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Biomechanics Laboratory

Laboratory Personnel

  • Zbigniew Gugala, MD, PhD - Associate Professor, Lab Director
  • William L. Buford, Jr., PhD, PE - Professor Adjunct
  • Randal P. Morris, BS - Lab Manager

The UTMB Orthopaedics Biomechanics Laboratory is devoted to the advancement of clinical care by continuously seeking improved knowledge of musculoskeletal function. The lab is an integral part of the department, providing the space and resources to host educational training, as well as support for faculty, resident, and student research.

Biomechanics Lab List

The Orthopaedics Biomechanics Laboratory facilities are located within the Rebecca Sealy in close proximity to the main orthopaedics department. The workspace is a Biosafety Level 2 area, and consists of two laboratories, an electronics shop, and the accompanying staff offices and student workstations.

adj_Research-AnatomyLabThe Anatomy Lab is primarily for orthopaedic resident training and education in specific anatomical areas, as well as research studies utilizing fresh frozen and/or embalmed cadaver specimens. The lab includes a walk-in -4 degree C freezer with an adjoining cold room, five anatomical workspaces, and a large selection of surgical instrumentation.

adj_Research-LabThe Biomechanics Lab is equipped with an MTS® 858 Mini-Bionix biaxial materials testing machine - a computer controlled, servohydraulic system capable of measuring axial forces up to 10,000N and torsional forces up to 100Nm with its largest load cell. The system also has 2500N and 250N load cells, linear extensometers, an environmental chamber, custom-made freeze clamps, and dual-gimbal clamps. This system is able to test the biomechanical properties of a wide range of physiological systems such as tendons and ligaments, joint systems, and large and small bones.

The lab also maintains motion analysis equipment from Motion Analysis Corp., consisting of 6 CCD analog cameras, calibration analogs, and kinematic analysis software. With this setup, we can record motion in cadaver specimens at the joint level, physiologic movement in live subjects, and simple gait analysis. We also employ a portable 2-camera video motion system for studies in sports medicine and physiology. Other equipment includes an 8-channel portable EMG (electromyography) system, a 4-channel research EMG system, a 6 degree-of-freedom Microscribe for detailed surface mapping and 3D displacement measures, and a FLIR thermal imaging camera system.

Research from the Orthopaedic Biomechanics Laboratory has been presented in many peer-reviewed journals, proceedings, and research presentations at local, national, and international conferences.


The origin of the Orthopaedics Biomechanics Laboratory began with faculty driven hand surgery research in 1984. Initial work in wrist anatomy and mechanics were spearheaded by Steven F. Viegas, MD and Allen Tencer, PhD. The group was soon joined by Rita Patterson, PhD in 1985, and Clarence Nicodemus, PhD, and William L. Buford, PhD in 1992. During this period, the Hand Surgery Division contributed greatly in the areas of wrist anatomy, bone contact pressures and load mechanics, kinematics and kinetics, 3D computer modeling and analysis. This innovative approach to orthopaedic research continued with further emphasis on biomechanical testing, 3D modeling and musculoskeletal animation and simulation. Collaborative efforts of the Orthopaedics Biomechanics Lab include a long list of medical students, orthopaedic residents, international research fellows, engineering master students, as well as doctoral candidates and post doctorate fellows.

What follows is a brief overview of some of the research techniques and projects developed in the lab through its first 25 years.

Bony Contact Pressure

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A novel procedure was developed using pressure-sensitive Fuji film to study the contact areas and pressures within the wrist joint in a variety of conditions. These studies included comparing wrist contact pressures under various loads, ligament injuries, fracture patterns and surgical procedures. These studies revealed that the areas of increased load coincide with where joint space narrowing and arthritis develop. These early contact area and pressure studies led to further development of new techniques to visualize the complex mechanics of joint systems.

