Mattress firmer is a central determinant of our sleeping experience. Unfortunately, few scientific studies deal with the impact of mattress firmness on sleep quality from the perspective of a consumer selecting and owning a bed bed mattress. The present interdisciplinary study brings together expertise in biomechanics, psychology, and sleep, with the objective of increasing our understanding of the impact of different firmness levels on the sleep experience. This is important in the context of the growing commercial interest in personalizing sleep solutions in order to support healthy, restful, and recuperative sleep. Comfort is typically established as a combination of personal and situational factors, combined with the physical ambient environment, of which the mattress profile has been recognized as an important part. Information about the history and development of mattress firmness studies, the impact of different mattresses under bed or laboratory study conditions, and firmness preferences in both the general population and specific clinical groups is provided to aid the reader in understanding the newer analytical techniques presented in this stepwise linear approach.
The number of legal requirements concerning the establishment of the materials found in or associated with commercially available sleep-related products is increasing. It is anticipated that the escalating demand for clean sleeping options will be a future major driver in the consumer bedding marketplace. In such a highly regulated environment, consumers should be provided with guidelines on how to select their best sleep solution, using this information to reduce their risk of future injury from non-optimized sleeping arrangements. For a given individual, there appear to be no relationships between one of eleven mattresses and their perceived overall comfort after three months with the mattress, nor was there any correlation between their overall judgment of comfort and their in-bed pressure distribution, total bed pressure, mattress index of hardness, mattress elasticity, or embodiment. Given the close relationship between mattress firmness preferences between samples, the general practical need for both manufacturers and clinics to investigate new mattresses seems to be limited.
Definition and Importance
Mattress firmness refers to the degree of resistance of the sleeping surface to the weight placed on it. To measure this, specific methodologies, either subjective or objective scales, or the combined values, are used. The subjective scale includes the personal perceptions of either sleep professionals or bed manufacturers. The objective scale, however, is based on the force-deflection measurement of the mattress surface. In many cases, mattress firms are listed in a series from soft to very firm. A person’s perception depends on psychological sensations, which in turn are caused by different mattress materials and constructions.
Mattress firmness is equally important to both health professionals and other people: those who need to treat sleeping disorders and patients for whom this factor might be unimportant, as well as lay sleepers. Different sleeping positions require different support values. For instance, while back sleepers need proper and constant spine alignment, side sleepers need deep comfort to achieve the same result; thus, they require a softer sleeping surface. Also, one’s body mass may drastically influence bed preference because when the weight of the person is not evenly distributed, especially when they are lying down on a less supportive surface, shoulders or hips might assume a greater sinking compared to the rest of the body, which may often result in a not medically advisable lack of curve in spine alignment. People with larger body mass often require a mattress with greater support to withstand the increased sinkability, as well as increased friction during lateral movements, increasing their support. Based on these facts, several firmness values can be established. Any person who wants to invest in a new mattress needs to know about this aspect because the quality of sleep provided by a new mattress may represent a distinct sum of money. Besides, inadequate spinal support caused by sleeping on an uncomfortable mattress can frequently lead to increased back pain in adults. It is estimated that approximately 900,000 people suffer daily from back pain severe enough to impact their daily lives. The same source of injury accounts for 17% of work-related productivity loss.
Factors Affecting Mattress Firmness
In general, the firmness of a mattress can be influenced by either a combination of different materials and the construction method used. Due to their characteristics, materials such as memory foam, latex foam, and innersprings have naturally occurring low, medium, and high levels of firmness. In addition, the softness and firmness of a mattress can be incorporated into the structure and design by varying the manufacturing process or technology, changing the density of the materials or padding, as well as by layering the substrates. Indeed, several regional practices in mattress manufacturing have reported how mattress top construction methods greatly determine the mattress top firmness compared to the bottom firmness, such as hinged springs in high-end mattresses. Another factor that can cause variations in mattress firmness is damage to the inner cushion or the breaking of internal springs. This type of damage can adversely affect the support given by a mattress, leading to areas with a lower firmness when users sleep on top of it. Furthermore, external factors such as temperature or humidity can cause the materials to lose their fluffy or cushioning properties. Therefore, the firmness and softness of a mattress are part of the physical and mechanical properties that can predict the mattress’s durability, wear, and deterioration. There are no general agreements on the subjective rating of mattress firmness. It is perceived differently among individuals based on their body weight distribution, position on the mattress, personal preference, body or muscle conditions, among others. A survey has shown the existence of different regional preferences because of the impact of cultural, historical, religious, traditional, gender, or lifestyle differences.
