Logan Steele
The latissimus dorsi is a large, flat muscle that covers the majority of the lower posterior thorax. The muscle's primary function is of the upper extremity, but it is also considered a respiratory accessory muscle. The latissimus dorsi is responsible for extension, adduction, transverse extension (also known as horizontal abduction or horizontal extension), flexion from an extended position, and medial internal rotation of the shoulder joint. It also plays a role in the extension and lateral flexion of the lumbar spine. The muscle is active in moving the trunk forward and upward when the upper extremities are fixed overhead, as in climbing or performing a chin-up.
| Characteristics | Values |
|---|---|
| Common name | Latissimus dorsi |
| Description | A large, flat muscle on the back that stretches to the sides, behind the arm |
| Location | Lower posterior thorax, lower two-thirds of the trunk |
| Function | Extension, adduction, transverse extension, flexion from an extended position, and (medial) internal rotation of the shoulder joint |
| Innervation | Thoracodorsal nerve (C6-C8) |
| Blood supply | Thoracodoral artery |
| Clinical significance | Chronic shoulder and back pain, posterior shoulder dislocations |
| Additional information | Works collaboratively with the teres major and pectoralis major muscles |
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What You'll Learn
- The latissimus dorsi is an extrinsic muscle of the back and shoulder
- It is a broad, flat muscle that covers the lower posterior thorax
- The muscle's primary function is of the upper extremity
- It is also considered a respiratory accessory muscle
- The latissimus dorsi is implicated in chronic back and shoulder pain
The latissimus dorsi is an extrinsic muscle of the back and shoulder
The latissimus dorsi is a large, flat muscle on the back that stretches to the sides, behind the arm. The name "latissimus dorsi" comes from Latin and means "broadest [muscle] of the back". The pair of muscles are often referred to as "lats", especially among bodybuilders.
The latissimus dorsi has a broad attachment to the spinous processes of the vertebrae, with the number of dorsal vertebrae varying from four to eight. It also attaches to the posterior iliac crest, the lower ribs, and the inferior angle of the scapula. The muscle fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus.
The latissimus dorsi is active in climbing, rowing, and swimming movements. When the arms are fixed above the head, it works with the pectoralis major to pull the trunk upward and forward. It also assists in depressing the arm and internally rotating the shoulder. Tightness in the latissimus dorsi can contribute to chronic shoulder and back pain.
Injuries to the latissimus dorsi are rare but can be treated with rehabilitation or, in the case of tendon avulsion injuries, surgery. The muscle is also used in surgical reconstruction of the anterior trunk, such as in breast reconstruction after mastectomy.
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It is a broad, flat muscle that covers the lower posterior thorax
The latissimus dorsi is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word "latissimus dorsi" comes from Latin and means "broadest [muscle] of the back", derived from "latissimus" (Latin for broadest) and "dorsum" (Latin for back). The latissimi dorsi, or "lats" as they are commonly known, especially among bodybuilders, are a pair of muscles that cover the lower posterior thorax.
The latissimus dorsi is an extrinsic muscle of the shoulder and back. It originates from the spinous processes of T7-T12, the iliac crest, the thoracolumbar fascia, and the inferior three ribs. The fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus. The muscle's primary function is in the upper extremity, but it is also considered a respiratory accessory muscle. It is responsible for multiple actions, including extension, adduction, transverse extension (also known as horizontal abduction or horizontal extension), flexion from an extended position, and medial internal rotation of the shoulder joint.
The latissimus dorsi plays a crucial role in climbing, rowing, and swimming. When the arms are fixed above the head, it works in synergy with the pectoralis major to elevate the trunk upwards. This muscle is also active during deep inspiration and forceful respiratory functions such as coughing and sneezing. In addition, the latissimus dorsi assists in holding the scapula against the thorax during upper limb movements.
The proper functioning and coordination of the latissimus dorsi with the teres major and pectoralis major muscles are essential for smooth and fluid movements of the upper extremity. Tightness in this muscle can contribute to chronic shoulder and back pain. Assessment of the length and flexibility of the latissimus dorsi is crucial for patients with low back pain due to its attachments to the spine and pelvis.
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The muscle's primary function is of the upper extremity
The latissimus dorsi is a large, flat muscle that covers most of the lower posterior thorax, stretching to the sides and behind the arm. It is one of the extrinsic back muscles and belongs to the muscles of the scapular motion. The primary function of the muscle is the movement of the upper extremity.
The latissimus dorsi is responsible for several movements of the upper extremity, including extension, adduction, transverse extension (also known as horizontal abduction), flexion from an extended position, and medial internal rotation of the shoulder joint. It also assists in depressing the arm, along with the teres major and pectoralis major muscles.
