Background: Altered proprioception may be a factor in low back pain (LBP).Sustained end-range flexion
appears to reduce proprioceptive acuity, as assessed by joint reposition sense, in healthy subjects. However,
no study has investigated whether this occurs with shorter periods of lumbo-pelvic flexion or extension. The aim
of this study was to examine the effects of a brief period (180 seconds) of sustained lumbo-pelvic spine
extension and flexion on repositioning sense in pain-free subjects, compared to immediate repositioning sense
(5 seconds).
Methods: Lumbo-pelvic repositioning sense was measured in 17 pain-free subjects. Participants were required
to replicate a detined target position of the lumbo-pelvic region after: (a) lumbo-pelvic extension of 5 seconds
and 180 seconds; and (b) lumbo-pelvic flexion of 5 seconds and 180 seconds.
Results: Two-way ANOVA's (duration x direction) found no significant differences (p>0.05) in repositioning
accuracy, in terms of either absolute error (AE) or constant error (eE). There were no significant effects for
direction (AE, p=0.244; cr. p=0.298), duration (AE, p=0.756; eE, p=0.657) or their interaction (AE,
p=0.340; Cf , p=0.288).
Conclusions: Lumbo-pelvic repositioning sense was not altered after a brief period of either sustained extension
or flexion. The duration which the postures were sustained for may have been insufficient to alter repositioning
sense. While prolonged end-range lumbo-pelvic postures may increase vulnerability to pain and injury, it is
unclear what constitutes a safe duration of exposure to end-range postures.