The application of 3D printing technology for developing a lumbar support garment for obese women

Abstract

The purpose of this study was to develop a lumbar support garment, using three-dimensional (3D) printing technology, that has a good fit and great aesthetics for obese women in their 30s and 40s. To this end, a survey was conducted to investigate consumers’ satisfaction with commercially available lumbar supports. One participant with class 2 obesity, aged between 30 and 49 years, with previous experience of back pain and wearing a lumbar support, was selected for the 3D body scanning procedure. A lumbar support was designed based on the 3D shape data obtained by the 3D body scan of the participant and was then printed using a 3D printer. The lumbar support garment was designed as a sleeveless wrap-style innerwear piece combined with lumbar support. Cross-sectional comparisons, a wear test, and an appearance evaluation were also conducted. The cross-sectional comparisons confirmed that wearing the lumbar support garment straightened the back and waist posture and tightened the abdomen. Three obese women in their 30s and 40s were recruited for the wear test and, based on the test results, the lumbar support garment scored very high on air permeability, material, washing, and long wearability. Furthermore, because the lumber support garment can be worn under another garment, the participants felt more comfortable psychologically. The support also received good scores on appearance evaluations. However, spine experts suggested reducing the support’s thickness to improve its functionality and appearance.

Keywords

Body scanning human sensory and comfort issues product design protective and other high-performance clothing systems sizing of apparel product and systems engineering

Obesity can cause herniated discs and back pain to develop because, when supporting a heavy body weight, the spine and discs become strained. People suffering from degenerative disc disease are more likely to experience accelerated disc degeneration and increased obesity.¹ Back pain is related not only to obesity but also to sociodemographic variables, such as body mass index (BMI), gender, environment, and education level; it also has a greater impact on women’s lifestyles than on those of men.²

Worldwide, the obesity rate is rising, including in Korea. The term ‘obese women’ generally refers to women who are overweight and have an excess of adipose tissue in their bodies.³ According to data from the National Health Insurance Corporation, the prevalence of obesity among Korean men and women in their 30s and 40s increased significantly between 2015 and 2017.⁴ Given that the obesity rate among the young and the elderly alike is rapidly increasing, it is imperative to pay attention to the incidence of back disease for women and men in their 30s and 40s. The Korean Society for the Study of Obesity and the World Health Organization (WHO) for the Asia-Pacific region define obesity level thus: overweight (pre-obesity) as a BMI of between 23 and 24.9 kg/m², class 1 obesity as a BMI of between 25 and 29.9 kg/m², class 2 obesity as a BMI of between 30 and 34.9 kg/m², and class 3 obesity as a BMI over 35 kg/m².⁵

As back pain increases, so does the need for lumbar support. However, most commercially available lumbar supports are manufactured based only on waist circumference, failing to consider gender, age, or body type, and therefore result in a relatively low level of satisfaction among consumers.⁶ Because a lumbar support is worn by people with many various body types, its design must take into account how well it fits with various body types and the wearer’s gender. In addition, improvements are needed in terms of convenience, such as its weight and wearing method.

Body circumferences vary significantly more between overweight and obese body types than they do between normal weight and overweight body types.⁷ Thus it is not advised to design a lumbar support for an obese body type based solely on one type of body measurement. However, lumbar supports sold in ready-made sizes, such as S, M, and L, differ only in incremental increases to the waist’s circumference; they are also based on the standard body type. Thus although sizes vary, consumers who have either a very small or a very large waist circumference, or those with different body shapes, find it difficult to choose the right size.⁸ As such, obese women may feel uncomfortable when wearing lumbar supports, compared with other consumers, such as standard or underweight women and men. What is more, lumbar supports sold on the market do not satisfy the preferences of women who value a good fit and aesthetics. Customer satisfaction regarding commercially available lumbar supports scored the lowest for color and pattern.⁶ Results from a previous study showed that commercially available lumbar supports do not look good when worn outside one’s clothing, and they tend to cause discomfort when worn for a long time. Another previous study suggested manufacturing a lumbar support combined with innerwear.⁸

Three-dimensional (3D) printing is indeed suitable for creating personalized products. It is used to produce custom-made dental devices, such as jaw models and teeth,⁹ artificial corneas,¹⁰ and artificial hearts.¹¹ This study uses 3D printing technology to develop lumbar supports that fitted a wide range of obese women’s body types that can also be worn as innerwear.

This study aimed to develop a lumbar support that offers both a good fit and great aesthetics for obese women in their 30s and 40s. Ultimately, this study intended to suggest a process suitable for developing a customized lumbar support using 3D printing technology, and for producing a lumbar support for both genders and body types.

Theoretical background

Definition and efficacy of lumbar support

Lumbar supports, also called ‘back supports,’ ‘lumbar support belts,’ and ‘abdominal belts’, are used in the medical field for rehabilitating and treating back diseases.¹² When worn properly, a lumbar support increases the pressure on the abdomen, helps strengthening the spine, reduces joint movement range, enhances intra-abdominal pressure through applying pressure on the spine, and reduces compressive loading on the lumbar spine.¹³ It also limits movement between vertebrae and reduces the burden on the lower back via direct transmission of the load, thereby reducing the likelihood of additional back injuries.¹⁴

Using a lumbar support that covers the spine and shoulder reduces back pain by more than 30%, and it also improves physical functions, especially the spine’s functionality.¹⁵ Lumbar supports also reduce a significant portion of the weight on the body when lifting an object. Lumbar supports increase abdominal strength and endurance, which are inversely related to the stress applied to the body when lifting an object.¹⁶ As such, they positively reduce back pain and prevent back diseases.

Currently, because the importance of protecting people’s backs has been highlighted, various lumbar supports have likewise been developed and sold on the market. Recently, LESHP, a US brand, developed a lumbar support that wraps around the shoulder area, rather than one that just encircles the waist, more effectively to reduce the workload.¹⁷ Bauerfeind, a German brand, developed its lumbar support based on 3D human body data,¹⁸ and Hiromasa and Yoshiuuki produced theirs using hybrid assistive limbs to reduce lumbar load.¹⁹ Fung designed a new textile-based scoliosis brace, whose strap adjuster is made using 3D printing.²⁰ Although 3D printers and 3D scanners are used for some commercially available lumbar supports, they have not yet been widely applied. Therefore, this study intended to design a functional and comfortable lumbar support that uses 3D technology, and that also considers consumers’ various body shapes.

