A term used to describe a position of the body or the arrangements of body parts relative to one another. Ideal postures are those assumed to perform an activity in the most efficient manner utilizing the least amount of energy.
Types of posture
- Inactive posture: These are postures adopted for resting or sleeping. They require minimal muscle activity, and are usually assumed in need of relaxation.
- Active posture: The integrated action of many muscles is required to maintain active postures, they are basically divided in two types
- Static postures- Body segments are aligned and maintained in a fixed positions. This is usually achieved by co-ordination and interaction of various muscle groups which are working statically to counteract gravity and other forces. Examples of static postures are standing, sitting, lying, and kneeling.
- Dynamic postures- In this type of posture body segments are moving. it is usually required to form an efficient basis for movement. Muscles and non-contractile structures have to work to adapt for changing circumstances. Examples are walking, running, jumping, throwing, and lifting.
To get an understanding of ideal posture, we need to know the ideal alignment of spine and other joints at rest. This is usually done by observation or using a plumb line, the line of gravity should pass through specific points of body if it is to be called ideal posture. On examination the body should be viewed from four aspects; anteriorly, posteriorly, and both sides.
- Line of gravity passes through the external auditory meatus
- Then through the shoulder joint
- Approximately midway from trunk, going through the bodies of cervical and lumbar vertebras
- At hip joint it passes through the greater trochanter of femur
- Anterior to the knee joint
- Anterior to lateral malleolus
When viewed from either the front or the back, the vertical line passing through the body's centre of gravity should theoretically bisect the body into two equal halves, with the body weight distributed evenly between the two feet.
Muscle action in posture
The balanced posture of the body reduces the work done by the muscles in maintaining it in an erect posture. It has been determined that, in general:
- The intrinsic muscles of the feet are inactive, because of the support provided by the ligaments.
- Soleus is constantly active because gravity tends to pull the body forward over the feet. Gastrocnemius and the deep posterior tibial muscles are less frequently active.
- Tibialis anterior is quiescent (unless high heels are being worn).
- Quadriceps and the Hamstrings are generally inactive.
- Iliopsoas is constantly active.
- Gluteus maximus is inactive.
- Gluteus medius and tensor fascia latae are active to counteract lateral postural sway.
- Erector spinae is active, counteracting gravity's pull forwards.
- The abdominal muscles remain inactive, although the lower fibres of the Internal obliques are active in order to protect the inguinal canal.
Examples of different faulty posture
Some of the examples of faulty posture can be as follows
- Lordotic posture
- Sway back posture
- Flat back posture
- Round back (increased kyphosis) with forward head
- Flat upper back and neck posture Scoliosis(postural