ABSTRACT Skier’s Edge: Biomechanical Analysis Benjamin T. Johannes The Skier’s Edge trainer can be used by novice or expert skiers. Testing was performed to analyze if the use of the Skier’s Edge could reduce in shear forces of the valgus moment on the knee joint and anterior cruciate ligament (ACL) due to lesser fatigue of muscle and a higher hamstring to quadricep (H/Q) ratio activity. This leads to a reduction of improper form and an increase in balance. Experiments performed observed the change in muscle activity with the use of the Skier’s Edge over time when compared to other forms of workout (elliptical and or a traditional ski conditioning workout). Comparison of the three workout methods was completed by collecting kinematic, kinetic and electromyographic (EMG) data. Each participant, 9 male skiers (22±3 years old, 70.56±3.44 inches, 206±54 lbs.) and 6 female skiers (22±4 years old, 66.25±3.25 inches, 148±72 lbs.), were separated into even groups between the workout types. Data was collected initially and after a four-week period of exercise for each respective workout group. A relative valgus moment was found with the force and valgus angle data and an H/Q ratio was created using the vastus medialis and semitendinosus EMG data for the respective muscles. The findings of this study show that there were no significant differences between the workout types for either reduction of valgus moment or an increase in H/Q ratio which are indicators of reduced ACL injury. Trends in the data indicate that the elliptical workout may have a positive impact on H/Q when compared to the Skier’s Edge workout. Recommendation for future study includes having participants complete a more intense and longer workout period or to focus on the elliptical and Skier’s Edge workout to test for significant differences to aid in ACL injury reduction.

A cirurgia de terceiro molar é um dos procedimentos mais realizados na área de cirurgia e traumatologia bucomaxilofaciais. A evolução pós-cirúrgica era baseada em evidência clínica. No nosso trabalho, propusemos acompanhar a evolução pós-cirúrgica através da utilização do eletromiografia de superfície. Realizamos quatro tomadas, no pré-operatório, normalizando, e três no pós-operatório, 7, 14, 21 dias, em amostra de 30 pacientes. Observamos, no vigésimo primeiro dia, recuperação próxima da normalização no gênero feminino e ainda aquém no gênero masculino. Constatamos que a eletromiografia de superfície é sensível para controle da evolução pós-cirúrgica, demonstrando ser um método eficaz e seguro. / The third molar surgery is one of the most frenquently performed procedures in the buccal-maxillary-facial traumatology and surgery areas, whereas the post-surgery evolution has been based on the clinical evidence until now. In our study, we proposed to analyze the post-surgery clinical evolution through the use of electromyograph of surface. We have made four takes, on the presurgery, normalizing, and three on the 7, 14 and 21 postoperative days, in a sample of 30 patients. We observed, in the twentieth-first day, a recovery close to normalization on women, but men did not reach normalization. The electromyograph of surface is sensitive to the post-surgery evolution control, and is an efficient and safe method.

A cirurgia de terceiro molar é um dos procedimentos mais realizados na área de cirurgia e traumatologia bucomaxilofaciais. A evolução pós-cirúrgica era baseada em evidência clínica. No nosso trabalho, propusemos acompanhar a evolução pós-cirúrgica através da utilização do eletromiografia de superfície. Realizamos quatro tomadas, no pré-operatório, normalizando, e três no pós-operatório, 7, 14, 21 dias, em amostra de 30 pacientes. Observamos, no vigésimo primeiro dia, recuperação próxima da normalização no gênero feminino e ainda aquém no gênero masculino. Constatamos que a eletromiografia de superfície é sensível para controle da evolução pós-cirúrgica, demonstrando ser um método eficaz e seguro. / The third molar surgery is one of the most frenquently performed procedures in the buccal-maxillary-facial traumatology and surgery areas, whereas the post-surgery evolution has been based on the clinical evidence until now. In our study, we proposed to analyze the post-surgery clinical evolution through the use of electromyograph of surface. We have made four takes, on the presurgery, normalizing, and three on the 7, 14 and 21 postoperative days, in a sample of 30 patients. We observed, in the twentieth-first day, a recovery close to normalization on women, but men did not reach normalization. The electromyograph of surface is sensitive to the post-surgery evolution control, and is an efficient and safe method.