Two Tips on Form
When performing a triceps pushdown, do not extend your wrists so that your palms face the floor while pushing the bar down. Rather, your palms should face your thighs, which will place less stress on the elbow joint.
When it comes to bench pressing , don't make like a pro. Some competitive weightlifters arch their backs in order to get maximum power for the ONE repetition they're judged on. For most of us -- who are building strength through multiple repetitions and sets -- proper form requires keeping the back on the bench while lifting the barbell.