Effects of Locomotor Exercise Intensity on Gait Performance in Individuals With Incomplete Spinal Cord Injury.
BACKGROUND
High-intensity stepping practice may be a critical component to improve gait following motor incomplete spinal cord injury (iSCI). However, such practice is discouraged by traditional theories of rehabilitation that suggest high-intensity locomotor exercise degrades gait performance. Accordingly, such training is thought to reinforce abnormal movement patterns, although evidence to support this notion is limited.


OBJECTIVE
The purposes of this study were: (1) to evaluate the effects of short-term manipulations in locomotor intensity on gait performance in people with iSCI and (2) to evaluate potential detrimental effects of high-intensity locomotor training on walking performance.


METHODS
A single-day, repeated-measures, pretraining-posttraining study design was used.


METHODS
Nineteen individuals with chronic iSCI performed a graded-intensity locomotor exercise task with simultaneous collection of lower extremity kinematic and electromyographic data. Measures of interest were compared across intensity levels of 33%, 67%, and 100% of peak gait speed. A subset of 9 individuals participated in 12 weeks of high-intensity locomotor training. Similar measurements were collected and compared between pretraining and posttraining evaluations.


RESULTS
The results indicate that short-term increases in intensity led to significant improvements in muscle activity, spatiotemporal metrics, and joint excursions, with selected improvements in measures of locomotor coordination. High-intensity locomotor training led to significant increases in peak gait speed (0.64-0.80 m/s), and spatiotemporal and kinematic metrics indicate a trend for improved coordination.


CONCLUSIONS
Measures of gait performance were assessed during treadmill ambulation and not compared with a control group. Generalizability of these results to overground ambulation is unknown.


CONCLUSIONS
High-intensity locomotor exercise and training does not degrade, but rather improves, locomotor function and quality in individuals with iSCI, which contrasts with traditional theories of motor dysfunction following neurologic injury.
K.A. Leech, PT, DPT, PhD, Interdepartmental Neuroscience Program, Northwestern University, Chicago, Illinois, and Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois.
Kristan A
KA
Leech
C.R. Kinnaird, ME, Sensory Motor Performance Program, Rehabilitation Institute of Chicago.
Catherine R
CR
Kinnaird
C.L. Holleran, PT, MPT, DHS, Sensory Motor Performance Program, Rehabilitation Institute of Chicago.
Carey L
CL
Holleran
J. Kahn, PT, DPT, Sensory Motor Performance Program, Rehabilitation Institute of Chicago.
Jennifer
J
Kahn
T.G. Hornby, PT, PhD, Interdepartmental Neuroscience Program, Northwestern University, Chicago, Illinois; Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois; and Department of Physical Medicine and Rehabilitation, Northwestern University, 345 E Superior St, Room 1382, Chicago, IL 60611 (USA). g-hornby@northwestern.edu.
T George
TG
Hornby
D000293:Adolescent; D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000502:physiology; D001696:Biomechanical Phenomena; D004576:Electromyography; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular; D013119:Spinal Cord Injuries / Q000503:physiopathology* / Q000534:rehabilitation*; D013997:Time Factors; D000072797:Walking Speed / Q000502:physiology*; D055815:Young Adult