Part 1 · Myth 5

You must never bend your back when lifting

Partial Truth

From the Clinic

I once watched a patient bend his knees to pick up a tissue from the floor. He did it slowly, deliberately, like he was defusing a bomb. He'd been told never to bend his back — and he believed it absolutely. That level of vigilance was doing him harm.

What Patients Say
My personal trainer told me I must always keep my back perfectly straight when picking anything up. I'm terrified of bending my spine — I even bend my knees to pick up a piece of paper.

Where Did This Come From?

Manual handling training. It's embedded in workplace safety courses, physiotherapy advice, and personal training culture. "Bend your knees, keep your back straight." It's repeated so often it's become almost gospel.

And look — it's not entirely wrong. For heavy lifting, particularly in a work setting, technique does matter. But the leap from "good lifting mechanics for heavy loads" to "you must never flex your lumbar spine at all, ever, including picking up a pen" is a massive overcorrection. And the anxiety this creates around normal spinal movement is, ironically, a significant driver of back pain disability.

What the Science Actually Says

The human spine is designed to flex. The concern about spinal flexion under load relates to torque — the turning force acting on the spine — which peaks with combination of heavy load and poor position, not with light everyday bending. Spinal flexion is a normal, healthy range of motion that the spine uses every single day — when you sit, when you tie your shoes, when you reach for something, when you do about 50% of all movement-related tasks in daily life.

Studies looking at the biomechanics of lifting find that the "perfect" straight-back technique, while reducing peak spinal loads for very heavy objects, is actually less efficient for light-to-moderate loads and doesn't predict back injury rates in real-world populations. Workers who use a "mixed" technique — some knee bend, some hip hinge, some spinal flexion — don't have higher injury rates than those who rigidly follow the straight-back model.

Moreover, maintaining a hyper-rigid "perfect posture" during everyday tasks actually increases muscular tension and fatigue, which can itself contribute to pain. And the fear and hypervigilance associated with avoiding spinal flexion has been shown to be a predictor of chronic pain, separate from any actual structural issue.

Let me be direct here: I have never, in my surgical career, seen a patient whose back problem was caused by bending over to pick up a light object with a slightly rounded back. Not once.

The Verdict

Good technique matters for heavy lifting. But the rule as applied — never flex your back, ever — is an overcorrection that does more harm than good through the fear and rigidity it creates.

Take-Home MessageYour spine is supposed to bend. Treat it like the flexible, strong structure it is — not like a china vase that will shatter if you tilt it. Yes, use good mechanics for heavy lifting. But please, bend down to pick up that pen without a second thought.

What To Do Instead

Learn the hip hinge for heavy lifting — this is genuinely useful biomechanics for loads above roughly 10–15kg
Stop catastrophising light-load spinal flexion — it's normal movement
Build overall strength and fitness rather than focusing obsessively on a single "correct" technique
If you have a specific acute injury (like a fresh disc herniation), your physio may temporarily guide you away from extreme flexion — but this is temporary, not permanent

Yellow Flags — Worth Monitoring

A specific pattern of injury — always hurts when bending in a specific direction — worth documenting and discussing with your clinician
Hypervigilance about movement — if you're spending significant mental energy monitoring how you move, that anxiety itself may be contributing to your pain

Red Flags — Get Checked Immediately

A specific acute incident while lifting that results in sudden severe pain with leg involvement — do get assessed promptly
Back pain from lifting that doesn't improve after 2–4 weeks with gentle activity — worth reviewing

Reference Note

Saraceni N et al., "To Flex or Not to Flex? Is There a Relationship Between Lumbar Spine Flexion During Lifting and Low Back Pain?" Physical Therapy, 2020. Dolan P & Adams MA, "Influence of lumbar and hip mobility on the bending stresses acting on the lumbar spine," Clinical Biomechanics, 1993. PAR T T W O Imaging & Diagnosis What scans actually show — and why your MRI report might be scaring you for nothing. MYTHS 6–9

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