Synergists for raising arm: Anterior Deltoid, Lateral Deltoid, Upper Pectoralis Major, Middle and Lower Trapezius, Serratus Anterior
Stabilizers of torso, legs, and core: Obliques, Iliopsoas, Tensor Fasciae Latae, Quadriceps, Sartorius, Sternal (Lower) Pectoralis major, Serratus Anterior, Pectoralis Minor
Get into a push-up position with your arms slightly closer than shoulder-width apart and your feet wider than shoulder-width apart.
Your body should form a straight line from your head to your heels.
Keeping your hips and torso square, exhale as you lift one arm off the floor.
Hold for a count of two.
Inhale as you lower your arm back to the starting position.
Repeat with the opposite arm.
Keep repeating and alternating arms until you have performed the prescribed number of repetitions.
Comments and tips
The high front plank with arm raise is a great exercise for developing rotational stability. When you raise your arm, your body is put off balance, activating your stabilizing muscles.
Developing rotational stability is important for functional fitness as this trains your core to remain still as your limbs (i.e. arms and legs) move. Movement during daily life often requires your limbs to move as your trunk remains stable (i.e. stepping up the stairs or eating a meal).
Keep your hips facing the floor as much as possible. Allowing your hips to twist as you lift your arm off the floor defeats the purpose of the exercise.