Concept of 3D printing and its trends

Currently, 3D printing is used widely across the world and contributes to producing open-source designs in various fields, such as mass customization and agriculture, and in the medical, automotive, locomotive, and aerospace industries.²¹ In fact, the 3D printing market is expected to grow at a compound annual growth rate of 22.5% by 2026, and government investments are increasing.²² Former US President Barack Obama endorsed 3D printing as an ‘innovation’ at the White House Maker Faire in 2014.²³ In the United Kingdom, Renishaw uses 3D printing technology and titanium material to produce bicycle parts,²⁴ while, in the United States, General Electric uses this technology to customize and produce aircraft parts.²⁵

Materials used for 3D printing are diverse, and each industry selects and uses a material that is suitable for their needs. Common materials include glycolmodified polyethylene terephthalate (PETG) with excellent elasticity; polylactic acid (PLA) that works at low temperatures; acrylonitrile butadiene styrene (ABS), a material with a solid structure; and thermoplastic polyurethane (TPU) with strong impact strength. In the apparel industry, for example, TPU and PLA are commonly used.²⁶ To study composite fibers, Störmer et al. analyzed the properties of two different woven cotton fabrics produced with 3D-printed TPU.²⁷ Pasricha and Greeninger developed fashion jewelry via 3D printing using eco-friendly and flexible PLA filaments.²⁸ Indeed, 3D printing technology is being introduced in various ways in the apparel industry and in its research and development. In the fashion sector, Iris van Herpen of The Netherlands introduced haute couture clothing produced with 3D printers in 2013.²⁹ Also in 2013, both Swarovski and Victoria’s Secret made lingerie using 3D printing.³⁰ In addition, Karl Lagerfeld created a 3D-printed suit for Chanel,³¹ and Nike produced and sold the first 3D-printed football shoes.³²

3D printers also produce mannequins and dress forms that have specific poses or that can be used as custom frames for specific body parts. For instance, in 2020, Ashdown and Vuruskan printed a dress form in a cycling pose. They used a stretchable TPU material to reproduce the human body’s softness, and the product was even subjected to a pressure test to determine the pressure change when wearing tight athleisure clothing.³³

Beecroft studied weft-knitted structures featuring flexibility, stretch, and strength using a 3D printer to investigate fabric production using 3D technology.³⁴ Beecroft’s study shows how it is possible to apply 3D printing to single and double weave structures, using the selective laser sintering process (SLS) on stretchable nylon powder. Melmikova, Ehrmann, and Finsterbusch printed knitted and lace fabrics using both the fused deposition modeling (FDM) process and 3D printers. They used both SLS and FDM processes to print fabrics through print structures with the smallest of diameters; in addition, they used Lay Tekkes, one of four types of porous filaments.³⁴ Another study presented textile-integrated wireless platforms using 3D printing and embroidery.³⁵

3D printing is also often utilized for developing healthcare and medical devices. EXOS, for one, has developed full-body armor orthopedic devices for patients with scoliosis and spinal deformities.³⁶ In addition, 3D printing is actively used in the dental industry, such as for conducting research on printing implants and drill guides for patient-specific acetabular fracture fixation; furthermore, this work is generating large market growth.³⁷

In summation, 3D printing is actively used in various industries to increase both production speed and precision. It is already being employed for developing a wide range of medical devices. Most salient to this paper’s project, 3D printing is expected to be vital to research on developing lumbar supports suitable for specific ages and body types.

Objectives

This study aimed to develop a lumbar support, using 3D technology, that is suitable for obese women in their 30s and 40s. The specific research objectives are outlined as follows. First, a survey was conducted among women in their 30s and 40s to assess consumers’ satisfaction levels regarding commercially available lumbar supports and their purchasing preferences. Second, one participant, whose body measurements approximated the average body measurements of obese women in their 30s and 40s, was selected and scanned using a 3D body scanner. Third, a lumbar support garment was created using 3D printing technology. Finally, the lumbar support’s functionality was verified through a cross-sectional evaluation, a wear test, and an appearance test.

Research method

Consumer survey

A survey was conducted to investigate consumers’ satisfaction with commercially available lumbar supports and their purchasing considerations. The questionnaire’s respondents were composed of South Korean women in their 30s and 40s, all of whom had previous experience of back pain and wearing a lumbar support. Although this study’s primary objective was to develop a lumbar support for obese women, women within a normal BMI range were included in the questionnaire pool to understand which lumbar support characteristics were preferred by obese women compared to women with a normal BMI. The questionnaire was composed of three questions related to demographics, four questions about back health status, seven lumbar support usage questions, 15 questions pertaining to lumbar support satisfaction, and 15 questions about lumbar support purchase considerations. Three items related to demographics and 10 items concerning lumbar support use were presented in multiple choice and short answer formats. In total, 100 surveys were conducted, and all questions used a five-point Likert scale. The 12 items related to lumbar support satisfaction were assigned the following scales: 1 = very dissatisfied, 2 = dissatisfied, 3 = neutral, 4 =satisfied, and 5 = very satisfied. The 15 items related to purchase considerations were as follows: 1 = not very important, 2 = not important, 3 = neutral, 4 = important, and 5 = very important. The data were analyzed using SPSS 28.0 for Windows.

The development of the lumbar support garment

The analysis of body measurements of obese women in their 30s and 40s

To determine the average body size of obese women in their 30s and 40s, measurement data from the 7th Size Korea National Anthropometric Report were analyzed. The 7th Size Korea National Anthropometric Report data were collected in 2015 to compile the body measurements of Koreans, a process done by using a body scanner.³⁸ In total, there were 1036 women in their 30s and 40s listed in the report, and obese women numbered 25. The obese women’s BMI scale corresponded to class 2 obesity (BMI 30 kg/m², or more and less than 35 kg/m²), as defined by the Korean Society for the Study of Obesity.⁵ Because the WHO defines obesity as BMI 30 kg/m² or more, and defines being overweight as BMI 25 kg/m² or more and less than 30 kg/m²,³ this study selected class 2 obesity as its target group. For these 25 obese women, a total of 16 measurement items related to the upper body were selected, of which the average was calculated.

3D body scan procedure

This study selected one participant whose body measurements were close to the average of women in their 30s and 40s in the 7th Size Korea National Anthropometric Report data, and who had previous experience of back pain and wearing a lumbar support. She was scanned three times using a 3D body scanner. The participant wore a bra with a T-shirt and bike shorts for the first scan, which was used to model a lumbar support in Rhinoceros 7 (Robert McNell and Associates, USA), a 3D modeling program. For the second scan, the woman wore a ready-made lumbar support, and for the third scan, she wore the lumbar support garment developed for this study. The second and the third scans were compared with the first to examine changes in body posture as a result of wearing the different lumbar supports.

