Comfort and Support Values of Different Pillow Designs
Condition: Sleep; Proprioceptive Disorders; Orthopedic Disorder
MeSH terms: Musculoskeletal Diseases; Somatosensory Disorders
Study type: Observational

Summary: 
      With the change in lifestyle, most physical tasks are now performed by machines. As a result,
      sitting has become the most common learning posture and office posture, and cervical and
      lumbar spondylosis are becoming increasingly prevalent in younger people. One-third of life
      is devoted to sleep, and bad sleeping posture can place incorrect strain on the cervical and
      lumbar spine, resulting in irreversible and detrimental repercussions if not treated
      seriously. Sleep disorders have become an important public health concern because they can
      have detrimental effects on both mental and physical health. A pillow can give adequate
      support for the head and neck and assist sleepers in maintaining proper neck and thoracic
      curvature. Studies have demonstrated that a comfortable sleeping pillow helps relax the neck
      muscles, hence facilitating sleep, and efficiently alleviate pain in the neck, shoulders,
      back, and head.

      There is consensus among researchers that supporting the natural lordotic curve of the
      cervical spine is necessary to achieve longer periods of deep sleep. In addition, a pillow
      can improve sleep quality by cooling the head, lowering body temperature, reducing sweating
      or slowing the heart rate during sleep. However, the level of evidence to support these
      claims is so far limited. It has been claimed by pillow manufacturers that many
      design-related pillow parameters are effective in improving sleep quality and reducing neck
      pain. However, most of these recommendations are based on personal experience.

      This study recommends the most suitable pillow for people in forward head postures based on
      the body pressure distribution of the head, neck and upper body. The proposed pillows were
      evaluated in two parameters: comfort and support.
    

Detailed description: 
      With the change in lifestyle, most physical tasks are now performed by machines. As a result,
      sitting has become the most common learning posture and office posture, and cervical and
      lumbar spondylosis are becoming increasingly prevalent in younger people. One-third of life
      is devoted to sleep, and bad sleeping posture can place incorrect strain on the cervical and
      lumbar spine, resulting in irreversible and detrimental repercussions if not treated
      seriously. Sleep disorders have become an important public health concern because they can
      have detrimental effects on both mental and physical health. A pillow can give adequate
      support for the head and neck and assist sleepers in maintaining proper neck and thoracic
      curvature. Studies have demonstrated that a comfortable sleeping pillow helps relax the neck
      muscles, hence facilitating sleep, and efficiently alleviate pain in the neck, shoulders,
      back, and head.

      While studies on the support and comfort of human contact surfaces generally focus on sitting
      posture, there is limited information available because the assessment of sleep position is
      more complex. The main reason behind this confusion is that the human body can take many
      different positions while sleeping. In supine, prone or side lying positions, the pressure or
      support properties of the human contact surfaces of the pillow against individuals vary
      greatly. In addition, head-neck curvatures that vary from person to person can also change
      their support and comfort needs.

      In current research on pillows, assessments can be made subjectively or objectively.
      Subjective evaluations are made by completing an evaluation form based on the person's
      self-report after the sleep test. In this evaluation form, the amount of comfort and support
      that the person gets from the pillow is questioned. Although this method directly reveals
      one's own thoughts, it has poor reproducibility, the results can be easily manipulated, it
      takes a long time to be done, and it is not suitable for complex experiments. Objective
      assessments can be made by analyzing body pressure distributions, EMG signals and
      anthropometric characteristics of individuals. According to the results of the studies, it
      has been shown that the evaluation method performed with body pressure distributions is the
      most effective method. This may be because body pressure distribution can respond quickly to
      materials used, support arrangements, human weight or lying positions.

