Lateral Raises (Shoulder Flys) Guide

The shoulder fly (also known as a lateral raise) works the deltoid muscle of the shoulder. The movement starts with the arms straight, and the hands holding weights at the sides or in front of the body. Body is in a slight forward-leaning position with hips and knees bent a little. Arms are kept straight or slightly bent, and raised through an arc of movement in the coronal plane that terminates when the hands are at approximately shoulder height. Weights are lowered to the starting position, completing one "rep". When using a cable machine the individual stands with the coronal plane in line with the pulley, which is at or near the ground. The exercise can be completed one shoulder at a time (with the other hand used to stabilize the body against the weight moved), or with both hands simultaneously if two parallel pulleys are available.

This movement, when the shoulder is kept in neutral rotation, primarily targets the middle head of the deltoid. The anterior (front) and posterior (back) heads of the deltoid will also co-contract to aid in the abduction function. If the shoulder is laterally (externally, outwardly) rotated, the anterior deltoid becomes the prime mover of the glenohumeral joint, the posterior deltoid de-activates, and the middle head assists. By bending at the waist or leaning against a bench, the line of pull created allows the lateral deltoid to be isolated to a higher degree.

If repetitions are done explosively, it is possible for form to deteriorate and other muscles may come into play to do work instead of the deltoid, by generating upward and rotation momentum. The muscles which can be used to "cheat" in this movement are primarily the serratus anterior and the upper fibers of the trapezius, both of which elevate and upwardly rotate the scapula.