Muscle coactivation occurs when agonist and antagonist muscles (or synergist muscles) surrounding a joint contract simultaneously to provide joint stability,[1][2] and is suggested to depend crucially on supraspinal processes involved in the control of movement.[3] It is also known as muscle cocontraction, since two muscle groups are contracting at the same time. It is able to be measured using electromyography (EMG) from the contractions that occur. The general mechanism of it is still widely unknown. It is believed to be important in joint stabilization, as well as general motor control.[1]