1. Back muscle strength and fatigue in healthy and chronic low back pain subjects: A comparative study of 3 assessment protocols 
Rubens A. da Silva, MSc, A. Bertrand Arsenault, PhD, Denis Gravel, PhD, Christian Larivière, PhD, Eros de Oliveira, MSc 
Archives of Physical Medicine and Rehabilitation 
Volume 86, Issue 4, Pages (April 2005)
DOI: /j.apmr
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

2. Fig 1
Subject positioned in the triaxial dynamometer with the trunk erect and knees slightly in flexion (upright position test).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

3. Fig 2
Subject in a semicrouched position pulling a handlebar attached to a floor-mounted load cell (semicrouched lifting test).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

4. Fig 3
Subject in a prone position on an adjustable couch composed of 2 parts separated by a pivot. (A) To measure forces created by the MUBM and Mcell. (B) To measure fatigue by the subject holding the unsupported trunk horizontally (Sorensen test).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

5. Fig 4
L5-S1 extension moment of control (•) and CLBP (■) subjects for the 3 assessment protocols (UPP, Sorensen test, LIF). *Statistically significant (P≤.05) differences between tests.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

6. Fig 5
RMS/time and MF/time slopes of multifidus muscle (L5) for the 3 fatigue tests. Results for the (A) control group and (B) CLBP group.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2005 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions