An articulated Ankle-foot orthosis with mechanical joints systematically changed the moment-angle relationship of the gait characteristics of stroke survivors.
Presenter Type
UNO Graduate Student (Doctoral)
Major/Field of Study
Biomechanics
Other
Biomechanics
Author ORCID Identifier
0000-0001-8154-0671
Advisor Information
Dr. Brian Knarr
Location
MBSC302 - G (Doctoral)
Presentation Type
Oral Presentation
Start Date
24-3-2023 10:30 AM
End Date
24-3-2023 11:45 AM
Abstract
Ankle foot orthoses (AFOs) are prescribed to stroke survivors to enable independent walking following a stroke. Stroke survivors experience hemiparesis in the part of their body contralateral to the affected hemisphere of their brain and may present with weakness of their ankle muscles, disrupting the normal gait. For example, in normal gait, the ankle dorsiflexor muscle tibialis anterior (TA) contracts eccentrically as the foot goes into plantarflexion to ensure the body weight is accepted at the loading response where stabilization occurs ahead of single limb stance. This TA function may be disrupted in stroke survivors and AFO(s) are prescribed to augment this function, although an existent issue of definitive prescription of AFOs exists in clinics. Clinicians are presented with the challenge of solving the problem of ankle instability without qualitative tools that enable specific AFO prescriptions. This study looked to inform AFO clinical prescription using an individual-focused study design.
Three males and two females (age:64.6 ± 5.7 years) were recruited, and the study was carried out in two sessions on two different days (1 week apart). First, participants were put through clinical tests to assess their level of functionality after which a 3D creaform scanner was used in scanning their shank-to-foot. The scanned image was used in designing and 3D printing each participant’s AFO using a predetermined design. This AFO was assembled with a mechanical joint which enabled the regulation of the resistance conditions of the AFO. At the second visit, the participants were fitted with their AFOs and we tested 3 plantarflexion resistance (PF) conditions (PF1-low, PF2-medium, PF3-high) for each participant. The ankle angle at initial contact (AAIC) and the peak dorsiflexion moment (PDM) were analyzed.
Participant 1 experienced significant changes when PF1-PF2-PF3 were compared for both AAIC and PDM, while participants 3 and 4 had significant changes for PF1-PF3 for the AAIC, and participants 4 and 5 had significant changes for PF1-PF3 for the PDM. Although the participants had distinct changes, we noted the tendency of the articulated AFO with mechanical joint to systematically impact the moment and angles of stroke survivors. Also, we noted that participant one, who was the most affected benefited most from the use of the articulated AFO in comparison to his clinically prescribed device. These results reinforce the potential of the articulated AFO with the mechanical joint as a viable assistive device for ‘onsite resistance tuning’ to aid the clinical prescription of AFOs for stroke survivors. Further investigation with a larger sample size could ensure the development of a standardized prescription mechanism.
Scheduling
10:45 a.m.-Noon
An articulated Ankle-foot orthosis with mechanical joints systematically changed the moment-angle relationship of the gait characteristics of stroke survivors.
MBSC302 - G (Doctoral)
Ankle foot orthoses (AFOs) are prescribed to stroke survivors to enable independent walking following a stroke. Stroke survivors experience hemiparesis in the part of their body contralateral to the affected hemisphere of their brain and may present with weakness of their ankle muscles, disrupting the normal gait. For example, in normal gait, the ankle dorsiflexor muscle tibialis anterior (TA) contracts eccentrically as the foot goes into plantarflexion to ensure the body weight is accepted at the loading response where stabilization occurs ahead of single limb stance. This TA function may be disrupted in stroke survivors and AFO(s) are prescribed to augment this function, although an existent issue of definitive prescription of AFOs exists in clinics. Clinicians are presented with the challenge of solving the problem of ankle instability without qualitative tools that enable specific AFO prescriptions. This study looked to inform AFO clinical prescription using an individual-focused study design.
Three males and two females (age:64.6 ± 5.7 years) were recruited, and the study was carried out in two sessions on two different days (1 week apart). First, participants were put through clinical tests to assess their level of functionality after which a 3D creaform scanner was used in scanning their shank-to-foot. The scanned image was used in designing and 3D printing each participant’s AFO using a predetermined design. This AFO was assembled with a mechanical joint which enabled the regulation of the resistance conditions of the AFO. At the second visit, the participants were fitted with their AFOs and we tested 3 plantarflexion resistance (PF) conditions (PF1-low, PF2-medium, PF3-high) for each participant. The ankle angle at initial contact (AAIC) and the peak dorsiflexion moment (PDM) were analyzed.
Participant 1 experienced significant changes when PF1-PF2-PF3 were compared for both AAIC and PDM, while participants 3 and 4 had significant changes for PF1-PF3 for the AAIC, and participants 4 and 5 had significant changes for PF1-PF3 for the PDM. Although the participants had distinct changes, we noted the tendency of the articulated AFO with mechanical joint to systematically impact the moment and angles of stroke survivors. Also, we noted that participant one, who was the most affected benefited most from the use of the articulated AFO in comparison to his clinically prescribed device. These results reinforce the potential of the articulated AFO with the mechanical joint as a viable assistive device for ‘onsite resistance tuning’ to aid the clinical prescription of AFOs for stroke survivors. Further investigation with a larger sample size could ensure the development of a standardized prescription mechanism.