Pillows and sleeping position

It may seem surprising, but pillow height, the type of pillow and how we sleep can contribute to some forms of shoulder, back and neck pain. After all, we spend considerable time each day laying in bed, during which time tissues and structures can experience sustained loading if inadequately supported. Waking up with neck pain or a sore neck in the night or morning may indicate issues with sleeping position or head support. However, in some cases, other irritant factors occurring during the day may only manifest during the night or overnight as neck pain. Effectively, loading refers to forces that stretch or compress tissues and underlying structures, and the article on Biotensegrity covers this in far more detail. Not only can our sleeping position directly impact the loads our bodies have to contend with while sleeping, but other factors, like pillow height and sleeping surfaces, our bed, also have relevance.

Tissues can respond to excessive short-term overloading and more prolonged overloading in slightly different ways, resulting in tension, pain, and restricted movement. Muscle spasms are one such typical tissue response, and they can prove extremely painful, though they are easily treatable with the right myofascial release techniques and knowledge. Myofascial trigger point formation is another typical tissue response to overloading or injury, and it can produce both local and referred pain. However, trigger points are easily treatable with the proper knowledge and myofascial release approach. Although we generally try to find the position of most comfort when in pain, doing so can make things worse over time if the initial cause of the pain is left unaddressed.

Front or prone sleeping can result in the neck being twisted to one side for extended periods, resulting in tissue adaptations, and so is best avoided. Equally, some people may sleep with their arm extended above their head and lay directly on the arm or place their hand/arm underneath the pillow. There is more of a tendency for people who sleep on their front or side to sleep with a hand or arm underneath their head. In many cases, such sleeping positions have become long-term habits, though there are effective ways to change habitual behaviours. In some cases, such as Thoracic Outlet Syndrome (TOS), people may sleep with their arm extended above their head or underneath their pillow, as such a position helps relieve symptoms. Although sleeping in such a position with TOS may provide temporary relief at night, doing so is gradually making things worse over time due to tissue adaptation. Hence, in such cases, getting the problem treated as soon as possible is best, enabling one to resume a normal sleeping position and reducing the chances of further issues. Sleeping on the back may also contribute to neck problems due to pillow height issues or disturbed sleep due to the effect of gravity on a relaxed tongue and the potential for airway obstruction. Incidentally, research has shown links between both forms of sleep apnea, obstructive sleep apnea (OBA) and central sleep apnea (CSA) and back sleeping. Some medical conditions may result in little choice in sleeping position due to position of comfort or other factors.

Pillows and pillow height can directly impact the head and neck position and the loads placed on soft tissues and other structures. Ideally, one wants to keep the head in a neutral position while sleeping and pillow selection can make a huge difference. Side-sleeping allows one to keep the head and neck in a neutral position. Pillows differ in size, shape and material composition and then compress with the head's weight, with the average adult head weighing similar to a 10 lb bowling ball. Hence, the correct pillow selection needs to consider the head's weight in maintaining a neutral neck position. The consequence of a pillow being too high or low is increased tissue and structural loading within the neck, shoulders and upper back. Such additional loading can then lead to back, neck and shoulder pain. Equally, adaptative tissue changes associated with shoulder and neck pain can contribute to other issues, including headaches and migraines.

It may seem surprising, but beds or sleeping surfaces are relevant to achieving the correct pillow height. Beds come in various types and firmness levels, and the bed's firmness directly impacts the correct pillow height. Hence, the correct pillow height to maintain a neutral neck and head position may vary between beds. For example, a softer bed may require a reduced pillow height due to the weight of the body sinking deeper into the mattress, and a firmer bed may require an increased pillow height due to the body barely sinking into the bed. Much like pillows, bed prices and types can vary hugely, though we spend a relatively high proportion of our lives in them, which is worth considering. Equally, beds past their effective service life can create neck and back problems, again due to a lack of adequate support. Most people will have experienced sleeping on a mate's sofa after an evening out, camping or extended travel at some point, resulting in an aching back and neck. Often, such situations involve a combination of incorrect pillow height and sleeping surface issues, resulting in tissue irritation and pain. Usually, such soft tissue irritation and associated neck pain resolve relatively quickly within days, provided no further irritation occurs.

The following two examples highlight how lateral neck flexion (curvature) can increase as a result of the of bed mattress and pillow selection.

Example of inadequate neck and head support (low pillow)

The above example demonstrates how a soft mattress and insufficiently supportive pillow combination can add additional load to tissues and structures. Such a position results in additional compressive forces on tissue structures within the upper left portion of the shoulder, back and neck. Equally, such a sleeping position also increases tensional forces to the upper right section of the back, neck and shoulder. Sleeping without a pillow is likely to result in a similar issues, even with or without existing neck pain.

Example of excessive neck and head support (high pillow)

An excessively high pillow creates tensional forces similar to an insufficiently high pillow, though in reverse. Effectively, the left upper quadrant of the body experiences increased tensional forces, and the right upper quadrant experiences increased compressive forces.

It is relatively easy to correctly support the weight of the head and neck when side-lying and without any specially shaped pillow. However, sleeping on the back creates additional and different support requirements for the head and neck. Effectively, the neck's arched shape needs increased pillow support, yet the head does not, which is why specific ergonomically designed contoured latex or memory foam pillows exist.

Although many professionals within the MSK therapy field sell expensive pillows within a clinical setting, the good news is one does not have to buy a costly pillow. The author prefers firmer pillows that maintain their shape, such as latex or memory foam pillows, which are readily available online or in most stores. Pillows also tend to come in set heights, so it is better to get one that is slightly too low than too high. It is then easy to customise pillow height by placing a folded towel or similar inside the pillowcase on the underside of the pillow to create the perfect height. Alternatively, one can place the folded towel underneath the pillow or put it in its pillowcase and underneath the pillow. The latter two options mean it is easier to turn the pillow over in the middle of the night and still sleep on the pillow rather than a folded-up towel. Having the towel in a pillowcase also helps preserve the towel's folded shape. The following example uses a firm mattress and includes a folded towel underneath the pillow to achieve a neutrally supported head position.

A neutrally maintained head and neck position.

Like neck pain , sleeping position can also aggravate or contribute to some types of back pain. For example, lower back pain is common during pregnancy due to increased ligament laxity and changes in weight carriage distribution throughout the pregnancy, as covered in the Biotensegrity article mentioned earlier. The position of our legs while sleeping can change loads placed on the lower back and may even contribute to some lower back issues. However, some simple changes in sleeping position can reduce loads on the lower back and help relieve back pain, especially in acute back pain cases. Although the fascial network connects everything within the human body, there are also specific connections between the legs and back. Sleeping with a leg across the body while side-sleeping increases load to the lower back via the hip and leg. Such a position effectively puts the hip joint in a non-neutral position.

Increased back load, leg across body.

Side-sleeping with the knees together does reduce some of the loads applied to the lower back via the hip and leg. Hence, the hip position is slightly more neutral than with the leg across the body.

Reduced back load, knees together

Side-sleeping with a pillow between the knees can often relieve pain, and similar is true for other lower back pain conditions. A pillow between the knees reduces the forces applied to the lower back via the hip and leg, creating a neutral hip position. On the other hand, sleeping with no pillow and the legs across the body increases such forces. Although many people may notice no benefit of sleeping with a pillow between the knees, it can make a big difference when dealing with many types of lower back pain. Some people also like to place a towel or small pillow between the ankles to reduce tension on the knee.

Neutral back loading via leg and hip