Posture describes the alignment of joints and is normally associated with the curves of your spine and the position of your head and pelvis. Poor posture can have a profound effect on your risk of developing lower back pain, headaches and other associated discomforts. There are a number of factors that can affect your posture.

Prolonged Sitting
Most people spend a large percentage of their time sitting down. Sitting down for long periods can have an adverse affect on your posture. Your hip flexor, hamstrings and abdominal muscles all become shortened while your gluteus maximus and erector spinae muscles become long and weak. This imbalance between your anterior and posterior musculature results in a flexed spine position called hyperkyphosis. In short—the more you sit, the better your body gets at adopting a seated position and the worse your posture can become.

Occupation
Certain occupations can have an adverse affect on your posture. In addition to jobs that require long periods sat down, some jobs also require a lot of bending forwards. Motor mechanics, carpet fitters, plumbers, and electricians all spend a great deal of time in a hunched over position which can affect posture. Jobs that require you to carry an asymmetrical load can also cause your posture to suffer. Postal delivery and newspaper delivery workers who carry their bags over one shoulder can develop a sideways postural abnormality called scoliosis.

Sporting Activities
While sport and exercise are usually considered to be very beneficial, some sports can have a negative effect on your posture. Spending long periods of time on a low-slung racing bicycle can result in over stretched back muscles and tight hip flexors and abdominals which can make standing up straight difficult. Running encourages a forward head position, a pronounced forward lean and short hip flexors which can result in an increase in kyphosis or rounded back posture. Many exercisers focus on the muscles they can see in the mirror, namely their chest, shoulders and arm muscles. These muscles can become too tight and pull your shoulders, head and upper body forward into a hyperkyphotic position.

General Fitness
Good posture requires strength and flexibility in equal measure. Your postural muscles must be strong enough to support your head and keep your spine upright. Any tightness in your opposing muscles can make this hard work. In addition, your core muscles must be strong enough to support the efforts of your arms and your legs. Your core, the collective term used to describe your abdominals, waist and back muscles, supports your spine from within by creating intra-abdominal pressure. Intra-abdominal pressure helps your postural muscles to maintain a neutral spine position where all of the curves in your spinal column are aligned to ensure that your head is supported with minimal loading on the passive structures—the ligaments and intervertebral discs.