Affiliations: [a] Centre for Interdisciplinary Research in
Rehabilitation of Greater Montreal (CRIR), Montreal Rehabilitation Institute,
Montreal, Quebec, Canada | [b] Centre for Research in Health Sciences, School of
Physical Therapy, Universidade Norte do Parana (UNOPAR), Londrina-PR,
Brazil | [c] School of Rehabilitation, Faculty of Medicine,
University of Montreal, Succursale Centre-Ville, Montreal, Quebec, Canada | [d] Occupational Health and Safety Research Institute
Robert-Sauvé, Montreal, Quebec, Canada
Note: [] Address for correspondence: Rubens A. da Silva, Ph.D., Centre
for Research in Health Sciences, School of Physical Therapy, Universidade Norte
do Parana (UNOPAR), 675 Paris Av, Londrina-PR, Brazil, CEP 86041-120. Tel.: +55
(43) 3371 7700, #7990; Fax: +55 (43) 3371 7721; E-mail:
rubens@unopar.br/rubensalex@hotmail.com
Abstract: The purpose of this study was to examine the effect of pelvic
stabilization and lower-limb configuration on trunk extension strength and to
test whether sex modify these effects. Twenty-two healthy volunteers (11 women
and 11 men: SEX factor), age range 20–55 years participated in this
study. Two isometric maximal voluntary contractions (MVCs) were performed in
extension and the moment was calculated relative to L5/S1, for each of six
experimental conditions. Two different positions were tested (POSITION factor):
I) seated position (knees at 90°) and II) semi-sitting position (knees at
45°). In each POSITION, three pelvic stabilization conditions were tested
(STABILIZATION factor): (1) unrestrained (control condition), (2) partially
restrained (posteriorly) and (3) totally restrained (posteriorly and
anteriorly). No significant main effects (p> 0.05) and no double and triple
(SEX × STABILIZATION × POSITION) interaction reached statistical
significance. Consequently, maximal trunk extension moment can be achieved with
the use of various stabilization and positioning modalities, at least when the
same apparatus allows such flexibility, and this as much in women as in men
subjects. These results have implications for the assessment of trunk extension
strength during pre- and post-training regiments during a rehabilitation
program for strengthening of back muscles in patients with low back pain.
Keywords: Back muscles, strength, rehabilitation, training, stabilization, position