Functional Measurement and Biomechanics

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Joint mechanics, physiologic systems, and the evaluation of surgical techniques and practices became an ever-expanding focus of the lab. These projects included comparative functional anatomy using human cadaver specimens, such as excursion measurement of the intrinsic tendons of the wrist, and muscle mechanics and balance of the knee before and after total knee replacement surgery. The lab also obtained a Microscribe probe which enabled direct 3D mapping of joint surfaces at the time more accurate than CT reconstructions.

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Various joint measurements in patient and volunteer populations were also a key focus. This included measuring the torque range of motion about the ankle, wrist and digits, as well as motion capture of discrete movements such as reaching, grasping, dart throwing, deep knee flexion and cutting movements in sports.

Biomechanical testing of physiologic systems (soft tissue, bone, tendons, cartilaginous structures, muscle systems) and the prosthetic and/or implant devices that enhance, correct, or rehabilitate these systems became a foundation of laboratory research after upgrading our materials testing system in 1999 to an MTS 858 Mini-Bionix. This new bi-axial system allowed us to perform a wide variety of biomechanical studies, including internal fixation techniques, tendon rupture repair, fracture management, ligament reconstruction mechanics, fracture mechanics of bone, and photoelastic measurement of surface strain, to name a few.

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3D Anatomic Reconstruction

Custom programming was developed in the Orthopaedic Biomechanics Lab to study 3D models of skeletal anatomy based on 2D CT scans. This technique involved edge identification and contouring of the cortical bone from individual CT images, assemblage, and final surface tiling and shading to create an accurate and quantifiable reproduction of the bone or joint. While this type of imaging is routine and automatic with medical imaging systems today, the development of these techniques at the time led to further expansion in the area of computational biomechanics and 3D kinematics.

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Motion Analysis and Kinematics

By combining the 3D reconstructions of a joint system with motion capture analysis of each individual bone in that joint system, the lab greatly expanded its capacity for investigating the mechanics of the joint in normal, diseased, and surgically altered conditions. In these cadaveric studies, a six camera motion capture system was used to track the motion of reflective marker triads inserted directly into the bones of interest. CT scans obtained before and after motion capture were used to reconstruct the individual bones along with the reflective markers allowing visualization of instantaneous screw axes, the changing positions of one bone relative to another, the proximity between two bones, and the inferred contact within given ranges.

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Musculoskeletal Simulation


The previous computational methods and laboratory studies provided the requisite analytical detail to develop a mathematical and computer simulation of the musculoskeletal system. This simulation was a major effort which culminated in a real time, interactive, 3D computer graphics model of the human body. The core structures of the simulation were built from CT scans obtained in the lab over many years, and now also includes complete skeletal reconstructions of the the Visible Human male and female.

In order to obtain a visual and quantitative verification of the appropriateness of one, two, and three degree of freedom models for motion, we developed an interactive system for the independent adjustment and definition of multiple degree-of-freedom linkage systems representative of human leg and arm motion. The system was built so that once the kinematic structure was defined, control points for interactive definition of muscle-tendon and ligament paths could be manually adjusted and refined, providing a tool for interactive musculoskeletal modeling and simulation.

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All kinematic transformation nodes were built as linkages within an openGL hierarchical structure. The structure for independent adjustment of each axis of motion required tracking the inverse of all transformations applied to the axis during visualization and adjustment. The inverse is applied to all structures below the axis of interest so that only the axis is effected during 3D adjustment. The system allows for the visual adjustment and verification of the placement of an axis or axes. This interactive task is carried out through control of the point of view by observer, the position and orientation of the view, and the position and orientation of each axis. These dynamic view and control commands are carried out simultaneously with rotational control of distal joint segments about their defined axis or axes. With such immediate and interactive flexibility, the user is able to rapidly iterate upon appropriate axis placement based upon a 3D visual verification of joint congruence throughout joint range-of-motion.

