SOFT TISSUE MASSAGE THERAPY KEY FEATURES OF MET AND PNF

MET n Lengthens contracted or spastic muscle n Strengthens physiologically weakened muscles n Reduces localised oedema n Mobilises ROM of joints with restricted mobility n Based on recruitment of postural muscles that are more susceptible to shortening and require stretching.

PNF n Manual resistance technique n Simulates patterns of movement to oppose motion in multiple planes at same time n Useful for stroke victims, children with cerebral palsy, and various orthopaedic conditions n Promotes functional movement through facilitation, inhibition, strengthening and relaxation of muscle groups n Uses patient-specific concentric, eccentric and static muscle contractions

in their clinical application. To date there is little research comparing them, and the lack of consensus and consistency among studies, combined with the development of both techniques at similar times, has resulted in an overlap between MET and PNF in many studies (10).

The rationale behind MET The initial definition of MET involved “resistive duction”, involving the application of pulsed contractions emerging from osteopathic traditions (11). However this is now termed as “pulsed MET” because it contradicts the modern approach that involves the application of slow controlled stretches in a specific direction. At about the same time the technique of PNF was being developed, at which point a number of inconsistencies in terminology arose within studies of the two approaches. To date there are few articles on the topic of MET, and only limited published research. There are few randomised controlled trials or peer-reviewed papers that substantiate the theory and support or validate its clinical use. Most

GLOSSARY OF TERMS Based on Adler 2003 (cited in Chaitow 2001), Chaitow 2001 (9), Sharman et al 2006 (19) Contract relax Contraction (approximately 75%) of the muscle being stretched

Hold relax Contraction (approximately 75%) of the opposing muscle to the one being stretched Modified PNF Immediate isometric contraction (approximately 75%) of specified muscle

Muscle energy technique (MET) Contraction (approximately 25%) to recruit postural muscles that are more susceptible to shortening and require stretching

Post-isometric relaxation (PIR) Slow isometric contraction (approximately 25%) of the muscle being stretched Proprioceptive neuromuscular facilitation (PNF) Manual resistance technique simulating fundamental patterns of movement to oppose motion in multiple planes Reciprocal inhibition (RI) Slow isometric contraction (approximately 25%) of the opposing muscle of the one being stretched

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THE CONTRACTED OR SPASTIC MUSCLE, BUT IT ALSO STRENGTHENS PHYSIOLOGICALLY WEAKENED MUSCLES

previous research considered the effect of MET on the range of movement (ROM) of the hamstrings, finding that ROM improved with this method (5,7,12). The hamstrings may be particularly good muscles to examine because they exhibit both postural and phasic muscle components, and are prone to shorten not only through pathological conditions but also under normal circumstances (10,13).

Other studies focused on the ankle (14–16 ) and cervical spine (15,16) and found that MET improved either the ROM or the pain level in both symptomatic and asymptomatic patients (but there were some methodological errors that must be taken into account). MET prefers the 25% contraction of available force to recruit the postural muscles that have shortened and require stretching. The theory is that increased contraction will lead to contraction of the phasic muscles, and decreased contraction is less likely to provoke cramp, tissue damage, or pain.

The rationale behind PNF PNF was a philosophy as well as a treatment method. It was developed in the 1940s to rehabilitate patients with paralysis. In the 1900s, Sherrington had considered the neuromuscular system in terms of maximal muscle contraction and recruitment of additional muscles for promoting strength and flexibility (cited in Chaitow (9)). From this original concept, Kabat (cited in Chaitow (9)) looked at the patterns of natural movement in rehabilitating the muscles of polio patients. PNF was seen as an integrated approach because each treatment was directed at a “total human being” rather than a specific problem or body segment (10). The treatment approach was always positive, reinforcing and making use of things that the patient was able to do, on a physical or psychological level, through the concept of applying spiral and diagonal patterns with stronger contractions. PNF has, therefore, been commonly used in both musculoskeletal and neurological environments. Knott and Voss (citied in Chaitow (9)) developed "modified PNF" that relates to the stretch concepts and principles in athletes regarding flexibility, muscle recruitment and rehabilitation patterns. It is often used to assist flexibility and coordination throughout the limbs' entire range of movement, helping the efficiency of recruitment of muscle fibres and ultimately biomechanics, thus preventing undue stress on other structures.

TYPES OF MET

As MET has progressed as a technique, two types evolved, namely post-isometric relaxation (PIR) and reciprocal inhibition (RI) (9) (see Figure 1).

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RESEARCH SUGGESTS THAT MET NOT ONLY LENGTHENS