Historical Evolution of Mattress Firmness
Consequently, the debate on mattress firmness dates back to ancient times. At that time, it was common to add a layer of straw, wool, horsehair, or feathers to the bed platform to make it more comfortable. Therefore, the firmness of the mattress was related to the material that was in direct contact with the sleeper: straw made a dry bed, wool had a certain resistance, and feathers turned a hard bed into something softer. The mattress stuffing was arranged in specific pockets or cavities to prevent the fillers from shifting.
The evolution of materials, machines, and the rapid market expansion as a result of the end of World War II allowed different levels of firmness to be obtained thanks to spring mattresses, which were followed by newer and more relaxing forms of polyurethane foam. In other words, firmness was no longer associated with the “comfortable material” that lies directly under the bed linen, but with an “independent” component of the springs. Similar solutions gave both Beck’s bed in England and the patented long-lasting steel springs. A feather-padded bag was then replaced by a box of springs and a mattress filled with materials capable of providing a level of comfort other than a mattress filled with other materials. Rather than considering the historical evolution of only hydraulic or air mattresses according to Asian and Japanese traditions, it is interesting to discuss the concept of mattress firmness as described by stating that “there are no right or wrong traditions, there are only different tastes”.
Traditional Mattress Materials and Firmness
The mandated choice of material was due to the necessity to provide the right level of comfort for the mattress user. Certainly, hay-filled mattresses or those made of strong-smelling goat hair would have been disregarded, as this was not seen to be the type of comfort a user would pay for. It is interesting to note that a parallel development between regional sleeping materials and the firmness of the mattress filling has always existed. Such differences in local attitudes support the argument that the selection of the mattress filling strongly depends on its inherent firmness characteristics. The regional variations may have been due to the availability of material. Materials such as hay, cornhusk, straw, chaff, heather, cotton, and corn did not vary in firmness.
Those mattresses that used wool, feathers, kapok, Spanish moss, sea grass, hair, bran, flax, and cotton could be considered adjustable, not in that the seller could provide mattresses of any consistency of firmness, but rather that the buyer received the mattresses filled with clean material at changing stages of softness or firmness. Cleaning of the selected mattress materials had an impact on the comfort characteristics of the mattress fillings. Cleaning wool, for example, increased material resilience but did not change the feel. Selecting the correct cleaning process boosts the characteristics inherent in the fiber; a process that is continually being developed. The randomness of the naturally filled adjustable mattresses produced inherent differences between supposedly identical mattresses. Hence, there was a perceived need for mass production of a standard product. As the character of the manufacturer could not be passed on, an obsession with personal cleanliness meant that a fresh start was required. In 1930, appraised attitude surveys indicated that to the majority of consumers, personal body hygiene and external appearance were paramount, leading to the widespread use of covering materials that can be wiped clean. In contrast to the largely natural mattress fillings used in traditional mattresses, the filling of choice has changed to foam – for the mattress of solemnity has not.
The Science of Sleep and Mattress Firmness
Sleep is an essential part of good health, and its quality is a measure of your overall wellness. Physical and mental health and safety are influenced by sleep and witnessed through quality and quantity. Many factors mimic sleep quality, and some of them may be more essential than a perfect mattress. Now, if we talk about how important the role of a good mattress is in achieving a good night’s sleep, the answer is significant. It may come as a bit of a surprise how much it affects the quality of your sleep.
