FitPointz

Here you will find an article on one exercise (new one every month). With a detailed analysis of the muscles used during the exercise and a informative description of how to both perform and assist in the actual performance of the exercise.

A full library of all previous exercises can be found at members online under the sub menu

Exercise: Overhead Barbell Shoulder Press

Client Instruction:

Starting Position

• Grasp the bar with a pronated grip, positioning your hands slightly wider than shoulder width apart. Secure the bar so that it rests on your chest.
  
• Your feet should be shoulder width apart and directly under the bar with your knees slightly bent. Your elbows should be pointed downward and to the side of your body
  
• Tighten your abdominals to secure your low back
  

Up Phase

• When your arms are almost fully extended, pause and slowly lower the weight back to the chest high starting position.
  
• Keep your back straight at all times and avoid hyperextending your trunk

Down Phase

• From this starting position, inhale and hold your breath as you press the bar upward. Continue to extend your arms until they are straight with your shoulders elevated. As you reach the final position in front of your upper chest, exhale during the final parts of the lift.

Muscle Analysis Chart

Up Phase

Down Phase**

**In the down phase of the exercise the weight is lowered slowly with gravity. The muscles that concentrically contracted to lift the weight are the same muscles that are eccentrically contracting to lower the weight.

General Kinesiological Analysis

In the shoulder press, the shoulder joint is abducted by the concentric contraction of the supraspinatus and anterior deltoid. The scapula is abducted by the serratus anterior and the pectoralis minor, followed by upward rotation from the contraction of the serratus anterior and the trapezius. The elbow joint is extended by the concentric contraction of the triceps and the anconeus.

Advanced Kinesiological Analysis

The supraspinatus and the anterior deltoid are the prime movers at the shoulder joint in a shoulder press. In a shoulder press, the humerus is laterally rotated prior to the press. This starting position places the anterior deltoid in the best position to pull on the humerus causing abduction. During abduction of the shoulder joint in the up phase of the shoulder press, the clavicular portion of the pectoralis major becomes active at approximately 110 degrees. At this point the muscle’s line of pull is above the centre of the shoulder joint, allowing the insertion to pull on the humerus.

As the anterior deltoid contracts to cause abduction, it also attempts to cause medial rotation and horizontal adduction of the shoulder joint due to its angle of pull. To prevent this from occurring, the infraspinatus and teres minor contract statically to neutralize this unwanted movement.

If the shoulder press is performed with a narrow grip and the elbows pointed forward of the body, the muscle recruitment pattern will change. In this starting position, the up phase is caused by the shoulder joint flexing caused by the concentric contraction of the clavicular portion of the pectoralis major, coracobrachialis, anterior deltoid and the short head of the biceps brachii. As these muscles cause flexion, they also have a tendency to cause medial rotation of the humerus. This unwanted movement is prevented by the static contraction of the infraspinatus and teres minor. The narrow grip shoulder press will recruit the clavicular portion of the pectoralis major throughout its full range of motion. The coracobrachialis and the biceps brachii are recruited in this exercise. These muscles are not recruited when the exercise is performed in a wide grip shoulder press.

The triceps and anconeus are the prime movers that extend the elbow joint. The anconeus plays a more significant role when the weight that is lifted is heavy. It has been reported that the lateral and medial heads of the triceps are more active in the shoulder press, while the long head is used sparingly.

As the shoulder joint begins to abduct to lift the weight, the trapezius, pectoralis minor and the rhomboids contract statically to stabilize the scapula allowing the supraspinatus and deltoid to contract from a firm base. Once the weight is being lifted, the scapula begins the move into abduction. At this time the degree of stabilization of the abdominals and the spinal extensors is increased.

In the initial movement of the scapula, the serratus anterior and pectoralis minor contract to cause abduction. For this to occur there must be a simultaneous neutralizing of their additional movements of upward and downward rotation. As the shoulder continues to abduct, the scapula must move into upward rotation caused by the concentric contraction of the serratus anterior and the trapezius. When both these muscles contract in unison to cause upward rotation, they neutralize the additional adduction and abduction that each will also cause.

© 2007 Fitness Institute Australia

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or any reliance on it. Users should satisfy themselves as to their own or clients medical and physical condition before adopting/using
the information or recommendations made. No responsibility or liability is accepted for any loss or damage suffered
by any person as a result of adopting the above information or recommendations.

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