Regarding technology, this study used the Artec Studio 14 Professional (Artec Group Company, USA), a handheld 3D scanner with a structured light method. This device captures measurements with great efficiency and accuracy. Participants were scanned with their legs standing shoulder-width apart and their arms spread out at 45 degrees while facing the front. Each held a 4-foot cane with both hands to minimize arm swaying.

3D modeling and printing of the lumbar support

The lumbar support was designed based on the 3D shape data obtained via the 3D body scan of the participant. Lumbar support modeling was done using the Rhinoceros 7 program, and the completed model was printed with a MA3D: Standard 3D Printer (Madeall, South Korea) using PETG material, which has high elasticity and impact. Next, the support garment was sanded with sandpaper after post-treatment to eliminate any rough feeling as it comes into contact with the skin. The lumbar support was designed to reflect consumer survey results. Additional interviews with two spine/joint experts were also conducted. A physical therapist specializing in spinal diseases and an exercise specialist for scoliosis treatment participated in the interviews, each of which lasted approximately 30 minutes.

A total of eight body scan data items from the 7th Size Korea National Anthropometric Report corresponding to class 2 obese body types were imported into the Rhinoceros 7 program in *obj format. The modeled lumbar support was then verified as to whether its shape was compatible with the various body types of different obese women. Finally, the curvature, width, and height of the lumbar support were corrected and supplemented.

Developing the lumbar support garment

The size of the garment with the lumbar support was determined by reflecting the average body size of obese women, which was derived from the 7th Size Korea National Anthropometric Report data. Afterwards, a pattern was made based on this selected size. A polyurethane and polyester blend fabric with good breathability and elasticity was selected as the material for the garment. To account for elasticity, lightness, and ease of washing, which are important characteristics of innerwear, six physical property tests were performed. The garment’s thickness, density, weight, tensile strength, elongation recovery rate, and wash dimensional change rate were analyzed by the FITI Testing and Research Institute. The test was conducted based on the standards of the Korea Industrial Standards Commission,³⁹ and the testing method for each item was as follows: thickness (KS K ISO 5084: 1996), density (KS K 0512: 2017), weight (KS K 0514: 2017), tensile strength (KS K 0642: 2016, 8.14.1, method B, C. R. E., grab method), elongation recovery rate (KS K 0642: 2016, 8.16.2, method D), and wash dimensional change rate (KS K ISO 5077: 2007, KS K ISO 6330: 2012, 5B).

Lumbar support garment evaluations

Cross-sectional comparison

Three items of 3D shape data obtained via the 3D scan were extracted in *.obj format and imported into the Geomagic DesignX program (3D Systems, USA) for cross-sectional comparison. The comparison was performed using cross sections derived from the participant’s three body scan meshes: one scan with the participant wearing a T-shirt and shorts, one wearing a ready-made lumbar support, and one wearing the lumbar support garment developed in this study.

Wear test

For the wear test, this study recruited three obese women in their 30s and 40s whose body measurements approximated the average of women in the same age range; the selected women also had previous experience with wearing a lumbar support (Table 1). One of the three participants was the same person who participated in the 3D body scan process. Each person came to the laboratory on different days, and the body measurements of the three participants were measured and photographs were taken. For the wear test, the participants wore a ready-made lumbar support and the lumbar support garment. The brand of the ready-made lumbar support was Hyundai Medical, and its size was XL. Notably, Hyundai Medical is one of the most popular brands among consumers, and it was selected by considering the fastening method and color that consumers prefer in the consumer survey. The selected ready-made lumbar support was made with nonwoven fabric and mesh material, and it had a Velcro fastening.

Table 1.

Participants’ body measurements (unit: cm)

Measurement item		Measurement method	Size Korea Mean	Participant 1 Mean	Participant 2 Mean	Participant 3Mean
Circumference	Chest	Horizontal circumference through the midpoint of the sternum	100.9	102.2	103	101.4
	Bust	Horizontal circumference through the nipple point	105.5	107.3	108.7	105.7
	Underbust	Horizontal circumference through the point below the breast	92.3	94	92.5	92.5
	Waist	Horizontal circumference through the point in front of the waist, the point next to the waist, and the point behind the waist	96.0	97.4	94.0	94.6
	Abdomen	Horizontal circumference of the body at the height of belly protrusion	101.5	102.2	101.0	100.9
	Hip	Horizontal circumference through hip protrusion	105.9	108.6	108.8	106.2
Length	Shoulder	Length from the side of the neck to the side of the shoulder	12.1	12.3	11.8	13.2
	Bishoulder	Length between the shoulder and shoulder points	39.5	39.2	38.4	39.5
	Neck point to breast point	Length from the side of the neck to the nipple	29.6	31.8	30.5	30.5
	Breast point to breast point	Straight line distance between nipples	20.1	22.0	21.9	21.0
	Waist front	Length from the front point of the neck to the front point of the waist	37.9	38.6	37.2	38.0
	Waist front (omphalion)	Length from the point of the neck to the point of the navel	43.1	44.8	44.0	45.0
	Waist back	Length from the back of the neck to the back of the waist	42.5	43.6	41.5	43.0
Stature		Vertical distance from the floor surface to the top of the head	158.5	162.5	156.0	162.0
Weight (kg)			79.4	84.7	78.8	83.2
BMI (kg/m²)			31.6	32.1	32.38	31.7

BMI: body mass index.

The participants completed the evaluation survey after wearing, in the desired place for 3 h each, both the ready-made lumbar support and this study’s lumbar support garment. Wearing time was determined based on the results of a consumer survey, whereby more than half of the respondents reported wearing the lumbar support for more than 1 h but less than 3 h a day. In addition, in the previous study, which verified the effect of the lumbar assist device, the experimental time was set to 3 h; the same duration was reflected in this current study.⁴⁰ To evaluate each lumbar support objectively, a gap of 2 h was allowed as an interval between wearing the two different lumbar supports. During the 3-h wearing times, the participants freely went about their normal, everyday routines in their usual environments. As per the researcher’s request, participants also performed three movements while wearing the lumbar support: raising both arms, turning the upper body to the side, and raising one leg to a 90° angle.

The wear test questionnaire was composed of 21 items pertaining to functionality and appearance, and 14 on ease of motion. The questions were evaluated on a five-point Likert scale, and the results were analyzed using SPSS 28.0 for Windows.

