Mainstream systems often treat capability as if it belongs inside the individual.

Can you walk?
Can you cook?
Can you travel?
Can you communicate?
Can you attend?
Can you manage?
Can you cope?

Those questions are too small.

They make the body carry the whole answer.

DCA asks better questions:

What does this body need in order to participate?

What load is currently being forced through the body that could be carried by tools, environment, community, time, knowledge, or workflow instead?

What would make this action possible at lower physical, sensory, cognitive, or emotional cost?

The goal is not to make the body perform more.

The goal is to design the system so the body does not have to carry what the ecosystem could carry.

The Body Layer is not fixed.

Capacity changes across the day, across environments, across weather, across pain levels, across hormone cycles, across sensory load, across social demand, across sleep, across food, across stress, and across time.

A person may be able to do something once, but not repeatedly.

They may be able to do it in one environment, but not another.

They may be able to do it with the right tool, but not without it.

They may be able to do it today, but not tomorrow.

This is not inconsistency.

This is variable capacity.

A good system expects variation.

A bad system treats variation as unreliability, laziness, exaggeration, or non-compliance.

The Body Layer includes:

• • pain

  • fatigue

  • mobility

  • balance

  • coordination

  • grip strength

  • bending, lifting, twisting, and carrying limits

  • sensory load

  • hunger and hydration

  • medication effects

  • sleep and recovery

  • executive function

  • attention

  • communication access

  • emotional and physiological state

  • injury history

  • trauma response

  • hormonal changes

  • energy available for participation

This layer is not only physical.

The body includes the nervous system, sensory system, communication system, and energy system.

Every task has a physical price.

Standing has a cost.
Sitting upright has a cost.
Travelling has a cost.
Carrying has a cost.
Bending has a cost.
Waiting has a cost.
Explaining has a cost.
Being disbelieved has a cost.

For some people, those costs are small enough to ignore.

For others, they decide whether participation is possible at all.

DCA treats physical cost as design information.

If a task repeatedly causes pain, collapse, overload, or recovery debt, the question is not:

How can I force myself through this?

The question is:

Where can this load be moved?

The Body Layer rejects the idea that a person must have one stable mobility identity.

Wheelchair user.
Walking person.
Crutch user.
Stick user.
Power attachment user.
Standing person.
Seated worker.
Floor worker.

Real mobility is more flexible than those categories.

The useful question is not:

What mobility aid does this person use?

The useful question is:

What tool best preserves participation in this context, with this body, on this terrain, on this day?

A wheelchair, walking poles, a Triride, an office chair, a perching stool, knee pads, a trolley, or a castor-mounted platform may all be part of the same mobility architecture.

The goal is not movement for its own sake.

The goal is participation with the lowest sustainable cost.

Many systems respond to access needs by asking the person to endure more.

Try harder.
Get stronger.
Be more resilient.
Attend anyway.
Explain again.
Wait longer.
Use the inaccessible route.
Manage the pain.
Control the meltdown.
Cope.

DCA reverses that logic.

If the task is too costly, redesign the interface.

Move the work surface.
Use wheels.
Stage the objects.
Reduce carrying.
Externalise memory.
Change the appointment format.
Add recovery time.
Use a different tool.
Shift the task to another layer.

The body should not be used as the shock absorber for poor design.

A system that only works on a good day is not an access system.

The Body Layer asks what still works when capacity is low.

Can food still happen?
Can water still happen?
Can toileting still happen?
Can communication still happen?
Can leaving the house still happen?
Can recovery still happen?
Can help still be requested?
Can the next step still be found?

Designing for the lowest usable capacity is not pessimism.

It is engineering.

It means the system is still there when the body cannot perform at its best.

The Body Layer may include:

• mobility aids

• seating systems

• pain-aware task design

• adaptive cooking positions

• floor-work supports

• hydration access

• clothing as participation infrastructure

• temperature management

• rest positions

• recovery planning

• pacing rules

• grip-saving tools

• low-lift storage

• body-position-specific workflows

• energy budgeting

• food and medication timing

• accessible routes

• fall-risk reduction

• communication plans for low-capacity states

Disabled, neurodivergent, chronically ill, injured, traumatised, ageing, or overwhelmed people are often assessed as if the body should be predictable.

But bodies are not machines with fixed outputs.

Bodies are living systems.

DCA does not ask the body to become less variable.

It asks the architecture to become more intelligent.

The Body Layer tells the truth about capacity.

It names what the body can carry, what it cannot carry, what changes, what costs too much, and what needs to be distributed elsewhere.

The body is not the failure point.

The body is the signal.

DCA listens to the signal, then redesigns the system.