|Is this you?|
There is so much going on in the body when you sit like this and its easy to see with the aid of this skeleton.
Rounded shoulders, pelvis is tilted, head and neck are forward, and the thoracic spine/upper back is super curved. The rib cage almost looks compressed as well. No doubt the shoulders are elevated into a shrug position. Its almost as if this person is trying to get into a teeny tiny ball. This posture leads to a lot of problems, namely pain and injury associated with your lower back and shoulders. Poor posture and poor mobility, especially in the shoulder joint tends to lead towards impingement, or rotator cuff problems. This presentation can also lead to tight hip flexors which will pull your pelvis into an anterior tilt and can be the cause of any of that low back pain you're experiencing.
Now if this is you, do yourself a favor, fix your posture. Straighten up, pull your shoulders back, and open up you chest. The more you focus on correcting and being aware of your posture, the less likely you'll be injured or have pain. Now it wont be an overnight success in correcting your posture. But the more you work at it, the better off you'll be.
Here are a few tips to help you along the way:
1. Stretch your chest, and hip flexors especially. Posture like this tends to present with tight pec muscles and tight hip flexors.
2. In addition to stretching, you should be foam rolling your upper back and hip complex in order to increase its range of motion. This especially includes the hip flexors.
3. Finally doing exercises that require you to strengthen muscles that have been weakened by your poor posture. For the upper back, you should focus on exercises that retract or squeeze your shoulder blades. This can include supermans, body weight rows, or dumbbell/machine rows. But you know i don't advocate machine use ;-) Maybe in this case only. Also work on simple retraction exercises with low weight. Also shoulder slides on the wall/stick ups are a great way to increase shoulder range of motion.
For the hips, concentrating on hip bridges, crab walks, and reverse planks should help "wake up" your glutes and help with that pelvic tilt.
In summary, this classic "office worker" posture is becoming more and more common in the gym and in clients that I see. If you let this slip for too long, it may lead to problems along the way. Do yourself a big favor, try working on the 3 tips I provided, and maybe you'll help correct the way you sit and even stand.