Latissimus Dorsi

Clinical Notes

• Contributes to conditions/subacromial-impingement — a tight latissimus restricts shoulder flexion and external rotation, forcing the humeral head to ride superiorly in the glenoid during overhead movements and narrowing the subacromial space.
• Involved in conditions/upper-crossed-syndrome as an accessory "tight" muscle — though not classically listed, a shortened latissimus contributes to medial rotation and depression of the shoulder girdle, reinforcing the protracted, internally rotated shoulder posture.
• The thoracolumbar fascia connection links latissimus function to conditions/low-back-pain — latissimus tensions the thoracolumbar fascia, contributing to lumbar stability but also potentially increasing compressive load on the lumbar spine when chronically hypertonic.
• Latissimus tendinopathy — overuse in overhead athletes (swimmers, climbers, baseball pitchers) produces posterior shoulder pain that is often misattributed to the rotator cuff. Pain with resisted shoulder extension, adduction, or internal rotation that localizes to the posterior axillary fold suggests latissimus tendinopathy.

• In clients with shoulder mobility restrictions, the latissimus is often shortened bilaterally but undertreated because it is in the "back" and students focus on the shoulder girdle muscles. A simple overhead arm raise assessment reveals latissimus shortening — if the client cannot fully flex the shoulder without compensatory lumbar extension, the latissimus is restricting.
• In swimmers and climbers, the latissimus is hypertonic and dominant, producing a "swimmer's posture" with internally rotated shoulders and a wide, V-shaped upper body.

• Responds well to broad longitudinal stripping from the thoracolumbar aponeurosis to the posterior axillary fold, and to sustained compression of TrPs in the axillary region.
• The posterior axillary fold is a particularly effective treatment site — grasping and compressing the fold between thumb and fingers addresses both latissimus and teres major simultaneously.
• Post-treatment, shoulder flexion ROM often improves immediately — the "wall test" (standing with back against the wall and raising the arms overhead) shows measurable improvement.

• The thoracodorsal nerve and the thoracodorsal artery run along the deep surface of the latissimus — they are vulnerable in the mid-axillary region. Avoid sustained deep pressure in the axilla proper.
• The long thoracic nerve runs superficially on the serratus anterior beneath the latissimus in the lateral chest wall — deep work through the latissimus in the lateral rib cage area should be performed with awareness of this nerve.
• The subscapular artery branches in the axilla — the axilla is a vascular region that requires gentle, measured techniques.

• Test latissimus length by asking the client to lie supine and raise both arms overhead, flat against the table. If the low back arches off the table, the latissimus is short — it is pulling on the thoracolumbar fascia and the lumbar spine as the arms elevate. This is the fastest way to screen for latissimus restriction, and it changes the treatment approach for both shoulder and low back complaints.