The Muscles Worked on the Lateral Raise Machine

There are exercise machines to work every major muscle group in your body. The lateral raise machine targets your shoulders, and can be done two to three times per week as part of your resistance-training program. Perform one to three sets of eight to 12 repetitions to help tone and define your shoulders.

Lateral Raise Machines

There are variations in lateral raise machines. Many are seated machines, but you may either face the machine or sit with your back to the weight stack. Either way there are common elements. Set the seat height so your shoulder joint is in line with the pivot point of the machine, so it moves like your shoulders. Select a light resistance to begin, and sit on the machine. Place your lower arms and elbows against the pads, and sit up tall with your shoulders back and down. Exhale and raise your arms out to the sides away from your body. Stop when your arms are parallel to the floor. Slowly lower back down as you inhale for one complete repetition.

Target Muscles

The target muscle of a lateral raise machine is the deltoid, specifically the lateral portion. There are three sections to your deltoids: anterior, lateral and posterior. The lateral portion is what can give your shoulders a rounded look when you develop them. It originates on your scapula, crosses the shoulder joint and inserts on the humerus, or upper arm. The primary action is abduction, as in the lateral raise exercise. It's also responsible for shoulder flexion and transverse abduction.

Synergists

When exercising you may focus on a particular muscle, but it's not working alone. These synergists assist the target muscle in performing certain movements, so they are getting some work even if you don't feel it. The synergists in the lateral raise machine exercise include the anterior portion of your deltoids, supraspinatus, the lower and middle portion of the trapezius and the serratus anterior. They help ensure smooth motion, and allow you to really challenge your lateral delts.

Stabilizing Muscles

Dynamic stabilizers also help ensure smooth motion when performing exercises. These muscles contract and stay that way in order to keep your body in the proper position. In the lateral raise your upper trapezius and levator scapulae are dynamic stabilizers. They contract to keep your shoulders down during the movement. One common problem trainers see in lateral raise exercises is shoulders shrugging up and down. This means the traps and levator are not properly contracted, and it can lead to neck and shoulder pain if done on a regular basis.