Study designs of evaluations included in the review
The inclusion criteria were not defined in terms of the study design. The primary studies included comparative studies.
Specific interventions included in the review
Studies that used SEMG to assess paraspinal muscles were eligible. In the included studies, the electrodes were located at L1 to L5, rectus abdominis, upper trapezius, erector spine, iliocostalis, gluteus maximus, multifidus and combinations of these. The EMG parameters assessed were: raw EMG, integrated EMG, average EMG, median frequency, median frequency slope, EMG activity and magnitude of myoelectrical activity. The test positions included: sitting with and without back support; standing; trunk flexion, extension or rotation; stooping; walking; isometric trunk testing; isometric extension; prone position; lifting two-pound disks; and unsupported trunk holding test.
Reference standard test against which the new test was compared
The reference standard was not explicitly stated but appears to have been a clinical diagnosis (no details provided) of lower-back pain.
Participants included in the review
Studies that included patients with LBP were eligible. The participants in the included studies that investigated the reliability of the EMG assessment were people with and without LBP, normal people and healthy females.
Outcomes assessed in the review
The inclusion criteria were not defined in terms of the outcomes. In the review, the outcomes were classified as positive if the original authors concluded there was a difference in measures recorded by EMG in LBP patients in any position, compared with normal people, in the total group or in a subgroup of the study population. The outcomes were classified as negative if the original authors concluded there was no difference between chronic LBP patients and normal people, in terms of the EMG measures.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.