      Studies have shown that long-term high pressure applied to certain parts of the human body
      can affect the human central nervous, blood circulatory and endocrine system. In addition,
      different parts of the human body show great sensitivity to pressure due to differences in
      subcutaneous tissue and tissue structures. In terms of ergonomics, the pressure perception of
      the human body can be divided into dull parts and sensitive parts. Dull parts can withstand
      more pressure, while sensitive parts can only feel comfortable when the pressure is low.
      Therefore, one of the main goals in pillow selection should be to reduce the pressure applied
      to sensitive points.

      Although it has been reported that the main role of the pillow is to optimize head and neck
      posture, there are limited studies on its effectiveness in terms of its effect on head and
      neck posture. About a third of human life is spent in sleep, during which the spine is beyond
      our conscious control. Therefore, pillows play an important role in maintaining ideal head
      and neck posture and can change muscle activities.

      Head and neck position is an important factor affecting sleep quality. It is reported that
      while sleeping, cervical control weakens and places excessive stress on spinal structures.
      Symptoms such as neck and shoulder pain, tension headaches and muscle stiffness that occur
      during this time reduce sleep quality. That's way, there is a serious requirement to
      investigate how different pillow designs can effectively support the cervical spine to reduce
      neck pain and thus improve sleep quality.

      Forward head posture (FHP) is the anterior alignment of the cervical spine; it is also known
      as "text neck," "scholar's neck," "wearies neck," "ihunch," and "reading neck." Several
      factors, including sleeping with the head lifted excessively high, prolonged use of
      computers, laptops, and cell phones, lack of developed back muscle strength, and nutritional
      deficiencies such as calcium, contribute to this postural disorder. Age is linked with
      decreased cervical ROM, thoracic kyphosis is associated with increased cervical flexion, and
      increased forward head posture is associated with larger deficits in cervical rotation and
      flexion ROM.

      Scientific evidence suggests that head postural changes affect the development and
      persistence of neck pain. Therefore, it should be one of the main factors for choosing an
      ergonomically correct pillow. In addition, the cervical muscles play an important role in the
      control of neck posture. The reduced ability of these muscles to maintain the upright posture
      of the cervical spine may indicate that their endurance is impaired and they are unable to
      maintain cervical lordosis. Since various studies often report a significant association
      between weak neck muscles, poor posture, and experience of neck pain, and considering that a
      pillow can reduce pain and disability, it should be considered that the pillow needs of
      individuals with a forward head posture may differ.

      Pillow comfort research is relatively new and the factors affecting the selection of the
      right pillow are still unclear. For example, it is not correct to accept the head and neck
      regions as a whole and accept comfort and support demands as similar. Because the position of
      the head with respect to the height differs in the normal head posture or tilting the head
      forward, and this may affect the comfort or support properties of the pillow. Due to
      differences in head posture, the comfort and support demands of the head and neck areas in
      contact with the pillow will also vary.

      There is consensus among researchers that supporting the natural lordotic curve of the
      cervical spine is necessary to achieve longer periods of deep sleep. In addition, a pillow
      can improve sleep quality by cooling the head, lowering body temperature, reducing sweating
      or slowing the heart rate during sleep. However, the level of evidence to support these
      claims is so far limited. It has been claimed by pillow manufacturers that many
      design-related pillow parameters are effective in improving sleep quality and reducing neck
      pain. However, most of these recommendations are based on personal experience.

      This study recommends the most suitable pillow for people in forward head postures based on
      the body pressure distribution of the head, neck and upper body. The proposed pillows were
      evaluated in two parameters: comfort and support.
    

Intervention name(s): XSensor
Intervention type(s): Device
Intervention description(s): A pressure mapping system (X3 SENSOR PX 100:64.160.02, X-Sensor®, Calgary, Canada) was used to record the pressure distribution in mmHg of the head and shoulder section [18,19]. Pressure distribution was recorded for 1 minute for each lying position. The purpose of these measurements was to describe the pressure distribution created by the participants in the pillow and the supported areas, as well as to find out the differences that may occur between the pillows. Lower pressure values measured by the device were defined as "high comfort", while more contact of the head area with the pillow was accepted as "high support".
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Healthy individuals