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

M-mode ultrasound evaluation of lateral abdominal muscle postural response to load: an exploratory study

Aim

There is a need to evaluate the tissue deformation index of lateral abdominal muscles using M-mode ultrasound in a cohort of healthy subjects to establish a convenient reference point for clinical reasoning in patients. The aim of the study was to assess differences in the tissue deformation index between individual lateral abdominal muscles regardless of body side, compare these differences in the tissue deformation index on the right and left sides of the body, and evaluate side-to-side differences in the tissue deformation index within individual lateral abdominal muscles.

Material and methods

In a group of 126 healthy volunteers (59 females), the postural response of lateral abdominal muscles to external perturbation in the form of rapid arm abduction with load was recorded on both sides of the body, and the tissue deformation index was calculated.

Results

The mean values of the tissue deformation index form an increasing gradient from deep to superficial lateral abdominal muscles: 0.06%/ms for the transversus abdominis, 0.084%/ms for the internal oblique and 0.151%/ms for the external oblique (p <0.001). Side-to-side intra-muscle differences were significant only for the transverse abdominis (right: 0.047%/ms; left: 0.070%; p <0.01).

Conclusions

The tissue deformation index values differ significantly among individual lateral abdominal muscles and form a characteristic gradient: transversus abdominis < internal oblique < external oblique. The transversus abdominis muscle shows significant asymmetry in the tissue deformation index between the left and right sides of the body.

Activation asymmetry of the lateral abdominal muscles in response to neurodevelopmental traction technique in children with pelvic asymmetry

Study aim: The aim of the study was to evaluate asymmetry of activation of lateral abdominal muscles (LAM) in response to neurodevelopmental traction technique in children with pelvic asymmetry.

Material and methods: Measurements of LAM activation asymmetry were performed during traction with the force of 5% body weight in two experimental conditions: 1) in neutral position, 2) in 20° posterior trunk inclination. Twenty-three healthy children with pelvic asymmetry participated in the study. To evaluate LAM activation asymmetry ultrasound technology was employed (two Mindray DP660 devices (Mindray, Shenzhen, China)). Activation asymmetry indices for each individual LAM were calculated.

Results: The magnitude of LAM activation asymmetry indexes formed a gradient, with the most profound transversus abdominis (TrA) showing the greatest asymmetry, and the most superficial obliquus externus – the smallest. The inter-muscle differences were most pronounced between the TrA and the two more superficial oblique muscles. There were no correlation between the magnitude of pelvic asymmetry and LAM activation asymmetry.

Conclusions: During the neurodevelopmental traction technique there is a difference in individual LAM activation symmetry, with deeper muscles showing greater asymmetry. The activation asymmetry of the LAM does not seem to be associated with the pelvic asymmetry. Results are similar to those recorded in earlier studies in samples where no pelvic asymmetry were subjected to analysis.

Automated ultrasound measurements of lateral abdominal muscles under controlled breathing phases

BACKGROUND AND OBJECTIVES

A breathing phase during ultrasound measurements of the lateral abdominal muscles (LAMs) are usually indirectly controlled by visual inspection of the position of the transversus abdominis (TrA) muscle. This is due to the lack of devices to directly control airflow that are connected to the ultrasound in order to automatically and simultaneously freeze ultrasound images at the programmed breathing phase. Such indirect control may be related with potential measurement error because LAMs are respiratory muscles. Thus, the aim of this study was to present a newly developed and automatic measurement procedure to directly control airflow and at the same time automatically collect ultrasound images at the programed breathing phase. Additionally, it was decided to compare LAMs measurements obtained manually by the examiner and with an external device controlling the peak phase of tidal inspiration and expiration and compare the elasticity and thickness measurements between tidal inspiration and expiration in young participants.

METHODS

The study was carried out on 10 healthy youth. The thickness and shear modulus were measured by an Aixplorer ultrasound scanner. The measurements were obtained manually by the examiner and with a newly developed external device controlling the peak phases of tidal inspiration and expiration.

RESULTS

A significant difference in external/internal oblique thickness between the expiration and inspiration phases depended on the measurement procedure. The TrA thickness was similar during inspiration and expiration. During inspiration, the TrA shear modulus was higher than during expiration, and the TrA shear modulus depended on the measurement procedure.

CONCLUSION

Although the raw LAMs thickness and external/internal oblique thickness/shear modulus data were similar, the measurement procedure may affect the interpretation of the results. The TrA shear modulus is the most vulnerable to errors related to the measurement procedure. Construction of this study device controlling airflow and automatically collecting ultrasound images at the selected breathing phase seems to be promising in future studies considering measurements of respiratory muscles in a strictly defined breathing phase.