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INTRODUCTION Echo intensity of skeletal muscle measured by means of ultrasonography has been used to assess muscle quality, however, the heterogeneity of echo intensity has not been thoroughly investigated. Therefore, this study examined echo intensity in different sections of panoramic ultrasound images captured in the transverse plane. METHODS Echo intensity of the vastus lateralis was assessed in 24 men (20.2 ± 1.6 years) using panoramic ultrasonography. Echo intensity homogeneity was examined by dividing each image into 3 compartments of equal horizontal length (tertiles). RESULTS No differences were found between echo intensity of the anterior tertile (59.1 ± 9.1 AU), posterior tertile (56.4 ± 9.9 AU), lateral tertile (58.7 ± 9.9 AU), or the overall panoramic image (58.0 ± 8.8 AU). CONCLUSIONS Echo intensity of the vastus lateralis appears to be homogeneous as assessed in the transverse plane. Further research is necessary to determine if still imaging is sufficient to obtain an accurate measure of echo intensity. Muscle Nerve 56: 93-98, 2017.

Introduction The purpose of this study was to determine the validity of the maximal distance-electromyography (Dmax-EMG) method for estimating physical working capacity at fatigue threshold (PWCFT ). Methods Twenty-one men and women (age 22.9 ± 3.0 years) volunteered to perform 12 sessions of high-intensity interval training (HIIT) over 4 weeks. Before and after HIIT training, a graded exercise test (GXT) was used to estimate PWCFT using the Dmax method and the original (ORG) method. Results There was a significant increase in PWCFT for both ORG (+10.6%) and Dmax (+12.1%) methods, but no significant difference in the change values between methods. Further, Bland-Altman analyses resulted in non-significant biases (ORG-Dmax) between methods at pre-HIIT (-6.4 ± 32.5 W; P > 0.05) and post-HIIT (-4.2 ± 33.1 W; P > 0.05). Conclusion The Dmax method is sensitive to training and is a valid method for estimating PWCFT in young men and women. Muscle Nerve 55: 344-349, 2017.

Introduction: Muscle morphology and architecture changes in response to 6 weeks of progressive resistance train- ing were examined in healthy older adults. Methods: In this randomized, controlled design, muscle strength, quality, and architecture were evaluated with knee extension, DEXA, and ultrasound, respectively, in 25 older adults. Results: Resistance training resulted in significant increases in strength and muscle quality of 32% and 31%, respectively. Cross-sectional area of the vastus lateralis increased by 7.4% (p � 0.05). Physiological cross-sectional area (PCSA) of the thigh, a composite measure of muscle architecture, was related significantly to strength (r 50.57; p � 0.01) and demonstrated a significant interaction after training (p � 0.05). Change in PCSA of the vastus lateralis was associated with change in strength independent of any other measure. Conclusions: Six weeks of resistance training was effective at increasing strength, muscle quality, and muscle morphology in older adult men and women. Muscle Nerve 49:584-592, 2014