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Tampo N.1,2, Soma T.1
1Graduate School of Niigata University of Health and Welfare, Niigata, Japan, 2TAKEDA General University Hospital, AIzuwakamatsu, Japan
Background: Lower limb orthosis with trunk belt (CVAid) is unique in linking trunk and lower extremity with elastic band and insole comparing to other orthoses. The immediate improvement of energy efficiency found in stroke patients' CVAid gait has been reported previously. However, the mechanical feature that produces the improvement is still undefined.
Purpose: The research attempts to find out the mechanical differences between plastic Ankle Foot Orthosis (AFO) gait and CVAid gait in a stroke patient.
Methods: Subject was a chronic hemiplegic patient (left hemiplegia, 34 years old, male, height 172cm, weight 77kg). The Brunnstrom Recovery stage of left lower extremity was IV, the Modified Ashworth Scale of left Triceps surae muscle was 1+, and the Functional Ambulation Classification was 4. Walking ability was independent outdoor with T-cane and AFO.
Gait patterns of AFO and CVAid were evaluated on a flat surface. The measurements were obtained during 10 gait cycles for 10 m distance on the floor reaction force gauge. Moreover, measurements of these two gait patterns were obtained at least an hour apart on the same day.
11 CCD cameras with three-dimensional movement analysis device (VICON Nexus), 6 floor reaction force gauge and Tension meter (Leptrino) for measuring tensile force of the elastic band were used. Sampling frequency was 100 Hz for three-dimensional movement analysis device and 1kHz for both floor reaction force gauge and tension meter. 15 infrared reflectiveness markers (diameter 15mm) were placed to the subject.
Analysis section was one gait cycle period of the CVAid with left lower extremity, from the initial contact to the next initial contact on the same side. Tensile force of elastic band was set as 3 kg. The analysis was processed by calculating arithmetic mean of 10 walking periods under 2 conditions. The lower extremity joint angles and joint moment before and after the heel being abutted onto the ground was calculated. The comparison of data was operated with the mean and standard deviation of each analysis subjects in AFO walking and CVAid walking.
Results: In stance phase, the joint angle of hip extension was (3.1±1.3/5.1±1.2)（degree）, of knee flexion was (31.0±3.7/33.9±1.4), and of plantar flexion was(6.7±0.7/3.1±0.8) respectively. In swing phase, the joint angle of hip flexion was (20.9±1.3/18.7±1.0), and dorsiflexion was (-5.1±0.7/-1.8±0.7).
In terminal stance, joint moment (17.1±3.6/17.7±2.3) (Nm) of hip flexion was, (2.4±1.5/3.1±0.9) of knee extension, and (-5.1±0.7/-1.8±0.7) of plantar flexion.
Conclusion(s): In terms of joint angle in CVAid gait, angle of hip extension in terminal stance phase, related to forward weight shift of center of gravity, increased. Dorsiflexion in initial swing phase related to foot clearance from floor also increased as well.
As these results, it is possible that CVAid gait would assist forward weight shift of center of gravity and forward propulsion of lower extremity with CVAid.
Implications: In general, orthoses are utilized to assist stability, but CVAid might be useful to assist mobility.
Therefore, CVAid might be useful orthoses for hemiplegic stroke patients with decreased locomotive function. Further research with more data is necessary to develop this study in the future.
Funding acknowledgements: None
Topic: Neurology: stroke
Ethics approval: The research approval from the ethical committee of the institution where the speaker is affiliated to.(Approval number 17622)
All authors, affiliations and abstracts have been published as submitted.
