Tribology of the sock-skin Interface - the influence of different fabric parameters on sock friction.

BACKGROUND: The purpose of this parametric design of experiments was to identify and summarize how the influence of knit structure (single jersey vs. terry), fiber composition (polyester vs. cotton), fiber linear density (30/1 Ne vs. 18/1 Ne & 1/150/34 vs. 2/150/34), and yarn type (filament vs. spun) affected the frictional profile across the sock-skin interface. METHODS: Friction testing trials were completed against both a polypropylene probe and a synthetic skin material (Lorica soft®) to determine if there was a difference in friction based on interface interaction. Friction testing was completed by sliding a probe across the inside bottom surface of the sock (the part that is usually in-contact with the bottom of the foot) while instantaneously measuring the frictional force every tenth of a second. RESULTS: For both trials (plastic probe and synthetic skin), in the dry condition, knit structure was found to be the most prominent fabric parameter affecting the frictional force experienced at the sock-skin interface. It was also determined that fiber linear density, and yarn type are tertiary factors affecting the frictional force measured at the sock-skin interface. Finally, in the dry state, it was determined that fiber composition had seemingly no effect on the frictional force experienced at the sock-skin interface. CONCLUSION: This parametric design of experiments has further enhanced the understanding of the tribology at the sock-skin interface. Through strategic design, four different textile parameters have been investigated, measured, and justified as to how each influence the friction measured between the two interfaces. This knowledge can be used to develop socks that mitigate the risk of friction blisters formation.

Nondestructive Quantitative Evaluation of Yarns and Fabrics and Determination of Contact Area of Fabrics Using the X-ray Microcomputed Tomography System for Skin-Textile Friction Analysis.

In different mechanical conditions, repetitive friction in combination with pressure, shear, temperature, and moisture leads to skin discomfort and imposes the risks of developing skin injuries such as blisters and pressure ulcers, frequently reported in athletes, military personnel, and in people with compromised skin conditions and/or immobility. Textiles next to skin govern the skin microclimate, have the potential to influence the mechanical contact with skin, and contribute to skin comfort and health. The adhesion-friction theory suggests that contact area is a critical factor to influence adhesion, and therefore, friction force. Friction being a surface phenomenon, most of the studies concentrated on the surface profile or topographic analysis of textiles. This study investigated both the surface profiles and the inner construction of the fabrics through X-ray microcomputed tomographic three-dimensional image analysis. A novel nondestructive method to evaluate yarn and fabric structural details quantitatively and calculate contact area (in fiber area %) experimentally has been reported in this paper. Plain and satin-woven fabrics with different thread densities and made from 100% cotton ring-spun yarns with two different linear densities (40 and 60 Ne) were investigated in this study. The measurements from the tomographic images (pixel size: 1.13 µm) and the fiber area % analysis were in good agreement to comprehend and compare the yarn and fabric properties reported. The fiber area % as reported in this paper can be used to evaluate the skin-textile interfaces and quantitatively determine the contact area under different physical, mechanical, and microclimatic conditions to understand the actual skin-textile interaction during any physical activity or sports. The proposed method can be helpful in engineering textiles to enhance skin comfort and prevent injuries, such as blisters and pressure ulcers, in diversified application areas, including but not limited to, sports and healthcare apparel, military apparel, and firefighter's protective clothing. In addition, the images were capable of precisely evaluating yarn diameters, crimp %, and packing factor as well as fabric thickness, volumetric densities, and cover factors as compared with those obtained from theoretical evaluation and existing classical test methods. All these findings suggest that the proposed new method can reliably be used to quantify the yarn and fabric characteristics, compare their functionality, and understand the structural impacts in an objective and nondestructive way.

Structured telephone training improves telephone competence in prelingually deafened children with a cochlear implant.

OBJECTIVE: The aim of the study is to assess the efficacy of a 6-month telephone use training programme in prelingually deafened children with a cochlear implant (CI). METHODS: Eleven children with a CI aged between 3.5 and 8 years participated in a step-by-step telephone training programme. After completion of 3 months of formal training provided by a special education professional, parents continued telephone training at home for 3 months and kept records. The outcomes of the entire 6-month telephone training were measured at three intervals using the Telephone Profile, the Iowa closed-set sentence test (Level A), and a parent questionnaire. RESULTS: The scores on the Telephone Profile and Iowa closed-set sentence test significantly increased between the pre-training assessment and the assessments at 3 and 6 months. The results on the Iowa closed-set sentence test significantly decreased between the 3- and the 6-month-post training assessments. The majority of parents reported 'slight improvement' in telephone skills after telephone training. No improvement was reported by the majority of parents in the use of repair strategies during telephone conversations. DISCUSSION: Telephone training provided by a special education professional appears effective in prelingually deafened children with a CI. Home training provided by parents is less effective, but helps maintain the skills acquired in the professional telephone training. CONCLUSION: Structured telephone training provided by a professional improves telephone skills in children with a CI. Repair strategies for telephone use should be incorporated into rehabilitation programmes for CI users.

A randomized, controlled study to assess the effect of silk-like textiles and high-absorbency adult incontinence briefs on pressure ulcer prevention.

Pressure ulcer prevention is an important aspect of nursing home care. A 20-week, unblinded, randomized, controlled trial was conducted to compare the rate of nursing home-acquired pressure ulcers and adverse events between residents managed using: 1) a silk-like textile for bedding paired with high-absorbency adult incontinence briefs or 2) usual-care, plain-weave cotton/polyester bed sheets and adult incontinence briefs. All residents with an expected length of stay 30 days or more who agreed to participate were enrolled in the study and assessed daily. A total of 46 residents (all men) was enrolled; 26 (median age 72.7 years, range 54 to 95 years) in the intervention group and 20 (median age 69.5 years, range 51 to 91 years) in the usual care group. At baseline, there were no significant differences in resident demographic variables, including Braden Scale risk scores. Fewer pressure ulcers developed in the intervention (six; average follow up 75.6 days/person) than in the standard care group (20; average follow up 95.6 days/person) (hazard ratio = 0.31, 95% confidence interval 0.12, 0.78) and the number of new non-Stage I ulcers was significantly lower in the intervention group (HR = .23, 95% CI .078, .69, P = 0.0084). The number of adverse events did not differ significantly between the two groups. Additional research is warranted on use of products with the silk-like fabric, alone or in combination with highabsorbencybriefs, in larger groups and different populations.