Understanding Which are pressure joints for a person lying on their side? A Guide to Pain Prevention

September 21, 2025 •

4 min read

According to the National Sleep Foundation, over 60% of adults are side sleepers, a position that, without proper support, can lead to discomfort and pain. To maintain your health, it is essential to understand which are pressure joints for a person lying on their side, so you can take steps to protect these vulnerable areas. This guide provides a comprehensive look at how to sleep better and prevent pressure-related injuries.

Quick Summary

When lying on your side, the most concentrated pressure is placed on the shoulder and hip of the dependent side. Other vulnerable areas include the ears, ribs, ankles, and knees, particularly where bony prominences meet the mattress. Understanding and managing these points is key to preventing pain, ensuring spinal alignment, and avoiding more serious issues like pressure ulcers.

Key Points

Shoulder and Hip are Key: The shoulder and hip on the dependent side bear the most weight and are the main pressure joints for side sleepers.
Alignment is Crucial: Improper spinal and pelvic alignment can cause or worsen pressure-related pain, especially in the sacroiliac (SI) joint.
Pillow Power: Using pillows between the knees and under the waist is a simple, effective way to maintain alignment and reduce pressure.
Mattress Matters: A supportive, conforming mattress (e.g., medium-firm memory foam) can significantly reduce pressure on vulnerable joints.
Repositioning is Protection: For those with limited mobility, regular repositioning (every 2 hours) is vital for preventing pressure ulcers.

Understanding Pressure Points When Side Sleeping

For those who prefer to sleep on their side, a distinct pattern of pressure points emerges where the body's weight is concentrated. These are often where bones are closest to the skin, with less soft tissue to cushion them from the surface below. Ignoring these areas can lead to aches and discomfort in the short term, and more significant issues like pressure ulcers over a long period.

The Primary High-Pressure Zones

When a person lies laterally, the majority of their body weight rests on a limited surface area. This creates high-pressure zones in two main areas on the side that is in contact with the bed:

The Shoulder: The dependent shoulder bears a significant portion of the upper body's weight, particularly if the individual's weight is not distributed properly. This can compress the soft tissues and joints in the shoulder, leading to discomfort.
The Hip (Greater Trochanter): The hip bone, or greater trochanter, is a prominent bony area that carries the bulk of the lower body's weight. Constant pressure here can irritate the hip joint and surrounding muscles, causing pain and stiffness.

Other Vulnerable Bony Prominences

While the shoulder and hip are the main concern, several other spots can also be at risk:

Ears and Side of the Head: The ear, especially if pressed against a firm pillow, can become sore.
Ribs: The ribcage on the dependent side can feel uncomfortable pressure.
Ankles (Malleoli): The bony protrusions of the ankles can rub together or press against the mattress, creating a friction point.
Knees: The sides of the knees, and the area between them, can be vulnerable, especially if the legs are stacked directly on top of each other.

The Role of Spinal and Joint Alignment

Correct alignment is paramount for relieving pressure and preventing pain, especially for the sacroiliac (SI) joint. The SI joints connect the base of the spine to the pelvis, and a misaligned sleeping posture can cause strain and irritation.

Avoiding Pelvic Twisting: Without support, the top leg can fall forward, pulling the pelvis out of alignment. This twisting motion puts stress on the SI joints, potentially leading to lower back and hip pain.
Maintaining Spinal Neutrality: The goal is to keep the spine as straight as possible, from the head down to the pelvis. This requires supporting the natural curves of the body and preventing sagging.

How Proper Support Reduces Strain

Using pillows strategically can make a profound difference in your side-lying posture and comfort.

Knee Pillow: Placing a firm pillow between the knees keeps the hips and pelvis stacked and aligned, preventing the top leg from pulling the spine out of position.
Waist Support: A small pillow or rolled towel placed in the gap between your waist and the mattress can prevent spinal curvature and provide crucial support.

Side Sleeping vs. Other Positions: A Comparison

To highlight the unique pressure challenges of side-lying, here is a comparison with other common sleep positions.


