Starting Strength

functioning as the interface between the body and the bench. Therefore, they cannot accommodate the humerus if it approaches the bony processes. Since the scapula cannot adjust to accommodate the humerus, the humerus must accommodate the scapula by staying out of the way of the bony processes so that they don’t saw a hole through the rotator cuff tendons.
    The lifter keeps the scapulas out of the way by lowering the elbows, and thus the humerus, from 90 degrees of abduction to about 75 degrees. This shift allows the humerus to travel from lockout down to a position that permits the bar to touch the chest – the longest range of motion that can be made with a straight bar – and back to lockout without approaching a position that would impinge the shoulder. But as mentioned earlier, there are mechanical considerations.

    Figure 5-14. The bench press has the potential to cause shoulder impingement. Right , At 90 degrees of abduction, the humeral head can mash the rotator cuff tendon up against the acromioclavicular joint. Left , To avoid this problem, place your elbows down below parallel, with the glenohumeral joints at about 75 degrees of abduction.

    The most mechanically efficient bar path would be one in which the bar traveled vertically down and up directly over the shoulder joints, with the elbows at 90 degrees of abduction. But since this would impinge the shoulders, we must tolerate some inefficiency in the form of a non-vertical bar path produced by the distance the bar travels down the chest as the elbows are lowered from 90 degrees of abduction. This non-vertical bar path creates a moment arm between the bar and the shoulder joints at the bottom of the movement; this moment arm is equivalent to the distance along the sagittal plane between the bar and the shoulder joints. The farther the elbows are allowed to drop out of abduction – i.e., the lower the bar is along the chest – the longer the moment arm is against the shoulder joints. The bar follows the elbows: if they rotate away from the ribs, the bar goes up the chest toward the throat, and if the elbows move toward the rib cage, the bar moves down toward the belly ( Figure 5-15 ).

    Figure 5-15. The upper arm angle determines the point where the bar will touch the chest. The lower the elbows, the lower the bar, and high elbows put the bar close to the throat. The moment arm is the distance between the bar and the shoulder joints, and it varies with the elbow position. ( M.A. = moment arm )

    Your elbow position is therefore related to the bar position and to your individual anthropometry. For example, an experienced, proficient lifter with good upper back flexibility can arch his chest up high, thus allowing the bar a shorter trip down and up. This technique will have the bar touching lower on the chest, toward the bottom of the sternum, as the rib cage rotates up. For a person with less flexibility in the upper spine, this bar position on the chest would require the elbows to be at an angle of perhaps 45 degrees to the torso, about halfway between touching the rib cage and in line with the shoulders. But since our experienced, flexible lifter has his chest up higher, his shoulders are closer horizontally to the bottom of his sternum, when viewed from the side. This effect is due to the steeper angle that his flexibility allows his upper back, and thus his chest, to attain. This steep chest angle allows his elbows to stay more in line with his shoulders than they would for a less flexible trainee.
    More important, as the chest rotates up, the shoulder joint rotates into a position more in line with the bar on the chest when the humerus is in the preferred 75 degrees of abduction. This rotation returns some verticality to the bar path and some mechanical efficiency to the movement by reducing the distance – and thus the moment arm – between the bar and the shoulder joint ( Figure 5-16 ).

    Figure 5-16. After lowering the bar down to the chest, you can recover the mechanical efficiency of a short moment arm by squeezing the chest up and rotating the shoulder joints back up under the bar. Doing this makes the bar path more vertical and shorter at the same time.

    The correct humeral angle can actually vary quite a bit among individual lifters, from 75 to perhaps 45 degrees depending on the flexibility of the upper back and the ability to produce a high arch. Some lifters use an elbow position where the humerus is essentially parallel to the