NMBL - Neuromuscular Biomechanics Lab

Medical Imaging We develop medical imaging techniques to determine muscle and bone geometry, measure in vivo joint and muscle motion, and characterize muscle architecture. Images are used to create models of the musculoskeletal system and characterize in vivo musculoskeletal function. Several of the imaging techniques used in our lab are described below.
	Static MRI We collect static MR images to characterize bone, cartilage, muscle, and joint anatomy. The images are used, for example, to create subject-specific models, measure joint contact areas, and determine muscle volumes.
Cine phase-contrast MRI Cine phase-contrast (cine-PC) MRI allows us to measure of muscle tissue velocities and displacements within an imaging plane during cyclical motion (animation shows regions of interest tracked during a knee flexion-extension motion). We have used this technique, for example, to test a basic assumption about the homogeneity of muscle contraction and to evaluate the relative motion of muscles following tendon transfer surgery.
Real-time MRI We are working with researchers from Radiology and Electrical Engineering at Stanford to develop and validate a system to quantify muscle and joint kinematics using real-time MRI, both in the traditional 1.5T scanner as well as the 0.5T open MR system.
	Load-bearing imaging in the open MR scanner The open configuration scanner is capable of imaging subjects under weight-bearing conditions. We are using this scanner to evaluate the mechanics of the patellofemoral joint to understand the causes of patellofemoral pain.
Ultrasound We have used ultrasound imaging to examine the arrangement of fascicles within, for example, the biceps brachii muscle, allowing us to appreciate the effect of prominent distal aponeurosis on the architecture of the distal biceps brachii.
Associated Publications Besier, Draper, Gold, Beaupre, and Delp. "Patellofemoral joint contact area increases with knee flexion and weight-bearing." Journal of Orthopaedic Research, 2005. (Download PDF file) Gold, Besier, Draper, Asakawa, Delp, and Beaupre. Weight-Bearing MRI of patellofemoral joint cartilage contact area. Journal of Magnetic Resonance Imaging, 2004. (Download PDF file) Gold, Asakawa, Blemker, Delp. "Magnetic Resonance Imaging Findings After Rectus Femoris Transfer Surgery." Skeletal Radiology, 2004. (Download PDF file) Asakawa, Pappas, Blemker, Drace, and Delp. "Cine Phase-Contrast Magnetic Resonance Imaging as a Tool for Quantification of Skeletal Muscle Motion." Seminars in Musculoskeletal Radiology, 2003. (Download PDF file) Asakawa, Nayak, Blemker, Pauly, Nishimura, and Delp. "Real-time imaging of skeletal muscle velocity." Journal of Magnetic Resonance Imaging, 2003. (Download PDF file) Asakawa, Blemker, Gold, and Delp. "In vivo motion of the rectus femoris muscle after tendon transfer surgery." Journal of Biomechanics, 2002. (Download PDF file) Pappas, Asakawa, Delp, Zajac, and Drace. Nonuniform shortening the the biceps brachii during elbow flexion. Journal of Applied Physiology, 2002. (Download PDF file) Asakawa, Pappas, Drace, Delp. Architecture of the biceps brachii characterized with ultrasound and MR. International Journal of Mechanics in Medicine and Biology, 2002. (Downloadf PDF file)