Pushups
Starting position:
Take the push-up position with your arms perpendicular to the floor mat and a little wider than shoulder-width apart. Your palms are pointing forward and your arms, including elbows, are outstretched. Your torso is firm and your pelvis is in a neutral position, with shoulder blades fixed in one position. Do not make a hunch on your upper back. Legs are stretched and are leaning on your toes which are a little less than shoulder-width apart.
Exercise:
From the starting position, move downwards by bending at your elbows. Your body core is fixed and not bent at the waist throughout the entire movement. Continue down till your chest touches the mat. Your elbows are at a 45-degree angle away from your body. Use the same route to go back up and do not change the bend of your spine. Inhale in the starting position and when taking the breath fix your body core for the entire movement and exhale as you return to the starting position. Do the required number of repetitions.
Note:
Keep your body core firm all the time and avoid over bending your back at the waist while keeping your pelvis in a neutral position. Make sure your shoulder blades are fixed and stay in the same position throughout the entire movement. Only your chest, not the whole body, should touch the mat in the lowered position. Do not twist your wrists sideways and keep them naturally straight.
Recommendation:
Exercise in front of a mirror to make sure you use the correct technique. If your fitness level requires, you can start doing this exercise while on your knees rather than on your toes.
***
Pushups (the British call them press-ups) are surely not a big mass-packer but they are a perfectly safe exercise for keeping fit. Safe, that is, as long as you do not overuse your shoulder joints and do not do very wide pushups without proper warming up.
Pushups strengthen – directly or indirectly - many muscle groups: pectorals (chest), triceps and anterior deltoids do the main job. The muscles of rotator cuff play an important role in stabilizing the shoulders (they are also used in bench press and related exercises). A whole number of other muscles is employed to keep the body stretched: abdominals, glutes, quadriceps and rhomboid are the major ones.
As in the bench press, the wider the hand positioning the more work is done by pectoral (chest) muscles as opposed to triceps muscles. It is also true that wider hand positioning is more damaging the shoulder joint and rotator cuff.
Many variations exist. You can change the hand positioning, angle of the body and the floor (by putting the hands or feet on elevated platform) and the overall technique.
Pushups with feet on elevated platform are broadly similar to incline barbell bench press and emphasize the upper part of the chest muscle.
Weaker athletes can lean on their knees.
The most demanding form of pushups is called planche pushups: only your hands are resting on the floor and the whole body is elevated. In this exercise the stabilizing muscles play a major role.