Reliability and minimal detectable change of thoracoabdominal mobility measurements using photogrammetry.

The knowledge about measurement errors of the measuring tool is important before its use, as clinical decisions are going to be made based on its results. Here we investigate intrarater and interrater reliability and the minimal detectable change (MDC) of thoracoabdominal mobility measurements using photogrammetry, considering novice and experienced raters. Thoracoabdominal mobility of 17 healthy participants was assessed; photographs during apnea in maximal inspiration and expiration were used to calculate latero-lateral and anteroposterior diameters of the thorax (at axillary and xiphoid level) and abdomen. One novice and one experienced rater measured the same photographs three times. We found good reliability for the experienced rater (average Intraclass Correlation Coefficient (ICC): 0.98; average MDC: 0.3) and for interrater comparison (average ICC: 0.97; average MDC: 0.35) for all measures, with poorer results for latero-lateral mobility of abdomen. The novice rater presented moderate reliability for latero-lateral mobility of the thorax at axillary level and abdomen (ICC: 0.52 and 0.61; MDC: 1.42 and 2.05, respectively) and good reliability for the other measures (average ICC: 0.81; average MDC: 1.52). The photogrammetric analysis of thoracoabdominal mobility presented itself as a reliable method when used by an experienced professional. However, considering that the measurement of latero-lateral mobility is more subjected to errors, it should be used with caution. The MDC presented should be taken into account as a threshold to be certain that the measure is not under the measurement error due to rater variability.

Wheelchair rugby improves pulmonary function in people with tetraplegia after 1 year of training.

This study investigated the effects of 1 year of regular wheelchair rugby training on the pulmonary function of subjects with tetraplegia. A total of 15 male subjects with tetraplegia participated in this study and were divided into an experimental group of rugby players (n = 8) and a control group (n = 7) of sedentary tetraplegic subjects. Both groups underwent spirometry, and the experimental group was tested before and after participating of a regular 1-year program of wheelchair rugby training. At the beginning of the training program, all the subjects presented reduced pulmonary function compared with predicted values (p < 0.05) for healthy subjects. There were a significant increase in forced vital capacity (FVC), forced expired volume after 1 second (FEV1), and maximal voluntary ventilation (MVV, p < 0.05) values after 1 year of regular wheelchair rugby training. The regression analysis between total training time and spirometric variables FVC (r = 0.97, p < 0.0001) and MVV (r = 0.58, p = 0.02) revealed that the players with longer training time had higher pulmonary function values. This study showed that regular wheelchair rugby training can improve the pulmonary function of subjects with spinal cord injuries.

A 3D kinematic analysis of breathing patterns in competitive swimmers.

The purpose of this paper was to understand which differences long-term swimming training can cause on trunk mechanics during breathing and how these differences are related to the years of swimming training. The variations and coordination among trunk compartments were considered as target movement patterns. Video-based plethysmography was utilised for data acquisition and pre-processing. A group of swimmers, who followed a long-term intensive swimming training previously to this study, was compared with a non-swimmer control group. The participants of both groups performed quiet breathing and vital capacity tests. From the compartmental volumes associated with each breathing curves, the relative amplitude and cross-correlation among these volumetric time-varying signals were calculated, in order to analyse the relative partial volume variation and the coordination among trunk compartments involved in respiration. The results of a Mixed-ANOVA test (P ≤ 0.05) revealed higher coefficient of variation (P < 0.001) and correlations among trunk compartments in the swimmers group when vital capacity was performed. Significant linear regression was found between the years of swim training and the coefficients of variation and correlation. The results suggest that after long periods of intensive swim training, athletes might develop specific breathing patterns featuring higher volume variations in the abdominal region and more coordination among compartments involved in forced respiratory tasks such as vital capacity.

Tracking of wheelchair rugby players in the 2008 Demolition Derby trial.

The kinematics of male wheelchair rugby players (n = 8) during the final match of the 2008 Demolition Derby were assessed using two cameras (10 Hz) and a tracking method based on image-processing techniques. The players' on-court trajectory, total and accumulated distances covered, distances covered during working and stopped game clock, and average velocity were calculated. The players covered 2294.7 +/- 391.5 m in the first half and 2245.4 +/- 431.5 m in the second half. The average velocity was 14.5% greater in the first (1.22 +/- 0.21 m . s(-1)) than in the second half (1.05 +/- 0.20 m . s(-1)). The reduction in velocity was most marked in players with less functional capacity. The working game clock represented 48% of total game time (32 of 66.8 minutes) and the distance covered by all players during working game clock was 60% of the overall distance covered during the whole game (36,323 m). The results provide new information regarding the dynamics of a wheelchair rugby match and should aid coaches in planning effective training and coaching strategies.

Coordination between ribs motion and thoracoabdominal volumes in swimmers during respiratory maneuvers.

This work aimed to verify if swimmers present better chest wall coordination during breathing than healthy non-athletes analyzing the correlation between ribs motion and the variation of thoracoabdominal volumes. The results of two up-to-date methods based on videogrammetry were correlated in this study. The first one measured the volumes of 4 separate compartments of the chest wall (superior thorax, inferior thorax, superior abdomen and inferior abdomen) as a function of time. The second calculated the rotation angle of the 2(nd) to the 10(th) ribs around the quasi-transversal axis also in function of time. The chest wall was represented by 53 markers, attached to the ribs, vertebrae, thorax and abdomen of 15 male swimmers and of 15 non- athletes. A kinematical analysis system equipped with 6 digital video cameras (60Hz) was used to obtain the 3D coordinates of the markers. Correlating the curves of ribs rotation angles with the curves of the separate volumes, swimmers presented higher values than non-athletes when the superior and inferior abdomen were considered and the highest correlation values were found in swimmers for the inferior thorax. These results suggest a better coordination between ribs motion and thoracoabdominal volumes in swimmers, indicating the prevalent and coordinated action of the diaphragm and abdominal muscles to inflate and deflate the chest wall. The results further suggest that swimming practice leads to the formation of an optimized breathing pattern and can partially explain the higher lung volumes found in these athletes reported in literature. Key pointsThe study revealed that swimmers present higher correlation between the ribs motion and the variation of abdominal volumes than non-swimmers, suggesting that swimming practice might lead to the formation of an optimized breathing pattern, increasing the coordination between the thoracoabdominal volumes and the ribs motion.No previous work was found in the literature reporting this optimized breathing pattern in swimmers.The higher coordination between the thoracoabdominal volumes and the ribs motion found in swimmers can partially explain the higher lung volumes reported in literature for these athletes.