Quadratus Lumborum
Sources and review status
Review pending — this text hasn’t been signed off by a reviewer yet.
Historical reference: its only source is the original reference manual, and some of it may be out of date. Not used for AI answers until re-sourced.
See this lesson’s sources0% read · 1 min left
A deep lower-back muscle important in lateral trunk flexion; trained with side bends and lateral pelvic tilts.
Detail
The quadratus lumborum is important in lateral trunk flexion. Side bends and lateral pelvic tilt movements effectively train this muscle. Origin: posterior inner lip of the iliac crest and the transverse processes of the lower four lumbar vertebrae; insertion: transverse processes of the upper two lumbar vertebrae and the lower border of the twelfth rib (Thompson, 1989). It works with the erector spinae and obliques to produce lateral flexion. It is one of the muscles the "lower back" comprises (along with the psoas and erector spinae).
Key facts
- Important in lateral trunk flexion.
- Trained with side bends and lateral pelvic tilts.
- Origin: posterior inner lip of iliac crest, transverse processes of lower 4 lumbar vertebrae; insertion: transverse processes of upper 2 lumbar vertebrae and lower border of 12th rib.
Connections
- Erector Spinae (Sacrospinalis) — co-produces lateral flexion.
- External Oblique / Internal Oblique — also assist lateral flexion.
- Side Bends — training exercise.
Sources
Exercise guides
Keep this lesson, or ask how it applies to you.
Educational content only — not medical advice. Always consult a qualified professional for individualized guidance, especially around injury, pregnancy, or medical conditions.