The Dangers of Suspension Trauma.

Dr. Dave Merchant, Technical Standards Manager at TAG, explains the life-threatening risks of suspension trauma and why standard first-aid techniques can sometimes kill instead of cure.

Suspension trauma — also known as orthostatic intolerance or harness hang syndrome — is a serious and potentially fatal condition. Although the risks have been known for decades, industry regulators, rescue professionals, and workers who rely on harnesses are only now fully recognising its dangers.

Two major drivers of this awareness were the Work at Height Regulations (WAHR) 2005 and British Standard BS 8473, both of which require work planners, employers, and operatives to consider the risk of suspension trauma whenever fall protection equipment is used.

It is no longer acceptable to write “call the fire brigade” in a method statement — you must have a dedicated rescue plan.

What the WAHR Require.

The Work at Height Regulations place a legal duty on all users of personal fall-protection systems — from simple lanyards to advanced rope access — to:

• Be trained in rescue
• Understand the causes and symptoms of suspension trauma
• Know how to prevent it
• Know how to treat it safely

Incorrect first aid, such as lying the casualty down, can be fatal.

What Suspension Trauma Is.

Suspension trauma is essentially fainting in an upright harness, caused by blood pooling in the legs. It can affect:

• Anyone suspended in a harness
• Regardless of age, sex, fitness, or underlying conditions
• Even if the person is not injured during the fall

Without intervention, a suspended worker may lose consciousness within 10 minutes, and death can follow shortly afterwards.

Why It Happens.

When a person hangs motionless in an upright harness:

• Leg muscles become inactive

• Blood pools in the legs

• Oxygen delivery to the brain drops

• The body attempts to compensate by increasing heart and breathing rates

• If this fails, the brain triggers fainting to force the body into a horizontal position

But in a harness, you cannot fall over, so the brain cannot correct the problem — the casualty then risks suffocation and oxygen starvation.

Symptoms and Timelines.

Symptoms can begin in 5 minutes:

• Anxiety
• Sweating
• Increased heart rate
• Dizziness / breathlessness

Loss of consciousness can occur within 10 minutes, and if the worker remains upright, they are at imminent risk of death.

Harness Design and Why Back Attachments Are Risky.

All fall-arrest harnesses are designed to hold the body upright after a fall. While expensive padded harnesses increase comfort, they do not prevent suspension trauma.

Key points:

• Rear (dorsal) attachment points keep workers upright and make knee-raising difficult
• Front attachment points allow better positioning and easier rescue
• TAG strongly recommends using front attachment points for anyone at risk of suspension

This is why Fallarrest.com recommends considering a Personal Rescue Device (PRD) for operatives — it allows rapid self-rescue after a fall.

Why Sitting Position Matters.

A person suspended in a harness can reduce the risk by raising their knees, which reduces the height difference between heart and legs.

If suspended mid-air, workers may need to create a knee loop using:

• Rope
• Tape
• Clothing
• A dedicated emergency kit

Raising the knees must happen within 10 minutes of the fall. A delay of 30 minutes is extremely dangerous and often fatal.

The Correct Rescue Method — And the Fatal Mistake to Avoid.

Standard first-aid protocols say that a person who faints should be laid down with legs raised.
For suspension trauma, this can kill the casualty instantly.

Why?

The blood trapped in the legs becomes:

• Oxygen-depleted
• Chemically toxic
• High in CO₂

If the casualty is laid flat:

• This “stale” blood surges back into circulation in one sudden movement

• It can overwhelm the heart and kidneys

• It can cause immediate cardiac arrest or multi-organ failure

Correct Approach:

• Lower the casualty into a sitting position

• Keep them upright for at least 30 minutes

• Prevent medical responders from laying the casualty down

• Send the casualty to hospital even if they feel fine

Risk Assessment and the 10-Minute Rule.

When risk-assessing any work at height, the critical question is:

“Can a worker be suspended in a harness for more than a few minutes?”

If the answer is yes, then suspension trauma is a risk.

TAG recommends:

• Every fallen worker must be rescued or repositioned (knees raised) within 10 minutes
• If this cannot be achieved, the work plan must change
• Workers should operate in pairs where possible
• Rescue equipment must be kept close to the work area
• Workers must carry phones, radios, and knee loops
• In situations where two-man rescue is impossible, automatic self-descent devices should be considered

WAHR makes it clear: you cannot rely on the emergency services. Call-out times are too long.

International Guidelines.

Further information on global best practice is available at:
www.suspensiontrauma.info

Suspension Trauma Basics.

• Hanging upright in a harness is an immediate danger to life
• Rescue or repositioning must occur within 10 minutes
• Raise the casualty’s knees into a sitting position without delay
• Call for urgent help
• Never allow the casualty to lie flat
• Keep them upright for 30 minutes after rescue
• Always send suspected cases to hospital

Further Information.

To learn more about the Personal Rescue Device (PRD) and how it can prevent fatalities, visit our PRD section.

To advertise with Fall Arrest or for any other enquiries please contact us here

• Image below is the Personal Rescue Device (PRD)
• For further information on the personal rescue device, please visit our PRD section