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).