Selected Publications

  • Viegas SF, Patterson RM, Tencer A, Peterson P, Roefs J, Choi S. The Effects of Various Load Paths and Different Loads on the Load Transfer Characteristics of the Wrist. J. Hand Surgery, 14A:458-465, May 1989.
  • Viegas SF, Rimoldi R, Patterson RM. A Modified Technique of Intramedullary Fixation for Wrist Arthrodesis. J. Hand Surgery, 14A:618-623, 1989.
  • Viegas SF, Patterson RM, Peterson PD, Pogue DJ, Jenkins DK, Sweo TD, Hokanson, JA. The Evaluation of the Biomechanical Efficacy of Limited Intercarpal Fusions for the Treatment of Scapho-Lunate Dissociation. J. Hand Surgery, 15A(1):120-128, January 1990.
  • Viegas SF, Patterson RM, Peterson PD, Pogue DJ, Jenkins DK, Sweo TD, Hokanson JA. Ulnar Sided Perilunate Instability: An Anatomic, Biomechanic, and Clinical Study. J. Hand Surgery, 15A(2):120-128, March 1990.
  • Viegas SF, Wagner K, Patterson RM, Peterson PD. The Medial (Hamate) Facet of the Lunate. J. Hand Surgery, 15A:564-571, 1990.
  • Viegas SF, Pogue DJ, Patterson RM, Peterson PD. The Effects of Radioulnar Instability on the Wrist: A Biomechanical Study. J. Hand Surgery, 15(5):728-732, September 1990.
  • Pogue DJ, Viegas SF, Patterson RM, Peterson PD, Jenkins DK, Sweo TD, Hokanson JA. The Effects of Distal Radius Fracture Malunion on Wrist Joint Mechanics. J. Hand Surgery, 15(5):721-727, September 1990.
  • Viegas SF, Patterson RM, Peterson PD, Crossley M, Foster RA. The Silicone Scaphoid: A Biomechanical Study. J. Hand Surgery, 16(1):91-97, 1991.
  • Viegas SF, Patterson RM, Hillman GR, Peterson PD, Crossley M, and Foster RA. The Simulated Scaphoid Proximal Pole Fracture: A Biomechanical Study. J. Hand Surg., 16A:495-500,1991.
  • Viegas SF, Patterson RM, Todd P, McCarty P. Load Transfer Characteristics of the Midcarpal Joint. J. Hand Surgery, 18A:14-18, January 1993.
  • Viegas SF, Hillman G, Elder K, Stoner D, Patterson RM. Measurement of Carpal Bone Geometry by Computer Analysis of 3-D CT Images. J. Hand Surgery, 18A(2): 341-349, March 1993.
  • Viegas SF, Patterson RM, Hokanson JA, Davis J. Wrist Anatomy: Incidence, Distribution and Correlation of Anatomy, Tears and Arthritis. J. Hand Surgery, 18A:463-475, May 1993.v
  • Tagare HD, Elder KW, Stoner DM, Patterson RM, Nicodemus CL, Viegas SF, Hillman GR. Location and Geometric Description of Carpal Bones in CT Images. Annals of Biomedical Engr. 21:715-726, 1993.
  • Viegas SF, Patterson RM, Ward K. Extrinsic Wrist Ligaments in the Pathomechanics of Ulnar Translation Instability. J. Hand Surgery, 20A(2):312-318, March 1995.v
  • Patterson RM, Viegas SF, Elder K, Buford WL, Jr. Quantification of Anatomic, Geometric, and Load Transfer Characteristics of the Wrist Joint. J. Arthroplasty, 6(1):13-19, January 1995.
  • Patterson RM, Viegas SF. Biomechanics of the Wrist, J. Hand Therapy, 8(2):97-105, June/April 1995.
  • Patterson RM, Elder KW, Viegas SF, Buford WL, Jr. Carpal Bone Anatomy Measured by Computer Analysis of 3D Reconstructions of CT Images. J. Hand Surgery, 20A(6):923-929, November 1995.
  • Patterson RM, Nicodemus CL, Viegas SF, Elder KW, Rosenblatt J. Normal Wrist Kinematics and the Analysis of the Effect of Various Dynamic External Fixators for Treatment of Distal Radius Fractures. Hand Clinics, 13(1):129-142, February, 1997.
  • Viegas SF, Patterson RM. Load Mechanics of the Wrist. Hand Clinics13(1):109-128, February, 1997.
  • Patterson RM, Nicodemus CL, Viegas SF, Elder KW, Rosenblatt J. High Speed, Three Dimensional Kinematic Analysis of the Normal Wrist. J. Hand Surg., 23A(3):446-453, May 1998.
