Monday, March 13, 2006

3 Common OMT Techniques

Source:http://www.md-do.org/NewOMMBoard%20Review02-REV.htm

Muscle Energy: (Golgi tendon organ reflex). (Direct method). A pull on the tendon sends signal from the Golgi tendon organ to spinal cord. At the spinal cord inhibitory interneurons synapse with alpha motor neurons causing a reflex relaxation of the muscle. When tension on a tendon becomes extreme the inhibitory effect from the organ can become so great it causes a sudden relaxation of the entire muscle. Golgi tendon organs respond to rate and changes in muscle tension. Summary: Activation of large myelinated group 1b afferent fibers from tendon insertion reflexively inhibits alpha motor neuron to muscle spindle. Buzz: Golgi, alpha motor neurons, tension/force, direct technique. Primary source: Kuchera and Kuchera, OPP



Counterstrain: Decrease gamma gain: "...stop inappropriate proprioceptor activity... shortening the muscle that contains the malfunctioning muscle spindle by applying a mild strain to its antagonist." (Jones) This is an indirect technique that employs the Muscle spindle reflex. This reflex responds to rate and changes of intrafusal fiber length. Hypershortening the extrafusal fibers by bringing the origin and insertion of the muscle mass closer together, decreases the length of the intrafusal fibers and relaxes them. This relaxation phase is followed by a slow return to neutral in order to allow the CNS to reset the gamma gain activity in the spindle to a new lower level. The end result of counterstrain on the muscle spindle fibers is a turning down of the gamma gain. Remember: Position of ease, slow return after 90 seconds. Red herrings: C3 posterior put into flexion. C4 anterior put into extension, inion put into flexion, lower pole L5 put into flexion. Key words: proprioceptor, gamma gain. Note: FPR also employs the muscle spindle reflex. Primary source: Kuchera and Kuchera, OPP



HVLA: Can involve both the Golgi tendon organ and muscle spindle reflex. HVLA may produce changes in muscle tension and length of muscle spindles.

1. Thrust activation initiates so much afferent input into the CNS, causing the CNS to turn down the gamma gain to the muscle spindles, which relaxes the tight muscle mass.

2. During a thrust the tension on the tight muscle firmly pulls on the tendon. This activates the Golgi tendon receptors, which in turn causes a reflex relaxation to that tight muscle.

3. The stretch of the extrafusal fibers of the tight muscle pulls on the Golgi tendon receptors, which will cause a reflex activation to inhibit the contraction of the same muscle.

4. HVLA of 1/8” to 1/4” of forceful stretching of a contracted muscle may produce such a barrage of afferent impulses from the spindles to the CNS causing the CNS to respond by sending inhibitory impulses to the gamma gain cell bodies. This turns down the gamma gain activity to the spindles, thus relaxing the muscle mass via a central inhibitory reflex. Kuchera and Kuchera, OPP

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