MET Flashcards
What is M.E.T
Muscle energy techniques are a form of soft-tissue, or joint, employed in the treatment of musculoskeletal dysfunction.
Aims to improve the immediate range of motion in a joint.
Uses of M.E.T
Reduce pain
Stretch tight fascia
Reduce localized edema
Mobilize an articulation with restricted mobility
Strengthen a physiologically weakened muscle(s)
Lengthen a shortened, fibrotic, or spastic muscle
Uses in acute Vs chronic injuries
In acute conditions the isometric contraction starts at the barrier, whereas in chronic conditions the contraction starts short of thebarrier.
Use of the antagonists to the affected muscle(s) offers an alternative to activation of an isometric contraction in such muscles ifthis proves painful or difficult for the patient to perform.
Isometric contration vs Isotonic
Isometric contraction is contraction of the muscle against a counterforce so that no movement occurs.
Isotonic contraction when contraction of muscle with same tension but changing length either shorter (Concentric Isotonic) or lengthening (Eccentric Isotonic)
Concentric Isotonic Contraction
Occurs when the therapist’s counterforce is weaker than the contractile force
allowing some movement to occur in the direction of the muscle force, therefore shortening and strengthening the muscle.
This technique is used to strengthen physiologically weak muscles.
Eccentric Isotonic Contraction
occurs when the therapist’s counterforce is stronger than the contractile force of the muscle and stretching and lengthening occur in the muscle tissue.
This is effective in short, fibrotic muscles allowing a controlled microtrauma to the muscle.
This results in a change to the muscles shortened structure and improves elasticity and circulation.
Two forms of isometric MET are :
Post-Isometric Relaxation (PIR) and
Reciprocal Inhibition (RI).
PIR
The muscle will be taken to a length just short of pain, or to the point where resistance to movement is first noted.
A contraction of 10-20% is performed away from the barrier for between 7-10 seconds and the therapist applies resistance in the opposite direction.
Patient should relax and inhale and exhale after this.
There will be a refractory period of 25 seconds where you are able to move more into the new barrier.
This should be repeated 3 times. After the 3rd time, just hold at end range for about 20 seconds.
In the refractory period, 15-25 seconds of mobilisation can be done to help mobilise the joint even more.
PIR
A strong muscle contraction against equal counterforce triggers the Golgi tendon organ (at Musculotendinous Jct & monitors for excessive tension)
The afferent nerve impulse from the Golgi tendon organ enters the dorsal root of the spinal cord and meets with an inhibitory motor neurone.
This stops the discharge of the efferent motor neurone’s impulse and therefore prevents further contraction, the muscle tone decreases, which in turn results in the agonist relaxing and lengthening.
Reciprocal inhibition (RI)
Use of the antagonists to the affected muscle(s) offers an alternative to activation of an isometric contraction in such muscles if this proves painful or difficult for the patient to perform.
Used when symptoms are acute and too painful to act on muscle directly.
This happens due to stretch receptors within the agonist muscle fibres – muscle spindles.
Muscle spindles work to maintain constant muscle length by giving feedback on the changes in contraction, in this way muscle spindles play a part in proprioception.
In response to being stretched, muscle spindles discharge nerve impulses, which increase contraction, thus preventing over-stretching.
The spindles discharge impulses which excite the afferent nerve fibres or the agonist muscle, they meet with the excitatory motor neurone of
the agonist muscle (in the spinal cord) and at the same time inhibit the motor neurone of the antagonist muscle which prevents it from contracting.
RI
RI refers to the inhibition of the antagonist muscle when isometric contraction occurs in the agonist.
This happens due to stretch receptors within the agonist muscle fibres – muscle spindles.
Muscle spindles work to maintain constant muscle length by giving feedback on the changes in contraction, in this way muscle spindles play a part in proprioception.
In response to being stretched, muscle spindles discharge nerve impulses, which increase contraction, thus preventing over-stretching.
The spindles discharge impulses which excite the afferent nerve fibres or the agonist muscle, they meet with the excitatory motor neurone of
the agonist muscle (in the spinal cord) and at the same time inhibit the motor neurone of the antagonist muscle which prevents it from contracting.
Guidelines to an MET
3-5 repetitions for 7-10 seconds each
20-50% of muscle strength
Isometric contraction should not be too hard
However, Isotonic contraction requires forcefulcontraction
Post contraction, a momentary pause should occur – a breath and stretch further.
Breathing during MET
Hold the breath during 7-10 sec ????
Inhale slowly as isometric contraction builds up
Release the breath as Pt slowly cease the contraction
Inhale and exhale fully once more following cessation of all effort
MET key points
- Patient : active muscle contraction
- Controlled joint position
- Controlled contraction intensity
- Muscle contraction in a specific direction
- Operator-applied distinct counterforce
- Refractory Rest Period of few seconds before stretch to new barrier
- Hold stretch for up to 30 seconds but no evidence of gains past stretch of 3-5 seconds
Bind
When muscle resistance is first felt.
