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Dynamic Musculoskeletal Imaging

Dynamic Measurement of Musculoskeletal Kinematics

Representative Publications

  1. M. Lebiedowska, S. Sikdar, “Knee joint angular velocities and accelerations during the patellar tendon jerk,” A. Eranki and L. Garmirian, J. Neuroscience Methods., vol. 198, pp. 255-259, 2011. 
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  2. A. Eranki, P. Otto, L. Curatalo, L. Prosser, K. Alter, D. Damiano and S. Sikdar, "Measurement of tendon velocities using vector tissue Doppler imaging and curved M-mode in patients with cerebral palsy, IEEE Ultrason. Sym., pp. 676-679, 2011. 

  3. A. Eranki, K. AlMuhanna and S. Sikdar, “Characterization of a vector Doppler system based on an array transducer,” IEEE Ultrason. Sym., pp. 1076-1079, 2010.

  4. A. Eranki, L. Bellini, L. Prosser, C. Stanley, D. Bland, K. Alter, D. Damiano and S. Sikdar, “Measurement of tendon velocities using vector tissue Doppler imaging: A feasibility study,” Proc. the 32nd Annual International Conference of IEEE EMBS, pp. 5310-5313, 2010. 
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  5. S. Sikdar, M. Lebiedowska, A. Eranki, L. Garmirian, and D. Damiano, “Measurement of rectus femoris muscle velocities during patellar tendon jerk using vector tissue Doppler imaging,” Proc. the 31th Annual International Conference of IEEE EMBS, pp. 2963-2966, 2009. 
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  6. A. Eranki and S. Sikdar, “Experimental characterization of a vector Doppler system based on a clinical ultrasound scanner,” Proc. the 31th Annual International Conference of IEEE EMBS, 2260-2263, 2009. 
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Brief Description

Ultrasound imaging is uniquely suited for directly measuring kinematics of muscle and tendons during dynamic biomechanical studies in a gait lab or for clinical assessment for rehabilitation applications. Currently, biomechanical assessments are typically performed using 3D motion capture for joint kinematics, force plates for measuring ground reaction force, and electromyography for monitoring electrical activity of muscle. Ultrasound imaging can provide complementary information by directly measuring muscle and tendon kinematics. While ultrasound has been widely used for static measurements of size and shape of muscles, and estimation of pennation angle of muscles, its use in dynamic studies has not been extensively investigated. 

We are developing new methods to quantify the contraction velocities, strain and strain rate and viscoelastic tissue properties of muscles and tendons. We utilize two ultrasonic methods: vector tissue Doppler imaging (vTDI) and curved M-mode (cMM) to quantitatively measure musculoskeletal motion. Vector Doppler estimates tissue motion in two or more independent directions using multiple transmitters and receivers oriented in different directions. The vector Doppler method combines the multiple velocity estimates producing a velocity vector with magnitude and direction [6]. Thus, vector Doppler can be used to estimate muscle and tendon velocities even if the motion occurs parallel to the skin surface, at a near orthogonal Doppler angle. Since this method relies on spectral Doppler, it provides quantitative estimates of tissue velocity with high temporal resolution. In preliminary studies, we have characterized the accuracy of this vector Doppler system based on clinical ultrasound scanner with a research interface and also shown the feasibility of measuring muscle and tendon contraction velocities in vivo. However, vector Doppler requires specialized equipment. To enable tendon motion quantification using a conventional ultrasound system, we developed a curved M-mode (cMM) method that requires only B-mode data. We have compared these two methods in a clinical setting to estimate motion of the tibialis anterior tendon in children with cerebral palsy and foot drop. We utilized simultaneous 3D joint motion capture to demonstrate the reproducibility of the two methods.
Axial and Lateral velocities during drop jump are compared to the sequence of video frames (upper panel). The lower panel is the axial and lateral velocities, where A corresponds to the initial knee flexion, B corresponds to the knee extension, C corresponds to the toe striking the ground, D corresponds to the heel striking the ground, E corresponds to knee flexion post landing and F corresponds to the knee extension and stabilization.
sikdar image


NSF CAREER: An Integrated Systems Approach to Understanding Complex Muscle Disorders

Abstract: The objective of this research is to investigate complex dynamic interactions between the musculoskeletal, circulatory and nervous systems involved in common, yet poorly understood, muscle disorders. The approach is to develop novel dynamic ultrasound imaging modes for quantifying anisotropic muscle kinematics, viscoelastic tissue properties and blood flow, and integrate these novel measures with conventional measures of tissue oxygenation, electrical activation, strength, and range of motion to characterize the underlying physiological systems.

Intellectual Merit: Real-time ultrasound imaging is uniquely suited for dynamic muscle function studies because it is cost-effective, portable and can be integrated with other measurements. However, lack of quantitative dynamic measures and challenges due to anisotropy of muscle have been barriers to widespread use of ultrasound. The proposed research is designed to overcome these barriers. The technical contributions are the theoretical and experimental investigation of novel ultrasound beam configurations, imaging modes and signal and image processing algorithms for quantitative imaging of anisotropic tissue motion and viscoelastic tissue properties.

Broader Impacts: This research will provide enabling tools for understanding functional limitations in musculoskeletal disorders and measuring treatment efficacy, potentially leading to more effective therapies for this significant public health problem. Research and educational objectives are integrated to engage graduate, undergraduate and high school students as part of a new bioengineering curriculum. Outreach efforts include summer research programs for high school students, a bioengineering demonstration kit encouraging students to pursue careers in science and engineering, and engaging the local K-12 community by presenting state-of-the-art research on muscle disorders affecting school-age children.