Asymmetry of activation of lateral abdominal muscles during the neurodevelopmental traction technique.

OBJECTIVE: The aim of the study was to evaluate the symmetry and pattern of activation of lateral abdominal muscles (LAM) in response to neurodevelopmental traction technique. DESIGN AND PARTICIPANTS: Measurements of LAM thickness were performed in four experimental conditions: during traction with the force of 5% body weight (5% traction): 1) in neutral position, 2) in 20° posterior trunk inclination; during traction with the force of 15% body weight (15% traction): 3) in neutral position, 4) in 20° posterior trunk inclination. Thirty-seven healthy children participated in the study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: To evaluate LAM activation level ultrasound technology was employed (two Mindray DP660 devices (Mindray, Shenzhen, China) with 75L38EA linear probes). An experiment with repeated measurements of the dependent variables was conducted. RESULTS: Side-to-side LAM activation asymmetry showed relatively high magnitude, however, significant difference was found only in case of the obliquus externus (OE) during stronger traction (P < 0.05). The magnitude of LAM thickness change formed a gradient, with the most profound transversus abdominis (TrA) showing the smallest change, and the most superficial OE - the greatest. The inter-muscle differences were most pronounced between the OE and TrA (P < 0.001). CONCLUSIONS: During the neurodevelopmental traction technique there is a difference in individual LAM activation level, with deeper muscles showing less intense activation. In statistical terms, the only signs of side-to-side asymmetry of LAM activation are visible in case of the OE, however, the magnitude of asymmetry is relatively high. The results allow to identify patterns of activation of LAM in children showing typical development that will serve as a reference in future studies in children with neurological disorder.

Reliability of the passive knee flexion and extension tests in healthy subjects.

OBJECTIVE: Information on the reliability of the passive knee extension (PKE) and passive knee flexion (PKF) tests is still incomplete. Moreover, standardization of the 2 test procedures could be enhanced. The present study investigates interrater and test-retest reliability of the modified versions of the PKE and PKF tests to establish whether the level of reliability is sufficiently high to justify their use in scientific studies and clinical practice. METHODS: A total of 14 healthy subjects met the selection criteria. The 2 tests were carried out successively by each of the 3 clinicians/raters involved in the study, and each test was repeated 3 times. Two series of such measurements were performed. To evaluate interrater and test-retest reliability of the 2 tests, we calculated the intraclass correlation coefficients (ICCs), the standard errors of measurement, and the smallest detectable differences. RESULTS: The PKE and PKF tests showed excellent and good reliability, respectively. Mean ICCs for the PKE were greater than those for the PKF. Mean ICCs for the interrater reliability (0.88-0.93) were higher than those for test-retest reliability (0.84-0.93). No mean ICCs lower than 0.84 were found (test-retest for PKF). The lowest ICCs of 0.73 and 0.75 were registered for the test-retest reliability of PKF in the case of rater 1. CONCLUSION: These results show excellent and good interrater and test-retest reliability of the PKE and PKF, respectively. The PKE test seems to be slightly more reliable. These findings may help clinicians when using these tests. For research purposes, investigators must critically evaluate whether the presented amount of error is acceptable for a specific setting.

Induced static asymmetry of the pelvis is associated with functional asymmetry of the lumbo-pelvo-hip complex.

OBJECTIVE: This study evaluates the hypothesis that triggering and eliminating induced static pelvic asymmetry (SPA) may be followed by immediate change in functional asymmetry of the lumbo-pelvo-hip complex. METHODS: Repeated measures experimental design with 2 levels of independent variable, that is, induced SPA triggered and induced SPA eliminated, was implemented. Three series of measurements were performed, that is, baseline, after triggering SPA, and after eliminating SPA. A group of 84 subjects with no initial symptoms of SPA was studied. Different forms of mechanical stimulation were applied aiming to induce SPA, and the 2 manual stretching-manipulating techniques were performed aiming to eliminate it. A hand inclinometer was used to measure SPA in standing posture. Selected ranges of motion of the hip joints and lumbar spine were used to depict functional asymmetry of the lumbo-pelvo-hip complex. The functional asymmetry indices for individual movements were calculated. Repeated measures design of analysis of variance, dependent data Student t test, and linear Pearson's correlation test were used. RESULTS: Assessment of the SPA showed its significant increase between baseline and series 2 measurements, with a subsequent significant decrease between series 2 and series 3 measurements. Values of the functional asymmetry indices changed accordingly, that is, they increased significantly between series 1 and series 2 and had returned to their initial level in series 3 measurements. CONCLUSIONS: Induced SPA shows considerable association with functional asymmetry of the lumbo-pelvo-hip complex.