Huiju Park

Impact of ballistic body armour and load carriage on walking patterns and perceived comfort

This study investigated the impact of weight magnitude and distribution of body armour and carrying loads on military personnels walking patterns and comfort perceptions. Spatio-temporal parameters of walking, plantar pressure and contact area were measured while seven healthy male right-handed military students wore seven different garments of varying weight (0.06, 9, 18 and 27 kg) and load distribution (balanced and unbalanced, on the front and back torso). Higher weight increased the foot contact time with the floor. In particular, weight placement on the non-dominant side of the front torso resulted in the greatest stance phase and double support. Increased plantar pressure and contact area observed during heavier loads entail increased impact forces, which can cause overuse injuries and foot blisters. Participants reported increasingly disagreeable pressure and strain in the shoulder, neck and lower back during heavier weight conditions and unnatural walking while wearing unbalanced weight distributed loads. This study shows the potentially synergistic impact of wearing body armour vest with differential loads on body movement and comfort perception. Practitioner Summary: This study found that soldiers should balance loads, avoiding load placement on the non-dominant side front torso, thus minimising mobility restriction and potential injury risk. Implications for armour vest design modifications can also be found in the results.

Effect of firefighters' personal protective equipment on gait.

The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance of the boots is the major contributor to restricted foot pronation and gait instability as evidenced by the greater decrease in excursion of COP in leather boots (greater flexing resistance) than in rubber boots (lower resistance). The leather boots also shows the greatest increase in foot contact time and stride time. These negative impacts can increase musculoskeletal injuries in unfavorable fire ground environments.

Effect of armor and carrying load on body balance and leg muscle function

This study investigated the impact of weight and weight distribution of body armor and load carriage on static body balance and leg muscle function. A series of human performance tests were conducted with seven male, healthy, right-handed military students in seven garment conditions with varying weight and weight distributions. Static body balance was assessed by analyzing the trajectory of center of plantar pressure and symmetry of weight bearing in the feet. Leg muscle functions were assessed by analyzing the peak electromyography amplitude of four selected leg muscles during walking. Results of this study showed that uneven weight distribution of garment and load beyond an additional 9 kg impaired static body balance as evidenced by increased sway of center of plantar pressure and asymmetry of weight bearing in the feet. Added weight on non-dominant side of the body created greater impediment to static balance. Increased garment weight also elevated peak EMG amplitude in the rectus femoris to maintain body balance and in the medial gastrocnemius to increase propulsive force. Negative impacts on balance and leg muscle function with increased carrying loads, particularly with an uneven weight distribution, should be stressed to soldiers, designers, and sports enthusiasts.

Impact of firefighter gear on lower body range of motion

Purpose – The purpose of this paper is to investigate the incremental impact of firefighter’s personal protective equipment (PPE) on lower body range of motion (ROM) while walking to suggest areas of design improvement for enhanced mobility and safety. Design/methodology/approach – Eight male and four female firefighters participated in the study. Lower body ROM was assessed while they walked in four different configurations of PPE, including turnout ensemble, a self-contained breathing apparatus (SCBA) and boots. The impact of each added PPE item, and gender differences were statistically analyzed. Findings – Wearing firefighter turnout ensemble and SCBA reduced ROM in the lower body in the sagittal and transverse planes. A significant reduction in ROM for anterior-posterior movement at the ankle and the ball of the foot was found while wearing rubber boots with turnout ensemble and SCBA. This puts firefighters at higher risk of experiencing foot injuries and physical strains. A significant increase in m...

Assessment of Firefighters’ needs for personal protective equipment

This study performed focus group interviews with 54 firefighters in four states in the United States to assess the needs for design of firefighters’ personal protective equipment. Firefighters’ responses indicate three major issues to be considered for improved mobility, comfort and safety: 1) consideration of human factors, 2) sizing and fit, and 3) integrity of protection in the interface between protective equipment and turnout ensemble. Ergonomic design issues were identified through firefighters’ responses about their limited mobility of the head and arms while wearing helmet and self-contained breathing apparatus (SCBA), restricted access to coat pockets, back pain and soreness while wearing SCBA. Sizing and fit issues such as the excessive length and bulkiness of glove fingers were identified as a major concern regarding fire gloves resulting in limited mobility and dexterity, negatively effecting firefighters’ work efficiency and safety. The integrity of protection in the interface between turnout ensemble, gloves and boots was reported as an important consideration for firefighter comfort, mobility and protection against heat hazards. Possible design solutions were also discussed.

