In this article it is my intention to start to explore the process of assessment and treatment of shortened postural muscles – the importance of which cannot be over stated when we consider the pains and dysfunctions of the musculoskeletal system.
Lewit summarises what manipulation [osseous or soft tissue] is concerned with,’restricted mobility’, with or without pain’.
Evjenth is equally succinct about what is needed to become proficient in treating patients with symptoms of pain or what he calls ‘constrained movement’ –
‘Experience gained by thoroughly examining every patient and restoration of muscle’s normal pattern of movement with freedom from pain’.
Janda is mainly concerned with ‘imbalances’ and the implications of dysfunctional patterns in which some muscles become weaker and others progressively tighter.
- ‘Restricted mobility’
- ‘Restoration of normal patterns of movement’
- ‘Implications of imbalance and dysfunctional patterns’
These key phrases highlight different aspects of the same situation in which an area has become dysfunctional, with aspects of an anatomical unit (say a joint) being unsynchronised, some of its muscular attachments and influences being hypertonic, short or restricted while others are weakened. The all too common ‘chain reaction’ of problems which such imbalances lead to is one which we can actually learn to ‘read’ by means of observation and palpation.
Grieve speaks of symptoms arising from “gradual decompensation demonstrating slow exhaustion of the tissue’s adaptive potential, with or without trauma”. He says that while treatment of specific tissues incriminated in producing such symptoms often gives excellent short-term results, “unless treatment is also focused towards restoring function in asymptomatic tissues responsible for the original postural adaptation and subsequent decompensation, the symptoms will recur”
Take someone with an anatomical short leg who has, superimposed on the adaptations which this calls, for additional demands caused by occupational, recreational, emotional or postural stresses. While attention to the results of these secondary stress factors would be helpful, until the underlying adaptation pattern was evaluated and helped, problems would be likely to recur.
Learning to evaluate and make sense of the patterns of adaptive dysfunction which result demands an understanding of the way different structures respond to acute and chronic forms of stress.
The Importance of Muscle Shortness.
Janda tells us that tight muscles usually maintain their strength, however in extreme cases of tightness some decrease in strength occurs. In such cases passive or active stretching of the tight muscle usually leads to a rapid recovery of strength (as well as toning of their antagonists because of the removal of reciprocal inhibition). It is therefore important that we learn to assess short, tight muscles in a standardised manner.
It is in shortened muscles, as a rule, that reflex activity is noted. This takes the form of local dysfunction, variously named as trigger points, tender points, zones of irritability, neurovascular and neurolymphatic reflexes etc.
and identification of these is possible via normal palpatory methods. Identification and treatment of tight muscles may also be carried out systematically.
Different Response to Stress of Postural and Phasic Muscles
One of the most important revelations over the past two decades has come from research by Lewit, Korr, Janda, Basmajian, and others which shows that muscles which have predominantly stabilising functions will shorten when stressed while others which have more active ‘moving’ or phasic functions will not shorten but will become weak (inhibited).
The muscles which shorten are those which have a primarily postural rather than a phasic (active, moving) role and it is possible to learn to conduct, in a short space of time (ten minutes or so) an assessment sequence in which the majority of these can be identified as being either short or normal.
Janda informs us that postural muscles have a tendency to shorten, not only under pathological conditions but often under normal circumstances. Postural muscles are genetically older; they have different physiological, and probably biochemical, qualities compared with phasic muscles which normally exhibit signs of inhibition in response to stress or pathology.
Those muscles which shorten in response to stress comprise the following:
Gastrocnemius, soleus, medial hamstrings, short adductors of the thigh, hamstrings,psoas, piriformis, tensor fascia lata, quadratus lumborum, erector spinae muscles, latissimus dorsi, upper trapezius, sternomastoid, levator scapulae, pectoralis major and the flexors of the arms.
The scalenes are a borderline set of muscles – which start life as phasic muscles but which can become through overuse/abuse more postural in their function.
It is now becoming clear that the function of a muscle can be modified – which helps to explain some mysteries – for example why the scalenes are sometimes short and sometimes weak and sometimes both, and yet are classified generally as phasic muscles and sometimes as ‘equivocal’ – maybe postural and maybe phasic’.
Lin, writing in The Lancet examined motor muscle physiology in growing children reviewing current understanding of the postural /phasic muscle interaction and reported that, ‘Buller and Eccles have shown that a committed muscle-fibre type could be transformed from slow-twitch to fast-twitch and vice-versa in their cross innervation experiments, confirming that impulse traffic down the nerve conditions the fibre type’.
The implication of this is that if a group of muscle such as the scalenes are dedicated to movement can, through stress such as occurs i constant upper-chest breathing for example, become ‘postural’ in type, and will therefore develop a tendency to shorten if stressed.
