Optic flow improves step width and length in older adults while performing dual task

Background Dual-task paradigms are used to investigate gait and cognitive declines in older adults (OA). Optic-flow is a virtual reality environment where the scene flows past the subject while walking on a treadmill, mimicking real-life locomotion. Aims To investigate cost of environment (no optic-flow v. optic-flow) while completing single- and dual-task walking and dual-task costs (DTC; single- v. dual-task) in optic-flow and no optic-flow environments. Methods Twenty OA and seven younger adults (YA) walked on a self-paced treadmill in 3-min segments per task and both environments. Five task conditions included: no task, semantic fluency (category), phonemic fluency (letters), word reading, and serial-subtraction. Results OAs had a benefit of optic-flow compared to no optic-flow for step width (p = 0.015) and step length (p = 0.045) during letters compared to the YA. During letters, OA experienced improvement in step width DTC; whereas YA had a decrement in step width DTC from no optic-flow to optic-flow (p = 0.038). During serial-subtraction, OA had less step width DTC when compared to YA in both environments (p = 0.02). Discussion During letters, step width and step length improved in OA while walking in optic-flow. Also, step width DTC differed between the two groups. Sensory information from optic-flow appears to benefit OA. Letters relies more on verbal ability and word knowledge, which are preserved in aging. However, YA use a complex speech style during dual tasking, searching for complex words and an increased speed of speech. Conclusions OA can benefit from optic-flow by improving spatial gait parameters, specifically, step width, during dual-task walking

Spring-loaded Shoe Affect Step Characteristics in Patients with Peripheral Artery Disease

Intermittent claudication is a common symptom observed in peripheral artery disease (PAD) that causes pain or discomfort in the calf muscle during walking. Shoe pitch and support provided to the ankle joint influence the metabolic demands of the calf muscle during walking. This research aims to evaluate spatiotemporal parameters of gait in patients with PAD when walking with regular, carbon fiber, and spring-loaded shoes. We hypothesized that carbon fiber and spring-loaded assistive shoes would improve gait characteristics by assisting the calf muscles during push off. Eight PAD patients engaged in a progressive treadmill test protocol, at a speed of 2 mph, while wearing regular, carbon fiber, and spring-loaded shoes across three conditions in a randomized order. Outcome measurements, step width, stride length, stride time, cadence, and velocity, were recorded for each condition. A one-way repeated measure analysis of variance (ANOVA) test was performed to investigate the effect of footwear on gait outcomes within three conditions. The mean percent difference (%difference) was assessed to compare changes in the mean values of the spring-loaded and carbon fiber conditions to the regular condition. No significant differences were seen in the spatiotemporal parameters across any of the conditions. In the spring-loaded condition, the %difference increased in stride length (10.1%), decreased in cadence (14%) and step width (11.4%), and no relevant threshold differences were observed in stride time or velocity. In the carbon fiber condition, %difference increased in stride length (8.3%), decreased in stride time (3.6%) and cadence (10%), and no relevant threshold differences were observed in step width or velocity. Previous studies have reported that selective footwear is not a solution to improving gait in PAD patients. While the statistical analysis did not provide significant differences, %difference changes in the spring-loaded and carbon fiber conditions were observed. The spring-loaded condition outperformed the carbon fiber condition by increasing stride length and inducing a faster gait. Further improvements were noted with a decrease in step width, indicating values closer to healthy individuals. A greater %difference in cadence is seen in the spring-loaded condition, indicating fewer steps were taken to achieve the same pace. The results of this study indicate that assistive shoes may have limited effectiveness for PAD patients upon immediate use. Furthermore, this study offers insights into potential enhancements in gait for PAD patients following a period of adaptation to assistive shoes

Ankle Foot Orthoses Improves Ground Reaction Forces in patients with Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by atherosclerotic blockage of the arteries in the legs. Globally, over 236 million people suffer from PAD. Intermittent claudication is the most common PAD symptom that includes muscle pain, cramping, and/or aching induced by physical activities and relieved with rest. PAD impacts gait patterns: specifically, rapid ankle plantar flexion after heel contact, which decreases optimal energy transfer. An ankle-foot orthosis (AFO) is an assistive device that improves gait in patients with neurological conditions. AFOs could help patients with PAD to improve walking kinetics. The purpose of this study was to determine the impact of AFOs on ground reaction forces (GRF) during walking in PAD patients. In this study, fourteen patients with PAD were assessed before and after a three-month intervention with AFO. GRFs data were recorded while participants walked with AFO (AFO) and without AFO (NAF) over the force platforms. Five successful heel strike and toe-off events in each condition were needed to complete the study. To prevent the onset of intermittent claudication, one minute of rest was required between each walking trial. Peak values from anterior-posterior, medial-lateral, and vertical GRFs were computed. The results showed AFOs improved vertical and lateral ground reaction forces, moving patients with PAD back towards the patterns of healthy older individuals without PAD. Additional studies of how AFOs and other assistive walking devices impact gait are needed to understand the potential for assistive device interventions to help patients with PAD