2019 Pennsylvania Academy of Science Student Abstracts Zachary McMaster ’19 Major: Exercise and Biological Science “Analysis of the Effects of Pre-operative Physical Therapy on Range of Motion in Individuals Undergoing Total Knee Replacements” Approximately 800,000 total knee replacement (TKR) procedures are performed annually in the United States. This number is projected to increase to 3.48 million per year by 2030. This study investigated knee range of motion of patients at various time points after TKR surgery, as well as the total number of visits required to regain full range of motion at the knee. One group of patients underwent pre-operative physical therapy, while the other group only had post-operative physical therapy. By strengthening the quadricep muscle before surgery, less atrophy may occur. The atrophy can occur due to a condition known as muscle inhibition. Having a stronger quadricep going into surgery may result in fewer post-operative physical therapy visits. Under the guidelines of Health Insurance Portability and Accountability Act (HIPAA) and Institutional Review Board (IRB) regulations, data regarding age, body mass index, knee range of motion, and clinical visits at Waynesboro Physical Therapy and Sport’s Medicine and its affiliates for patients who underwent a TKR in the previous five years was collected. When analyzing the data, an ANOVA and t-test will be most useful in determining the significance of differences between the groups. Analysis will also include the difference in knee range of motion at one-week post-op. A comparison of interest includes examination of BMI as it relates to the number of visits needed for pre-operative physical therapy, and post-operative physical therapy vs. solely post-operative physical therapy. Preliminary data indicates that patients that undergo physical therapy prior to surgery typically have better outcomes after TKR surgery. Advisers: M. Dana Harriger and Tonia M. Hess-Kling Katelynn Gilbert ’19 Major: Biology “Short-term Characterization of a Biofilm in a Free-flowing Freshwater Creek in Southcentral Pennsylvania” Previous research has been conducted on the relationship between bacteria and algae within lakes, and demonstrated a positive correlation between bacterial growth and algae mats as a type of biofilm. Biofilms are heterogeneous mixtures of microorganisms such as bacteria and algae that are held together by Extracellular Polymeric Substance (EPS). A free-flowing, freshwater system is a unique environment in comparison to a stagnant system. Many environmental factors can impact the aquatic system as it proceeds downstream from the headwaters. This then affects biofilm growth within the system to varying degrees. The purpose of this study was to characterize populations of microorganisms within a biofilm collected from a creek, and determine how the growth of those organisms was affected over time and with temperature changes. Five sample sites were used along the Conococheague Creek in Southcentral Pennsylvania, beginning 11.9km from the headwaters and ending 29.6km downstream from the headwaters. The factors examined in this experiment included ambient air and water temperature, Gram positive and negative bacteria, and photosynthetic autotrophs within the biofilm. Sampling was performed at each site on three days over a two-week period in November 2018. Three sub-samples of biofilm were collected at each site, one from each edge of the creek and from the middle. Data indicates that a common genus of algae between the five sites was Closterium, while points further downstream had genera of cyanobacteria that were not as prevalent in the headwaters, such as Lyngbya. Initial analysis indicates that over the course of the study, photosynthetic organism populations were more greatly affected by temperature than bacterial populations. Statistical analysis is ongoing to determine whether there is significance between, or trends evident among, experimental parameters. Advisers: Deborah Austin, Rachael Zhu and M. Dana Harriger
