Tests & Measures: A Resource for Pediatric Physical Therapy Practitioners

Comparison of the Physiological Responses Induced by Different Pediatric Exercise Field Tests in Children

Title: Comparison of the Physiological Responses Induced by Different Pediatric Exercise Field Tests in Children

Reference: Scalco JC, Minsky RC, Mayer AF, Caputo F, Schivinski CIS. Comparison of the physiological responses induced by different pediatric exercise field tests in children. Pediatr Pulmonol. 2019;54(9):1431-1438. doi:10.1002/ppul.24423

Purpose: The purpose of this study was to evaluate and compare three different exercise tests, the 6-minute walk test (6MWT), modified shuffle walk test (MSWT), and pediatric Glittre activities of daily living test for children (TGlittre-P), and observe their physiological effects in healthy children. Due to the ever-changing development of children, it can be challenging to determine the physiological deficits that children with chronic diseases are experiencing throughout the course of their disease. This study aimed to gain more insight into the typical responses of healthy children in order to guide the interpretation of these walk tests when used on children with chronic diseases and help providers identify potential deficits.

Study Population: The population was comprised of 24 school-aged children in good health with an age range between 6 and 12 years (mean age of 9.78 ± 1.27 years); there were 15 girls and 9 boys. Each participant was enrolled in high-performance sports as well as met strict inclusion criteria requiring the absence of pulmonary, cardiorespiratory, neuromuscular, musculoskeletal, and acute respiratory illnesses or diseases at the time of the study.

Methods: This study was an observation and cross-sectional study. There were 3 different days for data collection with at least 24 hours but no more than 5 days in between each session. Testing started with anthropometric measures on the first day, along with spirometry measures. All participants performed the TGlittre-P on the first day, the 6MWT on the second, and MSWT on the third day, and each test was performed 2 times with a 30-minute interval. Several measures were recorded immediately before and after testing: SpO2, BP, and dyspnea on the Modified Borg Scale. During each test, the following were measured via portable telemetric gas analyzer: RR, HR, VT, ventilation, inspiratory time, expiratory time, oxygen uptake, carbon dioxide output, RER, oxygen pulse, ventilatory equivalent for oxygen and CO2, SpO2, and METs. Ventilatory threshold was also measured visually. Each walk test was administered accordingly to their approved guidelines and procedures. Statistical analysis included the Wilcoxon test for comparison of baseline and end of the test, a repeated measures ANOVA was used to compare the 3 conditions, and correlations were determined using Pearson’s or Spearman’s correlation coefficient.

Outcome Measures: This study used the 6MWT, MSWT, and TGlittre-P to evaluate the physiological responses of the participants. The 6MWT is used to evaluate functional capacity, the MSWT is used to induce maximal exertion to test exercise capacity, and the TGlittre-P tests walking, sitting, standing, stair climbing, and moving objects to assess ADL capability.

Intervention: There was no intervention applied in this study other than the 3 different walk tests.

Results: For the MSWT, the mean final velocity was 7.45 km/h and the test was completed between levels 7 and 13. Additionally, 67% of the participants reach maximal effort. In comparison, the mean velocity from the 6MWT was 6.01 km/h and the mean time for the TGlittre-P was 169.13 ± 22.24 seconds. The VO2 peak reached during the MSWT was much higher at 1409.94 mL/min in comparison to 982.19 mL/min and 982.85 mL/min during the TGlittre-P and 6MWT, respectively. The max HR in the MSWT was the highest at 192.57 bpm or 94.56% of age-predicted max HR, followed by 156.17 bpm and 76.70% in the 6MWT, and 142.31 bpm and 69.89% in the TGlittre-P. The MSWT shows responses that indicate a more maximal exercise test, whereas the 6MWT and TGlittre-P have the responses of submaximal exercise tests. Most of the measured physiological responses during the 6MWT and TGlittre-P were very similar and therefore, showed no statistical significance. On the other hand, the majority of physiological measures recorded during the MSWT were statistically significant in comparison to the 6MWT or the TGlittre-P, or both. These results reinforce the use of the TGlittre-P and 6MWT to test functional capacity as they always have been as indicated by their submaximal responses.

Strengths: This study’s main strength is the quantity and variety of physiological responses that they measured at each stage of the tests. Another strength of this test was the fact that this was one of the first studies to evaluate these responses in healthy children, rather than those who have been diagnosed with a chronic disease. Although the sample size is small, the small range in ages allows for fewer differences due to puberty that may have occurred with older participants.

Limitations: One major limitation is the small sample size of 24 participants and the lack of variety of ages within the sample. Another major limitation is the lack of measurement of blood lactate levels during the tests because this would have allowed for a better understanding of the metabolic changes that were happening as well. Additionally, since the study intends for this data to be used to compare to children with chronic diseases, it could have been clearer about how they will continue this research in the future with different populations.

Conclusion: The conclusion of this study was that the TGlittre-P and 6MWT demonstrated similar responses physiologically when tested on healthy school-aged children and these responses mimic those of submaximal exercise tests. When compared to the MSWT, the other 2 tests had lower cardiovascular, metabolic, and respiratory responses which put this test in a category of its own for potential maximal exercise testing. The TGlittre-P and 6MWT are submaximal tests because the physiological variables were able to plateau during testing, whereas the nature of the MSWT requires incremental increases in workload until maximal exertion is reached. Providers should take these variables into consideration when choosing which test is most appropriate for each individual patient.