Débora Rafaelli de Carvalho

Are 30 minutes of rest between two incremental shuttle walking tests enough for cardiovascular variables and perceived exertion to return to baseline values

Objective: To verify whether 30 minutes of rest between two incremental shuttle walking tests (ISWT) are enough for cardiovascular variables and perceived exertion to return to baseline values in healthy subjects in a broad age range. Method: The maximal exercise capacity of 334 apparently healthy subjects (age ≥18) was evaluated using the ISWT. The test was performed twice with 30 minutes of rest in between. Heart rate (HR), arterial blood pressure (ABP), dyspnea, and leg fatigue were evaluated before and after each test. Subjects were allocated to 6 groups according to their age: G1: 18-29 years; G2: 30-39 years; G3: 40-49 years; G4: 50-59 years; G5: 60-69 years and G6: ≥70 years. Results: All groups had a good performance in the ISWT (median >90% of the predicted distance). The initial HR (HRi) of the second ISWT was higher than the first ISWT in the total sample (p<0.0001), as well as in all groups (p<0.0001). No difference was observed in the behavior of ABP (systolic and diastolic) and dyspnea between the two tests, but this difference occurred for leg fatigue (greater before the second ISWT) in G1 (p<0.05). Most subjects (58%) performed better in the second test. Conclusion: 30 minutes of rest between two ISWTs are not enough for all cardiovascular variables and perceived exertion to return to baseline values. However, this period appears to be sufficient for blood pressure and performance to recover in most subjects.

Static and Functional Balance in Individuals With COPD: Comparison With Healthy Controls and Differences According to Sex and Disease Severity

BACKGROUND: Studies have shown that individuals with COPD have impaired body balance, probably caused by the diseases multisystemic manifestations plus age-related decline in balance, potentially increasing the risk of falling and its consequences. However, little is known about the profile of individuals with COPD who present balance impairments, especially related to sex and disease severity stages. The aim of this work was to compare static and functional balance between subjects with COPD and healthy controls and to check possible differences according to sex and degrees of disease severity. METHODS: Forty-seven subjects with COPD and 25 healthy controls were included in this study. Their static balance was assessed in one-legged stance using a force platform and functional balance with the Timed Up and Go test. Additionally, participants performed spirometry, the 6-min walk test and isometric quadriceps maximal voluntary contraction assessment. Disease severity was classified according to the Global Initiative for Obstructive Lung Disease stages and BODE (body mass index, air-flow obstruction, dyspnea, and exercise capacity) scores. RESULTS: In comparison with healthy controls, subjects with COPD had worse static (center of pressure displacement area: 9.3 ± 1.9 cm2 vs 11.6 ± 4.0 cm2, respectively, P = .01) and functional balance (Timed Up and Go test: 8.5 ± 1.3 s vs 10.3 ± 1.8 s, respectively, P < .001). In the COPD group, men performed better in the Timed Up and Go test than women (9.8 ± 1.2 s vs 10.9 ± 2.2 s, respectively, P = .03), whereas women presented a better static balance in comparison with men for all parameters related to center of pressure (P < .005 for all). Disease severity did not affect any balance results. CONCLUSIONS: Individuals with COPD had worse static and functional balance in comparison with healthy controls. Sex can mediate these results, depending on the type of balance evaluation (force platform or functional test). Balance performance was similar among the groups classified according to disease severity.

Reliability of the force platform in patients with COPD: Preliminary results

Background: The force platform (FP) is considered the gold standard method to assess static balance in healthy elderly people. However, its reliability in patients with COPD remains unknown. Aim: To verify the reliability of the FP in patients with COPD and its association with the Timed up & go test (TUG) and risk and number of falls. Methods: Nine patients (8 male, 69±5 years, FEV1 46±16 %pred) were assessed by the FP in the following conditions: standing with feet hip-width apart with eyes opened (FHEO) and eyes closed (FHEC); standing with feet hip-width apart with a short base (FHSB) and one-legged stance (OLS). The evaluation was performed twice (test and retest) with one week interval. The studied parameters were: the center of pressure area (COP-area), the anteroposterior mean velocity (MVel-A/P) and frequency (Fre-A/P) and the medial-lateral mean velocity (MVel-M/L) and frequency (Fre-M/L). The history of falls in the preceding year was checked and the risk of falling was assessed by Risk of Fall Downton Score. Patients also performed the TUG. Results: All parameters of the FP presented a good agreement between the two tests for all conditions (ICC 0.84-0.98). No differences were observed between the first and second evaluation (p>0.05 for all parameters). The FP parameters correlated with the TUG (0.71≤r≤0.87). Risk of falling and number of falls correlated with MVel-A/P and COP-area, both in the FHEC condition (r=0.72 and r=0.75, respectively; p Conclusion: These preliminary data showed that the FP is a reliable instrument to assess balance of patients with COPD. In addition, the FP parameters correlated with functional balance and risk and number of falls.