Investigations on the effects of seat shape and slope on posture, comfort and back muscle activity

Graf, M.; Guggenbühl, Urs; Krueger, Helmut

doi:10.1016/0169-8141(93)90041-b

Cited by 17 publications

(9 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A reclined position reduces the load on the intervertebral discs and on the back muscles by an increased lordosis angle, which was shown by Colombini et al [20]. Graf et al [21] demonstrated a certain discomfort with a tilting seat angle of more than 15°. Apparently, the biomechanical analysis of the lordosis angle is of relevance when determining the influence on posture and wellbeing.…”

Section: Introductionmentioning

confidence: 94%

The Spinal Curvature of Three Different Sitting Positions Analysed in an Open MRI Scanner

Baumgartner

Zemp

List

et al. 2012

The Scientific World Journal

View full text Add to dashboard Cite

Sitting is the most frequently performed posture of everyday life. Biomechanical interactions with office chairs have therefore a long-term effect on our musculoskeletal system and ultimately on our health and wellbeing. This paper highlights the kinematic effect of office chairs on the spinal column and its single segments. Novel chair concepts with multiple degrees of freedom provide enhanced spinal mobility. The angular changes of the spinal column in the sagittal plane in three different sitting positions (forward inclined, reclined, and upright) for six healthy subjects (aged 23 to 45 years) were determined using an open magnetic resonance imaging (MRI) scanner. An MRI-compatible and commercially available office chair was adapted for use in the scanner. The midpoint coordinates of the vertebral bodies, the wedge angles of the intervertebral discs, and the lumbar lordotic angle were analysed. The mean lordotic angles were 16.0 ± 8.5° (mean ± standard deviation) in a forward inclined position, 24.7 ± 8.3° in an upright position, and 28.7 ± 8.1° in a reclined position. All segments from T10-T11 to L5-S1 were involved in movement during positional changes, whereas the range of motion in the lower lumbar segments was increased in comparison to the upper segments.

show abstract

Section: Introductionmentioning

confidence: 94%

The Spinal Curvature of Three Different Sitting Positions Analysed in an Open MRI Scanner

Baumgartner

Zemp

List

et al. 2012

The Scientific World Journal

View full text Add to dashboard Cite

show abstract

“…Due to the compressive force imposed on the driver’s body and the seat interface, the blood flowing through large vascular blood vessels to the lower part of the anatomy will be obstructed. Consequently, this will lead to insufficient oxygen supply to the body, resulting in discomfort, fatigue and the longer term, will convert into severe pain and possible injury if untreated 8 , 9 , 10 , 11 , 12 , 13 , 14 ) .…”

Section: Introductionmentioning

confidence: 99%

Development of a statistical model for predicting seat pressure felt level in simulated condition based on direct and anthropometric measurement

Khamis

Deros

2018

J Phys Ther Sci

View full text Add to dashboard Cite

[Purpose] The purpose of this study was to investigate the effects of seat pressure distribution measurements based on a specific posture to predict the pressure felt level when seated. [Subjects and Methods] To examine the relationship between body pressure data and the driver’s perception, eleven subjects were selected to participate in a simulated driving experiment using a pressure mat as a direct measurement method to measure the seat pan’s pressure distribution. The buttock-popliteal length was measured using an anthropometer, and the pressure felt ratings evaluated after the body pressure measurements were recorded. Accordingly, this was then followed by performing statistical analysis using seat pressure measurements, and the buttock-popliteal length as independent variables along with subjective ratings selected of the pressure felt by the drivers’ as dependent variables. [Results] The findings of this study suggest that the direct measurements and anthropometric body data are positively correlated with the predictive model thereby confirming the validity of the model with an R2 value of 0.952. [Conclusion] The proposed model is expected to provide a useful reference value for new vehicle drivers by providing the pressure felt level based on direct and body measurements in a specific posture.

show abstract

“…Although not specific to school seating, several variations of contours of the region of the seat in front of the ischial tuberosities have been proposed to improve sitting posture. One type of contour consisting of the front of the seat sloping forward with a horizontal region under the pelvis has been proposed for sewing machinists (Yu and Keyserling 1988) and office workers (Graf et al 1993) . This contour is meant to assist in maintaining a lumbar lordosis by allowing the thighs to slope downward while still providing a stable base for the pelvis.…”

Section: Introductionmentioning

confidence: 99%

Seated buttock contours: a pilot study of Australian senior high-school students

2007

View full text Add to dashboard Cite

Both posture and comfort of a chair are influenced by the contour and characteristics of the seat. Knowledge of seat contours of a student population could thus be useful in the design of school chairs. This study investigated seated buttock contours of senior high-school students in order to determine: (a) their general characteristics, (b) the effect of gender and sitting posture and (c) the relationship between the contours and selected anthropometric variables (stature and mass). A contour measurement device was developed and used to measure buttock contours in five sitting postures (typing, sitting up, sitting back, slumping and writing). Buttock contours were quantified by constructing anterior-posterior (AP) and lateral profiles from which six discrete profile dimension measurements were made. AP and lateral profiles were found to have a consistent shape across all participants. Five out of six profile dimensions were significantly different between genders, with just one significantly different between sitting postures (typing and sitting back). Correlations between anthropometric measures and profile dimensions were relatively low (r < 0.34) with no clear patterns evident. Overall results of this study suggest that buttock contours are influenced by gender to a greater extent than sitting posture.

show abstract

Investigations on the effects of seat shape and slope on posture, comfort and back muscle activity

Cited by 17 publications

References 14 publications

The Spinal Curvature of Three Different Sitting Positions Analysed in an Open MRI Scanner

The Spinal Curvature of Three Different Sitting Positions Analysed in an Open MRI Scanner

Development of a statistical model for predicting seat pressure felt level in simulated condition based on direct and anthropometric measurement

Seated buttock contours: a pilot study of Australian senior high-school students

Contact Info

Product

Resources

About