8/11/2019 Afinal o que so as Muscle Energy Tecniques?

1/3

Sport | MET

26 Issue 97 July 2011 INTERNATIONAL THERAPIST www.fht.org.uk

Muscle Energy

An additional tool for the physicaltherapists manual therapy toolbox,Muscle Energy Techniques (MET) can help to

release and relax muscles, and promote the

bodys own healing mechanisms.

MET is unique in its application as the

client provides the initial effort while

the practitioner facilitates the process.The primary force originates from the

contraction of soft tissue, which is then

utilised to assist and correct the presenting

musculoskeletal dysfunction.

MET is generally classified as a direct

technique as opposed to indirect

because the muscular effort is from a

controlled position, in a specific direction,

against a distant counter force (usually the

practitioner). One of the main uses of this

method is to normalise joint range, rather

than increase flexibility, and techniques

can be used on any joints with restrictedrange of motion (ROM) identified during the

passive assessment.

The benefits of MET may include:

lRestoring normal tone in

hypertonic muscles

Physical therapists use MET to try to help

relax the hypertonic shortened muscles.

If a joint has limited ROM, then through

the initial identification of the hypertonic

structures, techniques can help to achieve

normality in the tissues. MET applied in

conjunction with massage therapy can be

very beneficial in helping to achieve this

relaxation effect.lStrengthening weak muscles

MET can be used to help strengthen weak,

or even flaccid, muscles, with the client

advised to contract the muscle classified

as weak against a resistance applied by the

therapist (isometric contraction). Timing of

techniques can be varied, for example, the

client resists the movement to approximately

20 to 30 per cent of their capability for five

to 10 seconds, resting for 10 to 15 seconds,

and then repeating the process five to eight

times. This can be improved over time.

lPreparing muscle for

subsequent stretching

In some circumstances, the sport a client

participates in may affect joint ROM.

Most people can benefit from improved

flexibility, and although the focus of MET

is to reach normal ROM, a more intensive

MET approach can beemployed to improve

flexibility beyond this.

This might involve the

client contracting beyond

the standard 10 to 20

per cent of the muscles

capability. Once MET has

been incorporated into the

treatment plan, a flexibility

programme could follow.

lImproved joint mobility

A stiff joint can become a

tight muscle and a tight muscle can becomea stiff joint. When used correctly, MET can

improve joint mobility, even when you are

relaxing the muscles initially. A relaxation

period follows the muscle contraction, which

then helps to achieve the new ROM.

The main effects of MET can be explained by

two distinct physiological processes: post-

isometric relaxation (PIR) and reciprocal

inhibition (RI). Certain neurological

influences occur during MET, but before

considering PIR/RI, it is useful to take into

account the two types of receptors involved

with the stretch reflex (Diagram 1):lMuscle spindles sensitive to change

in length and speed of change in

muscle fibres.

lGolgi tendon organs that detect prolonged

change in tension.

Stretching a muscle causes an increase in

the impulses transmitted from the muscle

spindle to the posterior horn cell (PHC) of

the spinal cord. In turn, the anterior horn

cell (AHC) transmits an increase in motor

impulses to the muscle fibres, which creates a

protective tension to resist the stretch.

But increased tension maintained for a fewseconds is sensed within the Golgi tendon

organs, which transmit impulses to the PHC

and has an inhibitory effect on the increased

motor stimulus at the AHC. This inhibitory

effect causes a reduction in motor impulses

and consequent relaxation. This implies that

the prolonged muscle stretch will increase

overall stretching capability due to the

protective relaxation of the Golgi tendon

organs overriding the protective contraction.

However, a fast stretch of the muscle spindles

will cause immediate muscle contraction

and if not sustained there will be noinhibitory action.

When an isometric contraction is

sustained, neurological feedback through

the spinal cord to the muscle itself results

in post-isometric relaxation (PIR), causing a

reduction in tone of the contracted muscle.

This lasts for approximately 20 to

25 seconds, during which the tissues can

be more easily manipulated to a new

resting length.

During reciprocal inhibition (RI) (Diagram

2), the reduction in tone relies on the

physiological inhibiting effect on antagonists

during the contraction of a muscle. Whenthe motor neurons of the contracting agonist

muscle receive excitatory impulses from

the afferent pathway, the motor neurons

of the opposing antagonist muscle receive

inhibitory impulses from their afferent

pathway. It follows that contraction or an

extended stretch of the agonist muscle must

elicit relaxation or inhibit the antagonist,

and that a fast stretch of the agonist will

facilitate a contraction. The refractory period

also lasts for approximately 20 seconds but,

with RI, it is thought to be less powerful

than PIR. In certain circumstances, use ofthe agonist may be inappropriate due to pain

or injury.

Method of treatmentMET can be used with both acute and

chronic conditions, but intensity and

John Gibbons, sports osteopath, lecturer, and

author, provides an introduction to MuscleEnergy Techniques (MET) before looking at

MET and the hamstrings in more detail

Diagram 1: the stretch reflex

8/11/2019 Afinal o que so as Muscle Energy Tecniques?

2/3

Case studyJames* is a 24-year-old male who plays rugby ata high standard. He has an ongoing right-sided

hamstring injury that has not responded to

conventional treatment. He has had some soft

tissue work on his problematic hamstring with

advice on a stretching programme.

