The Stochastic Component of the Postural Sway Variability Is Higher in Children With Balance Impairments.

The Stochastic Component of the Postural Sway Variability is Higher in Children with Balance Impairments.

Ann Biomed Eng. 2013 May 4;
Kurz MJ, Arpin DJ, Davies BL, Harbourne R

Children with balance impairments have an increased amount of variability in the sway of the center of pressure (COP) during standing. Limited efforts have been made to quantify the nature of the variability. This exploratory investigation examined the deterministic and stochastic features that comprise the time-dependent postural sway variability during standing. We measured the COP in standing of a heterogeneous group of children with balance impairments and an age-matched cohort of typically developing children, both with and without vision. The standard deviation of the COP was used to quantify the amount of variability present in the postural sway. A Langevin equation methodology was additionally employed to reconstruct the deterministic and stochastic features that comprised the postural sway variability. Our experiment resulted in three key findings: (1) removal of visual information increased the stochastic features of the postural sway variability, (2) the stochastic features were greater for the children with balance impairments, (3) the change in the amount of variability was strongly correlated with change the stochastic features. These results imply that the inability to suppress the stochastic features present in the nervous system may play a prominent role in the balance problems of children. Moreover, our results imply that alterations in the stochastic features drive the postural system away from successful balance strategies. HubMed – rehab


The use of normalized cross-correlation analysis for automatic tendon excursion measurement in dynamic ultrasound imaging.

J Appl Biomech. 2013 Apr; 29(2): 165-73
Pearson SJ, Ritchings T, Mohamed A SA

The work describes an automated method of tracking dynamic ultrasound images using a normalized cross-correlation algorithm, applied to the patellar and gastrocnemius tendon. Displacement was examined during active and passive tendon excursions using B-mode ultrasonography. In the passive test where two regions of interest (2-ROI) were tracked, the automated tracking algorithm showed insignificant deviations from relative zero displacement for the knee (0.01 ± 0.04 mm) and ankle (-0.02 ± 0.04 mm) (P > .05). Similarly, when tracking 1-ROI the passive tests showed no significant differences (P > .05) between automatic and manual methods, 7.50 ± 0.60 vs 7.66 ± 0.63 mm for the patellar and 11.28 ± 1.36 vs 11.17 ± 1.35 mm for the gastrocnemius tests. The active tests gave no significant differences (P > .05) between automatic and manual methods with differences of 0.29 ± 0.04 mm for the patellar and 0.26 ± 0.01 mm for the gastrocnemius. This study showed that automatic tracking of in vivo displacement of tendon during dynamic excursion under load is possible and valid when compared with the standardized method. This approach will save time during analysis and enable discrete areas of the tendon to be examined. HubMed – rehab


Lumbar muscle activity during common lifts: a preliminary study using magnetic resonance imaging.

J Appl Biomech. 2013 Apr; 29(2): 147-54
Mayer JM, Graves JE, Manini TM, Nuzzo JL, Ploutz-Snyder LL

The purpose of this preliminary study was to assess lumbar multifidus, erector spinae, and quadratus lumborum muscle activity during lifts as measured by changes in transverse relaxation time (T2) from magnetic resonance imaging (MRI). Thirteen healthy adults performed dynamic squat, stoop, and asymmetric stoop lifts at a standard load, with each lift followed by MRI. Increase in T2 for the multifidus and erector spinae was greater for the stoop than squat. No difference in T2 increase was noted between the multifidus and erector spinae for the squat or stoop. Increase in T2 for the contralateral multifidus was less for the asymmetric stoop than stoop. Future research using MRI and other biomechanical techniques is needed to fully characterize lumbar muscle activity during lifts for various populations, settings, postures, and loads. HubMed – rehab


[Conservative lymphedema therapy-Lymphological rehabilitation treatment.]

Wien Med Wochenschr. 2013 May 4;
Apich G

The most important column in the conservative lymphedema therapy still represents the complex decongestive physical therapy/KPE.This is a multimodal therapy, which consists of four components. (1) skin restoration and/or skin care, (2) manual lymphatic drainage, (3) compression therapy and (4) decongestive exercises. The KPE is also divided into two phases. Phase 1-the decongestion-serves primarily the mobilization and transporting away the banked protein-rich oedema fluid and seamless transition into the Phase 2-the maintenance phase, which serves to preserve the achieved treatment success. The implementation of the KPE should be stage-adjusted, but depends also on the location (genital, head, face), and on co-existing comorbidities (congestive heart failure, diabetes mellitus, obesity, muscular-skeletal disorders, mental illness, etc.). It should be modified for children, elderly persons and for patients with malignant lymphedema. HubMed – rehab