Does good posture matter?

Author: Lynn X. Li (Msc OT Candidate)

Editor: Dr. Tina Lam Reviewed by Dr. Grace Lee (MD)

Poor posture can cause many skeletomuscular injuries, such as joint pain and muscle strain. Due to COVID-19 related nationwide lockdowns, we have plenty of time to occupy ourselves with home activities. Do you get a sore body at the end of the day? Today, let us discuss postures and how we keep a good posture to avoid injuries.

ANATOMY OF SPINE

[Picture 1] – Spinal anatomy

The spine has four curvatures, the cervical, thoracic, lumbar and sacrococcygeal curves. The cervical and lumbar curve convex anteriorly, and they are called Lordosis. The thoracic and sacrococcygeal curves convex posteriorly, and they are called Kyphosis. The spine consists of a sequence of vertebrae, each of which is separated by one intervertebral disc. The intervertebral discs are the cushions between vertebrae to avoid direct bone-to-bone contact.

Poor posture can cause extra stress on the spine and change the degree of the curvatures. In some severe situations, poor posture can cause intervertebral disc herniation, which can compress the nerves running through the spine. SITTING POSTURE

[Picture 2] – Different sitting postures

The first posture showed in the picture is incorrect. The pelvic tilt posteriorly when the upper body leans backward, which leads to a less degree of anterior convex at the lumbar curvature. Also lowering your head can cause less cervical curvature. Muscle soreness of neck and lower back will occur if you keep this posture for a long period of time.

The second posture demonstrated in the picture is also incorrect. Leaning forward can result in a greater thoracic curvature. You will feel tight and sore on the upper back in a prolonged sitting with this posture.

The third one is good posture. You should keep the curvatures as natural as possible when sitting. It is also suggested to add a cushion between the lower back and the chair. There is a gap between the lower back and the chair as the lumbar curvature convex anteriorly. The cushion can fill the gap and provide support for the lower back.

READING POSTURE

[Picture 3] – Different reading postures

Does the second posture in the above picture look familiar to you? Hold a book or magazine on the lap and start your reading? Generally, reading is around 30 mins or even longer. It is quite long to bring about neck discomfort when you read with lowering your head. It may also cause dizziness and eye soreness. Cervical curve convex anteriorly and lowering head forward will decrease the curve, also known as flat neck syndrome. The flat neck can bring about a series of problems, such as neck pain, neck stiffness and limited mobility. The right way to do this is putting your book on a desk and keep your neck as neutral as possible.

LIFTING TECHNIQUES

[Picture 4] – Different lifting techniques

Let us look at the incorrect demonstration first. When lifting a box, all the pressure is centred on the lower back because the hips and knees are not bent. This could lead to muscle strain on the lower back. Even if the object is not very heavy, this posture can cause a high risk of chronic lower back pain when you lift objects this way repetitively.

What is the correct way to do a safe lifting? First, you should step close to the object. Bend your hips and knees to squat down. Hold the object close to your body and use your leg strength to slowly stand up. Base on the lever principle, the arm of the force becomes shorter when you are closer to the object and thus the force added to your body is less. Therefore, the closer you hold the object, the less strength is needed and the easier to lift it up.

REACHING FROM ONE SIDE

Top[Picture 5] – Incorrect posture to reach item from one side

Bottom[Picture 6] – Recommended range of motion for the shoulders

The picture on the top demonstrates reaching an object from the left side when facing the front. This posture increases the risk of overstraining the shoulder, especially when the object is heavy or when this activity is repetitive due to the nature of your work. The most functional arc of motion for the shoulder is 90 degrees anteriorly to the scapular plane, as shown in the picture on the right. Movement within this range can generate the least tension on the rotator cuff. Any position exceeding this range will have a higher risk of shoulder injuries. You can quickly resolve the problem by adjusting your upper body from facing the front to facing the object you are aiming to reach. You can apply this technique to the activities you perform in the kitchen, such as turning your upper body to face the utensils you are reaching. Would you want to know more about occupational therapy? Visit: https://seminarinfoaime.wixsite.com/aime/single-post/2019/12/08/What-is-Occupational-Therapy

References

[1] https://www.sci-info-pages.com/anatomy-of-the-spine/

[2] https://yourstory.com/mystory/e0ec978a97-6-reasons-why-yoga-imp

[3] https://www.hart2harttraining.com/

[4] https://www.ausmed.com/cpd/articles/introduction-to-occupational-health-and-safety

[5] Pain, 2020, Anatomy and Biomechnics of the Human Shoulder, University of Toronto, Slides 31

[6] https://orthop.washington.edu/patient-care/articles/shoulder/evaluation-of-the-stiff-shoulder.html

Legal Disclaimer

These presentations are intended for general information purposes only. Audience are recommended to consult with qualified medical healthcare provider and obtain professional advice and subsequent management for your particular conditions. The views and opinions expressed by the speakers do not necessarily reflect the policy or position of Assisting in Medical Expectations.