>>56464He's right though, imagine the motion of a peck deck for example, you are rotating your shoulders and whole arm towards the center of your body and holding them outwards in front of you, if you do it now and also try to flex your chest muscles hard as you do it you can feel the point where they are getting squeezed. If you prioritise 'activating' your chest muscle this way as part of your form, even if you're just pushing your arms outwards, you should end up getting more work out of those muscles first which will strengthen them more than your arms doing the majority work. if you're at home then doing pushups with the form of elbows touching your side will majorly use the chest and triceps muscles with some use of your back, shoulders and biceps