Table 1.
Study design and methodological issues
| Study/country of origin | Subj. selection | Controlmatch | Justification. for sample size: | Electrode Position Reproducible | Reliability tested | Tester blind to group allocation | Sufficient results in text or supplied by authors | Score |
|---|---|---|---|---|---|---|---|---|
| Score | 1 | 1 | 1 | 1 | 1 | 1 | ||
| Bandholm 2006 Denmark [6] | NS | Y | NS | Y | NS | NS | **Y | 3 |
| Brox 1997 Norway [12] | N | NS | NS | Y | N | NS | N~ | 1 |
| Clisby 2008 Australia [13] | NS | N | NS | Y | NS | NS | N~ | 1 |
| Cools 2003 [18] 2007 [14] Belg. |
NS | Y | Y | Y | Y N |
NS | Y Y |
5 4 |
| Finley 2005 USA [16] | NS | Y | NS | Y | NS | NS | **Y | 3 |
| Ludewig 2000 USA [7] | Conv | Y | Y | Y | Y | NS | **Y | 5 |
| 2008 Moraes [19] DeMorais-Faria [15] Brazil |
NS | Y | NS Y |
***Y | NS | NS | N Y |
2 4 |
| Reddy 2000 USA [17] |
NS | NS | NS | NS | NS | NS | N | 0 |
| Wadsworth 1997 USA [20] | Conv | *Y/N | N | ***Y | Y/N* | N | N~ | 2 |
Abbreviations: Com.obs - Comparative observational,. Conv - convenience, NS - not stated, NA - Not applicable, Y - Yes, N - No. Subj. - subject, *Incomplete data, ** Authors provided on request,. *** Via reference, ~in chart form
Note: The reviewers recorded that matching of subjects and controls took place when this was stated by the authors and accompanied by supporting demographic details in the text. When full demographic details (mean age, SD and population for selection) were provided in the text without an indication of whether or not there was active matching the reviewers made their own judgement based on predetermined criteria; matching was judged to have taken place when all participants in both groups were selected from similar sporting or occupational activities and when the mean age and SD place did not differ more than 5 years.