WHAT IS A GOOD SITTING POSTURE -
WHAT IS A BAD SITTING POSTURE -
Sitting Posture and Back Health: An Updated Perspective
The Problem with Traditional Sitting
Modern life often necessitates prolonged periods of sitting, despite the fact that humans were not "created to sit down for long hours." This sedentary lifestyle, particularly when combined with suboptimal sitting postures, puts significant strain on the spine and its associated ligaments. Over time, this can lead to:
- Pain (especially in the lower back)
- Deformity
- Chronic illness
- Disk movement and discomfort
A staggering 70 to 85 percent of people will experience back pain in their lives, with some Canadian data indicating a lifetime prevalence of back pain as high as 83.8% in certain regions (e.g., Alberta and Saskatchewan, based on a 2013 survey). Back pain is also a leading cause of worker compensation claims in Canada.
The 135-Degree Solution: A Biomechanical Breakthrough
Contrary to popular belief and common advice to "sit up straight" (often at a 90-degree angle), scientific research, including a study led by Dr. Waseem Amir Bashir from the University of Alberta Hospital, indicates that a 135-degree body-to-thigh sitting posture is the best biomechanical sitting position.
Key Findings of the 135-Degree Posture:
- Reduced Disk Movement and Discomfort: MRI scans demonstrated that disk movement and discomfort were least pronounced in the reclined 135-degree position. This is because it minimizes harmful pressure and compression on the spinal disks.
- Natural Spinal Curve: This reclined posture helps maintain a natural hollow or "S-shape" in the lower back, similar to the spine's natural alignment when standing.
- Improved Blood Flow: A more open hip angle can contribute to better circulation in the lower extremities.
Achieving the Optimal 135-Degree Posture
While achieving a precise 135-degree angle throughout the workday might not always be practical for active work, the principle is to recline slightly rather than sitting rigidly upright or slouching.
Practical Tips for Optimal Sitting:
- Recline: Aim for a slightly reclined position, allowing your back to lean gently backward. Many ergonomic experts suggest a range of 100°-110° for active work, with the option to recline further to 135° during breaks.
- Lumbar Support: Maintain a natural hollow in your lower back. This can be achieved by:
- Utilizing the adjustable lumbar support feature of an ergonomic chair.
- Placing a rolled-up towel or a specialized lumbar roll in the small of your back.
- Feet Flat: Keep your feet flat on the floor or on a footrest if your feet don't reach comfortably. Avoid crossing your legs or ankles, as this can introduce biomechanical stress.
- Knee Position: Ensure your knees are at the same height or slightly lower than your hips. There should be a small gap (about three fingers' width) between the back of your knees and the edge of the chair.
- Arm and Shoulder Position: Relax your shoulders. Your forearms should be parallel to the floor, forming an L-shape at the elbows, with elbows at your sides. Use armrests to support your arms and reduce strain on your neck and shoulders.
- Monitor Placement: Position your computer monitor at arm's length, with the top of the screen no more than 2 inches above your natural line of sight. Use a monitor arm for better adjustability.
The Importance of Movement and Breaks
Even with the best posture, prolonged static sitting is detrimental. Regular movement is crucial for spinal health and overall well-being.
- Change Positions Frequently: "It's good to get up and change positions throughout the day to flex and unflex the back muscles and balance things out."
- Take Regular Breaks: Aim for a 10-minute break for every hour of sitting. During these breaks, stand, stretch, and move around.
- Alternate Sitting and Standing: Consider using a standing desk to vary your posture throughout the day.
Ergonomic Chair Considerations
Investing in an appropriate ergonomic chair is essential for supporting optimal posture. Look for chairs that offer:
- Adjustable Recline: The ability to recline and lock at various angles, including a significant recline that approaches the 135-degree recommendation.
- Adjustable Lumbar Support: To maintain the natural curve of the lower back.
- Adjustable Seat Height: To ensure feet are flat and knees are at the correct height.
- Adjustable Armrests: To support the arms and shoulders.
- Headrest: To provide neck and head support, especially when reclined.
- Breathable Material: Mesh backs are often preferred for airflow.
Realistic Costs for Ergonomic Chairs (as of mid-2025):
- Budget-Friendly ($100 - $300): These chairs offer basic adjustability and decent lumbar support. Examples include some Sihoo models.
- Mid-Range ($300 - $600): You'll find more comfort, better build quality, and increased adjustability (e.g., adjustable armrests, tilt tension). Autonomous ErgoChair Pro falls into this category.
- High-End ($600 - $1,500+): These chairs offer top-tier comfort, durability, and extensive adjustability, often with premium materials and advanced features. Examples include Steelcase Gesture.
Workplace Policies and Employer Responsibility
Employers have a significant role to play in promoting spinal health and preventing back pain among their staff.
- Provide Appropriate Seating: Offer ergonomic chairs that support the 135-degree posture and provide comprehensive adjustability. This can reduce lost work hours due to back pain.
- Encourage Movement and Breaks: Implement policies that encourage employees to take regular breaks and change positions.
- Ergonomic Assessments: Provide ergonomic assessments of workstations to ensure proper setup and identify potential risks.
- Training: Educate employees on proper sitting posture, lifting techniques, and the importance of movement.
- Wellness Programs: Support or provide fitness programs that encourage physical activity.
- Modified Duty Programs: For employees experiencing back pain, a well-structured modified duty program can facilitate early and safe return to work, which has been shown to improve recovery outcomes.
References:
http://www.yogaback.com