Posture Can Kill! It sounds extreme, but it’s true.
In this article, we examine the impact of poor posture on bodily structures and functions. If left uncorrected for an extended period, poor posture can significantly harm overall health and may even lead to premature death.
What is posture?
Posture is the position of the body in relation to the surrounding space. It is maintained through the coordination of various muscles that move the limbs, and requires constant muscular effort.
What is good posture?
Good or correct posture while seated is described as a position where:
- Weight is evenly distributed through both ischial tuberosities (ITs)
- The pelvis is in a minimal anterior tilt
- The head is balanced and aligned above the hips
- The feet are in a neutral, rested position
This posture is considered ideal as it requires minimal effort to maintain, balances the body’s weight, and provides a stable centre of gravity, ensuring safety and security.
What are the goals of seating?
When conducting a seating assessment, there are often numerous goals to achieve with a single seating solution. Each person involved in the assessment may have different priorities. The patient may seek comfort, therapists may aim to promote function and activity, while nurses may focus on maintaining skin integrity. It is particularly important to understand the link between seating and the development of pressure injuries.
Seating goals can be divided into three categories:
- Physiological Goals: Swallowing, respiration, digestion, elimination.
- Psychological Goals: Effective communication, socialising, self image.
- Functional Goals: Feeding, drinking, reading.
Deviated vs. Normal Posture
Identifying and understanding an individual’s posture is a crucial step towards improving their seating position and overall wellbeing. This process involves evaluating the causes and effects of deviated postures, and determining how to correct or improve these.
Pelvic Assessment
When conducting a seating assessment, the first step is to evaluate the pelvis. There are four common pelvic deviations that can contribute to poor posture. Any tilt or deviation due to deformity or lack of support forces the muscles in the hips, trunk and neck to work harder to maintain balance and a midline position.
Posterior Pelvic Tilt
A posterior pelvic tilt occurs when the posterior superior iliac spine (PSIS) is lower than the anterior superior iliac spine (ASIS), with the pelvis tilted backwards. Known as ‘sacral’ sitting, it leads to weight being placed on the sacrum.
Causes: Clinical causes of posterior pelvic tilt including sliding forward in the seat, tight hamstrings, limited hip flexion, or an increase in muscle tone. Technical causes include a seat depth that’s too long or footplate that’s too low.
Effects: A posterior pelvic tilt can have various physical and psychological effects, including difficulty swallowing, communicating and breathing. A person sitting in a posterior pelvic tilt is at high risk of pressure ulcers, notably on the sacral region, but also the heels/feet, which may be used to anchor from sliding.
Anterior Pelvic Tilt
A less common pelvic position, anterior pelvic tilt occurs when the PSIS is higher than the ASIS, tilted forward.
Causes: An anterior pelvic tilt can result from various factors, including weak abdominal muscles, obesity, spinal lordosis, overtly vertical chair backs, or excessively sloped seats. It is common among those who sit for long periods at desks, or in people with obesity who have increased mass at the front of the body, pulling the pelvis forward and placing weight on the pubic region.
Effects: As the ITs push backward, the person’s weight is transferred to the pubic region, creating a high pressure risk. An anterior pelvic tilt can lead to bladder issues, digestive problems, and spinal or back pain.
Pelvic Obliquity
A pelvic obliquity occurs when one side of the pelvis is higher than the other, causing uneven weight distribution through the ITs.
Causes: Pelvic obliquity can result from instability of the person or their chair. Leaning to one side due to lack of support, such as a chair being too wide, or having a weakness on one side, such as with hemiplegia, can cause pelvic obliquity. It is also common with conditions like scoliosis or hip dislocation/subluxation.
Effects: Pressure injuries can develop on the lower IT, which is bearing extra weight. Scoliosis can be both a cause and effect of pelvic obliquity, potentially impacting internal organs on the affected side and possibly the ribcage. Increased muscle tone may also result from trying to stabilise in an ill-fitting chair.
Pelvic Rotation
Pelvic rotation occurs when one ASIS is in front of the other, named for the direction of the rotation.
Causes: Pelvic rotation can result from a leg length discrepancy, hip dislocation, subluxation, or uneven hip flexion/adduction. Technical causes include a seat that is too wide, or a chair lacking adequate trunk support.
Effects: Pelvic rotation is common in those with pelvic obliquity, and can lead to a windswept deformity.
3 Different Spinal Presentations
When performing a seating assessment, it’s important to consider both pelvic and spinal presentations. Here are the three main spinal presentations to note:
Lordosis: Lordosis is an increased curve in the lower back, often linked to anterior pelvic tilt. It can be caused by weakened abdominal muscles or tight hip flexors, and can result in significant back pain.
Scoliosis: Scoliosis can be “C” or “S” shaped and is often associated with pelvic obliquity. It’s crucial to determine if the scoliosis is fixed, partially fixed, or correctable. Severe scoliosis can impact internal organs and the ribcage.
Kyphosis: Kyphosis is marked by a ‘hump’ in the upper back and is usually associated with posterior pelvic tilt. It can impair physiological function and needs to be accommodated in seating. It’s essential to establish if the posture is fixed, partially fixed, or correctable.
Hamstrings
The hamstrings cross both the knee and hip joints, and can significantly impact posture when tight or contracted. It’s important to measure hamstrings accurately and adjust seating accordingly. Many clinicians do not realise the importance of this, or may be unsure of how to measure hamstrings correctly.
Fixed or Flexible Posture?
When assessing pelvic and spinal presentations, it’s important to determine if the positions are fixed, partially fixed, or flexible. A seating solution can then be tailored to the patient’s needs.
If the posture is fixed, it needs to be accommodated by the functions of the chair, helping to slow deterioration. Flexible or partially fixed postures may be gradually corrected with the right seating and accessories.
The best first step is to book a complimentary seating assessment for the patient.
How can 24-hour postural care help?
Effective postural care can have numerous benefits for both the patient and their care team. This includes protecting the body’s natural shape, improving sleep quality, balancing muscle tone, lessening pain, and making physical care easier.
The best and most effective postural care revolves around the prevention of body shape changes. These changes may otherwise be caused by a combination of soft tissue shortening (contractures) and the effects of gravity, which will amplify any asymmetry in positioning.
Without 24-hour postural care, patients may experience secondary complications including infections, pain, muscular contractures, fatigue, discomfort, pressure injuries, poor lung capacity, impaired mobility, decreased mental health, and even premature death.
Why is clinical seating important?
Clinical seating is an essential element of 24-hour postural care.
Seating Matters chairs have been specifically designed to accommodate and manage various postures, following the four key principles of clinical seating. This is essential to:
- Mitigate the effects of gravity and prevent the emergence of secondary complications
- Provide postural supports to reduce postural asymmetry and improve functional support
- Provide physical benefits e.g. facilitating respiration, digestion and elimination, and reducing development of pressure injuries
- Provide psychological benefits e.g. self esteem, independence
- Facilitate engagement in functional tasks
- Help maintain mobility and range of motion