To pick the right mattress for the sleeper, the internationally recommended push-through test is regularly used. Skin pressure, pressure on the selected three body parts, along with small pressure differences between gender, size, and BMI, are considered. Mattress firmness not only affects sleep factors (e.g., sleep quality, comfort, and sleep behavior), but mattress comfort and sleep quality are subject to subjective indicators (such as body pain, pressure in the body, rolling/movement turbulence, sound, and sleep breakpoints), and it can lead to the occurrence of certain sleep illnesses (such as back pain, discomfort, and neck pain) in some age groups and genders. Negative sleep quality, back pain, and mattress comfort with age and gender: the mattress comfort was not age-dependent or gender-dependent. Female sleepers reported better bed comfort than male sleepers. A normal pillow sleeper had a smoother transition during bedtime with excellent comfort. A bed that dispels pressure on the limbs, keeping your shoulders and hips apart, is ideal. Sleep and comfort will enhance sleep quality. A mattress with the push-through value of the features on the body provides better results for pillows and sleepers, which leads us to advise: a sleeper should prefer to use the pillow, and the make can be advised with the push-through value shown. As the sleeper passes the push-through test, the relationship between sleep qualities as the primary result and age or gender with mattress comfort/difficulty was not affected. The age group of 40-50 years had a lower chance of high back pain due to good comfort compared to the 60-year age group. The pillows had, therefore, less advantage in spinal comfort and sleep quality due to age than the second pillows. Since the percentage of Eastern 40- to 50-year-old men was smaller, Eastern men had a higher chance of good comfort in sleep and a lower chance of intense back pain. A good level of disposable mattress importance would also reduce pain for young adult men and children. The push-through test would choose the mattress that comforts the weak and men of the East. With growing age or weight, the examination was somewhat difficult, which means the four beds are just too soft. The correct type of bed according to the individual’s research situation will help prevent back pain and neck pain. Customization based on individual sleep comfort will prevent sleep discomfort.
Impact of Mattress Firmness on Sleep Quality
Multiple research studies, as well as expert opinions, suggest that mattress firmness can have an impact on sleep quality, mainly through sleep disturbances and restfulness indicators. A mattress needs to have firmness that matches a person’s spine alignment, which can help reduce back pain issues. Interestingly, several studies have also found that the interplay between a person’s weight or sleep position aligns and affects the mattress’s best firmness. Subjective indicators have also been largely discussed as relevant in choosing mattress firmness. These factors are related to physiological or psychological comfort, such as reporting that a supportive mattress promotes restful sleep.
The perception of mattress support was associated with reduced sleep problems. Almost 11,000 respondents from a poll were side sleepers, followed by back sleepers and stomach sleepers. Qualitative research, as well as expert career panel forums and sleep study reports, suggests that the ‘right’ mattress firmness is the one that makes you feel well if you wake up relaxed, rested, and ready for the world. After their previous mattress was removed, a percentage of participants experienced restful features when buying a mattress that makes them relaxed. Standard static analysis was used to model the full sample and 25-year-old data.
Comparative Analysis of Mattress Firmness in Different Countries
There are differences between the preferences of various nations and regions. The U.S. market prefers mattresses classified as being “medium firm to firm,” while the Chinese market prefers a harder to more moderate “firm” feel. This shows that the needs and discussions around mattress firmness can also be influenced by the culture of a given country. Along this line of thinking, there is less talk about mattress quality in some countries and more discussions about firmness and perhaps comfort based on firmness. With recent mattress purchases being made online and personalities who had an early co-sleeping exposure, we might see a blue ocean in that country.
Other mattress case studies can be made or at least listed that are completely opposite to the findings in this study. For example: India: Based on past Indian companies, the market overall prefers “leadership-based”. The inner spring was the preference, though it has largely gone to all-polyurethane today. The polyurethane was “hard.” People slept on their sides about 15% of the time, mostly center. However, the preference was not to promote a soft “side” position in the marketing, because people saw the floor mats as being “hard” and wanted their beds to be as well. The firmness translated into strength in the workers’ arms to push themselves up out of it, creating the oxygen benefit positioning of the claim. Consumers lie on their back; side sleep is secondary. Workers did not lie on their sides when testing beds in the stores.
Case Study: Mattress Firmness in Japan
In Asian countries, as well as in other regions, comfort preference for mattresses is largely influenced by cultural factors. In Japan, a traditional belief is that sleep is best done in minimalism, therefore giving rise to the popularity of futons – thin, firm mattresses. A nationwide survey conducted on 2,000 adults with an equal gender ratio revealed that 61.7% of adult respondents use a futon. The survey shows that there is a preference by Japanese consumers for thin and firm mattresses, with more than 45.4% of futon users choosing a firmer mattress than before.
Futons have been a beloved and popular choice of mattress in Japan for centuries. In the past, most households with tatami flooring would not be without a futon. In fact, one-time free samples of futon mattresses were found included inside boxes of washing powder – a weekly consumable that says a lot about how important they were. In a predominantly Buddhist and Shinto society, beliefs related to the sacred nature of sleep, hygiene, and dirt have impacted futon usage. However, modern trends are evident, and more consumers choose western-style mattresses over futons. In spring 2013, the first container-sized ships carrying made-in-Chicago mattresses launched in Japan, in response to a rise in demand for innovative, contouring foam in this predominantly futon country. The success of these mattresses will be a launching pad for other western brands to initiate their conquest of local preferences in the years after.
