Q: Can you write about the expression “weak in the knees”? I know it has to do metaphorically with fear or apprehension, but as someone who suffers from literal weak knees I’d like to know more about it.
A: The image of weak or unsteady knees as a metaphor for vacillation—being indecisive or afraid, lacking faith, not standing firm—came into English from biblical writings. It can be found in ancient Hebrew and Greek versions of the Bible and in later Latin translations.
The imagery was preserved in early English translations of the Bible, where the knees of people lacking spiritual stamina were first described as “trembling” and “feeble” (1300s) and later as “weak” (1500s).
And in wider, secular use, irresolute or faint-hearted people went from having “weak knees” to being “weak in [or at] the knees” (1700s) or “weak-kneed” (1800s).
Here’s a closer look at the history.
As we mentioned, the metaphoric equivalent of “weak knees” was known in biblical Hebrew, Greek, and Latin. The noun “knee” in Hebrew is ברך (berek), in Greek γόνατο (gonato), and in Latin genu. The adjectives used in the metaphor can be translated as feeble, weak, trembling, unable to move, and so on.
In Hebrew, various Old Testament figures who are struck with terror or who are unsteady in their faith are said to have weak or feeble knees, as in ברכים כרעות (birkayim karaot, Job 4:4) and ברכים כשלות (birkayim kashalot, Isaiah 35:3).
This imagery was passed along in Greek translations of the Old Testament and of the New Testament as well.
For example, in Hebrews 12:12 in the New Testament, where the people are admonished to bear up and keep their faith, the Greek phrase used in describing their vacillation is παρaλυτα γόνατα (paralya gonata), literally “paralyzed knees.” Biblical scholars say the Greek verb παραλύειν (paralyein, paralyze) is used idiomatically here, so that to “lift up one’s paralyzed knees” means to gain courage, be unafraid, stand firm.
Biblical translations in Latin used similar imagery to express fear or faithlessness; genua trementia confortasti (strengthen trembling knees) in Job 4:4; genua debilia roborate (strengthen feeble knees) in Isaiah 35:3; soluta genua erigite (lift up weak knees) in Hebrews 12:12; omnia genua ibunt aquae (all knees will be weak as water) in Ezekiel 7:17.
By the way, the image of weak or trembling knees as a metaphor for fear was known earlier in Greek mythology and in Latin lyric poetry. It can be found, for example, in the Greek legend of Tiresias, whose knees shake in terror before the king, and in the Odes of Horace, where Chloe’s knees tremble in fear.
But we won’t dwell on the earlier literary sources, since the metaphor found its way into English via the Bible.
The earliest English version, the Wycliffe Bible, was made in Middle English in 1382 from late fourth-century Latin versions. And in rendering that metaphor, it has “knees tremblynge” (Job 4:4), “feble knees” (Isaiah 35:3), and “knees shall tremble” (Ezekiel 7:17).
As far as we know, the earliest example of the exact phrase “weak knees” used figuratively is in a translation of the New Testament by William Tyndale, published in 1534. Here’s Tyndale’s rendering of Hebrews 12:12, made from Greek and Hebrew texts: “Stretch forthe therfore agayne the hondes [hands] which were let doune & the weake knees.”
Tyndales’s work was completed and greatly enlarged by Miles Coverdale, whose 1535 translation from Greek and Hebrew was the first English version with both Old and New Testaments. Here’s how Coverdale rendered that passage: “Life [lift] vp therfore the handes which were let downe, and the weake knees.”
This image became a familiar theme of sermons and commentaries from the later 16th century onwards. For instance, John Calvin evoked it in a sermon delivered in January 1556: “It is the ministers charge to strengthen the weake knees.”
The figurative use of “weak knees” as a religious device became more or less official when the Anglican priest and scholar Thomas Wilson included it his popular book A Christian Dictionarie (1612), his attempt to define English words as used in the Old and New Testaments. Wilson defined “weak knees” as meaning “feeble, remisse, and slothfull mindes” (citing Hebrews 12:12).
Wilson’s dictionary went through many editions. A 1661 printing, edited after his death, added the literal condition of “weak knees” and also expanded the figurative meanings to include “dejected in courage, and faint-hearted,” “fearful and dejected in minde,” and “sluggish in the way of godliness” (citing Job 4:4, Isaiah 35:3, and Hebrews 12:12).
By the mid-1600s, “weak knees” was in secular use as well, meaning not only fearful and irresolute but disloyal. The earliest example we’ve found is in John Ford’s play The Chronicle Historie of Perkin Warbeck (1634), about a foiled plot to overthrow King Henry VII.
Here Sir Robert Clifford, a leader of the plot, has decided to plead for his life in return for betraying his co-conspirators: “Let my weake knees rot on the earth, / If I appeare as leap’rous in my treacheries, / Before your royall eyes; as to mine owne / I seeme a Monster, by my breach of truth.”
The longer phrase “weak in the knees” didn’t appear in writing until the late 18th century, as far as we can tell. The earliest example we’ve found is in a work of astrology, where it’s listed among character faults attributed to people born under the sign of Capricorn:
“weak in the knees, not active or ingenious, subject to debauchery and scandalous actions; of low esteem, &c. amongst his associates.” (From Astronomy and Elementary Philosophy, Ebenezer Sibly’s 1789 translation of a Latin work written in 1650 by the Italian scholar Placidus de Titis.)
The variant phrase “weak at the knees” followed a half-century later. The oldest use we’ve found is from an anonymous collection of Irish verse: “What an ease to the minds of the mighty J.P.s, / Who felt chill at their hearts and grew weak at the knees” (The Lays of Erin, 1844).
The Oxford English Dictionary has no entries for “weak knees” or “weak in [or at] the knees.” But it does have an entry for the adjective “weak-kneed,” which it defines as “having weak knees,” and says is a “chiefly figurative” expression meaning “wanting in resolution or determination.”
We found this example in a Missouri newspaper: “So come out, you weak-kneed false-tongued slanderer of the Whig press of Missouri.” (From the Hannibal Journal, May 12, 1853, quoting a dispatch in the St. Louis News.)
The OED’s earliest example appeared a decade later: “But we must forego these comforts and conveniences, because our legislators are too weak-kneed to enact a tax law.” (From the Rio Abajo Press, Albuquerque, Feb. 24, 1863.)
Help support the Grammarphobia Blog with your donation. And check out our books about the English language and more.