Lateral Raise: Good vs Bad Form

In the mirror, a bent-arm lateral raise looks almost right. From behind, the elbows fold.

Why it matters: bending the elbow brings the dumbbell closer to your shoulder. That shortens the lever, so the same weight asks less of your side delts. The rep feels easier because they are doing less. Swing it up past shoulder height and the upper traps rotate the shoulder blade to finish the rep.

The fix: keep a soft, fixed elbow from bottom to top, stop at shoulder height, and check your form from behind, not only in the mirror.

In this 3D model, the mirror view hides about a third of the elbow bend, because the forearm folds toward the mirror.