Evaluation of dynamic gait stability after a single-session of waist-pull perturbation training in Parkinson’s disease using an Active Tethered Pelvic Assist Device (A-TPAD). (P1.071)

Objective: To analyze adaptations in dynamic gait stability after perturbation-based balance training (PBT) in Parkinson’s disease (PD). Background: Postural instability is one of the contributing factor to falls in PD. Previous studies evaluating stability, while reacting to unexpected perturbations during standing, have shown that PD patients have smaller stability margins compared to healthy peers and this can improve after perturbation-based training. However, few studies have evaluated gait stability when perturbations were delivered during walking. Design/Methods: Seven PD patients were tested in the clinically defined ‘on’ state. They wore a hip brace with cables attached to motors, capable of creating waist-pull perturbations of desired amplitude, duration, and direction during walking. Kinematic data was collected using a motion capture system. The training session consisted of repeated unexpected Antero-Posterior (AP) and Medio-Lateral (ML) waist-pulls of increasing intensity. Adaptations were evaluated by comparing stability during (i) the response to 10 diagonal perturbations and (ii) 5 minutes of free walking before and after training. Paired sample t-tests and one-way repeated measures ANOVA were performed to test differences in the average AP margin of stability (MoS AP ) at (i) first heel strike during the first and last sets of perturbations and (ii) free walking during pre-training and the early and late phases of post-training. Results: Subjects significantly increased their average MoS AP when measured during (i) the response to the perturbations ( p =0.02) from pre-(354.5±20.8 mm) to post-training (393.2±16.3 mm) and (ii) free walking ( p =0.009) from pre-training (391.4±18.6 mm) to the early (403.8±16.5 mm) and late (401.1±17.2 mm) phases of post-training. Conclusions: PD patients improved gait stability during perturbed and free walking after a single PBT session as measured by their average MoS AP . We envision that this paradigm can be used to implement an innovative multi-session waist-pull training program to reduce the risk of falling in PD. Disclosure: Dr. Luo has nothing to disclose. Dr. Martelli has nothing to disclose. Dr. Kang has received research support from Allergan. Dr. Fahn has nothing to disclose. Dr. Agrawal has nothing to disclose.