A central disability associated with post-stroke hemiparesis is that muscle excitation is impaired, and thus muscles fail to produce properly graded and timed force. With impaired muscle coordination, walking subtasks required to achieve normal speed, such as trunk forward progression (acceleration), swing initiation (kinetic energy of the leg at the end of stance) and muscle power generation, may not be satisfactorily performed. The relationship between impaired muscle force production and walking speed in persons with hemiparesis is unknown, yet this is extremely important for the design of effective gait rehabilitation strategies in hemiparetic populations. In the proposed study, experimental data from individuals with post-stroke hemiparesis across a range of functional walking levels and speed-matched healthy elderly individuals will be combined with a theoretical modeling framework based on dynamic simulations to quantify muscle force contributions to walking. The PIs propose to use this scientific model-based framework to understand and quantify how abnormal muscle force production reduces walking speed in post-stroke gait disorders.
Specific aims are to (1) determine how deficits in trunk forward progression, swing initiation and muscle power generation are caused by abnormalities in muscle force production during pre-swing in the paretic leg, and how abnormalities during concomitant early stance in the non-paretic leg compensate; and (2) determine how muscle coordination must be improved for subjects with hemiparesis to increase their functional walking status. The long-term objectives of the proposed work are to show that measures of abnormal muscle coordination in post-stroke walking will predict the outcome of therapy, assist in defining the specific muscle coordination changes associated with various therapeutic interventions, and correlate with structural and functional studies of the nervous system such that the underlying mechanisms can be better understood.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD046820-01
Application #
6771639
Study Section
Special Emphasis Panel (ZHD1-RRG-K (11))
Program Officer
Quatrano, Louis A
Project Start
2004-06-01
Project End
2009-05-31
Budget Start
2004-06-01
Budget End
2005-05-31
Support Year
1
Fiscal Year
2004
Total Cost
$318,189
Indirect Cost
Name
University of Florida
Department
Other Health Professions
Type
Schools of Public Health
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Balasubramanian, Chitralakshmi K; Li, Chih-Ying; Bowden, Mark G et al. (2016) Dimensionality and Item-Difficulty Hierarchy of the Lower Extremity Fugl-Meyer Assessment in Individuals With Subacute and Chronic Stroke. Arch Phys Med Rehabil 97:582-589.e2
Clark, David J; Neptune, Richard R; Behrman, Andrea L et al. (2016) Locomotor Adaptability Task Promotes Intense and Task-Appropriate Output From the Paretic Leg During Walking. Arch Phys Med Rehabil 97:493-6
Dean, Jesse C; Kautz, Steven A (2015) Foot placement control and gait instability among people with stroke. J Rehabil Res Dev 52:577-90
Nott, C R; Neptune, R R; Kautz, S A (2014) Relationships between frontal-plane angular momentum and clinical balance measures during post-stroke hemiparetic walking. Gait Posture 39:129-34
Allen, Jessica L; Kautz, Steven A; Neptune, Richard R (2013) The influence of merged muscle excitation modules on post-stroke hemiparetic walking performance. Clin Biomech (Bristol, Avon) 28:697-704
Routson, Rebecca L; Clark, David J; Bowden, Mark G et al. (2013) The influence of locomotor rehabilitation on module quality and post-stroke hemiparetic walking performance. Gait Posture 38:511-7
Raja, Bhavana; Neptune, Richard R; Kautz, Steven A (2012) Quantifiable patterns of limb loading and unloading during hemiparetic gait: Relation to kinetic and kinematic parameters. J Rehabil Res Dev 49:1293-304
Allen, Jessica L; Neptune, Richard R (2012) Three-dimensional modular control of human walking. J Biomech 45:2157-63
Raja, Bhavana; Neptune, Richard R; Kautz, Steven A (2012) Coordination of the non-paretic leg during hemiparetic gait: expected and novel compensatory patterns. Clin Biomech (Bristol, Avon) 27:1023-30
Day, Kristin V; Kautz, Steven A; Wu, Samuel S et al. (2012) Foot placement variability as a walking balance mechanism post-spinal cord injury. Clin Biomech (Bristol, Avon) 27:145-50

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