Appearance evaluation

Eight apparel and three spine/joint experts participated in the appearance evaluation. Together, the 11 experts evaluated the garment’s appearance by means of a questionnaire, which they filled out after looking at photos taken of the front, side, and back of the three participants wearing a lumbar support garment. The evaluation included a flat sketch of the lumbar support garment, a photo of the lumbar support produced with a 3D printer, and its specifications. Appearance was evaluated on a five-point Likert scale; the questionnaire had 18 questions, and the results were analyzed using SPSS 28.0 for Windows. Descriptive statistics were also analyzed to derive the mean and standard deviation for each evaluation item. A Wilcoxon signed-rank test for the two-group paired samples were performed to compare the evaluations made by apparel and spine/joint experts. When parametric statistics were conducted to compare results between the expert groups, normality was unsuitable because there were too few experts in each group. Therefore, a nonparametric test, a Wilcoxon signed-rank test, was used.

Results

Consumer survey

A total of 35 people in their 30s (35%) and 65 in their 40s (65%) participated in the consumer survey. Among the respondents, 5% were underweight, 74% were of normal weight, 11% had pre-obesity (overweight), 15% had class 1 obesity, and 10% had class 2 obesity.

In response to the question regarding back pain causes, 44.5% attributed the pain to a herniated disc and 40.3% to a lumbar sprain. When asked about the status of wearing a lumbar support, that is, about the reason for wearing a lumbar support, the most common response was ‘relief of pain in daily life,’ accounting for 57.1% of the total responses. Other answers were ‘rehabilitation after treatment’ (25%) and ‘preventive purposes’ (13.6%). On enquiring about the environment or circumstances in which they wear their support, the highest percentage (44.8%) answered ‘in daily life,’ 24% chose ‘when working in a sitting position,’ and 20.8% replied ‘when working in a standing position.’ The results showed that the average time per day spent wearing the lumbar support for the majority was longer than 1 h but less than 5 h. Table 2 presents the results for lumbar support usage status.

Table 2.

Lumbar support usage status


The purpose of wearing a lumbar support	The environment or circumstances in which you wear the lumbar support	Average time spent per day in the lumbar support
Relief of pain in daily life	In daily life	Less than 1 h
Rehabilitation after treatment	When working in a sitting position	More than 1 h but less than 3 h
Preventive purposes	When working in a standing position	More than 3 h but less than 5 h
Essentially worn only at work/work	Worn when lifting heavy objects	More than 5 h but less than 7 h
Wear during exercise	After surgery	More than 7 h
–	When exercising

Table 3.

Customer satisfaction with commercially available lumbar supports

Items	Means (S.D.)					F value
Items	Underweight (n = 8)	Standard weight (n = 57)	Overweight (n = 10)	Obesity (n = 25)	Total (n = 100)	F value
Convenient to carry	3.25A (0.89)	2.93A (1.18)	3.20A (1.03)	2.24A (0.93)	2.81 (1.13)	3.390*
Easy to wash and manage†	3.25A (0.71)	2.75AB (1.11)	2.60AB (1.27)	1.84B (0.80)	2.55 (1.10)	5.849***
Availability of various sizes	3.00A (0.76)	2.72AB (0.82)	2.80A (1.03)	1.72B (0.98)	2.50 (1.03)	7.929***
Easy to find a lumbar support that fits my body type	2.50AB (0.76)	2.88AB (1.07)	3.20A (1.03)	1.88B (0.97)	2.63 (1.11)	6.672***

*P < 0.05, **P < 0.01, ***P < 0.001.

Alphabet is the result of a post-hoc test (Sheffe test, †Games–Howell test). (A>B>C).

Table 4.

Important factors when purchasing a lumbar support

Items	Means (SD)					F value
Items	Underweight (n = 8)	Standard weight (n = 57)	Overweight (n = 10)	Obesity (n = 25)	Total (n = 100)	F value
Shape	3.63B (0.92)	3.91AB (0.76)	3.90AB (0.99)	4.52A (0.59)	4.04 (0.80)	4.758**
Fastening method	3.88B (0.84)	4.16AB (0.80)	4.30AB (0.68)	4.72A (0.46)	4.29 (0.76)	4.514**
Size†	4.13A (0.35)	4.28A (0.73)	4.10A (0.57)	4.68A (0.56)	4.35 (0.67)	3.164*

*P < 0.05, **P < 0.01, ***P < 0.001.

Alphabet is the result of post-hoc test (Sheffe test, †Games–Howell test). (A>B>C).

Regarding the following items, general customer satisfaction with the commercially available lumbar support was relatively high (3 points): ‘easy to put on and take off’ (M = 3.86), ‘pain is relieved’ (M = 3.70), ‘abdominal pressure is appropriate’ (M = 3.60), and ‘fixes the waist well’ (M = 3.57). These results suggest that the commercially available lumbar supports are generally satisfactory and effectively relieve back pain. However, some items related to size and design diversity scored relatively low.

Satisfaction with wearing the commercially available lumbar support for a long period of time was low, which is consistent with the previous study’s results,⁹ indicating that, overall, people feel uncomfortable wearing a commercially available lumbar support. Satisfaction with washing and portability was also low, suggesting that consumers may be dissatisfied with the material used in commercially available lumbar supports – nonwoven fabric and mesh material – which require handwashing.

Satisfaction regarding the following items differed according to the degree of obesity, ranging from ‘convenient to carry’, ‘easy to wash and manage’, ‘availability of various sizes’ and ‘easy to find a lumbar support that fits my body type’ (Table 3). For the item ‘easy to wash and manage,’ overweight and obese consumers reported lower satisfaction levels than underweight and normal-weight consumers. This may be due to the increased frequency of washing and managing on the part of obese people, who tend to sweat more.⁴¹ Thus with the aim of increasing obese women’s satisfaction in this, it is necessary to develop a machine-washable lumbar support.

Moreover, the average satisfaction rate of obese consumers pertaining to the following items was very low (1 = very dissatisfied, 3 = neutral, 5 = very satisfied): ‘availability of various sizes (1.72)’ and ‘easy to find a lumbar support that fits my body type (1.88)’. Such results indicate that obese consumers have difficulty finding commercially available supports that fit their body types.

In terms of the factors that consumers consider when purchasing a lumbar support, ‘for ease of movement’ (M = 4.65) and ‘for relieving back pain’ (M = 4.44) scored highest. Such results indicate that consumers value functionality the most when purchasing a lumbar support. Notably, color (M = 3.40), brand (M = 2.91), and pattern (M = 2.77) are low-ranking considerations.