In March 2018, the company’s 17-year long success story ended, as the brand rebranded existing market locations predominantly into Tempur and opened company-owned showrooms to encourage walk-in customers. The Japanese consumer continues to prefer firmness, the mark of traditional simplicity and minimalism. However, the number of options continues to grow, driving brand differences. Customers today have embraced options, and this includes embellishment in their rest purchases. A sleep survey indicated that 26% of adult respondents claim that they own 2-3 futons because of the different sleeping experiences they report, and ornamental detailing becomes a more relevant factor. Longitudinal data looks at 750 mattresses from 100 different retailers and compares detailed reviews going back to purchase, including feedback from three years after purchase. The data now includes a total of 8,202 consumer sleep term feedback reports.
Innovations in Mattress Technology for Adjusting Firmness
Mattress engineers continue to innovate in the quest for mattress firmness that caters to individual sleepers’ preferred levels of firmness. One way mattress engineers have approached this has been by allowing consumers to alter the firmness level somewhat on their own. Individuals can do this by purchasing a topper or a separate pillow top that can be added to the top of a mattress to adjust firmness. Another way that people can graphically adjust their own firmness is through zoned mattresses promoted for couples’ comfort. Continuous accessible firmness has also been achieved in some all-foam mattresses by dividing them into several layers that can be rearranged. For a period of time, a few companies made multi-layered mattresses with zippers between the solid layers, marketed on the basis that the firmness could be adjusted by rearranging layers. Recently, this zipper technology has been made available in an all-foam mattress with five layers that come in a single box. A few companies sell mattresses that allow firmness to be adjusted through an opening and closing system. Their bed has gel matrix layers with pressure sensors. This mattress can automatically adjust to body movements.
While a burgeoning set of mechanically driven adjustable mattresses with proprietary technology are in existence, other mattresses can have their firmness adjusted via existing assistive technologies, such as motors and an app that a consumer can control. There are other all-foam adjustable firmness systems in operation, including one with proprietary technology compressing the bed, a digitally controlled system configured to actuate the desired firmness, and digital aerated firmness systems. Some beds are examples of firms that allow either side (and in the case of one mattress, further individual zones) to be electronically controlled to adjust the bed’s firmness, thereby catering to couples’ different firmness preferences. Interest in self-adjustable firmness bed systems has been documented in an analysis of trends occurring from June 2004 to February 2020, with the highest of the trends from 2020 more recently. Lastly, although the adjustable mattress market is relatively niche, it is suggested that any development in this area will be of interest to consumers and manufacturers alike. Discussing the problems faced by adjustable mattresses, some issues are similarly true now: a bed technology consumer survey pointed to concerns related to cost, breakdown of technology, longevity, and comfort when users had tried them. Furthermore, the lack of mass consumer awareness over the beds represents a notable marketing focus.
Smart Mattresses and Adjustable Firmness
Many sophisticated mattress products provide the ability to adjust the firmness settings. In smart mattresses, the sensors can send the usage information to an application. By analyzing the user’s data such as movements and biological signals, the system can adjust the firmness for different body parts automatically. Furthermore, the mined data can be used to give suggestions and feedback. These suggestions include better sleeping positions for the user and other important cues for sleep health. The recommendation might not only be the firmness of the bed but various other conditions that could improve sleep. Data about external factors such as ambient light and noise could also be taken into account. Additionally, based on the patterns of individual usage, sleep times, sleep positions, or restlessness, a recommendation for a better sleep environment could be given to the user. Further recommendations to healthcare providers or professionals could be given based on patterns of symptoms like an irregular heartbeat or irregular nighttime breathing. Using a graph database, we would categorize these recommendations. A graph data representation can be designed to include first and second order effects for actions on the body.
Smart mattresses promise to create a trend for the increasing role of technology in the optimization of sleep. Discomfort characteristics and objective evidence of pressure distribution can be used to inform the design process for more adaptive mattresses that change their shape or firmness based on feedback from the user. This is part of an overall idea that cushion design can be based on many factors related to the user such as blood pressure. It is estimated that 65 to 75 percent of people sleep in different locations every night, and the idea of shape-changing surfaces for sleep is very attractive as we transition into supportive systems. Such systems may enable new designs for sleep.
