hamstrings can be lengthened ad stretched by combinations of;
-Pivoting forwards from the hips (trunk flexion)
-Raising the knee (hip flexion)
-Extending the leg at the knee (leg extension)

What to Do in Practice…

1. Learn how to activate the appropriate muscles
Rowers have releatively weak trunk flexors in comparison to their back extensor muscles. Make sure that you develop an ability to activate the deep stabilizing muscles of the spine (core stability) and trunk muscles (flexors and extensors) and then develop their strength and endurance.

2. Look out for the lumbar spine
If you are a coach, think of rowers as being more than complicated stick figures (pictured); observe the amount of pelvic tilt and any bend at their lumbar spine, and note when this occurs in the recovery.

If you are a rower get your coach to video you and to look at the body movement that you obtain; is it pivot from the hips, or are you compensating and bending from the lumbar spine or reaching from the shoulders?

3. Monitor the effects of fatigue!
Rowers might start off with good stickman-esque posture in an outing, but poor core stability, trunk strength and/or endurance may mean that their body positions and sequencing degrades.

Capture some video early in the outing and some towards the end; are there changes in the postures? For how long can the posture be maintained?

With fatigue and at higher rates, rowers tend to tilt their pelvis forward less coming to the catch, and increase the bend at their lower back to compensate, making the spine work through a larger range of motion; look out for changes throughout and outing.

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