Results also show that the higher the degree of obesity, the more consideration is given to the lumbar support’s shape. This may be because obese women have larger girth dimensions, less back curvature, and greater abdominal curvature,⁷ which lead them to consider whether the lumbar support fits their waist curve, has an appropriate height, and does not compress the chest. Women with a high degree of obesity also considered the convenience of the fastening method and the size of the lumbar support more. This is presented in Table 4.

The development of the lumbar support garment

Expert interview

Two spine/joint experts were interviewed, and each provided important points to consider for designing the lumbar support (Table 5). The interviews were conducted orally and the questions were designed based on the consumer surveys’ content. The lumbar support modeling was designed based on both the interview and the survey results.

Table 5.

Results of an expert interview on developing a lumbar support

Interview results
• The weight of the support should not be too heavy
• The support should not be too thick
• The corners of the support should not be angled
• The support should have a means of ventilation. A device for ventilation is needed in the middle of the support to prevent sweating
• The support should cause no difficulty in movement and provide some ease without completely adhering to the waist flexion
• It should give a sense of stability by wrapping from the waist to the pelvis
• An auxiliary support should be included to give a sense of stability to the waist
• It should be possible to wear it slightly away from the bottom of the chest
• To assist the consumer’s posture and muscle distribution, the lumbar support should be symmetrical

3D body scan

The data captured by the 3D scanner were processed using Artec Studio 14 Professional, and those data were processed using the Artec Studio program’s autopilot function. After saving the first set of scan data in an *.obj format file, the data were then imported to the Meshmixer 3.5 program (Autodesk, USA). Because it is mainly the abdomen data that are used for producing the back supporter, this study deleted the meshes for the face, arms, and legs. The rough body scan surface was smoothed using the Sculpt tool, and the mesh data were symmetrically modified with the Mirror tool to facilitate creating a symmetrical waist supporter. Generally, the human body is not perfectly symmetrical; however, spine/joint experts advised that the lumbar support should be symmetrical to help balance the body and intentionally relocate the muscles. A personalized and asymmetrical lumbar support may be needed only in cases of severe body imbalance, such as body scoliosis.

3D modeling and printing of the lumbar support

The consumer survey results showed that obese women regard the shape of the lumbar support as important. In response, 3D modeling was used to ensure that the central support of the lumbar support fitted the body shape of obese women. In addition, the central support was designed in response to low levels of consumer satisfaction with the ventilation of commercially available lumbar supports. Holes were added in the 3D printed central support to increase ventilation.

The lumbar support was designed with one central support that covered the body from the waist to the pelvis and two auxiliary supports that covered both sidelines. Central support size was 310*185*3 (mm), and auxiliary support size was 15*140*3 (mm). A hole 45 mm in width and 120 mm in length was added in the middle of the center support to prevent sweat from accumulating on the back; an addition 28 small holes were made throughout the support to ensure good ventilation and a lightweight design.

The lumbar support was designed using the Rhinoceros 7 program, and to produce the size and shape, a surface of the desired size was created. By employing the Rebuild tool, a curvature suitable for the obese body type was generated. The Filet Edge tool was utilized to round the support’s corners. In addition, the Boolean Subtract tool was selected for making uniform holes throughout the support.

To verify its suitability for the varying body types of women other than the study’s participants, the modeled lumbar support was compared with the 3D shape data of eight obese women in their 30s and 40s from the Size Korea in the Rhino program (Figure 1). The width and curvature of the lumbar support were adjusted, and its height was modified so that when the waist tilted, the user did not feel any discomfort. Its width was also adjusted so that the waist fixing force would not decrease due to the space remaining in the support when worn by an obese woman with a small body size. The modeled lumbar support is shown in Figure 2 and the 3D printed lumbar support is depicted in Figure 3.

Figure 1.

A comparison of three-dimensional (3D) human body shape data and lumbar support flexion.

Figure 2.

Three-dimensional (3D) scan data and the modeled lumbar support.

Figure 3.

Three-dimensional (3D) printed lumbar support.

Figure 4.

Flat sketch.

Developing the lumbar support garment

This study’s lumbar support garment was designed as a sleeveless wrap-style innerwear piece combined with lumbar support and a Velcro fastener on the front ( Tables 6, 7 and 8). To wear the lumbar support garment without requiring an additional bra, bra pads were inserted into the bust area. The central and auxiliary supports feature lip pockets with snap buttons for inserting and detaching 3D printed supports, thereby facilitating an ease of washing and maintenance (Table 9).

Table 6.

Participant 1’s measurement clothes, ready-made lumbar support, and lumbar support garment

	Measurement clothes	Ready-made lumbar support	Lumbar support garment
Front
Side
Back

Table 7.

Participant 2’s measurement clothes, ready-made lumbar support, and lumbar support garment

	Measurement clothes	Ready-made lumbar support	Lumbar support garment
Front
Side
Back

Table 8.

Participant 3’s measurement clothes, ready-made lumbar support, and lumbar support garment

	Measurement clothes	Ready-made lumbar support	Lumbar support garment
Front
Side
Back

Table 9.

Detailed images of the lumbar support garment

Outer appearance of the central support pocket	Outer appearance of the auxiliary support pocket

Interior view of the central support pocket	Added Velcro and nonwoven fabric

Table 10.

Overlapped cross sections

Body center	Bust point
			Measurement clothesReady-made lumbar supportLumbar support garment
Chest circumference	Bust circumference	Underbust circumference

Waist circumference	Abdomen circumference	Hip circumference

Because the garment is worn directly against the body, a soft material blended with polyurethane was chosen to ensure good elasticity and durability. A nonwoven fabric was added to the lumbar support to add thickness and to apply adequate pressure to the waist and abdomen, yet simultaneously create a cushioning feel. To prevent the lumbar support’s color affecting the appearance of clothes worn over it, a skin-tone color was chosen for the material. The flat sketch of the lumbar support garment is presented in Figure 4.

Evaluation results for the lumbar support garment

Cross-sectional comparison results

A sum of eight cross-sections were compared: two vertical cross-sections at the bust point and body center and six horizontal cross-sections at the chest, bust, underbust, waist, abdomen, and hip circumferences (Table 10).

Regarding the vertical cross-section image based on the body center and bust point, the participant’s back appeared straighter with the ready-made lumbar support and the lumbar support garment than when no support was worn at all.

