Mechanical action of wool fibres on the skin also affects blood supply to this organ. Appropriate roughness of wool fabrics produces – during the use and due to non-irritating friction – some extra heat. This micromassage leads to neurohormone activation, which increases superficial blood flow and rises skin temperature. Thereby, thermal and insulation properties of wool fabrics become further enhanced. Using thermography and thermistor skin temperature measurements, Sefton et as well as Gieremek et al. (Sefton et al, 2010; Gieremek et al, 1991) confirmed the effect of therapeutic massage on skin temperature alterations directly associated with changes in peripheral blood flow in the treated areas as well as in adjacent not-massaged areas. Local use of thermal energy triggers several physiological reactions including increases in blood flow, muscle tension release, decrease of joint stiffness, oedema reduction, and, most importantly, pain relief. Impressions of temperature and pain are conveyed to higher centres through the same nerve tracts. General well-being associated with heat therapy is brought about by the release of endorphins and other neurotransmitters modifying the sensation of pain. The complex and interdisciplinary issues of the effect of heat on the skin became the domain of skin biothermomechanics. Thermomechanics also refers to mechanical tension (deformation) of skin collagen, also epidermal collagen. Thus, heat also modifies the sensation of pain via mechanical action (Xu et al, 2008). Page 183
Fornalczyk and Kuliński (Fornalczyk & Kuliński, 2008) point out the importance of physical therapy in the prevention and treatment of crural ulceration. The authors emphasize the significance of thermal effects of therapeutic ultrasound. Following injuries to the extremities, Complex Regional Pain Syndrome often develops, also referred to as Reflex Sympathetic Dystrophy Syndrome. Blood vessels constrict due to increased sympathetic activity; thereby the thermoregulatory control of skin blood flow becomes impaired (Wasner et al, 2000). Maintaining thermal comfort of the dystrophic area helps reduce the suffering. Vascular disturbances along with autoimmune processes also play a role in the development of neurodegenerative changes in patients with multiple sclerosis. Especially those over the age of 45 might benefit from appropriate thermal insulation to control microcirculation dysfunctions (D’haeseleer et al, 2011). Peripheral circulation impairment, manifested by decrease in skin temperature, commonly develops as a complication of peripheral nerve injury. Physical therapy is usually complex; the rate of nerve fibre regeneration depends on providing the tissues of the affected segment with thermal comfort (Druschky, 1979). Standard therapy includes wearing warmers. Satoshi (Satoshi et al, 1991) investigated the effects of a chronic constriction injury to the sciatic nerve of rats accompanied by an abnormality of cutaneous temperature regulation. Pain resulting from peripheral circulation impairment was almost always associated with skin temperature changes. These results emphasize the need to warm the affected extremity. Hornyak et al. (Hornyak et al, 1990) have confirmed the relationship between regional denervation, sympathetic system and blood supply. Damage to peripheral vessels accompanied by pain is also found in diabetic neuropathy and diabetic foot (PI-Chang, 2006). Providing gentle heat not only helps delay neurological changes but also promotes pain relief. Pain is frequently associated with sympathetic system stimulation and almost always causes vasoconstriction and a resultant decrease in body temperature (Birklein et al, 1998). Longterm emotional stress may act as an additional factor activating the sympathetic nervous system; it often underlies psychosomatic syndromes including locomotor organ disorders. Dry or moist heat application provides therapeutic benefits (Fechir et al, 2009). Heat therapy is a standard therapy in soft tissue contractures, which decrease joint mobility. Leung MS and Cheing GL demonstrated several beneficial effects of deep heating in the management of frozen shoulder (Leung & Cheing, 2008). The efficacy of such treatment may be increased by maintaining higher temperature of a given body part with the use of so called shoulder warmers. Heat, in the form of physical energy, has also been used in rheumatoid arthritis and arthroses. Ayling J. and Marks R. report multiple advantages of heat therapy in rhematoid arthritis especially as procedures preparing the patients to therapeutic exercises (Ayling & Marks, 2000). Heat therapy procedures are most frequently applied in the treatment of degenerative spine disease. Thus, the importance of wool warmers should not be underestimated. Page 184,185
Summary and conclusions
A considerable number of diseases are concurrent with primary or secondary peripheral, cutaneous and muscular circulation disorders. For example, primary circulatory disturbances result from peripheral vascular disease, which commonly affects the arteries supplying the leg and is mostly caused by atherosclerosis. Secondary changes occur in patients with limb paresis or paralysis following stroke, peripheral nervous system injury as well as in those suffering from muscle tension increase due to chronic pain (Moncur & Shields, 1987: Strass et al, 2002). Whether primary or secondary, the disorders result in reduced arterial and venous blood supply associated with lowered lymph flow dynamics. All patients diagnosed with the above mentioned circulatory impairments (except those with accompanying acute inflammatory conditions) might benefit from the prevention of heat loss through the affected body part. It should be remembered that heat loss is directly proportional to the temperature gradient between the skin and surrounding environment (Straburzyński & Straburzyńska, 2000). Thus, the reduction of heat loss emerges as the basic objective of therapeutic interventions. The rate of peripheral nerve regeneration is positively affected by the temperature of surrounding tissues and metabolism, which directly depends on peripheral, and even capillary circulation (Straburzyński & Straburzyńska, 2000). Thus, doctor’s and physiotherapist’s recommendations regarding the use of body warmers should be considered highly advisable from the medical point of view. Warmers enhance the capability of moisture absorption and ensure air exchange of the body part with its surroundings without excessive heat loss. Heat accumulates in the affected site and, through warming, entails its therapeutic effects. Increased sweating during exercise does not cause unpleasant cooling effects since wool fiber molecules generate heat. Page 189.
The quotes and references are from the following physiotherapy studies and scholarly works:
Krzysztof Gieremek and Wojciech Ciesla (2012). Natural Wool Fabrics in Physiotherapy, Physical Therapy Perspectives in the 21st Century - Challenges and Possibilities, Dr. Josette Bettany-Saltikov (Ed.), ISBN: 978-953-51-0459-9, InTech, DOI: 10.5772/38432.
Available from: http://www.intechopen.com/books/physical-therapy-perspectives-in-the-21st-century-challenges-and-possibilities/natural-wool-fabrics-in-physiotherapy