Perception of Firefighters' Turnout Ensemble and Level of Satisfaction by Body Movement

This study investigates firefighters’ perception of the protective turnout ensemble, more specifically, the level of satisfaction for a set of commonly performed body movements. Five hundred sixteen male and female firefighters completed our online survey. The current study identifies (1) the level of satisfaction with the fit of the turnout ensemble, (2) perceived reasons for discomfort and movement restriction in areas with low satisfaction, and (3) gender-specific fit issues. Female firefighters showed significantly lower satisfaction with the fit and functionality of the turnout ensemble in multiple areas than males. Common fit issues such as a stiff or oversized neckline and inappropriate location of knee pads, tightness in the lower pant leg, and inaccessibility of pockets that affect male and female firefighters are addressed. This study offers important implications to industry and academia involved in the study of protective clothing to increase the mobility, safety, and comfort of todays firefighters.

Scientometric analysis of research in smart clothing: state of the art and future direction

The purposes of this study were to investigate research trends on smart textile and clothing and to suggest future research directions on smart textile and clothing by using scientometrics approach. The research of smart clothing was divided into five categories: technology, human factors, application, manufacturing, and consumer demands and retailing. Technology emerged as the dominant category suggesting technological development of smart materials and wearable input devices have been intensively studied and have provided a solid foundation for smart clothing research. The number of research on output devices and data and power transportation showed a gradually increasing trend since 2000. Analysis on technical collaboration among each research field showed a high correlation between input technology and the three main categories: smart materials, functional application and, manufacturing. Material sciences, electronic engineering and computer sciences were shown to be major research disciplines to lead smart clothing research based on quantity of publications.

3D Virtual fit simulation technology: strengths and areas of improvement for increased industry adoption

ABSTRACT This study aims to provide practical implications about 3D virtual fit simulation technology as a fit assessment tool in the fashion industry by analysing similarities and discrepancies between actual and virtual garments in analyses made by users. Basic woven and knit dresses were made using a dressform used in young women’s apparel industry. Fit analysis on the actual and virtual garments showed similar results in the garment total length and width. However, a few areas, such as the neckline, sleeve cap, and shoulder slope, as well as fit issues such as hiking, draglines, gapping, puckering, and roll out, showed significant differences in fit evaluation. A more realistic visualisation of fit issues needs to be developed by building a database of characteristics of various seams and fabrics on the body. This study provided suggestions for areas of improvement in 3D virtual fit simulation technology for increased adoption of the 3D technology for effective prototyping and quality assessment in the fashion industry.

What do firefighters desire from the next generation of personal protective equipment? Outcomes from an international survey

The purpose of this study was to investigate smart features required for the next generation of personal protective equipment (PPE) for firefighters in Australia, Korea, Japan, and the USA. Questionnaire responses were obtained from 167 Australian, 351 Japanese, 413 Korean, and 763 U.S. firefighters (1,611 males and 61 females). Preferences concerning smart features varied among countries, with 27% of Korean and 30% of U.S. firefighters identifying ‘a location monitoring system’ as the most important element. On the other hand, 43% of Japanese firefighters preferred ‘an automatic body cooling system’ while 21% of the Australian firefighters selected equally ‘an automatic body cooling system’ and ‘a wireless communication system’. When asked to rank these elements in descending priority, responses across these countries were very similar with the following items ranked highest: ‘a location monitoring system’, ‘an automatic body cooling system’, ‘a wireless communication system’, and ‘a vision support system’. The least preferred elements were ‘an automatic body warming system’ and ‘a voice recording system’. No preferential relationship was apparent for age, work experience, gender or anthropometric characteristics. These results have implications for the development of the next generation of PPE along with the international standardisation of the smart PPE.

A sizing improvement methodology based on adjustment of interior accommodation rates across measurement categories within a size chart

Purpose The purpose of this paper is to identify common issues among commercial body size charts, and to propose a sizing improvement methodology without changing the number of sizes in the range. One goal is to equalize the number of people accommodated by each size within the range, and to propose a way to evaluate the effectiveness of the improvement. Design/methodology/approach The proposed method consists of three phases: (Phase I) identify target population; (Phase II) analysis of existing size charts; and (Phase III) improvement of the initial size chart. Phase III is the key process, which includes repeated manipulation of intersize intervals of the three primary measurements (chest, waist and hip) for improved consistency of overall and interior accommodate rates among the three measurement categories. A program was developed in RStudio® to generate trials and side-by-side bar plots for visualization of the differences in accommodate rates. Findings The main issue in commercial body size charts observed is the inconsistency of the interior accommodation rates among measurement categories. Some other issues include: lack of important measurements, failure to provide ranges and gaps between measurement ranges of adjacent sizes. Originality/value This paper proposed a complete work flow to improve body size charts to fix the common issues. The method integrates historic size information and new anthropometric information extracted from a national-scale sizing database (e.g. SizeUSA). The study also brought association of the secondary body measurements with primary measurements without using linear regression. Hence, information from body size charts can be more efficiently used in acquiring other size information.