Posture and Body Mechanics

 I observed my friend Rod, as he performed his every day tasks:

1. Enjoying the lake               2. Spending time with his           3. Working at his computer,
    view from his kitchen            favorite dog, Kai!                         making assessments.
    table.

I chose picture number three to analyze because this is the position that Rod and many others spend their days in while they work, especially in remote job positions. When Rod was captured in this position, he was exhibiting a slight posterior pelvic tilt, meaning the pelvis is rotated backward from its typical neutral position. The postural compensations of a posterior pelvic tilt are the lumbar spine to being flexed and the hip joint being extended past 90 degrees of flexion when sitting; you can see in the picture that the spine is flexing forward, opposing the slight lordosis of normal sitting posture, and the right femur at the hip joint is pointed at a downward angle past 90 degrees of flexion that we would expect to see in this position. Going up his body, Rod continues to adjust his posture to the positioning of his pelvis and the demands of his work. His thoracic spine is flexed further than the body's normal kyphotic curvature when sitting and shoulders are rounded due to scapular protraction. The typically lordotic curvature of the cervical spine is being hyper extended in the opposite direction and his head is tilted at a downward position to stare at the screen in front of him. 

In the seated position, Rod has points of contact with both the chair and his desk, meaning that his base of support spans both of those objects. His center of gravity falls well within the base of support, increasing his stability and decreasing his mobility. In order to increase mobility, Rod could take his wrists off his desk to decrease his base of support, then he could move his center of gravity closer to the outside of his base of support. This could be easily done because his upper extremities are in an open chain of movement unless he uses the desk as a support or types on his key board. 

While sitting in a posterior pelvic tilt, Rod is likely putting pressure on his ischial tuberosities and sacrococcygeal area (Kemmoku et al., 2012). This can cause pain if he sits in the same position for an extended period of time. He will probably shift every 15-30 minutes depending on how much pressure he is putting on those areas, his perception of discomfort, and even the makeup of his chair. Rod's posture does not support joint alignment. His forward head posture when looking at his computer increases the curvature of the neck, out of cervical lordosis, which can lead to a shift in the type of lever found at the atlanto-occipital joint, increasing the weight of the head about 10 pounds per inch moved forward.   

It is important that we teach proper posture to people so they can perform their daily activities to the best of their abilities. If we taught Rod the proper posture for sitting in a chair, he might be able to work longer without breaks, which might make him a more efficient worker. We also want to teach correct posture to prevent posture from getting worse, potentially causing discomfort, pain, weakened muscles, strained ligaments, and potential disk injury. As postures become more fixed, they may begin affecting more important areas of a person’s life; in its later stages, forward head posture of the neck can impair a person's ability to swallow food, stripping them of an important ADL. 

One plan I would implement to help my clients improve their posture for a seated position would be to put velcro on their boney areas that touch a seat and attach to another piece to the place on the seat that matches up to correct body positioning, then when they shift into a position that does not line up with correct positioning, they will hear the sound of the velcro. Another intervention I would use would be having my client adjust my body mechanics based on a picture or graphic that I create ahead of time so that they can learn how to see corrections that need to be made to their own posture. In addition to activities, there are many adjustments to the client's environment we could make to improve posture. This includes adjusting height of computer, changing to an ergonomic chair, being fitted for shoe inserts, back braces and supports. 

                                                                          References

Kemmoku, T., Furumachi, K., & Shimamura, T. (2012). Force on the sacrococcygeal and ischial areas during posterior pelvic tilt in seated posture. Prosthetics and Orthotics International, 37(4), 282–288. https://doi.org/10.1177/0309364612465429

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