Refined Kano Model Ranks What Wearers with Lower Limb Disabilities Need Most in Trousers

Using a refined version of the Kano model combined with sensitivity analysis and exploratory analysis of variance, a team at Shanghai University of Engineering Science evaluated thirty adaptive design attributes based on survey data from 214 respondents with unilateral or bilateral lower limb disabilities. Their findings, published in the journal Fashion and Textiles, show that physiological comfort and accessible donning mechanics form the non-negotiable baseline of user satisfaction, while aesthetic and purely decorative features often contribute little, or in some cases actively generate negative reactions.

The study responds to a persistent gap between what adaptive clothing users need and what the market provides. According to the World Health Organization figures cited by the authors, roughly 1.3 billion people, about sixteen percent of the global population, experience significant disability, and nearly eighty percent of persons with disabilities live in low- and middle-income countries. Individuals with lower limb disabilities often face mobility constraints and body asymmetries that make routine dressing difficult or dependent on assistance. When standard ready-to-wear garments fail to accommodate these conditions, the consequences extend beyond inconvenience: reduced autonomy, diminished social participation, and lowered quality of life. Adaptive clothing has emerged as an assistive intervention addressing these problems, yet user satisfaction with commercially available products remains persistently low.

A central reason, the authors argue, is heterogeneity. Physical impairments vary widely, and users with different disability types exhibit systematically different requirements in clothing styles, garment structure, dressing mechanisms, and functional features. Existing design and garment development approaches, however, still largely rely on aggregated or averaged user assumptions, which limits mass customization and produces a homogenized market. Many current designs overemphasize functional accommodation, resulting in medicalized appearances that can reinforce disability stigma and fail to support social identity expression. User expectations, meanwhile, have shifted from purely functional requirements toward integrated aesthetic, identity-related, and dignity-oriented needs.

To capture these nonlinear preference structures, the team turned to the Kano model, originally proposed by Noriaki Kano in 1984. The model classifies product characteristics into five categories based on how their presence or absence influences satisfaction: must-be qualities, whose absence causes extreme dissatisfaction; one-dimensional qualities, whose satisfaction rises proportionally with performance; attractive qualities, which delight users when present but whose absence causes no dissatisfaction; indifferent qualities, which have negligible impact; and reverse qualities, which cause dissatisfaction when present. Conventional Kano analysis assigns categories by maximum response frequency at the population level, which can obscure differences among user segments. The researchers therefore refined the approach with Better-Worse coefficients, where the Better coefficient, ranging from zero to one, quantifies how much satisfaction increases when an attribute is provided, and the Worse coefficient, ranging from minus one to zero, quantifies dissatisfaction when it is absent.

The thirty requirement elements were distilled from an initial pool of approximately fifty-two items generated through literature review, internet research, market investigation, and user feedback, then screened by a panel of five domain experts with more than ten years of professional experience each: two rehabilitation physicians, two adaptive clothing designers, and one occupational therapist. Items scoring below 3.5 on five-point relevance and clarity scales were removed, and redundant items were merged, yielding the final set of thirty attributes organized into eight primary categories.

The questionnaires were distributed through visits to adult day centers for disabled individuals, nursing homes, and disability associations, as well as online through platforms such as the China Self-Empowering Public Welfare Forum and dedicated communities and mobile applications for people with lower limb disabilities. Participants had to have a unilateral or bilateral lower limb disability, verified through institutional registration for offline respondents or self-screening questions online, and be at least fourteen years old. Caregivers and experts were excluded so that the data reflected direct users alone. Of 229 questionnaires distributed, 222 were returned, and after eight invalid responses were removed, 214 valid questionnaires remained, a validity rate of 93.45 percent. The protocol was approved by the Ethics Committee of Shanghai University of Engineering Science, and written informed consent was obtained from all adult participants, with parental or guardian consent secured for those under eighteen.

The questionnaire showed acceptable internal consistency, with Cronbach’s alpha coefficients ranging from 0.7 to 0.9, a mean Kaiser–Meyer–Olkin measure of 0.916, and a significant Bartlett’s test. When the responses were classified, the thirty attributes distributed across four quadrants. The first quadrant held nine one-dimensional qualities, predominantly functional and service-related attributes such as zippers, Velcro, insulation, and one free alteration, whose fulfillment directly and proportionally increases satisfaction. The fourth quadrant contained six must-be qualities centered on baseline comfort and utility, including softness, air permeability, and easy fit. These foundational attributes are expected by default, and failing to meet them causes a drastic drop in satisfaction. The second quadrant comprised five attractive qualities, value-added features such as abrasion resistance, waterproofness, and neutral color, which delight users when present but whose absence does not inherently cause dissatisfaction. The third quadrant held ten indifferent qualities, leaning toward purely aesthetic or restrictive designs such as complex styling, slim fit, and patterned fabrics, whose presence or absence has negligible impact on satisfaction.