However, the pressure exerted by the ready-made lumbar support was stronger, leading to a tight compression of the flesh around the waist, chest, and back. This can cause discomfort when obese women with excess back and belly fat wear a ready-made support for a long time. In contrast, the lumbar support garment did not generate as much compression as the ready-made lumbar support. However, the garment did result in participants having a straighter posture in terms of both sides of the shoulder when this study’s garment was tightened around the abdomen and lower back.

Wear test results

The wear test results related to the functionality and appearance of the developed garment are shown in Table 11, Table 12, and Table 13; those pertaining to its motion suitability are given in Table 14, Table 15, and Table 16. The evaluation items were composed of function, appearance, and motion suitability, while the functional and appearance items pertained to size, waist protection, convenience, and appearance. The motion suitability items were related to movement.

Table 11.

Wear test: functionality and appearance (ready-made lumbar support)

Table 12.

Wear test: functionality and appearance (lumbar support garment)

Table 13.

Wear test: functionality and appearance

Evaluation item			Means (SD)
Evaluation item			Ready-made lumbar support (n = 3)	Lumbar support garment (n = 3)
Functionality	Appropriate dimension	Q1: Is the size of the lumbar support appropriate?	4.33 (1.16)	4.67 (0.57)
		Q2: Is the height of the lumbar support appropriate?	4.67 (0.58)	4.67 (0.58)
		Q3: Is the width of the lumbar support appropriate?	4.33 (1.15)	4.67 (0.58)
		Q4: Is the thickness of lumbar support appropriate?	4.67 (0.58)	4.33 (0.58)
		Q5: Does the support fit the body’s curvature well?	4.33 (1.16)	4.33 (1.16)
	Waist protection	Q6: Does the lumbar support fix the waist well?	5.00 (0.00)	4.00 (1.00)
		Q7: Is the pressure on the waist appropriate?	4.67 (0.58)	4.00 (1.00)
		Q8: Is the pressure on the abdomen appropriate?	4.00 (1.00)	4.00 (1.00)
		Q9: Does it help relieve back pain?	4.67 (0.57)	3.67 (0.57)
	Convenience	Q10: Is it comfortable to put on?	3.67 (0.58)	5.00 (0.00)
		Q11: Is it comfortable to take off?	4.33 (0.58)	5.00 (0.00)
		Q12: Can you intuitively figure out how to wear it?	4.00 (0.00)	5.00 (0.00)
		Q13: Is it breathable?	2.67 (1.16)	4.67 (0.58)
		Q14: Is there any discomfort when the material touches the skin?	2.33 (0.57)	5.00 (0.00)
		Q15: Do you think it is easy to wash?	2.00 (0.00)	4.67 (0.58)
		Q16: Do you think it is suitable to wear for a long time?	1.67 (1.16)	5.00 (0.00)
		Q17: Do you think it is convenient to carry around and store?	4.33 (0.58)	4.00 (0.00)
		Q18: Are you psychologically comfortable wearing it, without being conscious of other people’s gaze?	1.67 (0.58)	4.33 (0.58)
		Q19: Is it good to use regardless of time and place?	2.00 (1.00)	4.33 (1.16)
Appearance		Q20: Do you like the design?	3.00 (0.00)	4.67 (0.58)
Appearance		Q21: Do you like the color?	3.33 (0.58)	4.33 (0.58)

Table 14.

Wear test: motion suitability (ready-made lumbar support)

Table 15.

Wear test: motion suitability (lumbar support garment)

Table 16.

Wear test: motion suitability

Measurement item		Means (SD)
Measurement item		Ready-made lumbar support (n = 3)	Lumbar support garment (n = 3)
Daily life	Q1: Do you encounter any inconvenience in performing small movements in your daily life?	4.00 (1.00)	4.67 (0.58)
	Q2: Do you encounter any inconvenience when standing up?	4.67 (0.58)	4.67 (0.58)
	Q3: Do you encounter any inconvenience when sitting down?	2.33 (0.58)	5.00 (0.00)
Motion 1	Q4: Do you feel any discomfort in the shoulders when you raise your arms?	4.33 (0.58)	4.67 (0.58)
	Q5: Do you feel any discomfort in the bust when you raise your arms?	4.00 (1.00)	4.00 (1.00)
	Q6: Do you feel any discomfort in the abdomen when you raise your arms?	4.00 (1.00)	4.67 (0.58)
	Q7: Do you feel any discomfort in the waist when you raise your arms?	4.33 (0.58)	4.67 (0.58)
Motion 2	Q8: Do you feel any discomfort in your shoulders when you turn your upper body sideways?	4.67 (0.58)	4.67 (0.58)
	Q9: Do you feel any discomfort in your bust when you turn your upper body sideways?	3.67 (1.53)	4.67 (0.58)
	Q10: Do you feel any discomfort in the abdomen when you turn your upper body sideways?	3.67 (1.16)	4.67 (0.58)
	Q11: Do you feel any discomfort in the waist when you turn your upper body sideways?	4.33 (0.58)	4.33 (0.58)
Motion 3	Q12: Do you feel any discomfort in your bust when you raise one leg at a 90° angle?	4.00 (1.00)	4.67 (0.58)
	Q13: Do you feel any discomfort in the abdomen when you raise one leg at a 90° angle?	3.00 (1.00)	4.67 (0.58)
	Q14: Do you feel any discomfort in the waist when you raise one leg at a 90° angle?	3.00 (1.00)	5.00 (0.00)

Across all items, the lumbar support garment received an average score of 3 or higher. In terms of size, the lumbar support garment was more highly evaluated than the ready-made lumbar support. Given that the lumbar support garment was developed for obese women in their 30s and 40s, it fitted the participants better. Regarding height, both the ready-made lumbar support and the lumbar support garment garnered an equally excellent evaluation score of 4.67. As for width, the lumbar support garment scored higher than the ready-made lumbar support did. When it came to thickness, the ready-made lumbar support was evaluated better than the lumbar support garment. (Its thickness was 2 mm, whereas that of the lumbar support garment was 3 mm.) Also notable was the opinion that the thinner lumbar support garment had the advantage in appearance when worn under other garments.

The lumbar support garment received an excellent score of 4 for the following items: waist fixation force, waist pressure, and abdominal pressure. The participants reported feeling a comfortable sense of stability, as their waist was supported while wearing the lumbar support garment. However, they also noted that they did not feel that the garment’s fixation force was as strong as that of the ready-made lumbar support. The latter exerted a stronger pressure on the abdomen, but it also resulted in body swelling or pain after being worn for an hour. By contrast, the lumbar support garment exerted less pressure to straighten the waist and created no discomfort when worn for more than an hour.

