ABSTRACT
CONTEXT: Postural control plays an essential role in concussion evaluation. The Stability Evaluation Test (SET) aims to objectively analyze postural control by measuring sway velocity on the NeuroCom VSR portable force platform (Natus, San Carlos, CA). OBJECTIVE: To assess the test-retest reliability and practice effects of the SET protocol. DESIGN: Cohort. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: 50 healthy adults (20 men, 30 women, age 25.30 ± 3.60 y, height 166.60± 12.80 cm, mass 68.80 ± 13.90 kg). INTERVENTIONS: All participants completed 4 trials of the SET. Each trial consisted of six 20-s balance tests with eyes closed, under the following conditions: double-leg firm (DFi), single-leg firm (SFi), tandem firm (TFi), double-leg foam (DFo), single-leg foam (SFo), and tandem foam (TFo). Each trial was separated by a 5-min seated rest period. MAIN OUTCOME MEASURES: The dependent variable was sway velocity (deg/s), with lower values indicating better balance. Sway velocity was recorded for each of the 6 conditions as well as a composite score for each trial. Test-retest reliability was analyzed across 4 trials with intraclass correlation coefficients (ICCs). Practice effects analyzed with repeated measures analysis of variance, followed by Tukey post hoc comparisons for any significant main effects (P < .05). RESULTS: Sway-velocity reliability values were good to excellent: DFi (ICC = .88; 95%CI: .81, .92), SFi (ICC = .75; 95%CI: .61, .85), TFi (ICC = .84; 95%CI: .75, .90), DFo (ICC = .83; 95%CI: .74, .90), SFo (ICC = .82; 95%CI: .72, .89), TFo (ICC = .81; 95%CI: .69, .88), and composite score (ICC = .93; 95%CI: .88, .95). Significant practice effects (P < .05) were noted on the SFi, DFo, SFo, TFo conditions and composite scores. CONCLUSIONS: Our results suggest the SET has good to excellent reliability for the assessment of postural control in healthy adults. Due to the practice effects noted, a familiarization session is recommended (ie, all 6 conditions) before data are recorded. Future studies should evaluate injured patients to determine meaningful change scores during various injuries.
ABSTRACT
BACKGROUND: Functional heartburn (FH) patients have a profound impact on the response to anti-reflux therapy of the nonerosive reflux disease (NERD) group as compared to the response of the erosive esophagitis group. Thus far, there is paucity of information about their physiological and clinical characteristics that may separate them from the other NERD patients. AIM: To compare physiological and clinical characteristics of patients with FH to their counterparts within the NERD group (NERD-positive [NERD+]). METHODS: Subjects with typical heartburn symptoms, at least twice a week, were evaluated by an upper endoscopy. Only those with normal esophageal mucosa were recruited into the study and underwent pH testing to assess esophageal acid exposure. The patients were divided into those with normal pH test (FH) and those with abnormal pH test (NERD+). The groups were compared for demographics, gastroesophageal reflux disease symptom characteristics, psychological profile, and reported quality of life. Additionally, the two patient groups were compared for stimulus response functions to acid, autonomic function response, and rate of Helicobacter pylori infection. RESULTS: Fifty-two patients included 30 with FH and the rest with NERD+. There was no statistical difference in demographics, frequency of hiatal hernia and H. pylori infection between the two groups. Patients with FH had a significantly longer history of heartburn and reported more episodes of chest pain than NERD+ patients (M--7.5 yr and M--once a week vs M--3.5 yr and M--once a month, respectively, p < 0.05). Patients with FH scored significantly higher in the somatization domain than patients with NERD+ (M--60 vs 52.5, p < 0.05), but had similar reported quality of life. Patients with NERD+ demonstrated a significantly shorter time to symptom perception and higher intensity rating (p < 0.05). Only patients with FH demonstrated a statistically significant increase in heart rate and skin conductance after acid perfusion, as compared to those with NERD+ (p < 0.05). CONCLUSION: Patients with FH demonstrate increased reports of chest pain and somatization, an alteration in autonomic function but lack a uniform increase in chemoreceptor sensitivity to acid as compared to those with NERD+. This suggests that while FH patients harbor clinical traits of a functional bowel disorder, hypersensitivity to acid is not a general phenomenon.
