Strength vs. Motor Patterns — The Nitty Gritty

By Pam Marshalla

Q: I was at the IAOM convention in the fall of 2013, and I heard you speak on oral stability. You used your hands to describe the difference between oral strength and oral movement patterns. Can you post it here? I would like to share it with my colleagues and I can’t remember what you said.

This is probably the best way I have discovered to describe the difference between movement patterns and strength of movement.

Hand Movement vs. Hand Strength

Extend you arm forward and make a gentle fist. Now open your hand so the fingers extend.  Now do this several times in a row: Fist-open-fist-open-fist-open… This is the pattern of flexion and extension (fisting and opening).  To grasp an object we first extend to open the hand and then we flex to close the hand around the object.  The sequencing of extension and flexion is a basic movement pattern that humans use every day.  We can extend and flex with our hands, arms, legs, feet, head and neck, trunk, and so forth.

Now take your fist and grasp as hard as you can.  Fist really hard.  This is a representation of hand strength that can be measured.  Some of us can fist very hard and others not so much, but in either case we are talking about strength of fisting the hand.

I hope you can realize the difference between the two.  Opening and closing the hand is a movement pattern.  Fisting the hand with gusto represents its strength.

Oral Movement vs. Oral Strength

Now elevate your tongue-tip to your alveolar ridge to put it in position for L.  Then lower it and say Ah.  Now do it several times in a row: La-la-la-la…

This is another example of the flexion-extension pattern.  The tongue flexes (curls) upward so the tip can reach the alveolar ridge, and then it extends (lays back down) so that Ah can be produced.  “La-la-la-la” is flex-extend-flex-extend…  That is the movement pattern.

Now take your tongue-tip, place it on the alveolar ridge, and press it up there as hard as you can.  This is a representation of the tongue’s strength.  It is a force that can be measured.  Some of us have very strong tongues, and others less so.

I hope you can see that when we say La-la-la-la, very little actual strength is involved.  In fact very strong upward movement of the tongue will impair production of this sequence.  The upward movement of the tip needs to be soft, gentle, light, and refined.  It is this gentle movement pattern that is important, not the strength or power of upward movement.

Strength and Speech

Research shows that oral strength is not a problem when it comes to clients with articulation deficit, phonological delay, or apraxia.  There is no need to work on oral strength in these clients.  They need to learn the movement patterns.  They do not need stronger movements.

Limited oral strength is only a problem in dysarthric clients.  Strength within the oral mechanism can be so low in some dysarthric patients that they cannot lift the tongue at all.  Others can lift the tongue, but it is weak, shaky, and tremulous, with limited excursion and restricted capacity to hold positions firmly.  In such cases we work on strength so the client can attain enough movement to achieve the required oral position.

A clear understanding of what needs to be fixed is what guides therapy.  Does the client have weak muscles and therefore need help with strength so that he can achieve these movements?  Or does he simply need to learn the motor patterns themselves?   For most of our clients, it is the latter.

3 thoughts on “Strength vs. Motor Patterns — The Nitty Gritty”

  1. Thank you for this post. I am happy that you have this site. I always learn something new from it or it confirms what I am doing.

    Georgia

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