EVMM Proprioceptors

Question 1

The function of proprioceptors in general

Answer 1

Give info about movement and position of the body and stimulate muscle reflexes

Question 2

Location of GTOs, what stimulates them and the effect of their stimulation

Answer 2

Musculotendinous junction, stimulated by muscle contraction and causes muscle to relax

Question 3

Define autogenic inhibition

Answer 3

Contraction of a muscle stimulates the GTO which cause relaxation of the muscle

Question 4

The functions of GTOs (2)

Answer 4

1. Monitor contraction

2. Cause muscles to relax

Question 5

How we ensure that our HVLA will stimulate the GTOs more than the MSCs

Answer 5

Joint is brought into tension

Question 6

Location of MSCs, what stimulates them, and the effect of their stimulation

Answer 6

• Middle of skeletal muscle fiber (muscle belly)
• Monitor changes in length of the muscle (stimulated by Stretch)
• Cause muscles to contract, cause synergistic muscles to contract, cause inhibition of antagonistic muscles

Question 7

3 parts of the MSC

Answer 7

1. Intrafusal fibers
2. Ia sensory neurons
3. Gamma motor neurons

Question 8

The characteristics of the Ia sensory fiber (large, small myelinated, unmyelinated)

Answer 8

Large diameter, myelinated

Question 9

The characteristics of the alpha motor neuron (large, small, myelinated, unmyelinated)

Answer 9

Large diameter, myelinated

Question 10

The significance of the Ia synapsing directly on the alpha motor neuron

Answer 10

Makes for a very fast transmission

Question 11

4 destinations of the Ia sensory fiber

Answer 11

1. Alpha motor neurons to the same muscle
2. Alpha motor neurons to synergistic muscles
3. Inhibitory interneurons to antagonistic muscles
4. Gamma motor to the same muscle

Question 12

In the patellar reflex why does the quick tap of the reflex hammer stimulates the MSC yet our HVLA stimulates the GTOs?

Answer 12

MSC – stretch reflex on a relaxed muscle, tap stretches the muscle more than the tendon and stimulates the Ia afferents leading to contraction
HVLA – joint in tension – fast stretch on tendon – GTO’s stimulated leading to muscle relaxation

Question 13

Define co-contraction and its effect

Answer 13

Contraction of both agonist and antagonist muscles – effect of stabilizing the joint

Question 14

How the Ia is able to provide information at all muscle lengths

Answer 14

Co-contraction

Question 15

Define gamma gain

Answer 15

Level of gamma motor activity

Question 16

Define high gamma gain

Answer 16

Small amount of stretch leads to a large increase in muscle tension

Question 17

Define low gamma gain

Answer 17

Large amount of stretch needed to result in the same amount of muscle tension

Question 18

4 functions of muscle tone

Answer 18

1. Stay upright against gravity
2. Keep center of gravity with in the base of support
3. Store energy
4. Allow for smooth movement

Question 19

How low gamma gain can lead to injury

Answer 19

Low gamma gain means the muscle will stretch more before the MSC responds. This means that the joints will have less support and can move beyond their normal ROM

Question 20

5 effects of clearing restrictions

Answer 20

1. Joints with normal ROM
2. Good muscle tone
3. Elasticity
4. Free of pain
5. MSC function well to keep brain healthy and the brain keeps the body moving – patients move freely