Loss of function in the lower limbs due to SCI can extend from complete paralysis to varying levels of voluntary muscle activation. The rehabilitation of lower extremity function after SCI has generally focused on the recovery of gait. Even when functional ambulation may not be possible (e.g. in complete tetraplegia), lower limb interventions can be targeted to maintain muscle health as well as reduce other complications, such as decreased cardiovascular health or osteoporosis. Minimizing the risk of these complications would ease health costs related to the treatment of these sequelae and also promote survivors’ participation in society as productive members of the workforce.
Conventional rehabilitation strategies for enhancing lower limb function after SCI have focused on range of motion and stretching, active exercises, electrical stimulation to strengthen functioning musculature, and functional training in daily mobility tasks. Standing and overground ambulation training are also important components of conventional rehabilitation using various bracing and assistive devices (O'Sullivan and Schmitz 1994; Somers 1992). In the last several years, we have seen increasing emphasis on providing task-specific training of functional movements, such as walking, with the help of body weight support and treadmills. We have also seen exciting advances in technology applications for facilitating or augmenting gait rehabilitation strategies, such as robotic devices for treadmill gait retraining (Hesse et al. 2004; Colombo et al. 2001) and the introduction of microstimulators for activating paralyzed muscles (Weber et al. 2004). In the following sections, we review evidence for the efficacy of these various lower limb rehabilitation interventions on lower limb muscle strength and ambulatory capacity following SCI. As will be evident from the review, injury level, severity, chronicity, as well as institutional resources must all be taken into account to help guide the clinical decision-making process and expected outcomes.