Optimal recovery of walking after spinal cord injury (SCI) depends on task-specific training tailored to distinct deficits. Eccentric motor control is impaired in both humans and animals with SCI and persists after treadmill training, suggesting that greater training specificity is needed. An eccentrically-focused treadmill training program has not been studied in human SCI but has shown good efficacy in rodent SCI. In a strong proof-of- principle design, this proposal will deliver downhill treadmill training in individuals wth incomplete SCI who completed traditional loco motor training at least 6 months earlier. Any further gains in eccentric control, functional performance and community participation will establish the importance of eccentric task-specific training. Because eccentric muscle activation is understudied in human SCI, the proposal aims to characterize eccentric motor control during locomotion (Aim 1) and efficacy of downhill training (Aims 2 and 3).
In Aim 2, we will determine downhill training effects on over ground locomotion by measuring biomechanics during the weight acceptance phase of locomotion when eccentric knee control in the sagittal plane prevails. Whether downhill training will promote gains in function and community participation will be tested in Aim 3. Preliminary evidence shows that excessive knee flexion or hyperextension during weight acceptance provides support for our theory that long-lasting eccentric motor deficits exist and reduce functional recovery. Therefore, we hypothesize that the presence and severity of eccentric deficits such as these will negatively impact loco motor recovery;will be reduced by downhill eccentric training and will translate into improved over ground locomotion and function.
The project will identify critical determinants of training-induced recovery after human spinal cord injury (SCI). We will identify how knee eccentric motor deficits and eccentrically-focused downhill training impacts over ground locomotion, functional recovery and community participation in individuals with incomplete SCI.