Glossary · Muscle
Latissimus dorsi
The widest muscle of the back runs from the pelvis and spine to the upper arm. It mostly moves the arm, and its link with the lower back is real but hard to pin down.
The latissimus dorsi, usually shortened to “the lats”, is a broad, flat muscle that covers most of the lower half of the back of the chest. Its main job is to move the arm, and it also works as an accessory muscle of breathing (Jeno & Varacallo, 2023).
Where is the latissimus dorsi?
It has an unusually wide origin. It starts from the spinous processes of the lower half of the thoracic spine (T6 to T12), the thoracolumbar fascia over the lower back, the top of the pelvis (the iliac crest) and the lowest three ribs. From there the fibres narrow into a tendon that attaches to a groove at the front of the upper arm bone (the intertubercular sulcus). It is supplied by the thoracodorsal nerve (TeachMeAnatomy).
Along with the trapezius, it is one of the two most superficial muscles of the back, lying just under the skin (TeachMeAnatomy). Over the lower back, its broad flat tendon makes up most of the outer layer of the thoracolumbar fascia, the tough sheet that encloses the erector spinae and other muscles beside the spine and anchors to the back of the pelvis (Willard et al., 2012).
What does the latissimus dorsi do?
- Moves the arm. It extends the arm (brings it back), adducts it (brings it in towards the body) and rotates it inwards (TeachMeAnatomy).
- Helps with breathing. It is counted among the accessory muscles of respiration (Jeno & Varacallo, 2023).
- May move the trunk, a little. Because it attaches to the spine and the thoracolumbar fascia, researchers have looked at its role in bending and turning the trunk. The evidence on how much it contributes is mixed (Jeno & Varacallo, 2023).
One detail shows how much other muscles share its work: surgeons sometimes move the latissimus dorsi to repair other parts of the body, and people lose only a limited amount of normal function afterwards (Jeno & Varacallo, 2023).
The latissimus dorsi and desk work
There is little research on the lats in office workers specifically. What exists points mainly to the shoulder.
In 30 sedentary young adults with shoulder impingement, compared with 30 matched controls, the latissimus dorsi was more active and the gluteus maximus less active while they raised the arm. The authors framed this as a kinetic chain pattern linking hip and shoulder, but the muscle activity was not meaningfully linked with pain or disability (Emara et al., 2026). It describes a difference, not a cause.
If raising your arm overhead feels restricted after a long day, the lats are not the only factor. In 34 healthy people, sitting slouched reduced how far the arm could be raised to the side by about 24 degrees compared with sitting upright (Kebaetse et al., 1999). More on this in shoulder pain from computer work.
Stretching the lats
Because the muscle pulls the arm down and in, movements that take the arm overhead and the trunk to the opposite side lengthen it. The side child’s pose on stretches before bed is one example. Side stretches of this kind are part of Bavelu’s sessions, designed and filmed by physiotherapists.
When to see a doctor
See a GP if shoulder pain gets worse or hasn’t improved after two weeks, or if it is very difficult to move your arm. Ask for an urgent appointment or contact NHS 111 if the pain is sudden or very bad, you can’t move your arm, or it started after a fall or injury (NHS). Back pain coming from the top of the back, between the shoulders, is also worth a GP visit, and back pain with chest pain needs a 999 call (NHS).
Questions people ask
What does the latissimus dorsi do?
It moves the arm: it pulls it down and back towards the body and turns it inwards. It also helps with breathing as an accessory muscle. How much it moves the spine itself is still debated.
Where do you feel the latissimus dorsi?
Along the side of the back below the armpit and across the lower and middle back. It starts on the lower half of the thoracic spine, the lowest ribs, the top of the pelvis and a sheet of connective tissue over the lower back, and attaches to the front of the upper arm bone.
Can tight lats cause lower back pain?
The lats are connected to the thoracolumbar fascia, a tissue sheet over the lower back, so a link is plausible. But the evidence on how much the muscle influences spinal movement is mixed, and we found no study showing that tight lats cause back pain.
How do you stretch the latissimus dorsi?
Because the muscle pulls the arm down and in, movements that take the arm overhead and bend the trunk the other way lengthen it. The side child's pose described on our stretches-before-bed page is one example from the app.
Terms on this page
- Thoracic spineThe twelve vertebrae of the upper and middle back, T1 to T12, where the ribs attach.
- TrapeziusThe large muscle over the back of the neck and shoulders, and the most common seat of desk-work neck tension.
- Erector spinaeThree long columns of muscle either side of the spine that straighten the back and control bending.
- Kinetic chainThe idea that joints and muscles work as linked segments, and how far the evidence supports it.
- Gluteus maximusThe large buttock muscle that straightens the hip when you climb, run or stand up.
- FasciaThe connective tissue that wraps, separates and links muscles, organs and other structures.
Sources
- Jeno SH, Varacallo MA. Anatomy, Back, Latissimus Dorsi. StatPearls (NCBI Bookshelf), 2023.
- TeachMeAnatomy. The superficial back muscles.
- Willard FH, Vleeming A, Schuenke MD, Danneels L, Schleip R. The thoracolumbar fascia: anatomy, function and clinical considerations. Journal of Anatomy, 2012.
- Emara NM et al. Altered gluteus maximus and latissimus dorsi activation in subacromial impingement syndrome: implications for kinetic chain dysfunction. Journal of Clinical Medicine, 2026.
- Kebaetse M, McClure P, Pratt NA. Thoracic position effect on shoulder range of motion, strength, and three-dimensional scapular kinematics. Archives of Physical Medicine and Rehabilitation, 1999.
- NHS. Shoulder pain.
- NHS. Back pain.
This page explains a topic in general terms. It is not a diagnosis and does not replace a doctor or physiotherapist. If something hurts badly, keeps getting worse or comes with numbness, weakness or fever, see a doctor.