Having initially carried out a thorough

assessment to consider other differential

diagnoses for the cause, rather than purely

treating the presenting pain, I found no

dysfunction present in the lumbar spine,

pelvis, hip or lower limb. James presented with

pain in his right hamstring, located more on

the lateral, central aspect, and he identifiedthe aggravating factor as the movement of

rotation when he played rugby. He was

relatively pain free when running in a straight

line, but if he rotated, changed direction or

passed a ball, then symptoms would worsen.

General assessment ofthe hamstringsThe hip flexion test helps to provide the

practitioner with an overall impression of the

general length of the hamstring muscles. The

client lies in a supine position with both legs

extended. The therapist passively guides theclients left leg into flexion until a point of bind

is felt. The normal range is between 80 and

90 degrees; less than 80 degrees determines

that the length of the hamstrings is held in a

shortened position. However, neural tension of

the sciatic nerve and specific hamstring injury

will also restrict the movement.

The client had 60 degrees of motion in

his right leg, but the symptoms were not

reproduced with the normal hip flexion test.

Assessment of thelateral hamstringsPictures 1 and 2demonstrate a specific testthat I used to determine whether the clients

(not pictured) lateral hamstrings were tight,

and involved a technique that individually

isolated and tested the lateral (biceps femoris)

and medial hamstrings (semitendinosus and

semimembranosus).

The therapist applies an internal rotation

and adduction, while the clients leg is taken

into passive flexion, which isolates the biceps

femoris. If the motion feels restrictive, the

therapist needs to determine whether the range

of motion is less than the original hip flexion

test, and if it is, then the lateral hamstringcan be identified as short. When this test

was carried out on James, it had the effect of

reproducing his symptoms, which indicated

that the biceps femoris is the muscle that is

responsible for his specific symptoms.

MET | Sport

www.fht.org.uk INTERNATIONAL THERAPIST Issue 97 July 2011 27

Techniquesduration of symptoms will determine which

variation of MET is suitable.

lTherapist guides muscle to point of

resistance (point of bind) before releasing

slightly from that position (especially if

the tissue is tender).

lClient isometrically contracts affected

muscle (PIR) or the antagonist (RI) to

approximately 10 to 20 per cent of its

strength capabilities against resistance.

lClient holds contraction for 10 to

12 seconds.

lClient relaxes fully by taking a deep

breath in and, as they breathe out, the

therapist passively guides the specific joint

that lengthens the hypertonic muscle intoa new position, effectively normalising

joint ROM.

lProcess repeated until no further progress

is made (normally three to four times) and

final stretch held

for approximately 20

to 30 seconds.

MET is quite a mild formof stretching when compared

to other techniques, such as

proprioceptive neuromuscular

facilitation (PNF), and MET is

therefore more appropriate for rehabilitation.

Most conditions involving muscleshortening will occur in postural muscles,

since these are composed predominantly of

slow twitch fibres, therefore a milder form of

stretching is perhaps more suitable.

2

1(All pictures are areconstruction using a model)

Diagram 2: reciprocal inhibition (RI)

8/11/2019 Afinal o que so as Muscle Energy Tecniques?

3/3

Sport | MET

28 Issue 97 July 2011 INTERNATIONAL THERAPIST www.fht.org.uk

PICTURES:LOTUSPUBLISHIN

G

Assessment of the medial hamstringsAlthough I was able to determine that it was the right lateral

hamstring, the biceps femoris, that was causing James problem,

to isolate the medial hamstrings in order to investigate whether

they were the restrictive tissue, the clients leg is externally

rotated and abducted, while the hip is being passively flexed

(Pictures 3 and 4).

For many athletes who present with hamstring injuries, it

is important to differentiate between the lateral and medial

hamstrings for a successful rehabilitation programme to be

achieved. A combination of corrective treatment and rest will

help to improve physiological function and sport performance

with a reduced risk of recurrent injury.

John Gibbons, sports osteopath, lecturer, author, and regular speaker/contributor

to FHT, owns Peak Sporting Performance at Oxford University Sports. His new

book, Muscle Energy Techniques, a Practical Guide for Physical Therapists, will be

available in September 2011 from Lotus Publishing (www.lotuspublishing.co.uk),

Physique and Amazon. T. 07850 176600 www.peaksport.co.uk

5

6

4

MET PIR treatment of thehamstrings (non-specic)James needs his right biceps femoris lengthened to the normal

ROM, and to achieve this, the hip needs to be taken into a

rotation (as above), and from this position an MET for the

specific muscle can be performed. It is important that the

hamstrings are treated in a position that is related to the clients

sport and the position that may have caused the initial trauma.James injured his right hamstring while rotating his trunk to the

left to pass the ball.

The following technique is very good for lengthening the

hamstrings as a group. The therapist adopts a standing

posture and passively guides the clients right leg into hip flexion

until a bind is felt in the hamstrings. From this position, the

clients lower leg is placed onto the therapists right shoulder

(Picture 5).

The client pushes down against the shoulder of the therapist

for 10 seconds. After the contraction of the hamstrings and

during the relaxation phase, the therapist passively takes the

right leg into further flexion (Picture 6).

To apply a RI method at this point, the client would flextheir hip while the therapist encourages passive hip flexion. This

involves the client contracting the hip flexors, which causes a

reciprocal inhibition in the hamstrings and promotes relaxation,

thereby helping achieve an increased ROM and new position.

*The clients name has been changed.

3