David A. Brown, PT, PhD
Professor and Program Director PhD in Rehabilitation Science
Office Phone: 205-975-2788
Office Fax: 205-975-7787
Office Location: SHPB 384
Department(s) and Affiliations
Physical Therapy; Occupational Therapy
Areas of Research
Motor Control; Movement & Rehabilitation; Neuromuscular Control of Locomotion; Rehabilitation Robotics
Focus of Research
The focus of the work in his Locomotor Control and Rehabilitation Robotics Laboratory, better known as the LocoLab, is directed towards the understanding of neuromusculoskeletal control during active movement in persons with individuals post-stroke. In particular, studies seek to understand the control mechanisms underlying locomotor behavior in persons with post-stroke hemiplegia. Related to this objective, the work is attempting to understand underlying mechanisms of poor control and to develop quantitative evaluation and intervention tools for the amelioration of locomotor deficits post-stroke. The experimental approach includes measurement of electrical muscle activity, lower limb force and movement trajectories, and electro-physiological reflex testing during cyclical locomotor movements such as walking and pedaling.
Current projects with post-stroke populations involve examination of spinal reflex modulation during locomotion, the study of motor adaptation to specific biomechanical constraints, and the development of a new framework for identifying specific locomotor impairments that result in walking dysfunction. Past and current funding sources include NIH, NIDRR, VA, and Foundation for Physical Therapy.
We have developed a laboratory apparatus, based on a bicycle ergometer that allows the systematic study of functional impairments post-stroke. This device enables the researcher to measure, during the pedaling task, weakness in paretic muscles, limb loading capability, speed of movement, lateral balance stability, and rhythmic muscle activity. Several studies have been completed that have shown the importance of addressing each of these impairments during the retraining of walking ability.
We have also developed, in collaboration with Drs. Michael Peshkin and Ed Colgate in the McCormick School of Engineering at Northwestern University, a new collaborative robotics system, the KineAssist Gait and Balance System. This system allows the study of balance and postural responses to challenging functional tasks such as climbing stairs, stepping over hurdles, walking on slippery surfaces, and forward/backward pushes.
Recent and Selected Publications
Alibiglou L, Brown DA: Relative temporal leading or following position of the contralateral limb generates different aftereffects in muscle phasing following adaptation training post-stroke. Exp Brain Res. May;211(1):37-50, 2011. Epub 2011 Apr 6. PMID: 21523333
Rogers LM, Stinear JW, Lewis GN, Brown DA. Descending control to the non-paretic limb degrades the cyclic activity of paretic leg muscles. Hum Mov Sci. Dec;30(6):1225-44, 2011. Epub 2011 May 20. PMID: 21601300
Alibiglou L, Brown DA: Impaired muscle phasing systematically adapts to varied relative angular relationships during locomotion in people poststroke. J Neurophysiol. 2011 Apr;105(4):1660-70. Epub 2011 Feb 9. PMID: 21307323
Rogers LM, Brown DA, Stinear J: The effects of paired associative stimulation on knee extensor motor excitability of individuals post stroke: a pilot study. Clin Neurophysiol. Jun;122(6):1211-8, 2011. Epub 2010 Dec 3. PMID: 21130032
Capewell, R.A, Brown, DA, Rockefeller, K. Evaluation of a tool kit for safe patient handling in the homecare setting. American Journal Safe Patient Handling & Movement, 1( 1,) 22-29, 2011.
Burgess JK, Weibel GC, Brown DA: Overground walking speed changes when subjected to body weight support conditions for nonimpaired and post stroke individuals. J Neural Engr Rehab 7:6, 2010. PMID: 20149244
Mulroy SJ, Klassen T, Gronley JK, Eberly, V, Brown DA, Sullivan, KJ: Gait parameters associated with responsiveness to a body weight supported treadmill training program in individuals post-stroke: An exploratory study. Physical Therapy, 90 (2): 209-223. 2010. Epub 2009 Dec 18. PMID: 20022996
Alibiglou L, López-Ortiz C, Walter CB, Brown DA: Bilateral limb phase relationship and its potential to alter muscle activity phasing during locomotion. J Neurophysiol. 102(5):2856-65. 2009. Epub2009 Sep 9. PMID: 19741107
Schindler-Ivens S, Brown DA, Lewis GN, Nielsen JB, Ondishko KL, and Wieser J.: Soleus H-reflex excitability during pedaling post-stroke. Exp Brain Res. 188(3):465-74. 2008. Epub 2008 Apr 22. PMID: 18427793
Patton J, Lewis E, Crombie G, Peshkin M, Colgate E, Santos J, Makhlin A, and Brown DA: A novel robotic device to enhance balance and mobility training post-stroke. Topics in Stroke Rehabilitation 15.2: 131-9. 2008.
