"Shoulders like boulders" is a term bandied about in fitness circles quite casually, although achieving that level of development in the shoulder muscles isn't easy by any stretch of imagination. Shoulders determine the gait and posture of a person besides helping in moving the arms about via the rotator cuff joint, where three bones come together.
Aesthetically, well-developed and rounded shoulders make a person appear taller and broader. It is necessary to target all the body parts each day, and shoulders require attention as well as they consist of many muscles like the traps and deltoids. Biceps, abs and chest may give your upper body an enhanced look, but it all is a waste if your structure doesn't appear broad from the shoulders.
Lateral exercises are designed to develop the shoulder muscles, or the lateral muscles, which also stands for the muscles on the sides of the body. While overhead or shoulder presses help developing the shoulder muscles directly, the lateral movements help build the muscles surrounding them, giving a more rounded appearance. It is an excellent core workout as well, as it engages the core muscles when you lift your arms straight either towards the front or your sides.
The lateral raise has three basic movements - to the front, sides or bent-over. These movements help develop the lateral, front and back deltoids, upper trapezius and the rotator cuff in the shoulders, as well as the sides of the chest. For intensity, you can always add different movements such as alternate raises or single-arm lateral raises. In the front version of the exercise, you can also use the barbell to target both sides together.