Pelvic Sagittal Torsion Caused by Induced Leg Length Discrepancy: Geometrical Illusion May Influence Measures Based on Superior-iliac Spines Positions.

OBJECTIVE: To investigate whether a common measure of sagittal pelvic torsion based on the superior iliac spines behave similarly to predictions of a rigid (non-torsioned) plane, when leg length discrepancies (LLD) are induced. METHOD: Twenty-four young asymptomatic participants were subjected to pelvic posture measurements that use the anterior-superior iliac spines (ASISs) and posterior-superior iliac spines (PSISs) as references, while standing on level ground and with a one-, two- and three-centimeter lifts under the left foot. A special caliper with digital inclinometers was used. The following angles were measured: angles of the right and left PSIS-to-ASIS lines; right-left relative angle (RLRA), as the angle between the right and left PSIS-to-ASIS lines, which is a traditional lateral-view measure intended to detect sagittal torsions; angle of the inter-ASISs line; angle of the inter-PSISs line; anterior-posterior relative angle (APRA), as the angle between the inter-ASISs and inter-PSISs lines. According to trigonometric predictions based on the geometry given by the lines linking the superior iliac spines (i.e. a trapezoid plane), a pure lateral tilt of the pelvis, without interinnominate sagittal motion, would change RLRA in a specific direction and would not change APRA. RESULTS: Repeated-measures ANOVAs revealed that RLRA (p<0.001) and right and left PSIS-to-ASIS angles (p≤0.001) changed, and APRA did not change (p=0.33), as predicted. CONCLUSIONS: At least part of the sagittal torsion detected by measures that assume the PSIS-to-ASIS angles as the sagittal angles of the innominates is due to pelvic geometry and not to the occurrence of actual torsion, when LLDs are induced.

Attention Focus Does Not Influence Performance of Sit-to-Stand in Young and Older Adults.

An external focus of attention can improve performance, but there is little research on effects for the elderly in every day, well-learned mobility tasks. 57 older and 59 young adults performed the sit-to-stand and stand-to-sit while holding a cup, at three difficulty levels (cup empty or full, at normal or fast speed). Half were instructed to focus internally (on their movements) and half externally (on the cup). The effects of focus, age, and difficulty level were tested for movement time, mean inclination of the cup, inclination variability, and smoothness with 2 × 2 × 3 ANOVAs. Significant effects of difficulty were consistent across variables (p < 0.05). An effect of focus was present only for the inclination variability of the stand-to-sit (p < 0.03), favoring an internal focus (less variability). The age × focus interaction was significant for mean cup inclination, but post hoc tests failed to reveal any significant differences. The results of this study, together with the literature, suggest that an external focus may not benefit the performance of young or older adults in general mobility activities of daily living. The prevalent assumption that an external focus is always beneficial for performance needs further empirical testing.

Coordination in adults with neurological impairment - A systematic review of uncontrolled manifold studies.

BACKGROUND: Analysis of sensorimotor synergies has been greatly advanced by the Uncontrolled Manifold (UCM) approach. The UCM method is based on partitioning inter-trial variance displayed by elemental variables into 'good' (VUCM) and 'bad' (VORT) variability that, respectively, indicate maintenance or loss of task stability. In clinical populations, these indices can be used to investigate the strength, flexibility, stereotypy and agility of synergistic control. RESEARCH QUESTION: How are synergies affected by neurological impairment in adults? Specifically, this study aimed to determine i) the impact of pathology on VUCM, VORT, and their ratio (synergy index); ii) the relationship between synergy indices and functional performance; iii) changes in anticipatory synergy adjustments (ASAs); and iv) the effects of interventions on synergies. METHODS: Systematic review of UCM studies on adults with neurological impairment. RESULTS: Most of the 17 studies had moderate to high quality scores in the adapted Critical Review Form and the UCM reporting quality checklist developed for this review. i) Most of the studies found reduced synergy indices for patients with Parkinson's disease (PD), olivo-ponto-cerebellar atrophy, multiple sclerosis and spinocerebellar degeneration, with variable levels of change in VUCM and VORT. Reduction in synergy indices was not as consistent for stroke, in three out of six studies it was unchanged. ii) Five of seven studies found no significant correlations between scores on motor function scales and UCM indices. iii) Seven studies consistently reported ASAs that are smaller in magnitude, delayed, or both, for patients compared to healthy controls. iv) Two studies reported increased synergy indices, either via increase in VUCM or decrease in VORT, after dopaminergic drugs for patients with PD. There were similar synergy indices but improved ASAs after deep brain stimulation for patients with PD. SIGNIFICANCE: UCM can provide reliable and sensitive indicators of altered synergistic control in adults with neurological impairment.

