1. Fast walking can be therapeutic if swinging arms from the shoulders (not just from the elbows).
2. If walking over rough terrain use the backpack low (closer to the low back) and high if walking over smooth terrain.
3. Use an ergonomic chair but more importantly avoid static posture; the key is to change postures to avoid loads on one tissue.
4. Get off of the chair at least every 50 minutes.  Stand from the chair and maintained a relaxed standing posture for 10-20 seconds.
5. Perform an exercise routine at some time during the day.  Ideal time would be some time in the work day. Midday would be ideal although this is not possible for everyone.
6. Although there is a “good posture” for sitting, the key is to change posture in order to distribute loads.
7. You need to be aware of these factors as they affect posture: a video display terminal, job stress, ergonomic deficiencies in workplace design and use, and insufficient rest or breaks from work. Similar factors can be present in the home and in the workplace.
8. Maintaining good posture and alignment of the head, neck, and trunk during rest and activities is important. This should include avoiding stressful head positions, and you should sleep on the side or the back, while avoiding sleeping with arms above the head.
9. The proper hand-to-eye work or reading distance of 16 to 20 inches should be maintained.
10. Efforts to reduce muscle tension and strain include the use of stretching exercises.
11. Proper body mechanics, including attention to proper lifting and positioning for physically stressful activities, should be maintained in activities at home and in the workplace.
12. Adaptive equipment, such as eye glasses appropriate for distance (eg, lenses designed to focus on a video monitor) and “hands-free” headsets or a speaker phone for prolonged or frequent telephone use, should be used to limit strain on the neck.
13. Maintain an appropriate weight to reduce stress on the spine, knees, feet, and ankles.
14. Regular exercise is recommended to help maintain function, joint range of motion, strength, and balance. All of these will contribute with keeping a good posture.
15. When walking: lift the chest, swing the arms from the shoulders, and take longer and faster steps. “Walk like you own the world” and “walk with no worries”.

Sources:

1. Uptodate
2. Low Back Disorders; Stuart McGill; second edition.