Dataset Information

Kinematic, muscular, and metabolic responses during exoskeletal-, elliptical-, or therapist-assisted stepping in people with incomplete spinal cord injury.

ABSTRACT:

Background

Robotic-assisted locomotor training has demonstrated some efficacy in individuals with neurological injury and is slowly gaining clinical acceptance. Both exoskeletal devices, which control individual joint movements, and elliptical devices, which control endpoint trajectories, have been utilized with specific patient populations and are available commercially. No studies have directly compared training efficacy or patient performance during stepping between devices.

Objective

The purpose of this study was to evaluate kinematic, electromyographic (EMG), and metabolic responses during elliptical- and exoskeletal-assisted stepping in individuals with incomplete spinal cord injury (SCI) compared with therapist-assisted stepping. Design A prospective, cross-sectional, repeated-measures design was used.

Methods

Participants with incomplete SCI (n=11) performed 3 separate bouts of exoskeletal-, elliptical-, or therapist-assisted stepping. Unilateral hip and knee sagittal-plane kinematics, lower-limb EMG recordings, and oxygen consumption were compared across stepping conditions and with control participants (n=10) during treadmill stepping.

Results

Exoskeletal stepping kinematics closely approximated normal gait patterns, whereas significantly greater hip and knee flexion postures were observed during elliptical-assisted stepping. Measures of kinematic variability indicated consistent patterns in control participants and during exoskeletal-assisted stepping, whereas therapist- and elliptical-assisted stepping kinematics were more variable. Despite specific differences, EMG patterns generally were similar across stepping conditions in the participants with SCI. In contrast, oxygen consumption was consistently greater during therapist-assisted stepping. Limitations Limitations included a small sample size, lack of ability to evaluate kinetics during stepping, unilateral EMG recordings, and sagittal-plane kinematics.

Conclusions

Despite specific differences in kinematics and EMG activity, metabolic activity was similar during stepping in each robotic device. Understanding potential differences and similarities in stepping performance with robotic assistance may be important in delivery of repeated locomotor training using robotic or therapist assistance and for consumers of robotic devices.

SUBMITTER: Hornby TG

PROVIDER: S-EPMC3925942 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundTreadmill training with bodyweight support and manual assistance improves walking ability of patients with neurological injury. The purpose of this study was to determine how manual assistance changes muscle activation and kinematic patterns during treadmill training in individuals with incomplete spinal cord injury.MethodsWe tested six volunteers with incomplete spinal cord injury and six volunteers with intact nervous systems. Subjects with spinal cord injury walked on a treadmill at six speeds (0.18-1.07 m/s) with body weight support with and without manual assistance. Healthy subjects walked at the same speeds only with body weight support. We measured electromyographic (EMG) and kinematics in the lower extremities and calculated EMG root mean square (RMS) amplitudes and joint excursions. We performed cross-correlation analyses to compare EMG and kinematic profiles.ResultsNormalized muscle activation amplitudes and profiles in subjects with spinal cord injury were similar for stepping with and without manual assistance (ANOVA, p > 0.05). Muscle activation amplitudes increased with increasing speed (ANOVA, p < 0.05). When comparing spinal cord injury subject EMG data to control subject EMG data, neither the condition with manual assistance nor the condition without manual assistance showed a greater similarity to the control subject data, except for vastus lateralis. The shape and timing of EMG patterns in subjects with spinal cord injury became less similar to controls at faster speeds, especially when walking without manual assistance (ANOVA, p < 0.05). There were no consistent changes in kinematic profiles across spinal cord injury subjects when they were given manual assistance. Knee joint excursion was approximately 5 degrees greater with manual assistance during swing (ANOVA, p < 0.05). Hip and ankle joint excursions were both approximately 3 degrees lower with manual assistance during stance (ANOVA, p < 0.05).ConclusionProviding manual assistance does not lower EMG amplitudes or alter muscle activation profiles in relatively higher functioning spinal cord injury subjects. One advantage of manual assistance is that it allows spinal cord injury subjects to walk at faster speeds than they could without assistance. Concerns that manual assistance will promote passivity in subjects are unsupported by our findings.

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