Latissimus Dorsi Strain

What Is It?

The latissimus dorsi is the broad back muscle powering pulling and the late-cocking/acceleration phases of throwing. Lat strains are increasingly recognized in pitchers and climbers.

A strain means muscle fibers were overstretched. We grade strains I–III: Grade I — mild, microscopic fiber injury; Grade II — moderate, a partial tear with strength loss; Grade III — severe, complete disruption.

How It Happens

High-velocity throwing, pull-ups/rows under fatigue, climbing moves, or swimming sprints.

What It Feels Like

Pain in the side of the back or the back of the armpit during pulling or throwing, tenderness along the muscle, pain with a full overhead stretch.

How Long Recovery Takes

• Grade I: 1–3 weeks
• Grade II: 4–8 weeks
• Grade III: high-grade tears in throwers may take 3–4 months and occasionally need surgical consultation

Treatment

Almost all muscle strains heal without surgery. For the first 72 hours: relative rest, ice 15–20 minutes several times daily, compression, and gentle motion — complete rest slows healing. Then a progressive program: pain-free motion → isometrics → strengthening → eccentric loading (strengthening the muscle while it lengthens — the phase that prevents re-injury) → sport-specific work.

Progressive pulling strength (rows → pull-downs → pull-ups) and, for throwers, a formal interval throwing program before mound work.

Returning to Sport

Return when strength is at least 90% of the other side, motion is full and pain-free, and you can perform your sport’s movements at full speed without hesitation. Returning before the muscle is re-strengthened is the main cause of re-injury.

Preventing the Next One

Managed throwing workloads and balanced pulling strength; gradual return after layoffs.

When to Call Us

In a pitcher: sudden sharp pain mid-throw with a drop in velocity — shut down throwing and come in; high-grade lat/teres tears benefit from early MRI.