Why Everyday Activities Load Your Spine More Than You Think
The human spine is a remarkable structure — designed to bend, twist, and carry heavy loads. Yet when you're in pain (as many people are when they visit my clinic), it’s easy to feel like your back is weak, fragile, or vulnerable.
In reality, most spines are far stronger than we give them credit for. You might be surprised to learn just how much force your spine handles during everyday movements.
How Much Load Goes Through Your Spine?
A recent research paper measured the compressive force on the lumbar spine — specifically the L4/L5 disc — during common activities. The results are striking:
Walking: ~2.5x your bodyweight
Running: ~6–8x your bodyweight
Bending forward: ~2.5x your bodyweight
Lifting a 20kg weight with poor form: up to 9x your bodyweight
If you weigh 80kg, walking alone can put around 200kg of force through your lower spine. Running or lifting could mean your back is dealing with several hundred kilograms of force.
Why Sitting Often Feels Worse
Ironically, while sitting often involves less load than walking or running, it can feel worse for those with back pain — particularly disc-related issues.
In clinic, one of the most common diagnoses I see is lumbar disc pathology. A clinical test I often use is the slump test. It involves asking the patient to sit tall, then slump forward — if this reproduces pain in the lower back or down the leg, it suggests disc involvement.
So why does sitting, especially slumping, feel worse for discs?
It comes down to how the load is applied:
Load direction: Slumping directs pressure into the back of the disc — the area most prone to injury.
Posture: Upright posture distributes force evenly; slumping shifts pressure backwards.
Static vs dynamic load: Walking alternates compression and decompression; sitting creates constant pressure.
Time: We sit for long stretches, while walking is broken into shorter bouts.
Muscle activity: Walking keeps spinal muscles active; sitting allows them to switch off, leaving discs and ligaments to bear the load.
What This Means For You
Your spine is designed to handle load — but it thrives on movement and variation.
Walking is medicine for your spine. It provides the gentle loading and unloading your discs need.
Sitting isn’t inherently bad, but sitting still for too long, especially in poor posture, can aggravate disc issues.
Three Quick Tips to Ease Spinal Strain When Sitting
Break it up: Stand and move every 30–45 minutes (or sooner if it’s sore).
Sit tall: Avoid slumping; keep a gentle curve in your lower back.
Use support: A small lumbar cushion or engaging your core can help share the load.
Load Tolerance: The Key to Managing Disc Injuries
Most injuries happen when a structure can no longer tolerate the load placed on it — whether that’s a bicep tendon doing too many curls, or a lumbar disc enduring too much pressure in one position.
In acute disc injuries, load tolerance is low, meaning small movements or positions may be painful. In chronic disc issues, the spine can usually handle more — but often still has limits. That’s why gradual exposure and load management are central to recovery.
Final Thought
Your discs are tougher than you think — but they still have limits. If back pain is stopping you from sitting, walking, or doing the things you enjoy, it’s worth getting assessed. Find out how Osteopathy can help in the management of disc injuries.
A tailored osteopathic assessment can help identify what’s going on and guide you with the right movements, support, and advice to get back on track.