Part I of Burkhart, Morgan, and Kibler's landmark three-part series on the disabled throwing shoulder. It asks: what is the true initiating pathology in the dead arm, and does anterior microinstability actually explain it? Using arthroscopic observations, cadaveric data, and clinical series, the authors build a biomechanical framework centered on posteroinferior capsular contracture and GIRD as the root cause.
For decades, the dead arm in overhead athletes was attributed to anterior microinstability, and many pitchers underwent capsulolabral reconstruction — with return-to-sport rates of only 50-68%. This paper is the reason we no longer reflexively offer stabilization surgery to a thrower with a positive drive-through sign.
When you see a pitcher with a dead arm, measure GIRD bilaterally with the scapula stabilized. A side-to-side deficit greater than 25° is the key physical exam finding. Start with a focused sleeper-stretch program. Roughly 90% of symptomatic throwers will normalize GIRD within two weeks. If stretching fails (typically older elite pitchers with chronic symptoms), the operative answer is posteroinferior capsulotomy combined with SLAP repair, not anterior capsulolabral reconstruction.
The broader lesson: the drive-through sign and apparent anterior laxity in a thrower are pseudolaxity from a broken labral ring and a shifted glenohumeral contact point. Treating the SLAP repairs the ring and restores the cam effect, eliminating the apparent instability without touching the anterior capsule.
Part I of Burkhart, Morgan, and Kibler's landmark three-part series on the disabled throwing shoulder. It asks: what is the true initiating pathology in the dead arm, and does anterior microinstability actually explain it? Using arthroscopic observations, cadaveric data, and clinical series, the authors build a biomechanical framework centered on posteroinferior capsular contracture and GIRD as the root cause.
For decades, the dead arm in overhead athletes was attributed to anterior microinstability, and many pitchers underwent capsulolabral reconstruction — with return-to-sport rates of only 50-68%. This paper is the reason we no longer reflexively offer stabilization surgery to a thrower with a positive drive-through sign.
When you see a pitcher with a dead arm, measure GIRD bilaterally with the scapula stabilized. A side-to-side deficit greater than 25° is the key physical exam finding. Start with a focused sleeper-stretch program. Roughly 90% of symptomatic throwers will normalize GIRD within two weeks. If stretching fails (typically older elite pitchers with chronic symptoms), the operative answer is posteroinferior capsulotomy combined with SLAP repair, not anterior capsulolabral reconstruction.
The broader lesson: the drive-through sign and apparent anterior laxity in a thrower are pseudolaxity from a broken labral ring and a shifted glenohumeral contact point. Treating the SLAP repairs the ring and restores the cam effect, eliminating the apparent instability without touching the anterior capsule.