Spasticity is a debilitating condition in people with upper motor neuron disorders that interferes with an individual’s activities of daily living and sleep. Spasticity can lead to loss of body control and balance resulting in falls, pressure injury of the skin, contractures, and pain. Spasticity hinders the ability to functionally use voluntary muscle contraction; thus, limiting body transfers, ambulation, and exercise. Despite the negative impact of spasticity in people with spinal cord injury (SCI), the available tools to manage spasticity and overcome functional deficits are limited. Oral medications are typically prescribed at the start of treatment due to its ease of administration; however, they may induce significant side effects including drowsiness and muscle weakness, and their effectiveness is sensitive to dosing fluctuations. Neurosurgery can treat severe spasticity, but it carries surgical risks, and the long-term benefits vary across individuals. Manual therapy and leg stretching are primary treatments for a large subset of people with spasticity, which is usually performed by caregivers and nurses with relatively low adverse effects. Manual stretching can provide relief from muscle spasms, decrease joint stiffness, normalize muscle tone, reduce pain, and improve range of motion. However, providing on-demand, reliable manual limb stretching is caregiver intensive and imposes a heavy burden on nurses in hospitals and caregivers at veterans’ homes. COVID-19 has exacerbated difficulties in receiving manual stretching to manage spasticity by limiting physical assistance in veterans with SCI due to family visit restrictions and staffing shortages. Moreover, existing devices used to mitigate spasticity such as passive stretchers, casts and night splinters do not fully conform to the user's body and are typically bulky and lack versatility to customize the forces applied to the user. People wearing them may feel discomfort, weakness, or pain, and even experience pressure sores. Our long-term research goal is to develop novel, non-invasive rehabilitation strategies addressing the debilitating effects of spasticity, which can play an integral role in improving quality of life and independence in persons with upper motor neuron injury. This feasibility study will establish preliminary evidence for the development of a novel wearable, portable leg exoskeleton capable of providing leg stretching - similar to the manual stretching provided by caregivers. The objectives in this project are to 1) integrate a wearable exoskeleton and its closed-loop control algorithm to provide strategic joint forces to assist dynamic leg stretching; and 2) evaluate the stretching approach in 10 veterans with spasticity to establish safety, acceptability, ease of use, and user satisfaction. Our central hypothesis is that the intelligent velocity control of the wearable device can apply safe forces about the hip and knee joints to yield safe, automated stretching...