Carolyn M. Eng

Muscle and Connective Tissue Physiology

I am broadly interested in the influence of elastic connective tissues on the energetics and mechanics of movement. Elastic connective tissues play a vital role in transmitting dynamic force and length changes from muscle to the skeleton and have a profound influence on muscle mechanics and energetics. Stretchy connective tissues including tendons, aponeuroses, and fascia are found throughout the body and are in close association with muscles. While the many functions of tendon are well described, only recently have we begun to understand the complex strain patterns in planar, sheet-like connective tissues such as fascia and aponeurosis. Many muscles in the limbs are attached to or enveloped by fascia, and whole muscle compartments are often covered in fascia. However, whether aponeuroses and fascia serve a function beyond just connecting and dividing structures in the musculoskeletal system is not well understood. My research combines anatomical studies, musculoskeletal models, and experimental animal models of connective tissue and muscle physiology to answer questions about how planar connective tissues function in the body and how they influence the forces and length changes transmitted from muscle.


Curvature-induced stiffening of the human foot

Using modeling and cadaveric measurements, I showed that transverse curvature stiffens the human foot through bending-stretching coupling.

The role of connective tissues in dynamic muscle gearing

I performed detailed muscle measurements to explore muscle gearing and its dynamic modulation.

In vivo evidence of fascia elastic energy storage

I used a goat model to perform in vivo tests of whether the goat fascia lata stores and recovers elastic energy.

Elastic properties of the iliotibial band (ITB) in human locomotion

I investigated the ITB’s role in locomotion and determined that the ITB elastically stores and recovers elastic energy during walking and running.

The evolution of the iliotibial band

Using chimpanzees as a comparison to humans, I found that the human ITB potentially stores up to 15 to 20 times more elastic energy than the chimpanzee fascia lata.

Rat muscle function

I used in vivo measures of muscle fiber length change, muscle force and muscle activity in rat triceps surae muscles to explore how muscle mechanics are modulated with gait and grade.


My complete CV is available here: Carolyn_Eng_CV.pdf

Peer-reviewed publications

  1. Venkadesan M, Yawar A, Eng CM, Dias MA, Singh DK, Tommasini SM, Haims AH, Bandi MM, Mandre S. Stiffness of the human foot and the evolution of the transverse arch. Nature 2020; 579: 97-100.
  2. Eng CM, Konow N, Tijs C, Holt NC, Biewener AA. In vivo force–length and activation dynamics of two distal rat hindlimb muscles in relation to gait and grade. Journal of Experimental Biology 2019; 222: 1-13.
  3. Roberts TJ, Eng CM, Sleboda DS, Holt NC, Brainerd E, Stover KS, Marsh RL, Azizi E. The multi-scale, three-dimensional nature of skeletal muscle contraction. Physiology 2019; 34(6): 402-408.
  4. Eng CM, Azizi E, Roberts TJ. Structural determinants of muscle gearing during dynamic contractions. Integrative and Comparative Biology 2018; 52(2): 207-218.
  5. Eng CM, Roberts TJ. Aponeurosis influences the relationship between muscle gearing and force. Journal of Applied Physiology 2018; 125: 513-519.
  6. Eng CM, Arnold AS, Lieberman DE, Biewener AA. The capacity of the human iliotibial band to store elastic energy during running. Journal of Biomechanics 2015a; 48: 3341-3348.
  7. Eng CM, Arnold AS, Biewener AA, Lieberman DE. The human iliotibial band is specialized for elastic energy storage compared with the chimp fascia lata. Journal of Experimental Biology 2015b; 218: 2382-2393.
  8. Eng CM, Pancheri FQ, Lieberman DE, Biewener AA, Dorfmann L. Directional differences in the biaxial material properties of fascia lata and the implications for fascia function. Annals of Biomedical Engineering 2014; 42(6): 1224-1237.
  9. Pancheri FQ, Eng CM, Lieberman DE, Biewener AA, Dorfmann L. A constitutive description of the anisotropic response of the fascia lata. Journal of the Mechanical Behavior of Biomedical Materials 2014; 30: 306-323.
  10. Mathewson MA, Kwan A, Eng CM, Lieber RL, Ward SR. Comparison of rotator cuff muscle architecture among humans and selected vertebrate species. Journal of Experimental Biology 2014; 217:261-273.
  11. Eng CM, Lieberman DE, Zink KD, Peters MA. Bite force and occlusal stress production in hominin evolution. American Journal of Physical Anthropology 2013; 151: 544-557.
  12. Ward SR, Sarver JJ, Eng CM, Kwan A, Wuergler-Hauri CC, Perry SM, Williams GR, Soslowsky LJ, Lieber RL. Plasticity of muscle architecture after supraspinatus tears. Journal of Orthopaedic & Sports Physical Therapy 2010; 40(11): 729-735.
  13. Eng CM, Ward SR, Vinyard CJ, Taylor AB. The morphology of the masticatory apparatus facilitates muscle force production at wide jaw gapes in tree-gouging common marmosets (Callithrix jacchus). Journal of Experimental Biology 2009; 212: 4040-4055.
  14. Taylor AB, Eng CM, Anapol F, Vinyard CJ. The functional correlates of jaw-muscle fiber architecture in tree-gouging and nongouging callitrichid monkeys. American Journal of Physical Anthropology 2009; 139(3): 353-367.
  15. Ward S.R., Eng CM, Smallwood LR, Lieber RL. Are current measurements of lower extremity muscle architecture accurate? Clinical Orthopaedics and Related Research 2009; 467: 1074-1082.
  16. Ward SR, Kim CW, Eng CM, Gottschalk LJ, Tomiya A, Garfin SR, Lieber RL. Architectural analysis and intraoperative measurements demonstrate the multifidus’ unique design for lumbar spine stability. Journal of Bone and Joint Surgery 2009; 91: 176-185.
  17. Eng CM, Smallwood LH, Rainiero MP, Lahey M, Ward SR, Lieber RL. Scaling of muscle architecture and fiber types in the rat hindlimb. Journal of Experimental Biology, 2008; 211: 2336-2345.
  18. Eng CM, Abrams GD, Smallwood LH, Lieber RL, Ward SR. Muscle geometry affects accuracy of forearm volume determination by magnetic resonance imaging (MRI). Journal of Biomechanics 2007; 40: 3261-3266.

Book chapters

  1. Taylor AB, Anapol FC, Eng CM, Vinyard CJ. The functional significance of jaw-muscle fiber architecture in tree-gouging callitrichids. In The Smallest Anthropoids: The Marmoset/Callimico Radiation. Davis LC, Ford SM, Porter LM (Eds.), New York: Springer, 2009.
  2. Taylor AB, Anapol F, Eng CM, Vinyard CJ. The relationship between jaw-muscle fiber architecture and feeding behavior in primates: Tree-gouging and nongouging gummivorous callitrichids as a natural experiment. In Primate Craniofacial Function and Biology. Vinyard CJ, Ravosa MJ, Wall CE (Eds.), New York: Springer, 2008.


Carolyn Eng