underwent tongue piercing by our physician-investigators. Four weeks later, each participant completed 12 weekly testing sessions. In 6 sessions, they used TDS to perform increasingly difficult computer tasks, including cursor navigation through a maze. These sessions were alternated with 6 weekly sessions using TDS to operate a power wheelchair through an obstacle course in un- latched, latched and semi-proportional control modes. Course com- pletion time and number of errors traveling outside the designated path were recorded. Ability to tilt the wheelchair using TDS was measured. They also operated a smart-phone using tongue move- ments. Measures were: “throughput” (average rate of successful message delivery over a communication channel), “error rate” (in percentage), and “task completion time” (in minutes). Performance data were compared across testing sessions. Setting: Rehabilitation research laboratory. Results: There were no serious complications of tongue piercing or TDS testing procedures. All participants were able to use TDS to perform all tasks, with improvement in performance across testing sessions. Throughput (bits per second) increased in vertical tap- ping, horizontal tapping, center-out tapping, multi-directional tap- ping, and information transfer rate. Error rate and completion time decreased across sessions in all of the same measures, and in maze navigation and obstacle course performance. Conclusions: Preliminary evidence suggests that TDS is a safe and effective way to control wheelchairs, computers, and smart- phones using tongue motion. Friday, November 16 3:30PM-5PM Convention Center, C204, Level 2 419. PEDIATRIC RESEARCH AND CLINICAL PEARLS Poster 435 Improvements in Functional Mobility After Hamstring Lengthening in Ambulatory Children with Cerebral Palsy. Erika E. Erlandson, MD (University of Kentucky, Lexing- ton, KY, United States); Henry J. Iwinski, MD; Hank White, PT, PhD. Disclosures: E. E. Erlandson, No Disclosures. Objective: To assess the effects of hamstring lengthening proce- dure on gross mobility, and oxygen requirements in ambulatory children with cerebral palsy, spastic diplegia. Design: Retrospective study of 78 children with cerebral palsy, spastic diplegia treated with a hamstring lengthening procedure performed between 1998-2010. Multiple measures related to gross mobility and functional ambulation (including oxygen require- ments) were used for assessment as part of their comprehensive evaluations pre-operative and post-operatively. It was hypothesized that gross motor function would significantly improve and oxygen cost and consumption during ambulation would significantly de- crease post-operatively. Setting: Free-standing pediatric orthopedic hospital. Participants: 78 ambulatory children with a diagnosis of cerebral palsy, spastic diplegia. Interventions: Hamstring lengthening procedure. Main Outcome Measures: Gross Motor Function Measure (GMFM) dimensions D (standing) & E (walking, running, and jumping), oxygen cost and consumption during ambulation. Results: There was a significant decrease in oxygen consumption and cost across all groups after surgical intervention (P.001). The GMFM dimensions D and E were significantly improved when performed barefoot for patients with a GMFCS level 3, P=.004 and .011 respectively, as well as FMS level 2 with P.03 for all dis- tances. In addition, GMFM dimension E barefoot was significantly improved in patients with GMFCS level 2 (P=.048). Conclusions: Hamstring lengthening procedures significantly improves gross mobility, functional ambulation, and oxygen re- quirements for ambulation in patients with cerebral palsy, spastic diplegia who ambulate with an assistive device (GMFCS level 3, FMS level 2). In addition, significant decreases in oxygen cost and consumption for all children included in our study. Poster 452 Risk Factors for Fractures Among Males with Duchenne or Becker Muscular Dystrophy. Susan Apkon, MD (Seattle Children’s Hospital and Uni- versity of Washington, Seattle, WA, United States); Emma Ciafaloni, MD; Christopher Cunniff, MD; Caleb Holtzer, MPH; Kathy James, PhD; Zhenqiang Lu, PhD; Katherine Matthews, MD; Lisa Miller, MD, MSPH; Shree Pandya, DPT. Disclosures: S. Apkon, No Disclosures. Objective: To determine the occurrence of fractures and risk factors for fractures among the Muscular Dystrophy Surveillance, Tracking and Research Network (MDSTAR Net) cohort, a large, multi-site sample of patients with Duchenne or Becker muscular dystrophy (DBMD). Design: Multi-site cohort study. Setting: Five surveillance sites including Arizona, Colorado, Geor- gia, Iowa, and Western New York. Participants: Patients with definite or probable DBMD, born between 1982 through 2006 and at least 4 years of age at the time of the last chart abstraction. Interventions: Risk factors associated with fractures in patients with DBMD were evaluated using multivariate Cox proportional hazard modeling and descriptive statistics. Case information was obtained from medical records including location and date of fracture; ambula- tion status; and medication use. Medication use included corticosteroid used longer than 6 months, calcium, vitamin D and bisphosphonates. Main Outcome Measures: First fracture occurrence during the time period beginning with case identification and ending with the last clinic visit abstracted including location and date of fracture, ambulation status, and medication use. Results: Of 747 subjects, 249 had at least one fracture (33.3 percent). Full-time wheelchair use increased the risk of fracture by 72%, and for every 12 months of corticosteroid use, the risk for fracture increased by 9%. Prior use of bisphosphonates or calcium/ vitamin D increased risk for fracture by 47% and 38%, respectively, however this group likely represents use among a population al- ready identified by clinicians as being at increased fracture risk. Conclusions: In this multivariate analysis of a large cohort of indi- viduals with DBMD there was a high frequency of fractures. Risk is increased among those using a wheelchair full-time and those using S183 PM&R Vol. 4, Iss. 10S, 2012