- long head: infraglenoid tubercle of scapula to olecranon process. functions in joint stability (shunt muscle) - medial head: dorsal surface of humerus to olecranon process.most active of the head in all three positions.- lateral head: dorsal surface of humerus to olecranon process.Strongest, but only active against resistance.unctions in joint stability (shunt muscle) - medial head: dorsal surface of humerus to olecranon process. most active of the head in all three positions. - lateral head: dorsal surface of humerus to olecranon process. Strongest, but only active against resistance.
The ES 500 is a great little backup unit. Easy to use, long battery life (about 25 min. with a desktop PC plugged in; 2 hrs. with a notebook PC plugged into it). It includes full surge protector capabilities, so you won't need to buy another one of those.
The life span of a laptop battery depends on how much you use it. The average life span of a Dell laptop battery is anywhere from 18 to 24 months. You should consider replacinâ¦g your battery when it stops being able to meet your everyday needs.