Although the lumbar support garment received a good score, 3.67, when rated on back pain relief, this score was lower than the ready-made lumbar support’s score. Because the lumbar support’s most essential function is relieving back pain, the fixation pressure exerted by the lumbar support garment may need to be increased slightly.

In terms of convenience, the lumbar support garment scored higher than the ready-made lumbar support for all items except for carrying and storage. Regarding ventilation, the ready-made lumbar support scored quite low (2.67), whereas the lumbar support garment received a significantly higher score (4.67). For the material, all three participants gave the lumbar support garment a score of 5. Noticeably, each participant said she felt that the material had good elasticity and was soft to the touch. The two products also differed significantly in terms of washing, with the lumbar support garment garnering a 4.67 score and the ready-made support scoring 2.00. Given that the lumbar support garment is detachable, machine washing it was easy.

An extremely high score of 5 was assigned to the lumbar support garment based on its suitability for long-term wear. In contrast, the ready-made lumbar support scored quite low (1.67). When evaluated for wearability without being conscious of another’s gaze, the lumbar support garment scored 4.33 and the ready-made lumbar support scored 1.67, thus showing a significant difference in this category. The participants reported that the lumbar support garment was worn under their clothing, but the ready-made lumbar support was worn outside their clothes, creating an important difference in terms of psychological burden related to the gaze of others. Similarly, on its wearability regardless of time and place, the lumbar support garment obtained a better score than the ready-made lumbar support.

When evaluated for appearance, such as design and color, the lumbar support garment obtained better results at 4 than the ready-made lumbar support did at 3. However, an opinion was expressed that a slightly thinner shoulder strap would look better for this study’s garment.

In terms of items related to motion suitability, the lumbar support garment received a high score of 4 or higher. The ready-made lumbar support also received good scores in terms of performing movements necessary for daily life and for standing posture. However, the latter received a low score of 2.33 for sitting posture.

Both the ready-made lumbar support and the lumbar support garment scored well in the category of raising both arms. However, in interviews, the participants did comment that, when wearing the ready-made support, they felt uncomfortable raising their arms above their heads because other layers of clothing would be swept up and would have to be rearranged. In terms of being able to turn the upper body sideways, the lumbar support garment obtained positive results, at 4. One participant noted that wearing the lumbar support garment involved no discomfort at all when raising one leg. The garment received a high score in this regard, consistent with the comment given in the interview.

Appearance evaluation results

To clarify the evaluation and improvement plans for a lumbar support garment regarding its apparel design aspects and its spine support function, a Wilcoxon signed-rank test was performed to compare appearance evaluation results between the apparel experts and the spine/joint experts. The developed garment received good evaluation scores for its front, side, and back appearance (Table 17). The average score for the bust area was also good at 3.88, but participant 2, who had a large bust circumference, reported that the garment’s ease around the bust was insufficient and looked like it was pulled towards the back. Many obese women have a large bust, and apparel experts say that such a body type should have an additional means to support the bust other than just a built-in bust pad. This problem may be solved if a nonstretchable material is used partially on the side lines.

Table 17.

Results of the experts’ appearance evaluation

Evaluation item		Means (SD)			Wilcoxon Z
Evaluation item		Total (n = 11)	Apparel expert (n = 8)	Spine/joint expert (n = 3)	Wilcoxon Z
Overall appearance	Does the front look good?	3.97 (0.88)	3.92 (0.94)	4.11 (0.84)	–0.289
	Does the left look good?	3.67 (0.60)	3.67 (0.67)	3.78 (0.51)	–0.649
	Does the back look good?	3.94 (0.68)	3.88 (0.67)	4.11 (0.84)	0.000
	Is the amount of ease regarding the bust good?	3.88 (0.73)	3.75 (0.81)	4.22 (0.38)	–1.000
	Is the amount of ease regarding the abdomen good?	4.21 (0.67)	4.00 (0.67)	4.78 (0.19)	–2.449^*
	Is the amount of ease amount regarding the back good?	4.12 (0.70)	4.00 (0.76)	4.44 (0.51)	–0.378
	Is the amount of ease regarding the armhole good?	3.67 (0.75)	3.71 (0.88)	3.56 (0.19)	–0.877
	Is the location of the shoulder line appropriate?	3.79 (0.75)	3.73 (0.82)	4.56 (0.19)	–1.155
	Is the location of the sideline appropriate?	4.09 (0.52)	4.04 (0.60)	4.22 (0.19)	–0.905
	Do you like the combination of the garment and the lumbar support?	4.09 (0.82)	3.83 (0.80)	4.78 (0.38)	–1.508
	Is the balance between the garment and the lumbar support good?	4.12 (0.64)	4.00 (0.62)	4.44 (0.69)	–0.632
	Do you like the material aesthetically?	4.03 (0.78)	3.79 (0.73)	4.67 (0.58)	–1.732
	Do you like the material’s color?	4.30 (0.64)	4.17 (0.64)	4.67 (0.58)	–1.732
	Do you think the overall design is good aesthetically?	3.91 (0.68)	3.67 (0.59)	4.56 (0.51)	–2.271^*
The outer appearance of the lumbar support	Is the height of the lumbar support appropriate?	4.12 (0.70)	4.00 (0.80)	4.44 (0.19)	–0.879
	Is the width of the lumbar support (center support) appropriate?	4.15 (0.52)	4.08 (0.58)	4.33 (0.33)	–0.707
	Is the height of the lumbar support (center support) appropriate?	4.00 (0.67)	3.92 (0.66)	4.22 (0.77)	–0.707
	Is the thickness of the lumbar support (center support) appropriate?	4.09 (0.56)	4.13 (0.56)	4.00 (0.67)	–0.173
	Is the curve of the lumbar support (center support) appropriate?	4.09 (0.70)	3.96 (0.74)	4.44 (0.51)	–1.667
	Is the width of the lumbar support (auxiliary support) appropriate?	3.97 (0.85)	4.00 (1.01)	3.89 (0.19)	–1.100
	Is the height of the lumbar support (auxiliary support) appropriate?	4.36 (0.62)	4.17 (0.62)	4.89 (0.19)	–1.994^*
	Is the thickness of the lumbar support (auxiliary support) appropriate?	4.27 (0.93)	4.13 (1.02)	4.67 (0.58)	–1.127
	Is the curve of the lumbar support (auxiliary support) appropriate?	4.18 (0.62)	4.08 (0.68)	4.44 (0.38)	–1.186
	Is the position where the lumbar support wraps around the waist appropriate?	4.24 (0.73)	4.00 (0.71)	4.89 (0.19)	–2.460^*
	Does the lumbar support fix the waist well?	4.27 (0.59)	4.33 (0.67)	4.11 (0.38)	–0.996
	Do you like the fastening method of the lumbar support?	4.42 (0.90)	4.25 (1.00)	4.89 (0.19)	–1.656
	Is the shape of the lumbar support pocket good?	4.12 (0.82)	3.96 (0.88)	4.56 (0.51)	–1.994^*
	Do you like the overall design of the lumbar support?	4.21 (0.90)	3.96 (0.93)	4.89 (0.19)	–2.081^*

*P<0.05, **P<0.01, ***P<0.001.

