Efficacy of Marker-Based Motion Capture for Respiratory Cycle Measurement: A Comparison with Spirometry.

Respiratory rate monitoring is fundamental in clinical settings, and the accuracy of measurement methods is critical. This study aimed to develop and validate methods for assessing respiratory rate and the duration leof respiratory cycle phases in different body positions using optoelectronic plethysmography (OEP) based on a motion capture video system. Two analysis methods, the summation method and the triangle method were developed. The study focused on determining the optimal number of markers while achieving accuracy in respiratory parameter measurements. The results showed that most analysis methods showed a difference of ≤0.5 breaths per minute, with R2 ≥ 0.94 (p < 0.001) compared to spirometry. The best OEP methods for respiratory rate were the abdominal triangles and the sum of abdominal markers in all body positions. The study explored inspiratory and expiratory durations. The research found that 5-9 markers were sufficient to accurately determine respiratory time components in all body positions, reducing the marker requirements compared to previous studies. This interchangeability of OEP methods with standard spirometry demonstrates the potential of non-invasive methods for the simultaneous assessment of body segment movements, center of pressure dynamics, and respiratory movements. Future research is required to improve the clinical applicability of these methods.

Effects of the heel-to-toe rocker sole on walking in able-bodied persons.

BACKGROUND AND AIM: The most commonly prescribed external shoe modification is the use of rocker soles. The aim of this study was to evaluate the effect of a heel-to-toe rocker sole profile on specific temporal-spatial parameters and the kinematics of walking when added to footwear. METHOD: Seventeen healthy adult volunteers participated in this study. For each subject, gait analysis was performed under two conditions that were tested in a random order: walking with either a baseline shoe with a flat sole or a modified shoe adapted with a heel-to-toe rocker sole. RESULTS: Significant differences were observed between rocker sole conditions during initial double-limb support and second double-limb support during stance phase. In frontal plane movement, significant differences were observed between the rocker sole conditions but only during second double-limb support phase. CONCLUSIONS: This heel-to-toe rocker sole may be useful for patients with conditions such as ankle arthrodesis or for use with ankle-foot orthoses where limited ankle motion is required.