RESUMO
Introduction: The ventilatory threshold (named as VT1) and the respiratory compensation point (named as VT2) describe prominent changes of metabolic demand and exercise intensity domains during an incremental exercise test. Methods: A novel computerized method based on the optimization method was developed for automatically determining VT1 and VT2 from expired air during a progressive maximal exercise test. A total of 109 peak cycle tests were performed by members of the US astronaut corps (74 males and 35 females). We compared the automatically determined VT1 and VT2 values against the visual subjective and independent analyses of three trained evaluators. We also characterized VT1 and VT2 and the respective absolute and relative work rates and distinguished differences between sexes. Results: The automated compared to the visual subjective values were analyzed for differences with t test, for agreement with Bland-Altman plots, and for equivalence with a two one-sided test approach. The results showed that the automated and visual subjective methods were statistically equivalent, and the proposed approach reliably determined VT1 and VT2 values. Females had lower absolute O2 uptake, work rate, and ventilation, and relative O2 uptake at VT1 and VT2 compared to men (p ≤ 0.04). VT1 and VT2 occurred at a greater relative percentage of their peak VO2 for females (67 and 88%) compared to males (55 and 74%; main effect for sex: p < 0.001). Overall, VT1 occurred at 58% of peak VO2, and VT2 occurred at 79% of peak VO2 (p < 0.0001). Conclusion: Improvements in determining of VT1 and VT2 by automated analysis are time efficient, valid, and comparable to subjective visual analysis and may provide valuable information in research and clinical practice as well as identifying exercise intensity domains of crewmembers in space.
RESUMO
BACKGROUND: Evaluation of maladaptive compensatory movement is important to objectively identify the impact of prosthetic rehabilitative intervention on body mechanics. The Capacity Assessment of Prosthetic Performance for the Upper Limb (CAPPFUL) scores this type of compensation by comparing movements of the prosthesis user to movements of individuals with intact, sound upper limbs (ULs). However, expected movements of individuals with sound, intact ULs have not been studied for the set of tasks performed in the CAPPFUL. OBJECTIVE: To enhance the scoring approach for the maladaptive compensatory movement domain of the CAPPFUL by defining normative kinematic movement and characterizing variability and repeatability. DESIGN: Clinical measurement. SETTING: Laboratories at the U.S. Food and Drug Administration (FDA) and University of Texas-Arlington. PARTICIPANTS: Convenience sample of 20 participants with no upper limb (UL) disability or impairment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASUREMENTS: Kinematic trajectories, range of motion, maximum angle, and completion time were calculated. Repeatability and intersubject variability were assessed by calculating Pearson's correlation coefficient (R), adjusted coefficient of multiple correlation (CMCadj), and max SD (SDmax) for nine joint angles at the elbow, shoulder, neck, and torso. RESULTS: For most joints evaluated, repeatability was lower (R < 0.8) for CAPPFUL 3-Zip vest, CAPPFUL 7-Cut w/ knife, and CAPPFUL 8-Squeeze water, implying inconsistent approaches within a subject from trial to trial for a given task. For most tasks, the joint angle SDmax across all participants was <20°. The approach for completing CAPPFUL 1 - Weights in crate and CAPPFUL 4 - Pick up dice was generally similar across participants (CMCadj >0.4). For other tasks, however, different approaches across participants at the torso and shoulder joint can be seen. CONCLUSION(S): This work established the expected movements of individuals with sound, intact ULs for tasks performed in the CAPPFUL that can be used to inform consistent, standardized scoring of the maladaptive compensatory movement domain.