There is no defined clinical assessment of what constitutes sufficient mobility and the aims of stretching differ according to the wider goals of the practitioner. Ancient Greeks used stretching in gymnastic training that included health maintenance, athletics and military physical training. Stretching in the context of manual therapy can be traced back to Hippocrates and Galen, chief physician to the gladiators in Pergamum from A.D.157 and therefore probably the original sports therapist. Osteopathy was founded by Dr Andrew Taylor Still in the US in 1874 attributing disease to ‘structural derangements’ amenable to spinal manipulation (Porter 1997). Passive stretching of soft tissue is a substantial component of osteopathic treatment that aims to restore normal structure and consequent normal function. Chiropractice was established in 1895 by Daniel David Palmer on the hypothesis that energy flow from the brain was a life giving force and disease resulted when obstructed. The spine usually provided the obstruction so chiro-practitioners concern themselves with spinal manipulation to remove the obstruction (Porter 1997). Osteopathy and chiropractice continue to lack scientific validation but their practice, incorporating some stretching of soft tissues of the low back, is widespread. Osteopathic techniques have influenced and merged with orthodox manual therapy and practiced by physio and sports therapists. Stoddard (1980) describes mobilization techniques used in osteopathy to remedy restricted joint movement that bear significant resemblance to techniques similarly employed by Kaltenborne. Kaltenborne was significantly influenced by osteopathic thought although he is probably best known for establishing the ‘concave-convex’ rule of arthrokinematic joint motion, subsequently developed by his student Maitland. (Lamb 1994). Evjenth was a close professional associate of Kaltenborne who published prolifically on stretching techniques. He divided stretching into ‘therapeutic stretching’ imposed by the therapist (Evjenth and Hamberg 1988) and ‘self stretching’ as used in exercise (Evjenth and Hamberg 1989). The two concepts were not mutually exclusive as these authors saw a role for the manual therapist in teaching their patients self-stretching to aid recovery. This is now the usual practice adopted by osteopaths, physio and sports therapists. These texts are encyclopedic and profusely illustrated with respective examples. McKenzie also provides ‘hands on’ stretching and is a campaigner for patient self help advocating simple ‘broad-brush’ techniques devoid of pretence and mystery enabling the patient to easily understand and administer treatment autonomously (Mckenzie 1981). This he implicitly contrasts with osteopathic practice whereby mobilizations have become increasingly subtle, intricate and precise (Lee 2003).

The numerous schools of chiropractice differ in their stated aims with some giving more priority to increasing range of joint motion and other prioritizing precision, specificity and correction of sublaxation. The manipulative force imposed in chiropractice adjustment is comparable to Maitland’s description of a ‘Grade V’ whereby the joint is taken with a high velocity thrust beyond the elastic barrier of resistance (Alter 1996). This usually produces cavitation as the tissue fluids release gas from the tissues being stretched. The release of gas is thought to produce the cracking noise associated with chiropractic manipulations (Sandoz 1976 cited in Alter 1996, p204). Cavitation occurs in tissues in response to the application of ultrasound and is associated with intracellular changes thought to promote tissue. Documentation was not found on whether this mechanism occurs in other techniques that stretch soft tissue or whether it produces the same reputed intracellular responses.

Yoga has evolved over several millennia across vast geographic terrain embracing philosophy, religion, ethics, psychology and physical health. The archeological evidence of yoga practices goes back to about 2000 BC when excavation in the Indes Valley uncovered seals depicting human figures in the lotus position (VW p11). Yoga was thought to be indigenous to Sramanism practiced by ‘free thinkers’ in Indian religious life who were driven from their communities into the forests by the Aryans as they arrived to conquer India up to 1500BC. The Aryans brought with them Brahaminism with which, at that stage, there was no association with yoga. The ensuing dialogue between the Aryans and the indigenous ‘free thinkers’ produced the Upanishads, the first literary exposition of yoga, appended to the Vedas, the scriptures of the Brahamins, around 800BC. The Upanishads discusses yoga as part of a range of spiritual and ethereal concepts. The Bhagavad Gita, (Vyasa, circa 300BC) superseded the Vedas in importance and influence with its elaboration on the spiritual and meditational aspects of yoga but the first reference to yoga postures or asanas appears in the Yoga Sutras of Patanjali. Patanjali is surrounded by mythology but is believed to have lived sometime between 500 and 200 BC. The Yoga Sutras of Patanjali decree “asana is perfect firmness of the body, steadiness of intelligence and benevolence of spirit”. (part 2, sutra 46). Further, “perfection in an asana is achieved when the effort to perform it becomes effortless and the infinite being within is reached” (Sutra 47). From then on the yogi is “undisturbed by dualities”, that is the dualities of mind, body and spirit are “united in a perfect posture”. (p149-151 Iyengar Patanjali).