Characteristics of Postural and Phasic Muscles:
|Postural Muscle||Phasic muscles|
|Type||slow twitch – white||fast twitch – red|
All muscles comprise both red and white, fast and slow, fibres which produce both postural and phasic functions, however the classification of a muscle into either a ‘postural’ or ‘phasic’ group is made on the basis of their predominant activity, their major functional tendency.
Janda has shown that before any attempt is made to strengthen weak muscles using exercise, any hypertonicity in their antagonists should be addressed by appropriate treatment, for example by stretching using Muscle Energy Technique (to be described in future articles).
Stretching and releasing a tight hypertonic muscle leads to an automatic regaining of strength of its antagonists. If the hypertonic muscle is also weak it commonly regains strength following stretch/relaxation.
Chiropractic rehabilitation expert, Craig Liebenson states:
‘Once joint movement is free, hypertonic muscles relaxed, and connective tissue lengthened, a muscle-strengthening and movement coordination program can begin. It is important not to commence strengthening too soon because tight, overactive muscles reflexively inhibit their antagonists, thereby altering basic movement patterns. it is inappropriate to initiate muscle strengthening programs while movement performance is disturbed, since the patient will achieve strength gains by use of ‘trick’ movements’.
A Common Phenomenon Even Amongst Athletes
Just how common such imbalances are was illustrated by Schmid who studied the main postural and phasic muscles in 8 members of the male Olympic ski teams from Switzerland and Liechtenstein.
He found that amongst this group of apparently superbly fit individuals fully 6 of the 8 had demonstrably short right iliopsoas muscles, while 5 of the 8 also had left iliopsoas shortness and the majority also displayed weakness of the rectus abdominus muscles. The conclusion was that athletic fitness offers no more protection from muscular dysfunction than does a sedentary lifestyle.
Important Notes on Palpation/Assessment of Short Muscles
When the term ‘restriction barrier’ is used in relation to soft tissue structures it is meant to indicate the first signs of resistance (as palpated by sense of ‘bind’, or sense of effort required to move the area, or by visual or other palpable evidence) not the greatest possible range of movement obtainable.
As an example let us take evaluation for shortness of the adductors of the thigh, as described by John Goodridge D.O. Before starting ensure that the patient/model lies supine, so that the nontested leg is abducted slightly, heel over end of table. The leg to be tested is close to the edge of table. Ensure that the tested leg is straight, not in rotation, knee in full extension.
1. ‘After grasping the supine patient’s foot and ankle, in order to abduct the lower limb, the operator closes his eyes during the abduction, and feels, in his own body, from his hand through his forearm, into his upper arm, the beginning of a sense of resistance’.
2. ‘He stops when he feels it, opens his eyes, and notes how many degrees in an arc, the patient’s limb has travelled.’
Goodridge is trying to establish that you sense the very beginning of the end of range of free movement, where easy motion ceases and effort on the part of the operator moving the part begins. This ‘barrier’ is not a pathological one, but represents the first sign of resistance, the place at which tissues require some degree of passive effort to move them.
This is also the place at which a sense of what is called ‘bind’ can be palpated.
Try this exercise several times, so that you get a sense of where resistance begins.
Then do the exercise again as described below.
Stand between the patient’s partially abducted leg and the table, facing the head of the table, so that all control of the tested leg is achieved by using your lateral arm/hand which holds and supports the leg at the ankle while your table-side hand rests on the inner thigh, palpating the muscles which are being tested. This palpating hand (often called a ‘listening’ hand in osteopathy) must be in touch with the skin, moulded to the contours of the tissues being assessed, but should exert no pressure, and should be completely relaxed.
Abduction of the tested leg is introduced passively by the outside hand/arm, until the first sign of resistance (‘effort’) is noted by the hand which is providing the motive force, i.e. the one holding the leg.
As you approach this point of resistance can you sense a tightening of the tissues in the mid-inner thigh which your table-side hand is touching?
This is ‘bind’. If this sensation is not clear then take the leg back towards the table and out again but this time go past the point where easy movement is lost and effort begins, and towards its end of range. Here you will certainly sense ‘bind’. As you once more take the leg back towards the table you will note a softening, a relaxation, an ‘ease’, in these same tissues.
Go through the same sequence with the other leg, becoming increasingly familiar with the sense of these two extremes, and try to note the very moment at which you can palpate the transition from ease to bind, not the extreme range of movement but where it first begins, whether you are moving from ease to bind or the other way. Normal excursion of the straight leg into abduction is around 45º, and by testing both legs in the manner described you can 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 may be more restricted than the other.
The point at which you first feel bind (or where the hand carrying the leg feels the first sign that effort is required) is the resistance barrier which will be referred to over and over again in future articles, it is the place where an isometric contraction can be introduced when Muscle Energy release methods are used, as will be outlined in future articles.
Leon Chaitow DO practices at The Hale Clinic London (0171-631-0156). He teaches widely in the UK, Europe and the USA, and is author of major textbooks including ‘Soft tissue Manipulation’ (available from Green Library). He is a senior lecturer on the University of Westminster’s MA in Therapeutic Bodywork.