Locomotor training and muscle function after incomplete spinal cord injury: case series.
OBJECTIVE
To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI).


METHODS
Longitudinal prospective case series.


METHODS
Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque 200), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle cross-sectional area (CSA) was measured prior to and after LT.


RESULTS
Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% +/- 20.0%), followed by the more-involved KE (21.1% +/- 12.3%). Even larger improvements were realized in Torque 200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque 200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles.


CONCLUSIONS
Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints.
Jayaraman
Arun
A
University of Florida, Gainesville, Florida, 32610, USA.
Shah
Prithvi
P
Gregory
Christopher
C
Bowden
Mark
M
Stevens
Jennifer
J
Bishop
Mark
M
Walter
Glenn
G
Behrman
Andrea
A
Vandenborne
Krista
K
D000328:Adult; D005260:Female; D006801:Humans; D007866:Leg / Q000294:innervation / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009133:Muscular Atrophy / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D010243:Paralysis / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D026741:Physical Therapy Modalities; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*; D013663:Teaching / Q000379:methods; D019415:Torque; D014836:Volition / Q000502:physiology