What muscle does lat have? The complete guide to the latissimus dorsi

October 2, 2025 •

3 min read

The latissimus dorsi, or 'lats,' are the largest muscles in the back, giving it that characteristic V-shape seen in athletes and bodybuilders. Understanding what muscle does lat have is key to a powerful physique and functional strength, as these large, triangular muscles are involved in everything from pulling exercises to maintaining posture.

Quick Summary

The term 'lat' refers to the latissimus dorsi, a pair of large, triangular muscles stretching across the middle and lower back. These muscles are responsible for shoulder adduction, extension, and internal rotation, playing a crucial role in pulling movements and overall back and core stability.

Key Points

Identification: The 'lat' refers to the latissimus dorsi, the largest muscle in the back, located in the mid and lower back region.
Function: The lats primarily control shoulder extension, adduction, and internal rotation, which are movements essential for pulling.
Exercises: Effective exercises for training the lats include pull-ups, lat pulldowns, various rows (barbell, dumbbell, cable), and dumbbell pullovers.
Anatomy: The lats have a broad origin across the spine, pelvis, and ribs, with a narrow insertion point on the upper arm bone (humerus).
Health Impact: Weak or tight lats can contribute to poor posture, shoulder instability, and back pain, making proper training and stretching important for overall health.
Associated Muscles: During pulling movements, the lats work with other muscles like the teres major, rhomboids, trapezius, and posterior deltoids.

Unveiling the Anatomy of the Latissimus Dorsi

The latissimus dorsi, commonly called 'lats,' are extensive, flat, and triangular muscles covering a significant area of the back, located beneath the shoulder blades. Their name, derived from Latin, signifies the 'broadest muscle of the back'.

Origin and Insertion: The Lats' Anchors

The function of the lats is dictated by their attachment points, known as the origin and insertion. The lats originate from a wide area including the lower six thoracic vertebrae, the thoracolumbar fascia connected to the lumbar and sacral vertebrae, the iliac crest, lower ribs, and the inferior angle of the scapula. The muscle fibers converge to a thick tendon that inserts into the floor of the intertubercular groove of the humerus (upper arm bone). This connection between the torso and arm is vital for powerful pulling and shoulder movements.

The Role of Synergistic and Stabilizing Muscles

The lats work in conjunction with several other muscles to achieve coordinated movement and stability. Synergists include the teres major, assisting with shoulder extension, adduction, and internal rotation, and the rhomboids, which retract the scapula. The trapezius and posterior deltoids stabilize the shoulder girdle, while the biceps brachii are heavily involved in exercises requiring elbow flexion like pull-ups and rows.

Function: The Lat's Versatile Contributions

Beyond aesthetics, strong lats are crucial for numerous functional movements and overall stability.

Primary Functions of the Lats

The main functions include shoulder adduction (bringing the arm towards the body), extension (moving the arm backward), and internal rotation (rotating the arm inward). The lats also stabilize the trunk during movements like pull-ups.

Accessory Functions

The lats also contribute to forced respiration and provide support for the lumbar spine, playing a role in spinal extension and lateral flexion. Their connection to the spine highlights why issues with the lats can lead to back pain.

Training the Lats: Your Exercise Arsenal

Effective lat training enhances overall upper body strength, posture, and injury prevention. Exercises can be grouped by movement pattern.

Vertical Pulling Movements

Pull-ups and chin-ups are highly effective bodyweight exercises. Wide grips emphasize the lats for back width, while neutral or underhand grips engage the biceps and lower lats more. Lat pulldowns, suitable for all levels, allow for controlled isolation with adjustable resistance and grip variations.

Horizontal Pulling Movements (Rows)

Barbell rows build back thickness and strength, engaging lats, traps, and rhomboids. Dumbbell rows, especially single-arm variations, address imbalances and offer a deeper range of motion. Seated cable rows provide consistent tension for building back width and thickness.

Accessory and Isolation Exercises

Straight-arm pulldowns isolate the lats with minimal bicep involvement. Dumbbell pullovers work both the lats and chest through a long range of motion.

Comparison of Lat Exercises


Exercise	Primary Action	Targeted Lats	Key Benefit	Notes
Pull-ups (Wide Grip)	Vertical Pull	Upper Lats, Teres Major	Builds back width and overall pulling strength	Requires significant body weight strength
Lat Pulldowns	Vertical Pull	Upper & Lower Lats	Isolates the lats with adjustable resistance	Ideal for all fitness levels
Barbell Rows	Horizontal Pull	Mid & Lower Lats, Rhomboids	Builds back thickness and overall posterior chain strength	Engages stabilizing core muscles
Dumbbell Rows	Horizontal Pull	Mid & Lower Lats	Addresses muscular imbalances, offers deep stretch	Requires core stability
Straight-Arm Pulldowns	Shoulder Extension	Upper & Lower Lats	Isolation, builds mind-muscle connection	Minimizes bicep involvement
Dumbbell Pullovers	Shoulder Extension	Upper & Lower Lats	Full range of motion stretch, works lats and chest	Versatile equipment

Conclusion

The latissimus dorsi, or 'lats,' are a fundamental muscle group for both appearance and function. Their role in pulling and shoulder movements is critical, and maintaining well-developed lats contributes to good posture, reduces the risk of back and shoulder pain, and enhances athletic performance. For comprehensive health and fitness, understanding and training the lats is essential. To delve deeper into muscle anatomy and training, consult authoritative sources such as the National Center for Biotechnology Information.

Frequently Asked Questions

The official name for the 'lat' muscle is the latissimus dorsi. This is a Latin term that translates to 'broadest muscle of the back'.

The latissimus dorsi is a large, triangular muscle that spans the mid and lower back. It extends from the spine and pelvis and connects to the upper arm, just below the shoulder joint.

Weak lats can lead to a variety of issues, including poor posture (such as rounded shoulders), shoulder instability, and compensatory movements that can result in back or shoulder pain.

Lat pulldowns are an excellent exercise for targeting the lats, particularly for beginners. However, other exercises like pull-ups and various rowing movements are also highly effective for building lat strength and width.

During a pull-up, the lats work to pull your body upward towards the bar while your arms are in a fixed overhead position. This powerful action makes them a crucial muscle for climbing and overhead pulling movements.

If your lats are tight, you might experience restricted movement when raising your arms overhead. This can cause your back to arch or rotate to compensate, leading to discomfort or an inability to achieve a full range of motion.

Yes, deadlifts are a compound exercise that engage the entire posterior chain, including the lats. The lats help to maintain a neutral spine and keep the barbell close to your body throughout the lift, contributing to overall back strength.