of Thesis entitled Musculotendon Modeling of the Elbow Joint for Unimpaired Subjects and Persons after Stroke using Noninvasive and In Vivo Information submitted by Li Le for the Degree of Doctor of Philosophy at The Hong Kong Polytechnic University in March 2007 Neuromusculoskeletal modeling provides insights into the muscular system which are not always obtained through experiment or observat...

We introduce a method, known as one-dimensional sonomyography (1-D SMG), that uses A-mode ultrasound signals to detect dynamic thickness changes in skeletal muscle during contraction. We custom-designed a 1-D SMG system to collect synchronized A-mode ultrasound, joint angle, and surface electromyography (EMG) signals of forearm muscles during wrist extension. We extracted the 1-D SMG signal fro...

AIM To evaluate female runners' pelvic floor muscles using three-dimensional ultrasonography (3DUS) and surface electromyography (SEMG). MATERIAL AND METHODS A cross-sectional study was conducted on 24 female runners. SEMG was performed using surface electrodes inserted in the vagina. 3DUS was performed using perineal convex transducer. SEMG was evaluated at rest and with maximum voluntary co...

Innervation zone (IZ) has been identified as the origin of action potential propagation in isometric contraction. However, IZ shifts with changes in muscle length during muscle activity. The IZ shift has been estimated using raw EMG signals. This study aimed to investigate the movement of IZ location during continuous dynamic muscle contraction, using a computer program. Subjects flexed their e...

It is generally accepted that our sense of limb position and movement is provided, in part, by signals from muscle spindles, while the sense of muscle force derives from signals in tendon organs. Experiments are described here, using human subjects, in which the effects of eccentric and concentric exercise of elbow flexor muscles are compared on the sense of forearm position and the sense of te...

We determined the local strain profile in sheared lamellar block copolymers. A trilayer model, based on elastic brushes separated by viscous interpenetration zones, captures the rheological response of these materials and provides a measure of the relative contributions of elastic versus viscous strain. The elastic chain distortions were evident from a reversible lamellar contraction, as measur...

We use liquid-phase transmission electron microscopy (LP-TEM) to characterize the structure and dynamics of a solution-phase superlattice assembled from gold nanoprisms at the single particle level. The lamellar structure of the superlattice, determined by a balance of interprism interactions, is maintained and resolved under low-dose imaging conditions typically reserved for biomolecular imagi...

Intracardiac blood flow patterns are potentially important to cardiac pumping efficiency. However, these complex flow patterns remain incompletely characterized both in health and disease. We hypothesized that normal left ventricular (LV) blood flow patterns would preferentially optimize a portion of the end-diastolic volume (LVEDV) for effective and rapid systolic ejection by virtue of locatio...

The present study determines the effects of summation of contraction on joint kinematics in human ankle and mechanomyography (MMG) signals during non-isometric contraction. The excursion and angular velocity of dorsiflexion and eversion were measured during several summation profiles during non-isometric contractions. The joint kinematics parameters and MMG responses to 1-8 pulses at a constant...

Posterior chamber intraocular lens (PC-IOL) subluxation is uncommon but represents one of the most serious complications following phacoemulsification. Late spontaneous IOL-capsular bag complex dislocation is defined as occurring three months or later following cataract surgery. Unlike early IOL dislocation, late spontaneous IOL dislocation is due to a progressive zonular dehiscence and contrac...