In terms of the amount of ease around the abdomen, the developed garment received an excellent score of 4.00 or higher from all the experts. On the Wilcoxon signed-rank test, apparel experts assigned significantly lower scores to this item than the spine/joint experts did. According to the apparel experts, the abdomens of participants 1 and 3 seemed to protrude when they wore the garment, although this may have been an issue of posture as well. Obese women prefer a lumbar support whose appearance complements their body shape, so the developed garment must be improved to make the abdomen look slimmer.

Although the developed garment scored well on the degree of ease around the armholes (3.67), this was also its lowest score. In particular, participant 2 rated the garment on this item relatively low (3.27), which may be because she had the shortest height and a short upper body, resulting in excessive ease. This problem can be addressed by making the shoulder strap’s length adjustable. The combination of and balance between the garment and the lumbar support aspects received a strong score of 4.00 or higher, confirming that the overall balance was excellent.

When evaluating the overall design, the apparel experts’ score was 3.67 and the spine/joint experts’ score was 4.56, which showed a significant difference of approximately 1 point. One reason for this difference may be that the apparel experts considered the design details, supplementation of the body shape, and function as an innerwear all together, while the spine/joint experts likely evaluated the design by considering mostly the lumbar support’s functionality.

The developed lumbar support’s height, width (particularly at the center), size, thickness, and curvature all received a satisfactory score of 4. For the auxiliary support height, the spine/joint experts awarded significantly higher scores than the apparel experts did, indicating that the height was appropriate. The scores for the auxiliary support’s width, height, thickness, and curvature were also evaluated well, ranging from 3 to 4. Both the width and height of the auxiliary support were appropriate, but one expert voiced the opinion that both the central and auxiliary supports were a little too thick.

A thin woman needs a lumbar support with a definite curve, but an obese woman has a large abdomen; as such, the developed support features a gentle curve that adjusts to the abdominal flesh when the wearer is in a seated position. The spine/joint experts regarded this design as suitable for the body types of obese women.

In terms of position and fixation force, both apparel experts and spine/joint experts scored the lumbar support highly at 4.24 and 4.27, respectively. In particular, the experts’ scores for the position in which the lumbar support wraps around the waist differed significantly. The central support wrapped around one-thirds of the waist’s width; thus the support was appropriate for obese women’s body types. This resulted in less wearing fatigue than the ready-made lumbar support.

Regarding the pocket shape, the spine/joint experts assigned this feature a significantly higher score than the apparel experts gave it, as they found the detachability of the 3D printed support to be a good option. However, the spine/joint experts suggested curving the bottom of the pocket further because there is a curve beneath the central support.

Overall, the lumbar support garment received positive evaluations in terms of appearance. Furthermore, the appearance evaluation results by the experts aligned with the wear test results by the participants. Wear test participants suggested that if the thickness of the support were a little thinner, it would be more comfortable to wear, which is consistent with the spine/joint experts’ opinion in the appearance evaluation. In addition, spine/joint experts found the curvature of the support inserted into the garment was suitable for obese women, and the wear test participants also said that the support was stable. The wear test participants reported that the lumbar support garment’s fixation force was weaker than the ready-made lumbar support’s, which, as the apparel experts noted, could be improved by using nonstretch fabrics on the side. In addition, the lumbar support garment’s design received good responses on both the wear test and the appearance evaluation, demonstrating that wearing the lumbar support garment had less psychological burden and could more fully satisfy the aesthetic needs of obese women. Improving the design according to the opinions given by both the experts and the participants would additionally improve the developed garment’s overall aesthetics, as well as its capacity to protect the lower back.

Conclusion and suggestions

This study sought to develop a lumbar support garment, using 3D printing technology, that has a good fit and strong aesthetics for obese women in their 30s and 40s. A survey was conducted to investigate consumers’ satisfaction with commercially available lumbar supports and to ascertain their considerations for purchase. The higher the degree of obesity, the more difficult it was for consumers to find an option offering a suitable size and ease in washing and care. When purchasing lumbar supports, respondents prioritized back protection/prevention of back pain and ease of movement. A participant’s level of obesity corresponded to how much she considered the shape, fastening method, and size of the lumbar support.

The functionality of this study’s lumbar support garment was verified using a cross-sectional evaluation, a wear test, and an appearance test. The cross-sectional evaluation showed that the garment compressed the lower back and providedgood lumbar support. The wear test’s results confirmed the developed garment to be excellent in terms of functionality and back support, and particularly so regarding back fixation and abdominal pressure. However, the garment did receive relatively lower scores than the ready-made lumbar support for exerting pressure on the back and relieving pain. In terms of ventilation, material, washing, and wearability for a long period of time, the ready-made lumbar support scored very low, whereas the developed garment garnered very high scores, indicating it provides greater convenience. Moreover, because the lumbar support garment can be worn under one’s clothing, it lessens one’s tendency to be conscious of another’s gaze, thereby providing greater psychological comfort.

In the category of appearance, the lumbar support garment was rated moderately, coming in at over 3.00. However, an expert opined that the garment must be improved around the chest and its sides because it made the shoulder line, sidelines, and armholes look as though they were leaning forward. A spine expert found the garment slightly too thick and suggested reducing its thickness by 1 mm to improve both its functionality and its appearance.

Although the PETG material used in the developed lumbar support was strong, it is somewhat inflexible. Thus to develop a lumbar support suitable for various body types, a material with more flexibility would be advised. This paper suggests that future studies should develop lumbar supports using diverse 3D printing materials.

This study developed a lumbar support garment for obese women in their 30s and 40s using the innovative technology of 3D scanning and printing technology. The 3D technology used in this study is considered idea for developing customized lumbar supports for individual body types. Finally, this study argued that the procedures of the current study provide valuable information and can offer new directions in developing diverse protective garments in apparel studies.

Footnotes

Acknowledgements

This work is based on the part of the master's thesis of the first author.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Dong-Eun Kim

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