People with spinal cord injury (SCI) experience a host of secondary complications that can impact their quality of life and functional independence. One of the more prevalent complications is spasticity, which occurs in response to spinal cord damage and the resulting disruption of motor pathways. Common symptoms include spasms and stiffness, and can occur more than once per hour in many people with SCI. Spasticity can have a negative impact over many quality of life domains, including loss of functional independence, activity limitations, and even employment. Its impact on health domains is also pronounced, with many people who have spasticity reporting mood disorders, depression, pain, sleep disturbances, and contractures. Spasticity can interfere with post-injury rehabilitation and lead to hospitalization. There are many treatments for spasticity in this population. However, many do not have long-term efficacy, and, if they do, they are often pharmacological in nature and carry side effects that could limit function or affect health. The goal of this pilot, randomized-controlled study is to investigate the potential efficacy and safety of a non-invasive treatment with a low side effect profile, extracorporeal shockwave therapy (ESWT). ESWT has shown some benefits in people with post-stroke spasticity with no long term side effects. Thirty individuals with chronic, traumatic SCI will be recruited. Fifteen will be provided with ESWT while the other fifteen will be given a sham treatment. Clinical and self-report measures of spasticity and its impact on quality of life will be collected, as well as quantitative ultrasound measures of muscle architecture and stiffness. The ultimate goal of this pilot project is to collect the data necessary to apply for a larger randomized-controlled trial. Conducting a larger trial will allow for a more powerful estimation of safety and efficacy of ESWT as a treatment for spasticity in people with SCI.