Static standing balance in adolescents with Down syndrome.

AIM: To analyse static-standing-balance of adolescents with Down syndrome (DS). METHODS: Thirty-two adolescents with DS aged 10-19 years (DSG); 33 adolescents, age/sex-matched, without DS (CG). Static-standing-balance under four conditions (C1: open-eyes/fixed-foot-support; C2: closed-eyes/fixed-foot-support; C3: open-eyes/compliant-foot-support; closed-eyes/compliant-foot-support) was examined by means of time and frequency Postural-Parameters (PPs). To evaluate the contribution of each sensory system influencing postural control ratios among the four conditions were calculated. Mean values of all PPs were higher in the DSG than in the CG. Mean values of time PPs were higher in both groups on compliant-foot-support (with open and closed eyes) than on fixed-foot-support. Ratios C2/C1 were significantly lower in DSG than in CG; ratios C3/C1 presented higher values in DSG than in CG, with significant differences in length path and RMS-velocity; there were no differences in ratios C4/C1. CONCLUSIONS: In our group of DS adolescents the shift from visual to multimodal control of stance had occurred and they showed similar postural control patterns than non-DS. Even though, they presented worse static balance than their peers without DS and they had more problems with altered somasosensory input. An adequate rehabilitation program insisting on somatosensory input could be a useful measure to improve balance.

The impact of exercise intensity on the release of cardiac biomarkers in marathon runners.

We sought to determine the influence of exercise intensity on the release of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in amateur marathon runners. Fourteen runners completed three exercise trials of the same duration but at exercise intensities corresponding to: (a) a competitive marathon [mean ± SD: heart rate 159 ± 7 beat min(-1), finish time 202 ± 14 min]; (b) 95% of individual anaerobic threshold [heart rate 144 ± 6 beat min(-1)] and; (c) 85% of individual anaerobic threshold [heart rate 129 ± 5 beat min(-1)]. cTnI and NT-proBNP were assayed from blood samples collected before, 30 min and 3 h post-exercise for each trial. cTnI and NT-proBNP were not different at baseline before each trial. After exercise at 85% of individual anaerobic threshold cTnI was not significantly elevated. Conversely, cTnI was elevated after exercise at 95% of individual anaerobic threshold (0.016 µg L(-1)) and to an even greater extent after exercise at competition intensity (0.054 µg L(-1)). Peak post-exercise values of NT-proBNP were elevated to a similar extent after all exercise trials (P < 0.05). The upper reference limit for cTnI (0.04 µg L(-1)) was exceeded in six subjects at competition intensity. No data for NT-proBNP surpassed its upper reference limit. Peak post-exercise values for cTnI and NT-proBNP were correlated with their respective baseline values. These data suggest exercise intensity influences the release of cTnI, but not NT-proBNP, and that competitive marathon running intensity is required for cTnI to be elevated over its upper reference limit.