Journal of Physical Therapy Science
Online ISSN : 2187-5626
Print ISSN : 0915-5287
ISSN-L : 0915-5287
Investigation of the Validity of an Experimental Model for the Estimated Shear Force on Buttocks in a Comfortable Sitting Posture
Kenichi KobaraAtsuko EguchiSusumu WatanabeYuichi IshiuraDaisuke FujitaTetsuya NishimotoKoichi Shinkoda
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2008 Volume 20 Issue 3 Pages 157-162


[Purpose] The purpose of the present study was to prepare an experimental model for estimating the shear force for a person sitting in a comfortable posture while leaning against a backrest, and then to verify its validity. [Subjects] The subjects were 16 healthy adult men without leg and trunk diseases (age: 21.6 ± 0.8 years; height: 172.5 ± 5.3 [cm]; and body weight: 63.4 ± 6.4 [kg]). [Methods] Using the model, the shear force applied to the gluteal region in a sitting posture was estimated, and at the same time, the shear force was measured using a force plate. The model's validity was assessed by comparing the estimated and measured values in terms of correlation coefficients. [Results] The average estimated shear force was 36.6 ± 11.8 [N], and the average reaction force in the posterior direction as part of the anteroposterior components of the floor reaction force (shear force in the anterior direction) was 35.9 ± 15.8 [N]. No significant difference existed (p=0.797), and the correlation coefficient was 0.897 (p<0.0001), thus exhibiting a strong positive correlation. [Conclusion] This result shows that the validity of the present experimental model is high, and the model is useful in clinical settings because shear force in a comfortable sitting posture can be relatively easily estimated without a special device.

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© 2008 by the Society of Physical Therapy Science
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