Notably, several attributes, including complex design, slim fit, and personalized design, showed reverse as the most frequently selected Kano category. Because reverse responses are excluded from Better-Worse coefficient estimation by convention, these attributes were subsequently classified as indifferent in the refined analysis, but the authors caution that the high proportion of reverse responses suggests these features may generate negative perceptions among certain users and deserve careful consideration.

The sensitivity analysis produced values ranging from 0.185 to 0.905, indicating substantial variation across attributes. Softness ranked highest at 0.905, followed by universal design at 0.828 and air permeability at 0.813. At the other end, slim fit scored 0.185 and complex design 0.220. Functional fastening elements such as Velcro at 0.761, elastic bands at 0.727, and zippers at 0.689 showed relatively high sensitivity, as did after-sales service attributes including sets of accessories at 0.739 and one free alteration at 0.721.

Beyond the overall ranking, the researchers examined how classifications shifted across demographic subgroups. Gender differences were relatively limited. For male users, abrasion resistance became a one-dimensional quality, suggesting higher expectations for durability, while neutral color and unpatterned fabrics shifted from indifferent to attractive. Female users, by contrast, showed contrasting colors and patterned designs shifting to attractive qualities, indicating a stronger preference for individuality in color and a greater tolerance for varied patterns.

Age produced more pronounced shifts. Among adolescents, personalized design moved from indifferent to one-dimensional quality and patterned fabrics entered the must-be region, while neutral color and three after-sales service elements dropped toward indifferent, suggesting this group prioritizes fashion, style, and trends over services. For young adults, universal design became one-dimensional, personalized design entered must-be quality, and patterned fabrics became one-dimensional, reflecting growing interest in individualized styles but less attention to functional aspects and additional services. Middle-aged and older adults focused on quality and functionality: laundry and care service shifted to one-dimensional quality, and the middle-aged group emphasized fit, with close-fitting designs becoming one-dimensional. In the older adult group, Velcro shifted from one-dimensional to must-be quality, waterproofness moved to one-dimensional, and neutral color faded from attractive to indifferent, changes the authors link to increasing fragility, extended periods spent bedridden, and the need for easy donning and doffing.

Disability type also mattered. For individuals with unilateral disabilities, close-fitting designs shifted from indifferent to attractive, drawstring closures and abrasion resistance moved to one-dimensional, and elasticity became must-be. The authors note that this group relies primarily on one leg for support and may benefit from structural features such as auxiliary belt loops that prevent legs from dragging or tangling in crutches. For those with bilateral disabilities, waterproofness and insulation transitioned from attractive to one-dimensional, reflecting the needs of people who may be sedentary or bedridden, experience poor thermal regulation, or require easy-to-clean, waterproof, and antibacterial fabrics, potentially alongside a diaper bag. Unpatterned fabrics entered one-dimensional quality for this group, whose members tend to be more cautious about drawing attention through patterns.

Finally, exploratory two-way ANOVAs on the full sample of 214 respondents tested interactions among age, gender, and disability type for each of the thirty attributes. Four patterns met the nominal significance threshold of p below 0.05. An age by disability interaction emerged for personalized design, with the contrast between unilateral and bilateral groups most pronounced among adolescents and diminishing in older age groups. A similar interaction appeared for Velcro, with bilateral participants showing stable preference scores across age groups while unilateral participants showed greater age-related variation. An age by gender interaction emerged for close-fitting designs, with male participants stable across ages and female participants showing lower ratings in young and middle adulthood but higher ratings in adolescence and older adulthood. A gender by disability interaction appeared for abrasion resistance, with unilateral participants reporting higher preference scores, and a moderate male-female difference within the bilateral group but little gender difference in the unilateral group.

The authors stress that these subgroup patterns are exploratory and best viewed as flexible design directions rather than prescriptive rules. They also acknowledge limitations: the cross-sectional, regionally bounded design, the absence of disability duration and socioeconomic variables, and uneven subgroup sample sizes, particularly the smaller adolescent group, all constrain generalization and the interpretation of the interaction analyses. Future work, they suggest, should employ more balanced sampling, longitudinal and cross-cultural designs, and emerging technologies such as 3D virtual fitting and wearable sensing to better capture how adaptive clothing needs evolve across populations.

Subject of Research: Prioritizing adaptive lower garment design attributes for people with lower limb disabilities using a refined Kano model and demographic interaction analysis

Article Title: Beyond functionality: prioritizing adaptive lower garment requirements for lower limb disabilities using a refined Kano model with demographic interaction analyses

Article References: Chang, H., Tao, X., & Han, H. (2026). Beyond functionality: prioritizing adaptive lower garment requirements for lower limb disabilities using a refined Kano model with demographic interaction analyses. Fashion and Textiles, 13(1), Article 41. https://doi.org/10.1186/s40691-026-00496-5

Image Credits: AI Generated

DOI: 10.1186/s40691-026-00496-5

Keywords: adaptive clothing, Kano model, lower limb disabilities, garment design, Better-Worse coefficients, two-way ANOVA, user satisfaction, inclusive design, assistive clothing, Fashion and Textiles, survey research, design prioritization