An Accelerometry-Based Comparison of 2 Robotic Assistive Devices For Treadmill Training of Gait.

International audienceOBJECTIVE: . Two commercial robotic devices, the Gait Trainer (GT) and the Lokomat (LOKO), assist task-oriented practice of walking. The gait patterns induced by these motor-driven devices have not been characterized and compared. METHODS: . A healthy participant chose the most comfortable gait pattern on each device and for treadmill (TM) walking at 1, 2 (maximum for the GT), and 3 km/h and over ground at similar speeds. A system of accelerometers on the thighs and feet allowed the calculation of spatiotemporal features and accelerations during the gait cycle. RESULTS: . At the 1 and 2 km/h speed settings, single-limb stance times were prolonged on the devices compared with overground walking. Differences on the LOKO were decreased by adjusting the hip and knee angles and step length. At the 3 km/h setting, the LOKO approximated the participant's overground parameters. Irregular accelerations and decelerations from toe-off to heel contact were induced by the devices, especially at slower speeds. CONCLUSIONS: . The LOKO and GT impose mechanical constraints that may alter leg accelerations-decelerations during stance and swing phases, as well as stance duration, especially at their slower speed settings, that are not found during TM and overground walking. The potential impact of these perturbations on training to improve gait needs further study

Reliability and validity of bilateral thigh and foot accelerometry measures of walking in healthy and hemiparetic subjects.

OBJECTIVE: Measures of walking ability in large clinical trials are usually limited to a timed short-distance walk and the distance walked in a fixed time. A new integrated system of 5 accelerometers was tested for reliability and compared to a footswitch system to determine if the accelerometers offered a practical option for the acquisition of spatiotemporal gait parameters. METHODS: Leg accelerations and decelerations were defined in relation to simultaneous kinematic and electromyographic data acquired from a healthy subject. Eight healthy adults and 6 independent ambulators with hemiparetic stroke walked 15 m at 2 different speeds wearing both the accelerometers and footswitches. Twelve healthy subjects walked at 5 different speeds repeated 3 times on each of 2 days wearing the accelerometers. Walking speed, cadence, stride length, and single- and double-limb support, swing, and stance times were calculated. RESULTS: No differences (t test, P > 0.2) were found between footswitch and accelerometer variables when comparing all left or right legs in healthy subjects and all paretic or unaffected legs in stroke subjects. A 2-way nested ANOVA model (speed, left and right legs, trial, and session) with the accelerometers at walking speeds from 0.5 to 1.8 m/s revealed high reproducibility of all measures. CONCLUSIONS: The accelerometry system provided reliable and valid spatiotemporal measures of gait for the upper range of speeds likely to be targeted for rehabilitation interventions in ambulatory subjects