## 5 Additional Functionality of Medical Compression Garments  
The effectiveness of compression therapy depends not only on the compression generated. Psychological and physiological barriers to wearing compression products have been researched by various scientists [18; 85; 88; 94; 108]. Noncompliance and non-usage are usually caused by the following factors: unable to specify a reason (30%), not prescribed by the primary physician (25%), did not help (14%), binding of circulation (13%), inappropriate thermal properties during wearing (8%), limb soreness (2%), poor cosmetic appearance (2%), disability to be applied without help (2%); contact dermatitis or itching (2%), and other--cost, work situation, etc. (2%) [109]. Other barriers to wearing compression gar ments are highlighted among teenagers and kids: the main cause is discomfort during wearing (55%), lack of understanding of their condition (45%), factors such as difficulty to apply, appearance and no perceived benefits are almost at the same level (35-38%) [110]. Lack of comfort while wearing compression garments negatively affects performance and people are not encouraged to do more activity. Compression stockings as well as orthopaedic compression supports have to fulfil comfort requirements that are demanded for long-lasting wearable products--air permeability, perspiration absorption, antibacterial effect, in some cases additional thermal therapy or transparency, etc. It is well known that the fabric composition and yarn properties have an influence on comfort properties such as thermal conductivity, water vapour permeability and air permeability [18; 111]. It is proved that thermal properties are hardly affected by the capillary structure of fibres and yarn surface geometry. Also, air in the knitted fabric structure plays a prevalent role in heat transfer [108; 112]. Air permeability may be defined as a function of the loop density, tightness and thickness whilst water vapour permeability greatly depends on the raw material properties [113]. To achieve these requirements, specific fibres are used, or treatment is applied. The most \"negative\" effect on air permeability has elastomeric yarns, especially high linear density elastomeric inlay yarns. Elastomeric yarns not only tighten the knitted structure but also, they themselves are not permeable to air. Even more, compression products are worn in a stretched state (usually stretched at 10-30% to generate the required level of compression). This deformation of the knitted structure also has an influence on the loop geometry and size of pores between the yarns and fibres through which the air circulates. Therefore, it is recommended to test the air permeability in the stretched state of the specimen at a specific elongation. It should also be noted that weakened blood circulation in common patients who are amputees and, as a result, lower body temperature leads to the need for additional thermal insulation, which, together with low ventilation of the micro-space, leads, in turn, to increased sweating under the compression textile product. To avoid deterioration of the thermal insulation of a textile material caused by moisture accumulation, the transfer of moisture in the form of sensitive and non-sensitive perspiration from the body to the environment must be allowed. The ability of textiles to transfer moisture in the vapour or liquid form is one of the most important factors influencing thermos-physiological comfort, which is especially important in conditions of increased sweating [106; 114; 115]. Indicators of ergonomics of textile materials, characterising the convenience of the product and the comfort of its operation, include two subgroups: hygienic indicators (determining the compliance of materials with the hygienic conditions of human life) and comfort indicators (determining the degree of compliance of materials with the physiological and psychological characteristics of a person). Comfort is usually described by hundreds of parameters.