Asanas may have developed from the practices involved in fertility rites and phallus and vulva worship performed by the ancient Sremanic communities. These rites became associated with Tantrism, based on a philosophy of active emotion or emotional worship, developed between 300 and 400 AD. Some of the techniques employed in the development of the siddhis or phychic powers may have been used in arousing states of ecstasy in tantric practices. Yoga asanas, mantras and meditation practices, described in the earliest written tantras appearing in the fourth century AD, evolved as accessories to the development of psychic practices. It is conceivable the ecstatic states aroused in the fertility rites and tantric practices became associated with psychic phenomena linked to the practice of asana and meditation. The Nath yoga sect of north India developed these yogic practices from the tenth to the twelfth century and distinguished them as ‘Hatha’ yoga. The sect left fragments of notes and instructions on asanas and other yogic practices and these were published in the fifteenth century as the Hathayogapradipika. The first section of this work lists fifteen asanas: Svastika, Gomukha, Virasana, Kurmasana, Kukkatasana, Uttanakurasana, Dhanurasana, Matsyendra, Paschimotanasana, Mayurasana, Shavasana, Siddhasana, Padmasana, Dimbhasana and Bhadrasana. The Hathapradipika decrees the practice of these asanas form part of the means of gaining mastery of the siddhis and describes the other necessary prerequisites that include pranayama and some esoteric cleansing practices.

Yoga is an accessory to Ayervedic medicine with both disciplines subscribing to the notion of ‘prana’ – thought to be a natural energy force flowing through the body. Yoga facilitates the directing of the flow of prana requiring subtle and precise minute detail in the practice of asanas. Yoga practice facilitates the flow of prana but, according to the Hathayogapradipika, may induce serious ill health if practiced incorrectly. The increase in energy resulting from asana practice can result in ‘blockages’ that need to be cleared if health is to be restored. Ayervedic practices serve to eliminate the blockages. The practice of ‘bhandas’, a series of muscular contractions, principally of the abdominal and pelvic floor muscles combined with a ‘chin-lock’ to the chest, are also prescribed to avert blockages. There is no scientific evidence for the existence of prana as it cannot be directly observed or falsified.

BKS Iyengar (1966) is credited with modifying and developing a system to the practice of yoga postures that renders them safe and effective. The ‘Iyengar method’ developed by trial and error working with practitioners of limited physical capabilities. Iyengar attracted attention from medical practitioners in the West and physiotherapy practices have been incorporated into yoga and vice versa. Props are used to enable the practitioner to perform postures with correct alignment of joints (Mehta 1992, 1994) reflecting Western practice in physical exercise and physiotherapy. Coultner (2001) is a set text for trainees in the British Wheel of Yoga that, together with Iyengar yoga, constitute most taught yoga in the UK. Coultner, a former medical school anatomy professor, succeeds in examining yoga in the light of modern biomedical science and couches his work in accepted anatomical and physiological terms. Stretching is also prominent in training in martial arts.

The ‘Pilates method’ is as an exercise system of controlled movements that engage both mind and body to improve flexibility and strength. It was developed in the 1920s by Joseph H. Palates and was taken up by dancers including Martha Graham and George Balanchine (Pilates web site). Pilates is becoming established alongside yoga as another health club studio based exercise class regime with a significant stretching component. Robinson (check) is the official training manual.

Texts discussing stretching and flexibility in the context of conventional Western physical fitness include Anderson (1981) who tables stretching routines and techniques recommended for sport and exercise programmes; Alter (1998) is similar in format to Anderson’s text. Alter (1996) is encyclopedic covering all aspects of stretching and flexibility in both conventional and esoteric practices. Bob Smith is a senior lecturer in sports science at Loughborough University who campaigns for safe stretching on Wheel of Yoga training courses and Smith (1994) typically reflects his work. Copyright David Tierney 2004