Table 4.

Quality total score (^#Studies investigated the effect of low back pain when normalization was not necessary were rated using a 13 point scale; ^*Studies investigated the effect of low back pain were rated using a 14 point scale).

Authors (year)	Score quality index (/10* or /11)	Score EMG (/3* or /4)	Total score (/13# or /14* or /15)	Note (%)
Akbari et al., 2015	7*	4	11*	78.6
Bazrgari et al., 2011	9	2	11	73.3
Dupeyron et al., 2010	8	4	12	80
Gao et al., 2014	9*	3	12*	85.7
Granata et al., 2001	6	3	9	60
Granata et al., 2005	9	2	11	73.3
Granata et al., 2004	6	3	9	60
Grondin and Potvin, 2009	8	4	12	80
Hendershot et al., 2011	10	3	13	86.7
Herrmann et al., 2006	8	4	12	80
Jacobs et al., 2011	10*	4	14*	100
Jones et al., 2012a	8*	4	12*	85.7
Jones et al., 2012b	10*	4	14*	100
Lariviere et al., 2010	9*	3	12*	85.7
Liebetrau et al., 2013	6*	3	9*	64.3
MacDonald et al., 2010	9*	3	12*	85.7
Mawston et al., 2007	9	4	13	86.7
Muslim et al., 2013	10	3	13	86.7
Newcomer et al., 2002	9*	3*	12#	92.3
Olson, 2014	9	4	13	86.7
Radebold et al., 2000	6*	3*	9#	69.2
Radebold et al., 2001	7*	3*	10#	76.9
Ramprasad et al., 2010	5*	4	9*	64.3
Reeves et al., 2005	8*	2*	10#	76.9
Rogers and Granata, 2006	9	4	13	86.7
Sanchez-Zuriaga et al., 2010	9	3	12	80
Shenoy et al., 2013	3*	3	6*	42.9
Stokes et al., 2006	7*	4	11*	78.6
Toosizadeh et al., 2013	10	3	13	86.7