Sleep Position	Primary Pressure Points	Key Concerns for Pressure	How to Relieve Pressure
Side	Shoulder, Hip, Ear, Knees, Ankles	Concentrated pressure on bony areas; potential for spinal twisting.	Pillow between knees, supportive mattress, regular repositioning.
Back	Back of Head, Shoulders, Elbows, Tailbone, Heels	Pressure distributed over a larger area, but can still lead to ulcers in specific spots.	Pillow under knees and neck; ensure full body contact with surface.
Stomach	Ribs, Hips, Knees, Chest, Face	Puts significant strain on the neck and spine; least recommended for joint health.	Thin pillow under pelvis; use a thin pillow or none for the head.

Preventative Strategies for Side-Lying Comfort

Preventing pressure-related issues involves a combination of smart positioning, the right equipment, and good habits.

Actionable Steps for Better Rest

Invest in a Supportive Mattress: A medium-firm mattress, especially a memory foam or hybrid, can conform to your body's contours and cradle your pressure points.
Use a Knee Pillow: This is the most effective and simplest way to keep your hips and spine properly aligned.
Adjust Head and Neck Support: Use a pillow that keeps your head and neck aligned with your spine, preventing strain on your neck and shoulder.
Reposition Regularly: If you are immobile or have limited mobility, it is crucial to be repositioned every two hours to prevent prolonged pressure on any single area.
Utilize a Body Pillow: A long body pillow can be a great investment, supporting your knees, hips, and back simultaneously.
Practice Pre-Sleep Stretching: Gentle hip flexor stretches before bed can help release tension that can worsen pain when side-lying.
Monitor Your Skin: Regularly check the pressure points for redness or sores, as early detection is key to preventing pressure ulcers from developing.

Conclusion: Prioritizing Your Body's Comfort

Understanding which are pressure joints for a person lying on their side is the first step toward achieving more comfortable and restorative sleep. By recognizing the risk areas—the shoulders, hips, and other bony prominences—and implementing simple strategies like using pillows for alignment and investing in a supportive mattress, you can significantly reduce discomfort and the risk of developing pressure-related injuries. Prioritizing proper sleep posture is not just about avoiding pain; it's a fundamental aspect of overall health and well-being. For further reading on the dangers of sustained pressure on vulnerable areas, consult authoritative medical resources like the National Center for Biotechnology Information on pressure ulcers.

Frequently Asked Questions

Your hips hurt when side-sleeping because of the concentrated pressure on the hip bone (greater trochanter) and potential misalignment of the pelvis. Placing a pillow between your knees can help keep your hips properly stacked and aligned, relieving pressure on the joint.

To protect your shoulder, ensure your pillow provides proper neck support, which prevents your head from dropping and putting pressure on the shoulder. Some side sleepers also find it helpful to hug a pillow to support their upper arm and reduce strain on the bottom shoulder.

Yes, a mattress plays a significant role in managing pressure points. A mattress that is too firm will not provide enough cushioning, while one that is too soft may not offer enough support. A medium-firm memory foam or hybrid mattress can effectively cradle the body's curves and distribute weight more evenly.

Pressure ulcers, also known as bedsores, are skin injuries caused by prolonged pressure on the skin. Individuals with limited mobility, such as the elderly or those with chronic conditions, are at higher risk, but anyone who stays in one position for too long without support can develop them.

For those with limited mobility, changing positions at least every two hours is recommended to prevent pressure sores. For active sleepers, the body naturally repositions itself, but intentional shifts can help if you experience discomfort.

From a pressure point perspective, alternating between sides is beneficial to prevent prolonged pressure on one hip or shoulder. Some sources suggest left-side sleeping may aid digestion and circulation, but the primary concern for joint health is managing pressure and alignment on both sides.

For a side sleeper, the best pillow is one that keeps your head and neck aligned with your spine. This often means a firmer, thicker pillow than what a back sleeper would use. A knee pillow is also highly recommended to maintain proper hip alignment.