1. Electromyographic assessment of back muscle weakness and muscle composition: Reliability and validity issues 
Christian Larivière, PhD, A.Bertrand Arsenault, PhD, Denis Gravel, PhD, Denis Gagnon, PhD, Patrick Loisel, MD, Roger Vadeboncoeur, MD 
Archives of Physical Medicine and Rehabilitation 
Volume 83, Issue 9, Pages (September 2002)
DOI: /apmr
Copyright © 2002 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

2. Fig. 1
Diagrams of the (A) subject positioning, (B) sign convention, and (C) L5–S1 moment equation. For simplicity, only the main frame shown is represented (with broken lines). In A, the adjustable components (pads and force platform) are represented by arrows using the same numbers. Reprinted with permission.41
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2002 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

3. Fig. 2
Trunk extension moment (Nm) at L5–S1 as a function of RMS amplitude (μV) (plots on the left) and MF (Hz) as a function of the trunk extension moment at L5–S1 (plots on the right) for 20 healthy and 20 chronic LBP (CLBP) subjects. Each curve represents the mean of 2 bilateral muscles, 3 ramps, 4 sessions, and all subjects in the group. SDs were omitted for clarity.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2002 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

4. Fig. 3
Trunk extension moment (Nm) at L5–S1 as a function of RMS amplitude (μV) (plots on the left) and MF (Hz) as a function of the trunk extension moment at L5–S1 (plots on the right) for 12 men and 13 women. Each curve represents the mean of 2 bilateral muscles, 3 ramps, and all subjects in the group. SDs were omitted for clarity.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2002 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions