What is Latissimus Dorsi?

What is Latissimus Dorsi?

The latissimus dorsi, usually shortened to lats, is the widest muscle in the human body and the muscle most responsible for the coveted V-taper look of a developed back. It is a large, thin, triangular sheet that covers the lower half of the back on each side, sweeping up from the pelvis and lower spine, wrapping around the side of the torso, and narrowing to a thick tendon that attaches to the front of the upper arm bone. Because it crosses the shoulder joint, the latissimus dorsi is functionally an arm muscle even though most of its bulk sits on the trunk. It has a very broad origin: the spinous processes of the lower six thoracic vertebrae (T7 to T12), the thoracolumbar fascia (a tough sheet of connective tissue linking it to the lumbar vertebrae and sacrum), the back of the iliac crest of the pelvis, the lower three or four ribs, and often a small slip from the inferior angle of the scapula. All those fibres converge and twist into a single flat tendon that inserts into the floor of the intertubercular groove of the humerus, right next to the pectoralis major and teres major. This wide-to-narrow shape is why the lats power such a big range of pulling movements and why they are the primary target of pull-ups, chin-ups, pulldowns and rows.

How it works

The latissimus dorsi produces three main movements at the shoulder, and understanding them explains how to train it. First, shoulder extension: because the lat attaches to the front of the humerus but originates behind and below, contracting it pulls the arm from an overhead or forward position down and back toward the trunk. This is the driving action of a straight-arm pulldown and the pulling phase of any row. Second, shoulder adduction: it draws the raised arm back down toward the side of the body, which is the dominant action of a wide-grip pull-up or lat pulldown as the elbows travel from overhead down to the ribs. Third, internal (medial) rotation: it rotates the arm so the palm turns inward. Because the lat can extend and adduct a fully overhead arm, it is exceptionally strong from a stretched, overhead position, which is why pulldowns and pull-ups load it so effectively through a long range of motion. The muscle is innervated by the thoracodorsal nerve, carrying fibres from spinal levels C6, C7 and C8 out of the posterior cord of the brachial plexus. When you pull your body up to a fixed bar rather than pulling a bar down to you, the origin and insertion effectively swap roles and the lat raises the trunk toward the arms, which is why it is a key climbing and pulling muscle. The lats also assist forced expiration and coughing by compressing the ribcage, contribute to lateral flexion of the trunk, and help transfer force between the upper and lower body across the thoracolumbar fascia, making them part of the posterior chain that stabilises heavy deadlifts. In training terms, the practical takeaway is that any movement bringing the elbow down and toward or behind the midline, especially from a fully stretched overhead start, is a latissimus dorsi exercise.

How to apply it

• Vertical pulls (pull-ups, pulldowns): Pull-ups, chin-ups and lat pulldowns load the lats in their strongest overhead-to-side range. Pull the elbows down toward the ribs, not the hands to the chest, for 6-12 reps per set to bias adduction and extension.
• Horizontal pulls (rows): Barbell, dumbbell and cable rows emphasise shoulder extension. Keep the elbow tucked closer to the body and drive it back past the torso; think of pulling with the elbow to reduce biceps takeover. Use 8-12 reps.
• Straight-arm pulldowns: A straight-arm cable pulldown isolates shoulder extension with no elbow bend, removing the biceps almost entirely. It is one of the best ways to feel and overload the lats directly. Use lighter loads for 12-15 controlled reps.
• Train the full stretched range: Let the arms travel all the way overhead at the top of each pull-up or pulldown so the lats reach full length under load. The lengthened, loaded portion of the range appears especially valuable for growth.
• Adjust grip width and orientation: A wider grip biases adduction while a closer, neutral or underhand grip lets the arm move through more extension. Rotating between grips over a training block hits the fan-shaped muscle from several angles.
• Mind-muscle connection and instruction: Consciously focusing on the lats and receiving simple cues to pull with the back rather than the arms measurably increases lat activation during pulldowns, so slow the eccentric and drive the elbows.

Types

Worked example

A simple weekly latissimus dorsi emphasis you could run across two back or pull sessions. It pairs one vertical pull, one horizontal pull and one isolation movement so the muscle is trained through both its adduction and extension actions with enough weekly volume for growth.

That is roughly 13 hard sets across the week, which sits comfortably inside typical hypertrophy volume targets for a large muscle. Progress the load or reps each week and keep at least one exercise in the fully stretched overhead position.

Latissimus dorsi vs pectoralis major

The lat and the pec share two actions, adduction and internal rotation, and their tendons insert only millimetres apart on the humerus. The key difference is extension versus flexion: the lat pulls the arm down and back, the pec pulls it up and forward, which is why they are trained by opposite movement patterns.

