Article from Frederick C. Hatfield, Ph.D., MSS

SHRUGS
Your trapezius muscles (called "traps") elevate and support your shoulder girdle (i.e., pull your shoulders toward your ears). Simply hold a bar in front of you and "shrug" your shoulders straight upwards. You don't have to rotate your shoulders -- just shrug.

An alternative method is to shrug with heavy dumbbells while either seated or standing. The straight bar must be held out in front of you, while seated dumbbell shrugs allow the arms to hang naturally at your sides. This makes dumbbell shrugs a bit more comfortable and definitely easier on your low back. Holding a heavy bar in front of you requires strong contraction of your erector spinae muscles.

Normal shrugging technique (as explained above) activates the two upper portions of your trapezius (i.e., trapezius I and II). By leaning forward (about 20-30 degrees), and then shrugging straight up -- not toward your ears, but vertically toward the ceiling -- you will activate trapezius III and IV. You may wish to support your upper body against a padded surface (like a preacher curl bench) in order to alleviate unnecessary stress on your lower back while leaning forward.

SEATED PRESS BEHIND THE NECK
Despite its popularity among bodybuilders, I'm "mildly" opposed to this exercise for at least two reasons. First, assuming that you wish to do "complete" presses to lockout, seated dumbbell presses accomplish the same thing without the same "interference" from having to "crunch" your upper back muscles in order to get the bar down to your neck. Having to contract your rhomboids, trapezius III and IV, and your posterior deltoids only serves to limit the amount of adaptive stress being delivered to your middle deltoids.

Secondly, after the bar has passed the top of your head, your deltoids are no longer the prime movers in the movement. The deltoids are statically contracting at that point, and the serratus anterior and triceps muscles take over to finish the press to lockout.

Actually, you can press much more weight to a head height position than you can press completely overhead. The reason for this is that your middle deltoids are much stronger than the combined strength of your triceps and serratus. Does it not therefore make more sense to use a heavier weight and do "partial presses?" I think it does, and the simple reason is that it will deliver a greater adaptive stress to your middle delts.

FRONT RAISES
The traditional method of exercising your frontal deltoids is to raise either dumbbells or a bar upwards and to the front of your body with slightly bent elbows. If dumbbells are used, they can be raised alternately or simultaneously.

Using dumbbells, alternately raise them upwards and to the front as described above, but with one significant difference. Before raising the dumbbell in your right hand, lean 20-30 degrees to the right. And, before raising the left one, lean to the left in a similar fashion. The dumbbells are raised to about head height to arm's length in front of your face.

The rationale for this departure from traditional technique is that your frontal deltoids originate and insert at about that angle from the vertical plane of your body. Bending sideward while performing the dumbbell raises places the targeted frontal delt perpendicular to the floor, thereby making its contraction (force output) more efficient. Do that, and the adaptive stress is improved.

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