I'm starting an on-going series of common fixes to common pains that arise during exercises. Most of the time, it's not the exercise that's causing pain, it's the execution that's the problem
It's not the appratus, it's the application.
*Note* These are general solutions that fit about 90% of the population and for those who don't have any injury that would cause pain inherently.
First up: Anterior shoulder pain or elbow pain during push ups.
1. Pull your elbows in to 45 degrees from the body (as opposed to 90 degrees from the body). The smaller angle of elbow-to-body allows for the shoulder blade to glide correctly along the rib cage. When the elbows flare, the shoulder blade tends to slide up towards the neck and can pinch things within the ball-and-socket part of the shoulder. It also places a fair amount of torque on the glenohumeral joint (the shoulder) and inhibits the scapula's ability to glide correctly.
2. Speaking of gliding shoulder blades, if the blade doesn't glide = big ouchie. Watch for scapular "winging." See below video.
Check out Mount Everest arising on the athlete's back. That's the scapula sticking up and not sticking down close to the rib cage as it should. This winging (or Mt. Everest-ing) results in pain in the shoulder and possibly the elbow too as the stress of the push-up is transferred down the chain. In a push up we want scapular retraction (think of pinching a pencil between your blades). Like thus:
How does one go from "winging" to "retracting" and thus from push up fail to push up success? There are two cues I generally give. One is to "pull yourself to the floor." Don't let gravity take over; be in charge and lower yourself on your own terms, not gravity's. The second is, "pretend your hands are on two peanut butter jars and you need to open the lids." Essentially, you're trying to twist your hands out (but don't actually move them). Both these cues activate the scapula retraction muscles (example: serratus anterior and lower trapezius).
Typically, those are the two cues that "fix" shoulder and/or elbow pain during a push up. (to say nothing of squeezing the butt and abs... different tale for a different day.)