The studies reviewed here suggest that facilitating the practice of walking during rehabilitation can enhance the recovery of functional ambulation in incomplete SCI. Although specific treatment parameters that depend on the injury location, severity, and chronicity remain to be elucidated, there exists some evidence to help guide the clinical decision-making process. Task-oriented gait retraining with partial body weight support, whether provided by a treadmill and partial BWS or overground with assistive devices, appears to be more beneficial when applied sooner rather than later after the onset of injury in people with motor-incomplete lesions. Where resources permit, therapists may use a body-weight support system combined with a treadmill and manual assistance from additional personnel to implement task-oriented gait training. However, there is increasing evidence that equivalent outcomes can be obtained independent of the specific gait retraining strategy (Dobkin et al. 2006; Field-Fote et al. 2005). Some recent preliminary evidence suggests that gait training strategies may also be potentiated by nutrient supplements (Nash et al. 2007) or resistance training of specific muscles (Gregory et al. 2007).

For individuals with more chronic spinal lesions and who have recovered some walking, FES may provide additional gains in functional ambulation. When resources are available, more complex FES systems, with or without bracing, may be used to provide support of upright mobility in individuals with complete paraplegia. Further evidence is required to determine whether combination therapies offer significant advantages over any given approach alone. Future studies should also examine the role of falls risk and history in ambulatory performance following SCI. Early evidence suggests that the more active a person is, the less likely that they will experience a fall (Brotherton et al. 2007). Finally, although this review has focused on functional ambulation outcomes following various rehabilitation strategies, we must also keep in mind the additional health benefits (e.g. improved cardiovascular or bone health) of performing gait exercises.

• There is level 2 evidence (Baldi et al. 1998) that PES-assisted isometric exercise reduces the degree of lower limb muscle atrophy in individuals with recent (~10 weeks post-injury) motor complete SCI, but not to the same extent as a comparable program of FES-assisted cycling exercise.
• There is level 4 evidence (Sabatier et al. 2006) that PES-assisted exercise may partially reverse the lower limb muscle atrophy found in individuals with long-standing (>1 year post-injury) motor complete SCI.
• There is level 2 evidence (Shields and Dudley-Javoroski 2006) that a program of PES-assisted exercise increases lower limb strength and muscular endurance.
• There is level 2 evidence (Baldi et al. 1998) that FES-assisted cycling exercise prevents and reverses lower limb muscle atrophy in individuals with recent (~10 weeks post-injury) motor complete SCI and to a greater extent than PES.
• There is level 4 evidence (Scremin et al. 1999; Crameri et al. 2002) that FES may partially reverse the lower limb muscle atrophy found in individuals with long-standing (>1 year post-injury) motor complete SCI.
• There is level 4 evidence (Gerrits et al. 2000) that FES-assisted cycle exercise may increase lower limb muscular endurance.
• There is level 3 evidence (Wernig et al. 1995) using historical controls that BWSTT is effective in improving ambulatory function. However, stronger evidence from one level 1 RCT (Dobkin et al. 2006) demonstrates that BWSTT has equivalent effects to conventional rehabilitation consisting of an equivalent amount of overground mobility practice for gait outcomes in acute/sub-acute SCI.
• There is level 1 evidence from 1 RCT (Field-Fote et al. 2005) that different strategies for implementing body weight support gait retraining all yield similar ambulatory outcomes in people with chronic, incomplete SCI. It is recommended that therapists may choose a body weight support gait retraining strategy based on available resources (Field-Fote et al. 2005).
• There is level 4 evidence from pre-test/post-test studies (Winchester et al 2009; Hicks et al. 2005; Wirz et al. 2005; Thomas and Gorassini 2005; Protas et al. 2001; Wernig et al. 1998) that BWSTT is effective for improving ambulatory function in people with chronic, incomplete SCI.
• There exists level 1 evidence (Walker and Harris 1993), limited by a small sample size, that GM-1 ganglioside combined with physical therapy improves walking ability in chronic incomplete SCI patients.
• There is limited level 4 evidence (Norman et al. 1998) that clonidine and cyproheptadine use in conjunction with BWSTT enhances walking ability in non-ambulatory incomplete SCI patients such that overground ambulation with assistive devices can be achieved.
• There is level 4 evidence (Thrasher et al. 2006; Ladouceur and Barbeau 2000a; 2000b; Wieler et al. 1999; Klose et al. 1997; Granat et al. 1993; Stein et al. 1993; Granat et al. 1992) that FES-assisted walking can enhance walking speed and distance in complete and incomplete SCI.
• There is level 4 evidence from 2 independent laboratories (Ladouceur and Barbeau 2000a,b; Wieler et al. 1999) that regular use of FES in gait training or activities of daily living leads to persistent improvement in walking function that is observed even when the stimulator is not in use.
• None of the studies investigating the effectiveness of brace/orthotic devices for upright support and mobility are randomized or blinded, but that is in part due to the ethical dilemma of providing safe and appropriate bracing and the fact that participants will be able to distinguish which device they received. There is weak evidence from post-test studies (Scivoletto et al. 2000; Franceschini et al. 1997) that bracing alone results in significant gains in functional ambulation for people with complete SCI. Two studies reported pre-test/post-test results (Nakazawa et al. 2004; Saitoh et al. 1996) (total n = 8) that the use of long-leg braces could enhance gait speed and endurance in people with complete SCI.
• There is level 4 evidence (Yang et al. 1996) that a combined approach of bracing and FES results in additional benefit to functional ambulation in paraplegic patients with complete SCI. However, in subjects who achieve little benefit from bracing alone, the addition of FES appears to help improve standing or short-distance walking function (Marsolais et al. 2000). In incomplete SCI, however, there is some indication that a combination of bracing and FES provides greater ambulatory function than either approach alone (Kim et al. 2004).
• There is level 4 evidence that whole body vibration improves walking function (Ness & Field-Fote, 2009).
• There is level 4 evidence (Field-Fote 2001) that most forms of locomotor training (i.e., including body weight supported treadmill training with various assists and FES-assisted overland training) increase lower limb muscle strength in chronic SCI as indicated by overall increases in total lower extremity motor scores.
• There is level 3 evidence (Wernig et al. 1995) that body weight supported treadmill training is not significantly different than conventional rehabilitation therapy in enhancing lower limb muscle strength in acute SCI, although these studies are confounded by the natural recovery that may take place in the acute period.
• There is level 4 evidence (Gregory et al. 2007) that a resistance and plyometric training program can enable improvements in overground gait speed in chronic incomplete SCI.