Influence of functional task-oriented mental practice on the gait of transtibial amputees: a randomized, clinical trial

BACKGROUND: Mental practice (MP) through motor imagery is a cognitive training strategy used to improve locomotor skills during rehabilitation programs. Recent works have used MP tasks to investigate the neurophysiology of human gait; however, its effect on functional performance has not been evaluated. In the present study, the influence of gait-oriented MP tasks on the rehabilitation process of gait in transtibial amputees was investigated by assessing the vertical (V), anterior-posterior (AP), and medio-lateral (ML) ground reaction forces (GRFs) and the time duration of the support phase of the prosthetic limb. METHODS: Unilateral transtibial amputees, who were capable of performing motor imagination tasks (MIQ-RS score ≥4), were randomly divided into two groups: Group A (n = 10), who performed functional gait-oriented MP combined with gait training, and Group B (n = 5), who performed non-motor task MP. The MP intervention was performed in the first-person perspective for 40 min, 3 times/week, for 4 weeks. The GRF outcome measures were recorded by a force platform to evaluate gait performance during 4 distinct stages: at baseline (BL), 1 month before the MP session; Pre-MP, 1–3 days before the MP session; Post-MP, 1–3 days after the MP session; and follow-up (FU), 1 month after MP session. The gait variables were compared inter- and intra-group by applying the Mann-Whitney and Friedman tests (alpha = 0.05). RESULTS: All volunteers exhibited a homogenous gait pattern prior to MP intervention, with no gait improvement during the BL and Pre-MP stages. Only Group A showed significant improvements in gait performance after the intervention, with enhanced impact absorption, as indicated by decreased first V and AP peaks; propulsion capacity, indicated by increasing second V and AP peaks; and balance control of the prosthetic limb, indicated by decreasing ML peaks and increasing duration of support. This gait pattern persisted until the FU stage. CONCLUSIONS: MP combined with gait training allowed transtibial amputees to reestablish independent locomotion. Since the effects of MP were preserved after 1 month, the improvement is considered related to the specificity of the MP tasks. Therefore, MP may improve the clinical aspect of gait rehabilitation when included in a training program.