Transcranial magnetic stimulation (TMS) studies investigating motor cortex reorganization in clinical populations use a variety of measurements, with some performed at rest and others with the muscle slightly contracted. Surprisingly there are still a limited number of studies focusing on relationship between TMS-measures obtained at rest and during active muscle contraction in healthy individuals. The purpose of this study was to: (1) compare resting and active TMS-measures and assess their association; (2) determine their respective short- and long-term reliability. Motor threshold (MT), motor evoked potentials (MEP) amplitude, map area, normalized map volume, map center of gravity (CoG) and short-interval intracortical inhibition (SICI) of the first dorsal interosseous (FDI) muscle were assessed in 12 healthy subjects. Subjects were tested three times (with a short (four days) and a long (>1 month) inter-session interval). No significant difference was found between resting and active measures, except for MT. Active MT was on average at 82% of resting MT. Good short- and long-term reliability were found for MT and CoG (in resting and active conditions), for the SICI and MEP amplitude at rest and for the normalized map volume under active condition. In conclusion, maps of FDI muscle obtained at rest and during active contraction are very similar to each other in healthy individuals when differences in MT are taken into account. Most TMS measures present good reliability when obtained under the appropriate condition, with comparable short-term and long-term reliability.
Low back pain is common during pregnancy. Lumbar stabilization and stretching exercises are recommended to treat low back pain in the general population. However, few studies have applied the effects of these two interventions in pregnant women with low back pain. To compare the effects of lumbar stabilization and stretching exercises for the treatment of gestational low back pain. A pilot randomized clinical trial. Laboratory of Functional Evaluation and Human Motor Performance and physical therapy clinics. Initially, 30 pregnant women with low back pain were recruited, of which 24 met the following inclusion criteria: being between 19-29 weeks of gestation; being in prenatal clinical follow-up; having nonspecific mechanical low back pain started in pregnancy; not participating in specific low back pain treatment in the last 3 months. A total of 20 women completed the study (10 each group). The main outcome measures were clinical (pain by Visual Analogue Scale (VAS) and McGill Pain Questionnaire and disability by Roland Morris Questionnaire), and secondary outcome measures were: postural balance (force platform); muscle activation level of multifidus, iliocostalis lumborum, rectus abdominis and external abdominal oblique (electromyography). The women were randomized into two groups for 6 weeks of intervention twice a week for a 50-minute treatment: 1) lumbar stabilization exercise protocol and 2) stretching exercise protocol. There was a significant reduction (P=0.03) in pain (1.68 in VAS and 4.81 for McGill questionnaire) for both interventions, but no change in disability score. In addition, both interventions were comparable for a significant improvement in postural stability (in mean d=0.77) for the velocity sway parameter, and significantly increased activation (P>0.05) of the external abdominal oblique muscle after intervention. Both modalities (lumbar stabilization and stretching) were efficient for pain reduction, improving balance and increasing one trunk activity muscle after 6 weeks of intervention in pregnant women with low back pain. The present study has implications, especially for clinical decision-making with regard to therapy choice in pregnant women with LBP to reduce pain and improve trunk function as measured through balance performance.
Purpose. The application of the margin of manoeuvre (MM) concept in work rehabilitation is new. It allows for variations in both health status and work demands, and the interaction between the two, to be taken into account. The objective of this exploratory study was to document the relationship between the presence of an MM in the workplace and the return to work (RTW), after a long-term absence. Methods. This study used the data collected during an earlier study that sought to identify the dimensions and indicators of the MM. The data were analysed on three levels, and the convergences and divergences in the MM indicators and dimensions in relation to the RTW were grouped accordingly. Results. Eleven workers and five clinicians participated in this study. The results support the proposition that the presence of a sufficient MM in the workplace is associated with RTW of individuals at the end of a rehabilitation programme despite a long-term absence (n == 6), and conversely, that its absence would appear to be associated with a non-return to work (n == 4). Conclusions. A better understanding of this concept will help further the development of a tool to assist clinicians in their task of assessing a worker's capacity to return to a given job.