(n.) Abnormally increased muscular movement; spasm.

bloat bloating breaking point distension extreme tension franticness frenziedness haul heave hyperactivity hyperkinesia hyperkinesis inflation officiousness overactivity overdistension overdrawing overexertion overexpansion overstrain overstraining overstress overstretching overtaxing pull rack snapping point strain straining stress stress and strain stressfulness stretch stretching swelling taxing tension tug