Matching Items (23)
Description
According to the Center for Disease Control and Prevention report around 29,668 United States residents aged greater than 65 years had died as a result of a fall in 2016. Other injuries like wrist fractures, hip fractures, and head injuries occur as a result of a fall. Certain groups of people are more prone to experience falls than others, one of which being individuals with stroke. The two most common issues with individuals with strokes are ankle weakness and foot drop, both of which contribute to falls. To mitigate this issue, the most popular clinical remedy given to these users is thermoplastic Ankle Foot Orthosis. These AFO's help improving gait velocity, stride length, and cadence. However, studies have shown that a continuous restraint on the ankle harms the compensatory stepping response and forward propulsion. It has been shown in previous studies that compensatory stepping and forward propulsion are crucial for the user's ability to recover from postural perturbations. Hence, there is a need for active devices that can supply a plantarflexion during the push-off and dorsiflexion during the swing phase of gait. Although advancements in the orthotic research have shown major improvements in supporting the ankle joint for rehabilitation, there is a lack of available active devices that can help impaired users in daily activities. In this study, our primary focus is to build an unobtrusive, cost-effective, and easy to wear active device for gait rehabilitation and fall prevention in individuals who are at risk. The device will be using a double-acting cylinder that can be easily incorporated into the user's footwear using a novel custom-designed powered ankle brace. The device will use Inertial Measurement Units to measure kinematic parameters of the lower body and a custom control algorithm to actuate the device based on the measurements. The study can be used to advance the field of gait assistance, rehabilitation, and potentially fall prevention of individuals with lower-limb impairments through the use of Active Ankle Foot Orthosis.
ContributorsRay, Sambarta (Author) / Honeycutt, Claire (Thesis advisor) / Dasarathy, Gautam (Thesis advisor) / Redkar, Sangram (Committee member) / Jayasuriya, Suren (Committee member) / Arizona State University (Publisher)
Created2020
Description
Between 20%-30% of stroke survivors have foot drop. Foot drop is characterized by inadequate dorsiflexion required to clear the foot of the ground during the swing phase of gait, increasing the risk of stumbles and falls (Pouwels et al. 2009; Hartholt et al. 2011). External postural perturbations such as trips and slips are associated with high rate of falls in individuals with stroke (Forster et al. 1995). Falls often results in head, hip, and wrist injuries (Hedlund et al 1987; Parkkari et al. 1999). A critical response necessary to recover one’s balance and prevent a fall is the ability to evoke a compensatory step (Maki et al. 2003; Mansfield et al. 2013). This is the step taken to restore one’s balance and prevent a fall. However, this is difficult for stroke survivors with foot drop as normal gait is impaired and this translates to difficulty in evoking a compensatory step. To address both foot drop and poor compensatory stepping response, assistive devices such as the ankle-foot-orthosis (AFO) and functional electrical stimulator (FES) are generally prescribed to stroke survivors (Kluding et al. 2013; S. Whiteside et al. 2015). The use of these assistive devices improves walking speed, foot clearance, cadence, and step length of its users (Bethoux et al. 2014; Abe et al. 2009; Everaert et al. 2013; Alam et al. 2014). However, their impact on fall outcome in individuals with stroke in not well evaluated (Weerdesteyn et al. 2008). A recent study (Masood Nevisipour et al. 2019) where stroke survivors experienced a forward treadmill perturbation, mimicking a trip, reports that the impaired compensatory stepping response in stroke survivors in not due to the use of the assistive devices but to severe ankle impairments which these devices do not fully address. However, falls can also occur because of a slip. Slips constitute 40% of outdoor falls (Luukinen et al. 2000). In this study, results for fall rate and compensatory stepping response when subjects experience backward perturbations, mimicking slips, reveal that these devices do not impair the compensatory stepping response of its users.
ContributorsAnnan, Theophilus (Author) / Honeycutt, Claire (Thesis advisor) / Abbas, James (Committee member) / Peterson, Daniel (Committee member) / Arizona State University (Publisher)
Created2021
Description
This research seeks to present the design and testing of exoskeletons capable of assisting with walking gait, squatting, and fall prevention activities. The dissertation introduces wearable
robotics and exoskeletons and then progresses into specific applications and developments in the
targeted field. Following the introduction, chapters present and discuss different wearable
exoskeletons built to address known issues with workers and individuals with increased risk of fall.
The presentation is concluded by an overall analysis of the resulting developments and identifying
future work in the field.
ContributorsOlson, Jason Stewart (Author) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / Honeycutt, Claire (Committee member) / Arizona State University (Publisher)
Created2021