Influencing kinetic energy using ankle-foot orthoses to help improve walking after stroke: a pilot study

Abstract

Background: An ankle-foot orthosis with an oil damper (AFO-OD) may improve kinetics and kinematics for efficient walking after stroke. Yet it is unknown whether hemiplegic walking behaves like "inverted-pendulum" gait and how it is modulated by using AFO-ODs for efficiency.Objectives: This study examined whether the use of AFO-ODs improves the kinetics of total vertical ground reaction force (vGRF) and kinematics of vertical pelvic displacement (vPD) in different walking phases, and gait speed following stroke. Also, the relationship between those gait parameters was examined to assess efficient walking.Study design: Observational study within subject. Methods: Eight participants with hemiplegia walked at self-selected speed without and with AFO-ODs over the walkway and gait speed was measured. Force plates were used to measure total vGRF during the double-limb support phase with the paretic leading limb and with the paretic trailing limb (DSPT). The vPD in the paretic and nonparetic stance phases was measured by a threedimensional motion analysis system. Results: Without AFO-ODs, reduced total vGRF during DSPT was related to greater vPD in the subsequent nonparetic stance. Using AFO-ODs significantly increased gait speed and total vGRF during double-limb support phase with the paretic leading limb and during DSPT, which were significantly correlated. Vertical pelvic displacement in the nonparetic stance was higher than the paretic stance in both conditions. Conclusions: Decreased total vGRF during DSPT was compensated by excessive vPD in the nonparetic stance phase without AFO-ODs, indicating inefficient walking. However, the use of AFO-ODs improved the kinetic energy of total vGRF during the doublelimb support phase, contributing to efficient walking. Clinical relevance statement: The AFO-ODs can be used to improve kinetic energy and to modulate functions in the weight transition during the double-limb support phase, with faster walking speed. Thus, AFO-ODs can be considered to be therapeutic AFOs to acquire efficient walking performance in poststroke rehabilitation.

Advances in the clinical application of orthotic devices for stroke and spinal cord injury since 2013

“…A study has shown that the newly developed AFO with spring damper is superior to the PLS AFO in improving balance (68). Studies of AFO with an oil damper (AFO-OD) have suggested that AFO-OD might significantly improve ankle joint motor function and gait parameters in stroke patients (69,70). Another study conducted a gait analysis after rehabilitation with different AFOs.…”

The impact of ankle-foot orthosis's plantarflexion resistance on knee adduction moment in people with chronic stroke

“…Adjustment of the resistance of an AFO is commonly achieved by changing trimlines, components, or setting of orthotic joints to improve lower limb joint kinematics and kinetics in the sagittal plane during gait. 22,23 However, it remains unknown whether this adjustment would affect the knee adduction moments in the coronal plane and increase the risk for inappropriate medial joint loading and potential osteoarthritis. Investigating the effects of AFO plantarflexion resistance on the lower-limb joints in the coronal plane will provide new information to guide clinical decisions by clinicians and orthotists and improve clinical care for people who are poststroke.…”

Corrigendum

“…In the article mentioned above, 1 the author has requested the following corrections:1. Another inclusion criteria has been added to the paragraph under Methods on page 514.…”