  • Yamaguchi S, Viegas SF, Patterson RM. Anatomic Study of the Pisotriquetral Joint: Ligament Anatomy and Cartilaginous Change. J. Hand Surgery, 23A(4):600-606, July 1998.
  • Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The Dorsal Ligaments of the Wrist: Anatomy, Mechanical Properties, and Function. J. Hand Surgery, 24A (3): 456-458, May 1999.
  • Self J, Viegas SF, Buford WL, Jr, Patterson RM. A comparison of double plate internal fixation methods for complex distal humerus fractures. J. Shoulder Elbow Surg. 4(1) Part 1:10-16; January/February 1995.
  • Patterson RM, Viegas SF, Elder K, Buford WL, Jr. Quantification of anatomic, geometric, and load transfer characteristics of the wrist joint. Semin in Arthrop. 6(1):13-19; January 1995.
  • Patterson RM, Viegas SF, Elder KW, Buford WL, Jr. Treatment of distal radius fractures using 3D kinematic analysis. Orthopaedic Transactions. 1997.
  • Buford WL, Jr, Ivey FM, Malone JD, Patterson RM, Pear G, Nguyen D, Stewart AA. Muscle balance at the knee-moment arms for the normal knee and the ACL minus knee. Trans. on Rehab. Engineering. 5(4):367-379; December 1997.
  • Grecula MJ, Morris RP, Laughlin JC, Buford, WL, Jr, Patterson RM. Femoral surface strain in intact composite femurs: A custom computer analysis of the photoelastic coating technique. IEEE Tran. Biomed. Eng. 47(7):926-33; July 2000.
  • Buford WL, Jr, Ivey FM, Nakamura T, Patterson RM, Nguyen D. Internal/External rotation moment arms of muscles at the knee-moment arms for the normal knee and the ACL-deficient knee. The Knee. 8(4):293-303; October 2001.
  • Andersen CR, Buford WL, Jr. The three-dimensional parametric ellipses. J. of graphics tools. 6(3):45-48; 2001.
  • Shah MA, Buford WL, Jr, Viegas SF. Effects of EPL Release and EIP transfer on thumb mechanics. J. of Venezuelan Soc. for Surg. of the Hand. 3(2):31; 2002.
  • Brown NA, Pandy MG, Buford WL, Jr, Kawcak CE, McIlwraith CW. Moment arms about the carpal and metacarpalphalangeal joints for flexor and extensor muscles in Equine Forelimbs. Am. J. of Veterinary Res. 64(3):351-357; March 2003.
  • Shah MA, Buford WL, Jr, Viegas SF. Effects of extensor pollicus longus transposition and extensor indicis proprius transfer to extensor pollicis longus on thumb mechanics. Am J. Hand Surg. 28 (4):661-668; July 2003.
  • Patterson RM, Moritomo H, Yamaguchi S, Mitsuyasu H, Shah M, Buford WL, Jr, Viegas SF. Scaphoid anatomy and mechanics: Update and Review. Oper. Tech. in Ortho. 13:2-10; 2003.
  • Yoshida R, Shah MA, Patterson RM, Buford, WL, Jr, Knighten J, Viegas SF. Anatomy and pathomechanics of ring and small finger carpometacarpal joint injuries. J. Hand Surg. American Volume. 28(6):1035-43; November 2003.
  • Osada D, Viegas SF, Morris RP, Patterson RM. Comparison of different distal radius fracture fixation plates: A biomechanical study. J. Hand Surg. 28A(1):94-104; January 2003.
  • Mitsuyasu H, Patterson RM, Shah MA, Buford WL, Jr, Viegas SF. The role of the dorsal intercarpal ligament in dynamic and static scapholunate instability. Am. J. Hand Surg. 29(2):279-88; March 2004.
  • Trevino SG, Buford WL, Jr, Nakamura T, Wright AJ, Brown S, Patterson RM. Objective differentiation of the adult diabetic foot and adult normal foot using a torque-range-of-motion device. Foot and Ankle International. 25(8), 561-567; August 2004.