Winstein CJ, Pate P, Ge T, et al; for the Physical Therapy Clinical Research Network (PTClinRes-Net) [Brown DA 8th author]. Physical Therapy Clinical Research Network (PTClinResNet): Methods, efficacy and benefits of a rehabilitation research network. Am J Phys Med Rehabil. 87(11):937-50. 2008. PMID: 18174846
Ryerson S, Brown DA, Hidler J: Altered trunk position sense and its relation to balance functions in people post-stroke. J Neurol Phys Ther. 32(1):14-20. 2008. PMID: 18463551
Schindler-Ivens S, Desimone D, Grubich S, Kelley C, Sanghvi N, and Brown DA: Lower extremity passive range of motion in community-ambulating stroke survivors. J Neurol Phys Ther. 32(1):21-31. 2008. PMID: 18463552
Sibley KM, Tang, A, Brooks D, Brown DA, and McIlroy WE: Feasibility of adapted aerobic cycle ergometry tasks to encourage paretic limb use after stroke: a case series. J Neurol Phys Ther. 2008 Jun;32(2):80-7. PMID: 18645295
Sullivan KJ, Brown DA, Klassen T, et al; for the Physical Therapy Clinical Research Network (PTClinRes-Net). Effects of task-specific locomotor and strength in training ambulatory adults after stroke: results of the STEPS randomized clinical trial. Phys Ther. 87(12):1580-602. 2007. Epub 2007 Sep 25. PMID: 17895349
Brown, DA, Nagpal, S., Chi, S. Limb-loaded cycling program for locomotor intervention post-stroke. Physical Therapy 85:159-68, 2005. PMID: 15679467
Schindler-Ivens, S., Brown, DA, Brooke, J.D. Direction-Dependent Phasing of Locomotor Muscle Activity is Altered Post-Stroke. J Neurophysiol. 92:2207-16, 2004. Epub 2004 Jun 2. PMID: 15175363
Jaffe, D., Brown, DA, Buckley, E., Pierson-Carey, C., Lew, H.L. Stepping over obstacles to improve walking in individuals with poststroke hemiplegia. J. Rehab. Res. Develop. 41:283-292. 2004. PMID: 15543446
Rogers, L.M., Brown, DA, Gruben, K.G. Foot force direction control during leg pushes against fixed and moving pedals in persons post-stroke. Gait and Posture 19:58-68, 2004. PMID: 14741304
Brown, DA, Katchuk, H. Limb Position Sense Accuracy is Phase and Movement-Dependent during a Locomotor Task. Neurology Report 27:61-6, 2003.
Kautz, S.A, Brown, DA, Van der Loos, H.F.M. Zajac, F.E. Mutability of bifunctional thigh muscle activity in pedaling from contralateral leg force generation. J Neurophysiol 88: 1308–1317, 2002. PMID: 12205152
Deutsch, J.E., Nicholson, D.E., Shumway-Cook, A., Brown, DA, Gordon, J. Updating neurologic curriculum using a peer review process. Neurology Report 24:101-110, 2000.
Brown, DA. How revolutions in science contribute to changes in practice in neurological rehabilitation - Part I. Neurology Report 24:38-41, 2000.
Ting, L.H., Kautz, S.A., Brown, D.A., Zajac, F.E. Contralateral movement and extensor force generation alter flexion phase muscle coordination in pedaling. Journal of Neurophysiology 83:3351-65, 2000. PMID: 10848554
Brown, D.A., Kautz, S.A. Speed-dependent reductions of force output in people with poststroke hemiparesis. Physical Therapy 79:919-30, 1999. PMID: 10498969
Ting, L.H., Kautz, S.A., Brown, DA. and Zajac, F.E. Phase reversal of biomechanical function pairs and muscle activity in backward human locomotion. Journal of Neurophysiology 81:544-551, 1999. PMID: 10036258
Ting, L.H., Raasch, C.C., Brown, DA, Kautz, S.A. and Zajac, F.E. Sensorimotor state of the contralateral leg affects ipsilateral muscle coordination of pedaling. Journal of Neurophysiology 80: 1341-1351, 1998. PMID: 9744943
Brown, DA. and Kautz, S.A. Increased workload enhances force output during pedaling exercise in persons with poststroke hemiplegia. Stroke 29, 598-606, 1998. PMID: 9506599
Kautz, S.A. and Brown, DA. Relationships between timing of muscle excitation and impaired motor performance during cyclical lower extremity movement in post-stroke hemiplegia. Brain 121, 515-526, 1998. PMID: 9549527
Brown, DA, Kautz, SA, and Dairaghi, CA: Muscle activity adapts to anti-gravity posture during pedaling in persons with post-stroke hemiplegia. Brain 120: 825-837, 1997. PMID: 9183253
Pierson-Carey, C, Brown, DA, and Dairaghi, CA: Changes in resultant pedal reaction forces due to ankle immobilization during pedaling. Journal of Applied Biomechanics 13: 334-346, 1997.
Brown, DA, Kautz, SA, and Dairaghi, CA: Muscle activity patterns are altered during pedaling at different body orientations. Journal of Biomechanics 29:1349-1356, 1996. PMID: 8884480
Brown, DA and Kukulka, C.G.: Human flexor reflex modulation during cycling. Journal of Neurophysiology 69: 1181-1191, 1993. PMID: 8492160
Kukulka, C.G., Brown, DA, and Weightman, M.M.: An objective method for assessing graded electrically evoked afferent activity in humans. EEG and Clinical Neurophysiology 81:312-318, 1991. PMID: 1714826
Brown, DA, and DeBacher, G.: Bicycle ergometer and electromyographic feedback for treatment of muscle imbalance in patients with spastic hemiparesis. Physical Therapy 67(11):1715-1719, 1987. PMID: 3671508
Editorials, Reviews, Chapters, Books, Commentaries
Hidler, J. and Brown, D.A. Robotic Devices for Overground Gait and Balance Training in Neurorehabilitation Technology by Dietz, Volker; Nef, Tobias; Rymer, William Zev (Eds.), Springer, 2012.
Hunter S.K. and Brown, DA. Muscle – The Ultimate Force Generator. in Kinesiology of the Musculoskeletal System - Foundations for Physical Rehabilitation 2 ed. by Donald Neumann, Mosby, Phila., 2010.