By goal

• Strength and powerlifting: Strong lats stabilise the bar path in the bench press and hold the bar close during deadlifts. Prioritise heavy weighted pull-ups and barbell rows in the 4-8 rep range to build back strength that transfers to the big lifts.
• Hypertrophy and physique: For the widest back, chase weekly volume of roughly 10-20 hard sets split across vertical and horizontal pulls, use a full overhead stretch, and include an isolation move like the straight-arm pulldown to keep tension on the lat.
• Rehab and shoulder health: Tight or overactive lats can limit overhead reach and tug the shoulder into internal rotation. Balance heavy pulling with overhead mobility work and mid-back exercises, and progress load gradually if you have a history of shoulder or low-back pain.

Common misconceptions

• "The lats are trained by pulling the bar to your chest." The lats work by moving the elbow, not the hands. Cueing hands-to-chest tends to recruit the arms and upper back. Thinking about driving the elbows down and toward the ribs keeps tension where you want it, on the latissimus dorsi.
• "Wide-grip pulldowns are the only way to build wide lats." Grip width shifts emphasis but no single grip is essential. Research on grip width in the lat pulldown shows only modest differences in latissimus activation. Full range of motion, progressive load and total volume matter far more than an extra-wide bar.
• "The lats are only a back muscle." Because the latissimus dorsi crosses the shoulder and attaches to the front of the humerus, it is functionally an arm and shoulder muscle. It also assists forced breathing, trunk side-bending and transferring force through the thoracolumbar fascia during deadlifts.
• "Rows and pulldowns hit the lats identically." Both train the lats, but pulldowns and pull-ups emphasise adduction from a stretched overhead position, while rows emphasise shoulder extension with the arm closer to the body. Including both gives more complete development of this fan-shaped muscle.

Related terms

Latissimus Dorsi FAQ

What is the latissimus dorsi?

The latissimus dorsi is the large, flat, fan-shaped muscle covering the lower half of the back. It runs from the lower spine, pelvis and lower ribs to the front of the upper arm bone, and extends, adducts and internally rotates the shoulder during pulling movements.

What does the latissimus dorsi do?

The latissimus dorsi performs three main shoulder actions: extension (pulling the arm down and back), adduction (bringing a raised arm to the side) and internal rotation. It also raises the trunk toward a fixed bar and assists forced breathing and trunk side-bending.

What are the best exercises for the lats?

Pull-ups, chin-ups and lat pulldowns are the strongest lat builders because they load the muscle from a full overhead stretch. Add horizontal rows and straight-arm pulldowns to train shoulder extension, and use a full range of motion on every rep.

Where does the latissimus dorsi originate and insert?

It originates from the spinous processes of the T7 to T12 vertebrae, the thoracolumbar fascia, the iliac crest of the pelvis and the lower three to four ribs. All of those fibres converge to insert on the floor of the intertubercular groove of the humerus.

How do I feel my lats working during pulldowns?

Think about driving your elbows down toward your ribs rather than pulling the bar with your hands, control the lowering phase, and start each rep from a full overhead stretch. Deliberately focusing on the lats has been shown to increase their activation.

Is the latissimus dorsi one muscle or two?

You have two latissimus dorsi muscles, one on each side of the back. Within each muscle the fibres are often described as upper, more horizontal portions and lower, more vertical portions, but it is a single continuous sheet on each side.

How often should I train my lats?

Training the lats twice per week suits most people, splitting your total weekly volume of roughly 10-20 hard sets across two sessions. This lets you accumulate enough volume for growth while giving the muscle time to recover between workouts.

Why do my arms give out before my lats?

During pulls the biceps and forearms often fatigue first, limiting the lats. Using lifting straps, choosing exercises like the straight-arm pulldown that remove the elbow bend, and focusing on elbow-driven pulling all help you fatigue the lats before your grip.

References

1. Jeno SH, Varacallo M. Anatomy, Back, Latissimus Dorsi. StatPearls, NCBI Bookshelf
2. Andersen V, et al. Effects of grip width on muscle strength and activation in the lat pull-down. J Strength Cond Res, 2014. PubMed 24662157
3. Snyder BJ, Leech JR. Voluntary increase in latissimus dorsi muscle activity during the lat pull-down following expert instruction. J Strength Cond Res, 2009. PubMed 19826307
4. Lusk SJ, Hale BD, Russell DM. Grip width and forearm orientation effects on muscle activity during the lat pull-down. J Strength Cond Res, 2010. PubMed 20543740