Arm crush (from side control)

Arm crush (from side control) is the colloquial name for the straight armlock entered from side control — describing the compression feel the bottom player experiences as the attacker drives the controlled arm against the chest line.

Etymology. The “arm crush” descriptor captures the proprioceptive experience of being on the receiving end. The “(from side control)” qualifier specifies the entry position, distinguishing this from other “arm crush” labels applied to inverted armbars and other compression variants in colloquial vocabulary. The compound form predominates in coaching speech where the entry position is the live tactical concern.

Mechanics. The straight armlock isolates the elbow and loads it against its natural range — the attacker’s chest serves as the fulcrum, and the compressive load through the chest contact registers as crushing pressure on the joint and surrounding tissue.

Cross-reference. “Straight armlock” is the canonical site label; “shoulder lock” is the broader informal label. Full mechanical coverage on Straight Armlock.