Pre-exercise exposure to the treadmill setup changes the cardiovascular and thermoregulatory responses induced by subsequent treadmill running in rats.

Different methodological approaches have been used to conduct experiments with rats subjected to treadmill running. Some experimenters have exposed rats to the treadmill setup before initiating exercise to minimize the influences of handling and being placed in an anxiety-inducing environment on the physiological responses to subsequent running. Other experimenters have subjected rats to exercise immediately after placing them on the treadmill. Thus, the present study aimed to evaluate the effects of pre-exercise exposure to the treadmill on physical performance and cardiovascular and thermoregulatory responses during subsequent exercise. Male Wistar rats were subjected to fatiguing incremental-speed exercise at 24°C immediately after being placed on the treadmill or after being exposed to the treadmill for 70 min following removal from their home cages. Core body temperature (TCORE), tail-skin temperature (TSKIN), heart rate (HR) and mean arterial pressure (MAP) were recorded throughout the experiments. Rats exposed to the treadmill started exercise with higher TCORE, lower HR and MAP, and unaltered TSKIN. This exposure did not influence performance, but it markedly affected the exercise-induced increases in the four physiological parameters evaluated; for example, the TSKIN increased earlier and at a higher TCORE. Moreover, previous treadmill exposure notably allowed expected exercise-induced changes in cardiovascular parameters to be observed. Collectively, these data indicate that pre-exercise exposure to the treadmill induces important effects on physiological responses during subsequent treadmill running. The present data are particularly relevant for researchers planning experiments involving physical exercise and the recording of physiological parameters in rats.

Auditory stimulation by exposure to melodic music increases dopamine and serotonin activities in rat forebrain areas linked to reward and motor control.

Listening to melodic music is regarded as a non-pharmacological intervention that ameliorates various disease symptoms, likely by changing the activity of brain monoaminergic systems. Here, we investigated the effects of exposure to melodic music on the concentrations of dopamine (DA), serotonin (5-HT) and their respective metabolites in the caudate-putamen (CPu) and nucleus accumbens (NAcc), areas linked to reward and motor control. Male adult Wistar rats were randomly assigned to a control group or a group exposed to music. The music group was submitted to 8 music sessions [Mozart's sonata for two pianos (K. 488) at an average sound pressure of 65 dB]. The control rats were handled in the same way but were not exposed to music. Immediately after the last exposure or control session, the rats were euthanized, and their brains were quickly removed to analyze the concentrations of 5-HT, DA, 5-hydroxyindoleacetic acid (5-HIAA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in the CPu and NAcc. Auditory stimuli affected the monoaminergic system in these two brain structures. In the CPu, auditory stimuli increased the concentrations of DA and 5-HIAA but did not change the DOPAC or 5-HT levels. In the NAcc, music markedly increased the DOPAC/DA ratio, suggesting an increase in DA turnover. Our data indicate that auditory stimuli, such as exposure to melodic music, increase DA levels and the release of 5-HT in the CPu as well as DA turnover in the NAcc, suggesting that the music had a direct impact on monoamine activity in these brain areas.