  • Patterson RM, Moritomo H, Yamaguchi S, Mitsuyasu H, Shah M, Buford, WL, Jr, Viegas SF. Scaphoid anatomy and mechanics: update and review. Atlas of the hand clinics: disorders of the wrist. 9:129-140; 2004.
  • Nagao S, Buford WL, Jr, Andersen CR, Shah MA, Viegas SF. Three-dimensional description of ligamentous attachments around the lunate. J. Hand Surg. (4):685-92; July 30, 2005.
  • Buford WL, Jr, Koh S, Andersen CR, Viegas SF. Understanding intrinsic-extrinsic muscle function through interactive 3D kinematic simulation. J. Hand Surg., 30a(6):1267-1275; November 2005.
  • Koh S, Andersen CR, Buford WL, Jr, Patterson RM, Viegas SF. Anatomy of the distal brachioradialis and its potential relationship to distal radius fracture. Am. J. Hand Surg. 31(1):2-8; January 2006.
  • Iwamoto A, Morris RP, Andersen CR, Patterson RM, Viegas SF. An anatomical and biomechanical study of the wrist extensor retinaculum septa and tendon compartments. J. Hand Surg. 31(6):896-903; July 2006.
  • Bu J, Patterson RM, Morris RP, Yang J, Viegas SF. The effect of radial shortening on wrist joint mechanics in cadaver specimens with naturally occurring differences in ulnar variance. J. Hand Surg. [Am] (10):1594-600; December 31, 2006.
  • Koh S, Morris RP, Patterson RM, Kearney JP, Buford WL, Jr, Viegas SF. Intrinsic Muscle Contribution to the Metacarpophalangeal Joint Flexion Moment of the Middle, Ring, and Little Fingers. Am J. of Hand Sur, Sep, 31(7):1111-7, 2006.
  • Koh S, Morris RP, Patterson RM, Kearney JP, Buford WL, Jr., Viegas SF. Volar fixation for dorsally angulated extra-articular fractures of the distal radius: A biomechanical study. J. of Hand Surg. [Am] 31(5):771-9; May 2006.
  • Nanno M, Buford WL, Jr, Patterson RM, Andersen CR, Clark R, Viegas SF. Three-dimensional analysis of the ligamentous attachments of the first carpometacarpal joint. J of Hand Surgery, 31(7), 1160-70, Sep 2006.
  • Conner CS, Morris RP, Vallurupalli S, Buford WL, Ivey FM. Tensioning of anterior cruciate ligament hamstring grafts: comparing equal tension versus equal stress.” Arthroscopy, Dec; 24(12):1323-9. Epub 2008 Aug 30. PMID: 19038701 [PubMed ], 2008.
  • Alemohammad AM, Yazaki N, Morris RP, Buford WL, Viegas SF. Thumb interphalangeal joint extension by the extensor pollicic brevis: association with a subcompartment and de Quervain’s disease. J. Hand Surgery Am., Apr, 34(4):719-23, 2009.
  • Trevino SG, Buford WL, Vallurupalli S, Rowell M, Panchbhavi VK. Use of patient-controlled stretching devoice to improve the ankle range of motion. Foot and Ankle Int., Feb, 30(2):110-4, 2009.
  • Conner CS, Perez BA, Morris RP, Buckner JW, Buford WL, Jr, Ivey FM. Three Femoral Fixation Devices for Anterior Cruciate Ligament Reconstruction: Comparison of Fixation on the Lateral Cortex Versus the Anterior Cortex. Arthroscopy. 2010 Jun;26(6):796-807, Apr 24, 2010.
  • Panchbhavi VK, Vallurupalli S, Morris RP, Patterson RM. The use of calcium sulfate and calcium phosphate composite graft to augment screw purchase in osteoporotic ankles. Foot and Ankle Intl. (6):593-600; June 29, 2008.
  • Yazaki N, Burns ST, Morris RP, Andersen CR, Patterson RM, Viegas SF. Variations of capitate morphology in the wrist. The Journal of Hand Surg. 33(5):660-666N; 2008.
  • Conner CS, Perez BA, Morris RP, Buckner JW, Buford WL Jr, Ivey FM. Three femoral fixation devices for anterior cruciate ligament reconstruction: comparison of fixation on the lateral cortex versus the anterior cortex. Arthroscopy. 2010 Jun;26(6):796-807.

