Muscle lengthening

Question 1

Why does tension decrease significantly when you increase muscle length beyond a certain point?
( Use tension muscle length graph)

Answer 1

This is as the sarcomeres will be at such a great length that only two myosin heads will be able to interact with actin filaments. Thus meaning little ATP will be produced resulting in a weaker muscle contraction and less tension.

Question 2

Explain why muscle tension is at its peak midway through the muscle length tension graph.

Answer 2

This is because the sarcomeres are closer together but not too close that they cross over and stop actin and myosin heads interacting. Therefore meaning this is the peak as all 16 myosin heads can interact with the actin so the most ATP will be produced here creating the strongest muscle contraction and must tension.

Question 3

Explain why muscle tension is at its lowest when the muscle is short.

Answer 3

Muscle tension is low when the muscle length is short as the sarcomeres will cross over preventing some actin and myosin filaments interacting. So less ATP will be produced thus meaning a weaker contraction and less tension.

Question 4

Outline 3 ways you could alter a patients muscle length and explain how you would carry out each one.

Answer 4

Stretching (Active and Passive)
MET
Strengthening

Question 5

Why do you want to lengthen a patients muscles?

Answer 5

As it can improve posture, prevent injury and reduce pain

Question 6

How does stretching lead to muscle lengthening?

Answer 6

Viscoelastic stress relaxation
Soft tissue creep
Also as it helps the muscle fibres in the connective tissue realign which will allow the tick and thin myofilaments to overlap lengthening the muscle.

Question 7

What is the most effective way to do a stretch?

Answer 7

15-30 seconds

2-4 reps

Question 8

Define muscle energy technique.

Answer 8

A muscle energy technique is a technique that uses the muscles own energy to relax the muscles via autogenic or reciprocal inhibition which will lead to the muscle lengthening.

Question 9

What is Autogenic inhibition?

Answer 9

1. The muscle will contract or stretch and the golgi tendons in the muscle will sense increased tension.

2 This will activate the golgi tendon and it will respond by activating the antagonist muscle and preventing the contraction of the agonist.

Question 10

How does Autogenic inhibition help lengthen the muscle?

Answer 10

Autogenic inhibition will help to lengthen the muscle as it will the golgi tendon response will inhibit the muscle spindle in the stretched muscle temporarily which will make it easier to stretch the muscle further.

Question 11

What is reciprocal inhibition

Answer 11

Reciprocal inhibition is when the muscle spindles stretch with the muscle which will cause the neural drive of the agonist to increases and the neural drive in the antagonist to decrease. This in turn will lead to the agonist contracting and the antagonist relaxing.

Question 12

How does reciprocal inhibition help to lengthen muscles?

Answer 12

Reciprocal inhibition helps to lengthen muscles as it will help to strengthen them as it will cause the muscle to have more forceful contractions.

Question 13

Identify the two different types of MET.

Answer 13

1. Autogenic MET
   There are two types of autogenic inhibition METs these are:
   - post isometric relaxation
   - post facilitation stretching
2. Reciprocal inhibition MET

Question 14

Explain how you would carry out post isometric relaxion on a patient.

Answer 14

1. Take the hypertonic muscle to a length just short of pain or resistance.
2. The patient should then try to do the painful or stiff movement whilst the therapist resists pushing the other way.
3. Afterwards let the patient relax for 10 seconds an take a deep breath in and out.
4. Then ask the patient to go to the new point of resistance and go again 3-4 times each one lasting about 10 seconds.

Question 15

Explain how you would carry out post facilitation stretch on a patient with muscle stiffness.

Answer 15

1. Place the hypotonic muscle inbetween a relaxed and fully stretched phase.
2. Then ask the patient to contract the agonist muscle for 5-10 seconds whilst the therapist resists the movement.
3. The patient will then be asked to relax as the muscle will be stretched to the new barrier of resistance by the therapist.
4. Next allow the patient to relax for 20 seconds before repeating 3-5 times.

Remember to place the muscle inbetween a fully stretched and relaxed state at the start of every repetition.

Question 16

Explain how you would carry out reciprocal inhibition on a patient who has lack of ROM.

Answer 16

1. Place the affected muscle in mid range.
2. Ask the patient to push the muscle to the resistance barrier whilst you resist it.
3. Allow the patient to relax whilst you stretch them to the new barrier of resistance.
4. Repeat this 3-5 times.