The muscle plays a crucial role in climbing or performing activities such as chin-ups, where it moves the trunk forward and upward while the upper extremities are fixed overhead. This muscle is also active during deep inspiration and forceful respiratory functions like coughing and sneezing.
The latissimus dorsi is an important muscle in rowing, swimming (especially during the downstroke), and chopping. It is also involved in violent expiration, as it attaches to the ribs and compresses the thorax and abdomen during a cough or sneeze.
The proper functioning and coordination of the latissimus dorsi with the teres major and pectoralis major muscles are essential for smooth and fluid movements of the upper extremity.
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It is also considered a respiratory accessory muscle
The latissimus dorsi is a large, flat muscle on the back that stretches to the sides, behind the arm. The muscle's primary function is in the upper extremity, but it is also considered a respiratory accessory muscle. The latissimus dorsi is involved in multiple actions, including adduction, extension, and internal rotation of the shoulder joint. It also assists in depression of the arm and has a synergistic role in the extension and lateral flexion of the lumbar spine.
The latissimus dorsi is an extrinsic muscle of the shoulder and back. It originates from the spinous processes of the seventh to twelfth thoracic vertebrae, the thoracolumbar fascia, and the inferior three ribs. The fibres converge into a tendon that attaches to the intertubercular sulcus of the humerus. The muscle's broad attachment to the spinous processes allows it to pull the trunk forward relative to the arms. This is particularly useful in activities such as walking with crutches or climbing, where the humerus becomes the fixed point.
Research has shown that the latissimus dorsi is active during deep inspiration and forceful respiratory functions such as coughing and sneezing. During a cough or sneeze, the muscle can be felt pressing forcibly inward as it compresses the thorax and abdomen. The muscle is also involved in violent expiration, as it attaches to the ribs.
The latissimus dorsi is an important muscle in rowing, swimming (especially during the downstroke), and chopping. It is one of the main stabilizers of the spine and can be trained with various exercises, including vertical and horizontal pulling movements such as pull-downs, pull-ups, and bent-over rows. Proper function and coordination with the teres major and pectoralis major muscles are crucial for smooth and fluid movements of the upper extremity.
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The latissimus dorsi is implicated in chronic back and shoulder pain
The latissimus dorsi is a large, flat muscle on the back, stretching to the sides and behind the arm. The name "latissimus dorsi" comes from Latin and means "broadest [muscle] of the back". The muscle is responsible for several functions, including extension, adduction, transverse extension, flexion from an extended position, and internal rotation of the shoulder joint. It also plays a role in the extension and lateral flexion of the lumbar spine.
Due to its attachment to the spine and the humerus, tightness in the latissimus dorsi can contribute to chronic back and shoulder pain. This tightness can manifest as sub-optimal glenohumeral joint (shoulder) function, leading to chronic pain, or tendinitis in the tendons connecting the muscle to the spine. A decrease in the length or an increase in the stiffness of the muscle can lead to altered movement patterns and postures, exacerbating low back pain.
Latissimus dorsi pain can be challenging to differentiate from other types of back or shoulder pain. It is typically felt in the shoulder, back, or upper and lower arm. The pain worsens when reaching forward, extending the arms, or reaching overhead. Overuse, poor technique, and inadequate warming up before exercising are common causes of this pain. Maintaining good posture, staying hydrated, and performing proper stretches and warm-up exercises can help prevent latissimus dorsi pain.
Assessment of the latissimus dorsi muscle is crucial for patients with upper extremity pathology and restrictions in shoulder movement. Proper function and coordination with the teres major and pectoralis major muscles are essential for smooth and fluid movements. Treatment for latissimus dorsi pain typically involves rest, physical therapy, and anti-inflammatory medications. In severe cases, alternative treatments or surgery may be considered.
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Frequently asked questions
The dorsi muscle, or latissimus dorsi, is a large, flat muscle that occupies the majority of the lower posterior thorax.
The name comes from Latin and means "broadest [muscle] of the back".
The muscle's primary function is in the upper extremity, but it is also considered a respiratory accessory muscle. It is involved in multiple actions, including adduction, extension, and internal rotation of the arm at the glenohumeral (shoulder) joint.
The latissimus dorsi is found in the lower back region, covering the serratus posterior muscles. It is an extrinsic muscle of the back, meaning it originates from the myogenic cells in the developing upper limb buds.
The power/size/strength of the latissimus dorsi can be trained with various exercises, including vertical and horizontal pulling movements such as pull-downs, pull-ups, and bent-over rows.
