Application of conventional ultrasound coupled with virtual touch tissue imaging and quantification in the assessment of muscle strength.

BACKGROUND: Grip strength is the gold standard for the assessment of muscle strength. The current methods of measuring grip strength can only reflect the overall function of the muscle group, not an actual muscle lesion or the cause of the lesion. Virtual touch tissue imaging and quantification (VTIQ) technology can provide a representation of muscle properties and quantify alterations in muscle mechanics through measurements of the mean shear wave velocities of the muscle group at a designated location. METHODS: A total of 70 healthy middle-aged females were included. The maximum grip strength and thickness of the forearm and hand muscle under relaxed conditions were measured, and the sum of the muscle thicknesses was calculated. VTIQ was used to measure the shear wave velocity (Vs) of the flexor pollicis longus, flexor digitorum profundus and flexor digitorum superficialis. Intra-group correlation coefficient (ICC) was used to evaluate the test-retest reliability of the grip strength and Vs values, and the correlation of the thickness and Vs of each forearm and hand muscle with grip strength was calculated. RESULTS: (I) The hand-held dynamometer and the VTIQ technology have good test-retest reliability in muscle evaluation (all P<0.001). (II) The muscle thickness of the lumbricals did not exhibit a significant correlation with grip strength (P>0.05). The forearm radial MT (muscle thickness), forearm ulna MT, summation of four MTs, and interosseous MT showed positive correlations with grip strength (r=0.445, 0.824, 0.722, and 0.359, all P<0.05). The Vs values of the flexor pollicis longus, flexor digitorum superficialis, and flexor digitorum profundus showed negative correlations with grip strength (r=-0.962, -0.919, and -0.456, all P<0.01). Stepwise linear regression revealed that forearm radial, ulnar muscle thickness, and flexor digitorum superficialis Vs can be utilized concurrently to predict 90.7% of the variability of grip strength (R2=0.907). CONCLUSIONS: The structure and stiffness values of skeletal muscles obtained through conventional ultrasound coupled with VTIQ showed good correlations with the variation in grip strength and can evaluate the changes of muscle strength.

Alternative water supply solutions: China's South-to-North-water-diversion in Jinan.

Inter-basin water transfers are intended to have a positive impact on the development of a region, but are always accompanied by huge energy consumption. The feasibility and effectiveness of water transfer projects have not yet been clearly evaluated, especially in the light of their energy consumption and effects on social development. This paper develops a method that combines life cycle approach and system dynamic model to reveal the effectiveness of different water supply alternatives (transferred water, reclaimed wastewater and rainwater harvesting) when they are all constrained to consume equal energy. This approach is applied to the case of Jinan city in Shandong province, China, the main water-receiving city on the Eastern Route of the South-to-North Water Transfer Project (ER-SNWTP). The results show that in normal years, Jinan's reclaimed water and rainwater harvesting supply are effective replacements for transferred water under the constraints of equal energy consumption and capital costs; even in dry years these two alternatives still play an important role. The results of this study indicate the relative effectiveness of reclaimed water and rainwater harvesting in supplying urban water while conserving energy and capital.