In the previous (#4 in this series) article we followed a simple assessment routine in which by using abduction of the leg as a model it was possible to learn to assess the point at which ‘bind’ or increased tension began.
Since the normal excursion of the straight leg into abduction is around 45º it is possible, by testing both legs in the manner described, to quickly evaluate whether they are both tight and short, or whether one is and the other is not. Even if both are tight and short one set of muscles may be more restricted than the other and this is the one to treat first, possibly using one of the various Muscle Energy Techniques (MET) which this article will describe.
It is suggested that before using MET clinically you practice performing palpation exercises for ‘ease’ and ‘bind’ on many muscles, until you are comfortable with your skill in palpating changes in tone. Subsequent articles in this series will explore assessment methods for shortness in specific muscles in greater detail.
Different Starting Points for MET
In order to use MET successfully the identification of the first sign of the barrier of resistance - where bind is first noted - is necessary - either as the starting point for MET in treating acute conditions, or as a marker when a starting point short of the barrier is selected in treatment of chronic conditions.
Goodridge continues his beginners exercise in MET application as follows:
‘By individually abducting the legs of the supine patient the operator compares the arc on one side with the arc produced on the opposite side. For example, if the abducted right femur reaches resistance sooner than the left, then restriction of abduction exists on the right. To reduce this restriction, the patient's limb is positioned in that arc of movement, where resistance is first perceived, and at this point the operator employs MET to lessen the sense of resistance, and increase the range of movement.’1
How is MET Used?
The following exercises in MET variations include the key features emphasised by some of the leading contributors to MET methodology.
Post Isometric Relaxation (PIR).
Having established the barrier of resistance where, in Goodridge’s words, ‘resistance is first perceived’:
- The patient/model is asked to use no more than 20% of their available strength to try to take the leg gently back towards the table, i.e. to adduct the leg, against your firm, unyielding resistance.
- In this example they are trying to pull the limb away from the barrier, while you hold it at the barrier.
- The patient/model should be using (contracting) the agonist, the muscle(s) which requires to be released because its shortness is preventing a full range of movement. In this example it is the inner thigh muscles, adductors and medial hamstrings which need releasing and which therefore are asked to contract during MET.
- As the patient holds the light contraction they are commonly asked to hold their breath.
- The isometric contraction should be introduced slowly and resisted without any jerking, wobbling or bouncing.
- Maintaining the resistance to the contraction should produce no strain in the operator.
- The contraction should be held for at least 7, and ideally 10, seconds - the time it is thought necessary for the ‘load’ on the Golgi tendon organs to become active and to neurologically influence the intrafusal fibres of the muscle spindles which inhibits muscle tone, so providing the opportunity for the area (muscle, joint) to be taken to a new resting length/resistance barrier without effort, or to stretch it through the barrier of resistance, if this is appropriate (see below).2