The Structure: The Absolute Phrase
An absolute phrase combines a noun with a participle (and sometimes other modifiers). It’s attached to a full sentence to provide extra context.

Formula: [Noun] + [Participle] + [Rest of Main Sentence]

Examples with Present Participle (-ing)
The present participle shows an action that is happening at the same time as the main verb.

Your Sentence:

He shed weight at an alarming rate, **his legs buckling** as he walked.

Noun: his legs

Participle: buckling

What it adds: It describes how he was shedding weight, showing the physical manifestation of his weakness.

The storm raged outside, its winds howling like a banshee.

Noun: its winds

Participle: howling

What it adds: This describes the nature of the storm, creating a more vivid soundscape.

She delivered the speech, her voice trembling with emotion.

Noun: her voice

Participle: trembling

What it adds: This tells us how she delivered the speech, revealing her internal state.

The work finally finished, we collapsed onto the sofa.

Noun: The work

Participle: finished

What it adds: This establishes the cause for the main action (collapsing).

Examples with Past Participle (-ed or irregular form)
The past participle often shows a state of completion or describes a condition.

His mission accomplished, the spy vanished into the night.

Noun: His mission

Participle: accomplished (describing the state of the mission)

What it adds: It explains why he was able to vanish.

The old man sat in his chair, his will read and his affairs settled.

Nouns: his will; his affairs

Participles: read; settled (describing the state of the will and affairs)

What it adds: It describes the circumstances surrounding the main action, giving a sense of finality.

She stared at the contract, her hopes dashed by the fine print.

Noun: her hopes

Participle: dashed (describing the state of her hopes)

What it adds: It provides the emotional consequence of the main action (staring at the contract).

Why Use This Structure?
Using absolute phrases makes your writing more concise, dynamic, and literary. Instead of writing multiple short, choppy sentences, you can combine ideas to show the relationship between them more elegantly.

Choppy: Peter was terrified. His heart was pounding. He ran from the room.

Dynamic with Absolute Phrase: **His heart pounding**, Peter ran from the room.