Shoulder muscle EMG activity during push up variations on and off a Swiss ball.

Background: Surface instability is a common addition to traditional rehabilitation and strength exercises with the aim of increasing muscle activity, increasing exercise difficulty and improving joint proprioception. The aim of the current study was to determine if performing upper body closed kinetic chain exercises on a labile surface (Swiss ball) influences myoelectric amplitude when compared with a stable surface.

Methods: Thirteen males were recruited from a convenience sample of college students.