Awkward Postures are the third Biomechanical Ergonomic Risk Factor. We have discussed an overview of all 7 risk factors in a previous post, and have already explored risk factors 1 & 2 – REPETITION and FORCE.
Awkward Postures refers to a posture that puts body tissues under undue stress. The tricky thing is that often the ideal posture for one tissue, is not ideal for another. Kourinka and Forcier (1995) developed the following terms to helps overcome this concern:
- Extreme Postures
- Postures where joints are near their end range of motion
- This requires an increase in internal force by passive tissues (such as ligaments) to support the joint in this position
- Once again though, some joints respond well at their end range – e.g. the knee
- Non-extreme Postures that expose the joint to loading from gravitational forces, requiring increased forces from muscles or load on other tissues
- Such as a 90 degree elbow angle that is against gravity, and if it is positioned away from the body
- Non-extreme Postures that change the musculoskeletal geometry, increasing loading on tissues or reducing the tolerance of these tissues
- Such as loading on the finger tips that causes the finger flexor tendons to compress the median nerve
Managing Awkward Postures
- Keep in mind the principles we learned from the risk factors of force and repetition – if we include these risks with awkward postures injury is almost inevitable
- Continue to change your posture
- Adjust the work environment instead of your body where possible – eg. raise the height of your desk
Awkward Postures are often difficult to manage – think of the dentist. But there are ways we can minimize our risk if we are aware of it. Keep an eye out for further posts in our Ergonomic Series.