NMBL - Neuromuscular Biomechanics Lab

Related Topics
Muscle Mechanics
Surgical Simulation
Surgical Navigation
Musculoskeletal Models

Anatomical Studies We make anatomical measurements to quantify muscle sarcomere lengths, muscle architecture, muscle moment arms, and joint kinematics and to prototype novel surgical navigation methods. Some examples of anatomical measurements made by NMBL researchers are listed below.
	Sarcomere Lengths Quantitative descriptions of muscle architecture are needed to characterize the force-generating capabilities of muscles. We have used laser diffraction techniques to determine the sarcomere lengths and optimal fiber lengths in muscles about the elbow and torso. Shown on the left is a diffraction pattern resulting from shining a laser through a muscle fiber. Sarcomere lengths are calculated based on the distance between the first order lines (the two diagonal lines).
	Muscle Moment Arms We have experimentally determined the moment arms of muscles spanning the elbow, hip and knee using the tendon displacement method. Using these data, we have studied the scaling of muscle moment arms with bone dimensions, validated our methods for constructing kinematic musculoskeletal models from MR images, and tested the predictions of surgical simulations.
	Prototyping Surgical Navigation Methods We used our computer-assisted surgical navigation system to characterize the variability associated with femoral rotational alignment techniques, as measured on cadaveric specimens, and to determine whether the use of our navigation system reduced this variability.
Associated Publications Siston, Patel, Gooidman, Delp, and Giori. "The variability of femoral rotational alignment in total knee arthroplasty." Journal of Bone and Joint Surgery, 2005. (Download PDF file) Siston and Delp. "Evaluation of a new algorithm to determine the hip joint center." Journal of Biomechanics, 2005. (Download PDF) Murray, Buchanan, Delp. "Scaling of peak moment arms of elbow muscles with dimensions of the upper extremity." Journal of Biomechanics, 2002. (Download PDF) Delp, Suranarayanan, Murray, Uhlir, Triolo. "Architecture of three major trunk muscles."Journal of Biomechanics, 2001. (Download PDF) Murray, Buchanan, Delp. "The isometric functional capacity of elbow muscles."Journal of Biomechanics, 2000. (Download PDF) Arnold, Asakawa, Delp. "Do the hamstrings and adductors contribute to excessive internal rotation of the hip in persons with cerebral palsy?" Gait and Posture, 2000. (Download PDF) Arnold, Salinas, Asakawa, Delp. "Accuracy of muscle moment arms estimated form MRI-based musculoskeletal models of the lower extremity." Computer Aided Surgery, 2000. (Download PDF) Delp, Hess, Hungerford, Jones. "Variation of rotational moment arms with hip flexion."Journal of Biomechanics, 1999. (Download PDF) Murray, Delp, Buchanan. "Variation of muscle moment arms with elbow and forearm position." Journal of Biomechanics, 1995. (Download PDF) Delp, Ringwelski, Carroll. "Transfer of the rectus femoris: effects of transfer site on moment arms about the knee and hip."Journal of Biomechanics, 1994. (Download PDF)