Ultrasound Assessment of Muscle Injury Associated with Closed Limb Fracture

Full-Field Strain Measurements of the Muscle-Tendon Junction Using X-ray Computed Tomography and Digital Volume Correlation

We report, for the first time, the full-field 3D strain distribution of the muscle-tendon junction (MTJ). Understanding the strain distribution at the junction is crucial for the treatment of injuries and to predict tear formation at this location. Three-dimensional full-field strain distribution of mouse MTJ was measured using X-ray computer tomography (XCT) combined with digital volume correlation (DVC) with the aim of understanding the mechanical behavior of the junction under tensile loading. The interface between the Achilles tendon and the gastrocnemius muscle was harvested from adult mice and stained using 1% phosphotungstic acid in 70% ethanol. In situ XCT combined with DVC was used to image and compute strain distribution at the MTJ under a tensile load (2.4 N). High strain measuring 120,000 µε, 160,000 µε, and 120,000 µε for the first principal stain (εp1), shear strain (γ), and von Mises strain (εVM), respectively, was measured at the MTJ and these values reduced into the body of the muscle or into the tendon. Strain is concentrated at the MTJ, which is at risk of being damaged in activities associated with excessive physical activity.

Volume Fluctuations in Active and Nonactive Transtibial Prosthetics Users

This study aims to evaluate the validity and reliability of the Biosculptor’s Bioscanner system in capturing transtibial residual limb volume fluctuations in active and nonactive amputees during walking activity. Residual limb volume was obtained by measuring the limb circumference after amputees walked for 5 to 25 minutes for five consecutive days. The comparison of mean circumference between Bioscanner and manual measurements (i.e., tape measure) showed that the Bioscanner gave a higher estimation of circumference for the different amputees. Short-term changes in girth and volume due to an activity such as walking do not fluctuate uniformly. The results reflected as such as nonconsistence circumference change identified at different locations of the circumference profiles. Both amputees experienced a significant increase in circumference at the distal end of the limbs after 5 minutes of walking (7.35% change in nonactive and 8.83% in active amputees), and the measurement decreased as amputees walked longer. At 4-8 cm below the mid-patella tendon (pressure tolerant areas), both amputees experienced minor changes in the size of their circumference. The residual limb volume calculation resulted in the percentage difference between the two methods ranging from 2.4% to 9.3%. Pearson coefficient correlation obtained showed a high correlation between the two techniques, ranging from 0.97 to 1. The analysis of the limit of agreements showed that the majority of measurements were closed to the mean, suggesting that Bioscanner and manual techniques may be interchangeable and agree with one another. This study has implied that Bioscanner is comparable to the standard measurement method and may serve as an alternative tool in managing daily residual limb volume change.

Inter- and Intra-Rater Reliability of Ultrasound Measurements of Superficial and Deep Fasciae Thickness in Upper Limb

Ultrasound (US) imaging is increasingly the most used tool to measure the thickness of superficial and deep fasciae, but there are still some doubts about its reliability in this type of measurement. The current study sets out to assess the inter-rater and intra-rater reliability of US measurements of superficial and deep fasciae thicknesses in the arm and forearm. The study involved two raters: the first (R1) is an expert in skeletal–muscle US imaging and, in particular, the US assessment of fasciae; the second (R2) is a radiologist resident with 1 year’s experience in skeletal–muscle US imaging. R2, not having specific competence in the US imaging of fasciae, was trained by R1. R1 took US images following the protocol by Pirri et al. 2021, and the US-recorded images were analyzed separately by the two raters in different sessions. Each rater measured both types of fasciae at different regions and levels of the arm and forearm. Intra- and inter-rater reliability was excellent for the deep fascia and good and excellent for the superficial fascia according to the different regions/levels (for example for the anterior region of the arm: deep fascia: Ant 1: ICC_2,2 = 0.95; 95% CI = 0.81–0.98; superficial fascia: Ant 1: ICC_2,2 = 0.85, 95% CI = 0.79–0.88). These findings confirm that US imaging is a reliable and cost-effective tool for evaluating both fasciae, superficial and deep.