Paralympic athlete runningClare Small 106 and 111
phone: 303-492-0926
fax: 303-492-4009

Research Interests

  • The biomechanical and metabolic effects of lower limb prostheses and exoskeletons on walking, running, hopping, jumping, bicycling, and sprinting.


  • Director: Alena Grabowski, PhD.
  • Postdoctoral Fellows: Janet Zhang, PhD.
  • Graduate Students:  Stephen Allen, Kara Ashcraft, Zane Colvin, Gabriela Diaz, Caelyn Hirschman, Josh Tacca
  • Collaborators: Christopher Arellano, Ph.D., Brown University; William Byrnes, Ph.D., University of Colorado Boulder; Susan D'Andrea, Ph.D., Providence VAMC; Hugh Herr, Ph.D., Massachusetts Institute of Technology; Trevor Kingsbury, Ph.D. Naval Medical Center San Diego; Rodger Kram, Ph.D., University of Colorado Boulder; William McDermott, Ph.D., The Orthopedic Specialty Hospital, Utah; Craig McGowan, Ph.D., University of Idaho; Justus Ortega, Ph.D., Humboldt State University; Mark Rentschler, Ph.D., University of Colorado Boulder; Anne Silverman, Ph.D., Colorado School of Mines.

ABL Lab 2022

(L to R): Stephen Allen, Josh Tacca, Caelyn Hirschman, Janet Zhang, Zane Colvin, Gabriela Diaz, Kara Ashcraft, Alena Grabowski.

Current Research Projects

  • What is the optimal model, stiffness, and height of a running-specific leg prosthesis? (Tacca, Grabowski)
  • Can sensory feedback training improve the biomechanical and metabolic effects of using passive or powered lower limb prostheses during walking for Veterans with transtibial amputations? (Hirschman, Zhang, Grabowski)
  • How do lower limb prosthetic stiffness and power affect the biomechanics, metabolic costs, and satisfaction of Veterans with transtibial amputations during walking?” (Colvin, Tacca, Grabowski)
  • Understanding the effects of a springy leg exoskeleton during hopping and running (Allen, Tacca, Grabowski)
  • What is the optimal stiffness of a pediatric prosthetic foot? (Ashcraft, Grabowski)
  • How does in-series or running-specific prosthetic stiffness affect long jump performance? (Ashcraft, Grabowski)
  • How does use of a running-specific leg prosthesis affect curve-running performance? (Alcantara, Diaz, Grabowski)
  • Optimizing orthotic and prosthetic components for military women with limb salvage or amputation. (Ashcraft, Grabowski)
  • Optimizing prosthetic and bicycle fit for Veterans with transtibial amputations (Allen, Grabowski)
  • Improving Socket fit in Veterans with transtibial and transfemoral amputations (Diaz, Grabowski)

Opportunities for Undergraduates

The requirements for undergraduate students who would like research experience in our Lab are:

  • Completed at least one year in college.
  • Will be at CU for at least two more semesters.
  • Available for 8-10 hours of time per week in blocks of 2-4 hours at a time.
  • IPHY, MCDB, PSYCH, Applied Math, and Engineering majors are encouraged.

For more information, contact Prof. Alena Grabowski ( Unfortunately, due to high demand, we cannot accommodate all qualified students.

Recent Publications

  • KR Ashcraft & AM Grabowski. Characterizing the Mechanical Stiffness of Passive-Dynamic Ankle-Foot Orthosis Struts. Front Rehab Sci, Published 15 April 2022
  • ON Beck, P Taboga, & AM Grabowski. Sprinting with prosthetic versus biological legs: insight from experimental data. Royal Society Open Science Published 2022-1-5
  • RS Alcantara, WB Edwards, GY Millet, & AM Grabowski. Predicting continuous ground reaction forces from accelerometers during uphill and downhill running: A recurrent neural network solution. PeerJ Published Jan. 4, 2022
  • RS Alcantara. EM Day, ME Hahn, & AM Grabowski. Sacral acceleration can predict whole-body kinetics and stride kinematics across running speeds. PeerJ Published 2021-04-12 DOI 10.7717/peerj.11199
  • EM Day, RS Alcantara, MA McGeehan, AM Grabowski, & M Hahn. Low-pass filter cutoff frequency affects sacral-mounted inertial measurement unit estimations of peak vertical ground reaction force and contact time during treadmill running. Journal of Biomechanics 119, 110323 (2021)
  • X Hu, NT Pickle, AM Grabowski, AK Silverman, SS Blemker. Muscle Eccentric Contractions Increase in Downhill and High-Grade Uphill Walking. Frontiers in Bioengineering and Biotechnology, section Biomechanics 14 October 2020
  • E Etenzi, R Borzuola, & AM Grabowski. Passive-elastic knee-ankle exoskeleton reduces the metabolic cost of walking. Journal of Neuroengineering and Rehabilitation 17, 104 (2020).
  • RS Alcantara, ON Beck, & AM Grabowski. Added lower limb mass does not affect biomechanical asymmetry but increases metabolic power in runners with a unilateral transtibial amputation. European Journal of Applied Physiology 2020.
  • CZ Zai & AM Grabowski. The metabolic power required to support body weight and accelerate body mass changes during walking on uphill and downhill slopes. Journal of Biomechanics 103, 2020
  • P Taboga, ON Beck, & AM Grabowski. Prosthetic configuration affects top sprinting speeds of athletes with bilateral transtibial amputations. Plos One Published: February 20, 2020.
  • P Taboga, EK Drees, ON Beck, & AM Grabowski. Prosthetic model, but not stiffness or height, affects maximum running velocity in athletes with unilateral transtibial amputations. Nature Scientific Reports 2020 10:1763 1;
  • LA Davis, SP Allen, LD Hamilton, AM Grabowski, & RM Enoka. Differences in postural sway among healthy adults are associated with the ability to perform steady contractions with leg muscles. Experimental Brain Research 2020
  • SP Allen & AM Grabowski. Hopping with degressive spring stiffness in a full-leg exoskeleton lowers metabolic cost compared with progressive spring stiffness and hopping without assistance. Journal of Applied Physiology 2019 127: 520–530
  • J Funken, S Willwacher, K Heinrich, R Müller, H Hobara, AM Grabowski, & W Potthast. Long jumpers with and without a transtibial amputation have different 3D centre of mass and joint take-off step kinematics. Journal of the Royal Society Open Science Published: 17 April 2019 6: 190107.  
  • H Hobara, S Hashizume, J Funken, S Willwacher, R Müller, AM Grabowski, & W Potthast. Vertical stiffness during one-legged hopping with and without using a running-specific prosthesis. Journal of Biomechanics 2019 86: 34-39.
  • J Funken, S Willwacher, K Heinrich, R Müller, H Hobara, AM Grabowski & W Potthast. Three dimensional take-off step kinetics of long jumpers with and without a transtibial amputation. Medicine and Science in Sports and Exercise 2019 Apr 51 (4): 716-725.
  • ON Beck & AM Grabowski. Athletes with Versus Without Leg Amputations: Different Biomechanics, Similar Running Economy. Exercise and Sport Sciences Reviews Published online 2019 Jan 47 (1): 15-21. doi: 10.1249/jes.0000000000000174