Combined Ultrasound Imaging and Biomechanical Modeling to Estimate Triceps Brachii Musculotendon Changes in Stroke Survivors

Figure 1

Typical ultrasonography imaging of the prime elbow extensors: long head of triceps brachii (LngHT), medial head of triceps brachii (MHT), and lateral head of triceps brachii muscle. (a) Original ultrasound image of MHT and LngHT; (b) MHT and LngHT image with labels; (c) original ultrasound image of LatHT; and (d) LatHT image with labels. In (a) and (b), the APO (bright fringe in the middle region) shows the boundary between MHT and LngHT. The white fringe in the lower range is the muscle-bone boundary (MHT-humerus). In (c) and (d), the bright fringe shows the muscle-bone boundary (LatHT-humerus). In (b) and (d), is the visualized part of the entire muscle fascicle length; MT₁ and MT₂ are the distance of the fiber proximal end to the bone and the distance of the fiber distal end point to the superficial aponeurosis, respectively; AT is adipose tissue; α is the pennation angle.

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