How Posture and Equipment Setup Can Influence Comfort/Discomfort Scott Openshaw Erin Taylor Allsteel Inc. Kevin Costello United States Ergonomics
Overview Discuss objectives Explain the study and data collection Give some examples of posture and equipment setup Talk about comfort and discomfort Discuss solutions
Objectives Understanding of the measures used in an office ergonomic assessment Understanding of common postures and equipment setups that are common in an office environment Understanding of relationships between comfort/discomfort and (1) posture of office workers (2) setup of office equipment Suggestions on how to improve comfort of workers
Overview of the Study Research conducted by US Ergonomics Assisted by Allsteel Observed 325 individuals in their offices 16 offices 6 states (West, Midwest, East) Did not make adjustments, just measured and took observations Goals were to understand what people used in their offices, what postures they assumed, and the correlation to comfort/discomfort
Distribution of People/Locations Visited 81/4 53/2 48/2 68/4 44/2 31/2
Examples of Participating Companies
Data Collected Survey Info Collected Total Variables Background Work practices, experience, job satisfaction, common tasks, ergonomics awareness and perceptions regarding their work setup. 44 Musculoskeletal Discomfort Body part specific aches, pains, discomfort 30 Anthropometry Seated and standing body dimensions 12 Equipment Checklist Documentation of equipment in use including keyboards, mice, monitors, trays, palm pads, etc. 37 Workstation Geometry Definition of workspace including, office sizing, chair features, environmental conditions, equipment positioning 64 Comments Comments from participants related to the criteria collected Overall Total Variables Text 187
Aches, Pains, Discomfort
Postures and Equipment Setup Postures Reclined/supported Perched on edge of seat Twisted Common Workstations Corner station Traditional Occasional use station L-shaped station Equipment Monitor height and depth Keyboard and mouse placement Papers and accessories
Comfort and Discomfort Looked at type and severity of discomfort Looked at frequency Looked combination of frequency and severity Correlated posture and equipment usage to above parameters
Musculoskeletal Stress Total Reports of Aches, Pains or Discomfort 120 Total Reports 100 80 60 n=295 40 20 m R.F ra Fo L. /E lb or am /E lb L. Sh ou ld R.S ho ul d Ba ck N ec k Le gs Ey es t ris W d/ an.h R L. H an d/ W ris t 0 Body Part Affected
Frequency & Severity Frequency and Severity of Aches, Pains & Discomfort Reported 7 6 5 Frequency Rating 4 Severity 3 Combined Freq. & Sev. 2 1 Body Part Affected es Ey gs Le k ec N ck Ba ld.s ho u ul d R ho L. S am R.F or ra Fo L. /E lb lb /E m W d/ an.h R L. H an d/ W ris ris t t 0
Relationship to Aches/Pains Neck pain significantly increased with phone use (r=0.144, p=0.018) Back pain increased as the time spent referencing documents and data increased (r=0.236, r=0.000) Left shoulder pain significantly increased with mouse use (r=0.135, p=0.026)
Distribution of Back Pain & Discomfort Reports of Back Pain or Discomfort (0=no pain, 10=severe pain daily) Normal 35 Mean 6.371 StDev 1.590 N 97 30 Frequency 25 20 15 10 5 0 2 4 6 Back 8 10
Visually Intensive Tasks Individuals more likely to experience the following: Increase in the risks of forearm/elbow (right: r=0.228, p=0.000, left: r=0.211, p=0.000) Increased risk of slouching (r=0.156, p=0.010) Increase in the total risks to the back for visually intensive tasks (r=0.133, p=0.005) More likely to use chairs with adjustable lumbar support (r=0.124, p=0.039) armrests (r=0.200, p=0.001) adjustable tension on the back recline (r=0.183, p=0.002)
Poor Posture Individuals who lean forward are more likely to experience the following: Forward head posture (r=0.221, p=0.000) Lack of lumbar support (r=-0.237, p=0.000) Increase right and left shoulder risks (right: r=0.208, p=0.001, left: r=0.234, p=0.000) People who slouch in the chair: Have significantly higher risks (primarily contact stress) on the forearms and elbows (r=0.192, p=0.001) Increased risk factors affecting the neck (r=0.120, p=0.043)
Postural Adjustments Frequency of Postural Adjustments at Workstation 120 100 1=Never 2=Infrequently 3=Occasionally 4=Often 5=Constantly Frequency 80 60 40 20 0 1 2 3 4 Adj. Posture at WkStn 5
Chair & Postural Adjustments Individuals reporting higher back pain frequently adjusted their postures and chairs. Back pain vs. Frequency of Adj. Posture at Workstation, (r= 0.154, p-value = 0.009) Back pain vs. Frequency of Adj. Chair, (r= 0.181, p-value = 0.002)
Chairs with Recline Associated with reductions in the reports of pain in the neck and to the eyes (r=-0.129, p=0.026 and r=0.157, p=0.007, respectively). The neck benefit may be attributable to the increased blood flow associated with changes in working posture Occasional changes in focal distance can also reduce eye fatigue Resulted in lower reports of left forearm/elbow aches and pains (r=-0.125, p=0.032 and r=-0.124, p=0.34, respectively).
Risk Factors Working Postures : Torso and Spine Lack of lumbar curve support significantly increases reports of back pain (r=-0.147, p=0.012) Lack of upper back and shoulder support significantly increases reports of back pain (r=-0.124, p=0.034) Increased torso twisting significantly increases reports of back pain (r=0.158, p=0.007) 200 150 No Yes 100 50 0 Lumbar curve supported Upper back supported Torso Slouched Leaning forward Working Postures: Torso and Spine 350 300 Observations Observations 250 250 200 No Yes 150 100 50 0 Side bending Torso twisting Lifting required Back Static load
Lumbar Support Lumbar Support: A lack of lumbar support, i.e., the lumbar area of the seat is not in contact with the occupant, results in higher ratings of back aches and pains. r= -0.147, p-value = 0.012 The simple presence of a lumbar support does not correlate with the presence or absence of back aches and pains. r= -0.057, p-value = 0.327 Chairs providing lumbar support correlated with reductions in leg discomfort r= -0.153, p-value = 0.008
Shoulder and Posture Hunched shoulders result in pain to left shoulder r=0.128 p=0.030 Static posture results in pain to left shoulder r=0.128 p=0.030 Higher risk factors to right shoulder Due to shoulder abduction and flexion
Monitor Distance and Discomfort Thigh Pressure: As the monitor distance increased so did the contact stress on the thighs (front edge of the seat pan) (r=0.141, p=0.019).
A Few Suggestions Following ergonomic principles Keep things close (mouse, keyboard, monitor) Use the tools and adjustments that are available Movement is important Static and perched postures increased discomfort, while reclined and supported back was more comfortable Education People claim they know what ergonomics is, but in the end they fail to follow the basics on a daily basis
Review Research conducted to observe workers in their workstation Measured equipment, anthropometrics, comfort, discomfort Found correlations between posture/equipment setup and comfort/discomfort Follow basic principles
Thank you Questions? Scott Openshaw OpenshawS@allsteeloffice.com