Task-specific Fall Prevention Training Is Effective for Warfighters With Transtibial Amputations

Key factors limiting patients with lower extremity amputations to achieve maximal functional capabilities are falls and fear of falling. A task-specific fall prevention training program has successfully reduced prospectively recorded trip-related falls that occur in the community by the elderly. However, this program has not been tested in amputees. In a cohort of unilateral transtibial amputees, we aimed to assess effectiveness of a falls prevention training program by (1) quantifying improvements in trunk control; (2) measuring responses to a standardized perturbation; and (3) demonstrating retention at 3 and 6 months after training. Second, we collected patient-reported outcomes for balance confidence and falls control. Fourteen male military service members (26 +/- A 3 years) with unilateral transtibial amputations and who had been walking without an assistive device for a median of 10 months (range, 2-106 months) were recruited to participate in this prospective cohort study. The training program used a microprocessor-controlled treadmill designed to deliver task-specific postural perturbations that simulated a trip. The training consisted of six 30-minute sessions delivered over a 2-week period, during which task difficulty, including perturbation magnitude, increased as the patient's ability progressed. Training effectiveness was assessed using a perturbation test in an immersive virtual environment. The key outcome variables were peak trunk flexion and velocity, because trunk kinematics at the recovery step have been shown to be a determinant of fall likelihood. The patient-reported outcomes were also collected using questionnaires. The effectiveness of the rehabilitation program was also assessed by collecting data before perturbation training and comparing the key outcome parameters with those measured immediately after perturbation training (0 months) as well as both 3 and 6 months posttraining. Mean trunk flexion angle and velocity significantly improved after participating in the training program. The prosthetic limb trunk flexion angle improved from pretraining (42A degrees; 95% confidence interval [CI], 38A degrees-47A degrees) to after training (31A degrees; 95% CI, 25A degrees-37A degrees; p < 0.001). Likewise, the trunk flexion velocity improved from pretraining (187A degrees/sec; 95% CI, 166A degrees-209A degrees) to after training (143A degrees/sec; 95% CI, 119A degrees-167A degrees; p < 0.004). The results display a significant side-to-side difference for peak trunk flexion angle (p = 0.01) with perturbations of the prosthetic limb resulting in higher peak angles. Prosthetic limb trips also exhibited significantly greater peak trunk flexion velocity compared with trips of the prosthetic limb (p = 0.005). These changes were maintained up to 6 months after the training. The peak trunk flexion angle of the subjects when the prosthetic limb was perturbed had a mean of 31A degrees (95% CI, 25A degrees-37A degrees) at 0 month, 32A degrees (95% CI, 28A degrees-37A degrees) at 3 months, and 30A degrees (95% CI, 25A degrees-34A degrees) at 6 months. Likewise, the peak trunk flexion velocity for the prosthetic limb was a mean of 143A degrees/sec (95% CI, 118A degrees-167A degrees) at 0 months, 143A degrees/sec (95% CI, 126A degrees-159A degrees) at 3 months, and 132A degrees (95% CI, 115A degrees-149A degrees) at 6 months. The peak trunk flexion angle when the nonprosthetic limb was perturbed had a mean of 22A degrees (95% CI, 18A degrees-24A degrees) at 0 months, a mean of 26A degrees (95% CI, 20A degrees-32A degrees) at 3 months, and a mean of 23A degrees (95% CI, 19A degrees-28A degrees) at 6 months. The peak trunk flexion velocity for the nonprosthetic limb had a mean of 85A degrees/sec (95% CI, 71A degrees-98A degrees) at 0 months, a mean of 96A degrees (95% CI, 68A degrees-124A degrees) at 3 months, and 87A degrees/sec (95% CI, 68A degrees-105A degrees) at 6 months. There were no significant changes in the peak trunk flexion angle (p = 0.16) or peak trunk flexion velocity (p = 0.35) over time after the training ended. The skill retention was present when either the prosthetic or nonprosthetic limb was perturbed. There were side-to-side differences in the trunk flexion angle (p = 0.038) and trunk flexion velocity (p = 0.004). Perturbations of the prosthetic side resulted in larger trunk flexion and higher trunk flexion velocities. Subjects prospectively reported decreased stumbles, semicontrolled falls, and uncontrolled falls. These results indicate that task-specific fall prevention training is an effective rehabilitation method to reduce falls in persons with lower extremity transtibial amputations. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.