Former Research Fellows

  • Marc El Beaino, MD, MSc, 2017-2019
  • Laura Wu, BS, 2016-2017
  • Andrew Patton, MD, 2014-2015
  • Shelton McKenzie, MD, 2013-2014
  • Santaram Valiparulli, MD, 2006-2008
  • Amir Alemohammad, MD, 2007-2008
  • Naoya Yazaki, MD, 2006-2007, Nagoya University, Japan
  • Geetinder Goyal, MD, 2005-2006, Punjab University, Chandigarh, India
  • Mitsuhiko Nanno, MD PhD, 2005-2006, Nippon Medical School, Tamanagayama Hospital, Tokyo, Japan
  • Akira Iwamoto, MD, 2004-2005, Dokkyo University School of Medicine, Tochigi, Japan
  • Janli Bu, MD, 2004-2005
  • Archana Sangole, PhD, 2004
  • Shukuki Koh, MD, 2003-2005, Nagoya University School of Medicine, Nogoya, Japan
  • Soya Nagao MD, 2002-2003, Nihon Univ. School of Medicine, Tokyo, Japan
  • Ryo Yoshida, MD, 2001-2002, St. Marianna University School of Medicine, Kawasaki, Japan
  • Hiromichi Mitsuyasu, MD, 2001-2002, Kyushu University, Fukuoka, Japan
  • Muhammad Jawaid Meraj, MD, 2001-2001, The Aga Khan University Hospital, Stadium Road, Karachi, Pakistan
  • Maria Angelica Orellana, MD, University of Buenos Aires, Buenos Aires, Argentina
  • Maged El-shennawy, MD, 1999-2001, Mansoura University Hospital, El-Mansoura, Egypt
  • Denju Osada, MD, 2000-2001, Dokkyo University School of Medicine, Tochigi, Japan
  • Koji Nakamura, MD, 1998-2000, St. Marianna University School of Medicine, Kawasaki, Japan
  • Hisao Moritomo, MD, 1998-1999, Kansai Rosai Hospital, Amagasaki City, Japan.
  • Johan Carel Goslings, MD PhD, 1998-1990, Surgical Resident Academic Medical Centre, Amsterdam, The Netherlands
  • Satoshi Yamaguchi MD, 1996-1998, St. Marianna University School of Medicine, Kawasaki, Japan
  • Andre Ayalla Rodrigues, MD, 1998-1999, Faculdade de Ciencias Medicas-Universidade de Pernambuco (discipline of orthopedic), Brazil
  • Emiko Horii, MD, 1994, Nagoya University, Nagoya Japan
  • Fan Li, MD; 1992-96