床垫硬度、性别和体型对体压分布的影响研究OA

Sleep quality has become a growing public concern worldwide.Among various external factors influencing sleep,the mattress serves as the primary interface between the human body and the sleep environment,playing a crucial role in determining sleep comfort and quality.Body pressure distribution at the human-mattress interface has been widely recognized as an objective indicator for evaluating mattress comfort,as it directly reflects the biomechanical interaction between the body and the support surface.However,existing mattress designs often lack sufficient consideration of user diversity in terms of gender and body type,despite increasing evidence suggesting that these physiological factors significantly influence pressure distribution patterns. This study systematically investigates the independent and interactive effects of gender,body type,and mattress firmness on body pressure distribution.A total of 101 young participants aged 20-30 were recruited,all in good health with no musculoskeletal disorders.Participants were divided into six groups based on gender and body mass index(BMI),following the guidelines of the working group on obesity in China(WGOC):underweight(BMI<19 kg/m2),normal(19 kg/m2≤BMI≤23.5 kg/m2),and overweight(BMI>23.5 kg/m2)for both males and females. Five commercially available mattresses with varying firmness levels were selected for this study.The mattresses differed in their structural compositions,including various combinations of pocket springs,natural latex,memory foam,coconut fibers,and 3D materials,representing a typical range of products available in the market.A flexible pressure sensing mat(SensAxis,1.9 m×1.2 m)with 1 152 sensors(36 mm×36 mm each)was used to collect pressure data at a sampling rate of 20 frames per second.Participants assumed a standardized supine posture with feet separated by 30 cm,arms relaxed at the sides,and body aligned parallel to the mattress surface.Pressure data were recorded for five seconds after stabilization,yielding 100 frames per trial,with each condition repeated three times.Three key indicators were extracted:average pressure(Pave5),calculated for sensor values above 5 mmHg to eliminate limb extremity artifacts),95th percentile peak pressure(P95),and contact area(AREA). A linear mixed model(LMM)was established with gender,body type,and mattress firmness as fixed effects,while individual differences were treated as random effects.Multivariate analysis of variance(N-way ANOVA)was employed to quantify the strength of main effects and interaction effects.Model validation showed conditional R2 values ranging from 0.84 to 0.94 across indicators,with residual analysis confirming normal distribution and model assumptions. The results revealed that mattress firmness was the most dominant factor determining average pressure(F=10.953,P<0.001)and P95 maximum pressure(F=9.660,P<0.001),followed by body type(F=6.883 for average pressure,F=5.477 for P95)and gender(F=3.657 for average pressure,F=3.527 for P95).Contact area was most significantly influenced by mattress firmness(F=58.004,P<0.001),serving as a key mediating variable in pressure regulation.Using thin females on the firmest mattress(No.1)as the baseline,the model predicted an average pressure of 19.74 mmHg and P95 of 36.64 mmHg.Males exhibited higher average pressure(+3.2 mmHg)and P95(+8.16 mmHg)compared to females.Overweight individuals showed substantially higher pressures,with average pressure increasing by 6.9 mmHg and P95 by 15.88 mmHg relative to thin individuals.Softer mattresses progressively reduced pressures,with the softest mattress(No.5)decreasing average pressure by 3.8 mmHg and P95 by 8.18 mmHg compared to the baseline. Interaction effects were generally non-significant across most combinations.However,a notable gender×mattress firmness interaction was observed for contact area(F=2.345,P<0.05).Interestingly,on flat-surfaced mattresses,females consistently demonstrated larger contact areas than males,despite males having larger body dimensions.This phenomenon can be attributed to gender differences in body fat distribution and pelvic structure.Females typically possess higher subcutaneous fat content,which enhances body conformity to the mattress surface,while wider pelvic angles in females increase sacral support area,collectively contributing to greater contact area.A sensitivity analysis excluding a mattress with an uneven surface design(No.2)further confirmed the dominant role of firmness in determining contact area(R2=0.975),while also highlighting surface design as a potential independent variable influencing pressure distribution. This study quantifies the independent effects of mattress firmness,body type,and gender on body pressure distribution,establishing a clear hierarchy of influence:firmness>body type>gender.The findings underscore the importance of considering user physiological characteristics in mattress design and provide a theoretical foundation for personalized mattress recommendations.