Chinese JoineryChinese Joinery
中文
Legs, tops and aprons
罗锅枨
luóguō chéng

Luoguo Cheng (罗锅枨): the Hump-Backed Stretcher of Chinese Tables

Humpback stretcher · 罗锅枨

By · Updated

A stretcher braces the legs best when it is low. But a low stretcher hits the sitter’s knees.

The hump-backed stretcher does both: low at the ends, raised in the middle.

Chinese
罗锅枨 · luóguō chéng
Joins
Two legs
Found in
Tables, stools and benches
Signature parts
Low ends · arched middle · end tenons
Compare
Short posts
Drag to rotate. Slide to take the joint apart, or press Assemble to watch it go together.

How it works

A compromise

Wang Shixiang explains that a stretcher set high stiffens the frame more, but gets in the way of the knees. Lowering both ends and raising the middle solves both problems at once. Ming stretchers were made straight or in this hump-backed form.

The end joint

The ends meet the legs as ordinary stretcher-to-leg T-joints: a tenon into a mortise in the leg, shouldered on the face. Short posts or carved spacers often stand on the hump to carry the top.

Proportions in the model are illustrative.

How it's made

  1. Stretcher
    Step 1

    Stretcher

    A stretcher between two legs.

  2. Hump
    Step 2

    Hump

    Raised in the middle.

  3. Low ends
    Step 3

    Low ends

    Low at both ends.

  4. Tenons
    Step 4

    Tenons

    Ordinary tenons at the ends.

  5. Legs
    Step 5

    Legs

    The legs close onto the tenons.

  6. Why
    Step 6

    Why

    Strong low joints, room for knees.

Variations

With short posts

Short posts (矮老) or carved spacers often stand on the hump.

Can you CNC this?

Yes, with small changes

The arched stretcher is a 2D profile cut from a flat board, and its end tenons and the leg mortises are ordinary. Round the mortise corners or the tenon edges to match.

Free STL downloads (one file per part)

Before cutting or printing, read the CNC and 3D-printing notes on tool radius, scaling the STL files and their licence.

In museum collections

Square table with hump-backed stretcher, 17th century, 17th c., Minneapolis Institute of Art, accession no. 94.30.1
Square table with hump-backed stretcher, 17th century
Minneapolis Institute of Art
Waisted stool, 17th century, 17th c., Minneapolis Institute of Art, accession no. 2003.139
Waisted stool, 17th century
Minneapolis Institute of Art

Where you’ll see it

  • Waisted stool · Stretchers: Many waisted stools add a hump-backed stretcher under the apron, low at the ends and raised in the middle.
  • One-leg-three-aprons table · Stretchers (when present): Some tables of this form also carry a hump-backed stretcher low on the legs.
  • Waistless square table · Hump-backed stretcher: A stretcher low at the ends and arched in the middle braces the legs without hitting the sitter’s knees.

Questions

Why the arch?

To keep the joints low while leaving knee room.

What joint is at the ends?

An ordinary tenon into the leg.

Where is it used?

Tables, stools and benches.

Further reading
  1. Square table with hump-backed stretcher, 17th century, Minneapolis Institute of Art (collection record)
  2. Waisted stool, 17th century, Minneapolis Institute of Art (collection record)
  3. 王世襄《明式家具研究》（Wang Shixiang, Research on Ming Furniture），第 114 页
  4. 王世襄《明式家具研究》（Wang Shixiang, Research on Ming Furniture），第 104–106 页，图 3.9–3.12