Lions and Tigers and Chairs, Oh My!
Lately we have been getting a lot of questions about the best chair, standing desks, or office set ups as it certainly can influence how well we survive our day at the office. Today we are more aware of our desk mechanics than ever before because we know the consequences of sitting with bad posture - neck pain, shoulder pain, RSI, and lower back pain.
In general, people perceived an upright posture with neutral lordotic lumbar spine as the best sitting posture, which is close to what a lot of physiotherapists perceived as well (O'Sullivan et al 2012 & O'Sullivan et al 2013). While there has not been enough strong evidence to suggest what is the best sitting posture or sitting ergonomics, it is logical to think sitting upright with a neutral spine helps to even load distribution through the body, which should prevent or manage non-specific lower back pain (O’Sullivan et al 2012 & O’Sullivan et al 2015).
Neutral spine vs lordosis vs kyphosis
To look into sitting ergonomics, first we need to understand differences in different spinal postures.
In general, there are three main types of sitting spinal postures: neutral, lordotic or kyphotic.
The following are the features of these spinal postures on a side view:
In neutral spine, the ears, shoulders, torso and pelvis are joined in one vertical line with normal spinal curvature along the spine.
In lordotic spine, there is excessive inward curve at the lumbar spine causing forward rotation of the pelvis, with the shoulders moving backward behind the torso and forward head posture.
In kyphotic spine, there is a lack of normal lordosis in the lumbar spine and that leads to backward rotation of the pelvis and a forward head and shoulder position. This is typically the hunchback sitting posture.
What are the pros and cons of different chairs?
Normal office chair vs inclined chair – kneeling chair, saddle seat, gym ball, backapp chair
Typically office chairs do not have an adjustable lumbar support. Therefore office chair users tend to either lean forward to a hunch back sitting posture or lean back too much to a slouch sitting posture. Research has shown that anteriorly tilt chair helps lower lumbar muscles activities in maintaining a neutral lumbar spine and there has been some evidence recommending a chair that encourages a neutral lumbar lordosis would help the management of lower back pain (Curran et al, 2015, O’Sullivan 2012 and O'Keeffe et al, 2013).
Hence, to improve sitting biomechanics, there have been a lot of ‘ergonomically designed’ chairs on the market to try to achieve that. The common features of these chairs are that the chair passively forces the pelvis to a slight forward rotation to create a lumbar spine lordosis or by lowering the legs to reduce hip flexion angle (Curran et al, 2015 & Bettany-Saltikov et al, 2008). Examples of these chairs include a kneeling chair/Balans chair, exercise ball, saddle seat chair or Backapp chair.
However, there are different downsides amongst these chairs. For example, the kneeling chair convert the weight bearing point from the feet to the knees which, is not desirable to anyone who has knee problems. An exercise ball might be too unstable for someone who has poor balance or lack of core strength, and the contact surface could cause excessive soft tissue pressure. A saddle seat may put too much pressure to the tail bone or groin area, that some might find it uncomfortable (McGill et al, 2006).
Summary
To sum up, there are proven advantages of using ergonomic chairs, but whether to use an ergonomically designed chair depends on the individual’s situation. Purely relying on these chairs to fix back and neck pain is not realistic and might create more discomfort (Curran et al, 2014). It has been found that sitting-related back pain tends to be multi-factorial and correcting lumbar spine curvature does not always correspond with an ideal neck posture (Curran et al, 2015 & Annett et al, 2012). Ergonomic assessments are warranted to further investigate if sitting related back issues are related to the chair or work station setup, particularly in subjects who spend prolong period of time sitting every day.
When it comes to getting your postural pains and workstation assessments, come in to see one of our highly skilled physiotherapists. Here at Thornleigh Performance Physiotherapy, we can give you an accurate diagnosis and treatment, as well as advise on the best course of action for your condition to get you feeling better than you could’ve imagined. We have an expertise in musculoskeletal physiotherapy and are near Beecroft, Cherrybrook, Hornsby, Normanhurst, Pennant Hills, Wahroonga, Westleigh, West Pennant Hills, and West Pymble. Here at Thornleigh Performance Physiotherapy, we can give you an accurate diagnosis and treatment.
References
Annetts, S., Coales, P., Colville, R., Mistry, D., Moles, K., Thomas, B., & Van Deursen, R. (2012). A pilot investigation into the effects of different office chairs on spinal angles. European Spine Journal, 21(2), 165-170
Bettany-Saltikov, J., Warren, J., & Jobson, M. (2008). Ergonomically designed kneeling chairs are they worth it? Comparison of sagittal lumbar curvature in two different seating. Research into Spinal Deformities 6, 140, 103.
Curran, M., O’Sullivan, L., O’Sullivan, P., Dankaerts, W., & O’Sullivan, K. (2015). Does Using a Chair Backrest or Reducing Seated Hip Flexion Influence Trunk Muscle Activity and Discomfort? A Systematic Review. Human Factors: The Journal of the Human Factors and Ergonomics Society, 0018720815591905.
Curran, M., Dankaerts, W., O'Sullivan, P., O'Sullivan, L., & O'Sullivan, K. (2014). The effect of a backrest and seatpan inclination on sitting discomfort and trunk muscle activation in subjects with extension-related low back pain. Ergonomics, 57(5), 733-743.
McGill, S. M., Kavcic, N. S., & Harvey, E. (2006). Sitting on a chair or an exercise ball: various perspectives to guide decision making. Clinical Biomechanics, 21(4), 353-360.
O’Sullivan, K., McCarthy, R., White, A., O’Sullivan, L., & Dankaerts, W. (2012). Can we reduce the effort of maintaining a neutral sitting posture? A pilot study. Manual therapy, 17(6), 566-571.
O'Sullivan, K., O'Keeffe, M., O'Sullivan, L., O'Sullivan, P., & Dankaerts, W. (2012). The effect of dynamic sitting on the prevention and management of low back pain and low back discomfort: a systematic review. Ergonomics,55(8), 898-908.
O'Sullivan, K., O'Sullivan, P., O'Sullivan, L., & Dankaerts, W. (2012). What do physiotherapists consider to be the best sitting spinal posture?. Manual Therapy, 17(5), 432-437.
O'Sullivan, K., O'Keeffe, M., O'Sullivan, L., O'Sullivan, P., & Dankaerts, W. (2013). Perceptions of sitting posture among members of the community, both with and without non-specific chronic low back pain. Manual therapy,18(6), 551-556.
O'Keeffe, M., Dankaerts, W., O'Sullivan, P., O'Sullivan, L., & O'Sullivan, K. (2013). Specific flexion-related low back pain and sitting: comparison of seated discomfort on two different chairs. Ergonomics, 56(4), 650-658.