OBJECTIVE: To determine whether there is side to side difference of the trunk rotation muscle in Korean male professional golf players. Healthy controls who did not play golf were also evaluated and compared with professional golf players. METHOD: Fifty-one professional golf players and 50 healthy controls participated in this study. Bilateral isokinetic trunk rotation strength that represented the aiming side and non-aiming side trunk rotator function in a golf swing and other parameters were evaluated using the Biodex System III Isokinetic Dynamometer at angular velocities of 30, 60, and 120 degree per second. RESULTS: The professional golf players' peak torque and total work on their aiming sides were significantly higher than on their non-aiming side at all angular velocities. Additionally, the golf players' peak torque on their aiming side was significantly higher than those of the healthy controls only at the 60 degree per second angular velocity, but there was a slight and consistent trend in the others. Finally, the difference between the aiming side and the non-aiming side of the professional golf players and the healthy controls was also significant. CONCLUSION: The aiming side rotation strength of the male professional golf players was higher than that of non-aiming side. The controls showed no side-to-side differences. This finding is attributed to the repetitive training and practice of professional golf players. A further study is needed to investigate if the strengthening of the trunk rotation muscle, especially on the aiming side, could improve golf performance.
Golf ; Humans ; Male ; Muscle Strength ; Muscles ; Torque ; Torso

OBJECTIVE: To evaluate the effects of physical properties of foods on the changes of viscosity and mass as well as the particle size distribution after mastication. METHOD: Twenty subjects with no masticatory disorders were recruited. Six grams of four solid foods of different textures (banana, tofu, cooked-rice, cookie) were provided, and the viscosity and mass after 10, 20, and 30 cycles of mastication and just before swallowing were measured. The physical properties of foods, such as hardness, cohesiveness, and adhesiveness, were measured with a texture analyzer. Wet sieving and laser diffraction were used to determine the distribution of food particle size. RESULTS: When we measured the physical characteristics of foods, the cookie was the hardest food, and the banana exhibited marked adhesiveness. Tofu and cooked-rice exhibited a highly cohesive nature. As the number of mastication cycles increased, the masses of all foods were significantly increased (p<0.05), and the viscosity was significantly decreased in the case of banana, tofu, and cooked-rice (p<0.05). The mass and viscosity of all foods were significantly different between the foods after mastication (p<0.05). Analyzing the distribution of the particle size, that of the bolus was different between foods. However, the curves representing the particle size distribution for each food were superimposable for most subjects. CONCLUSION: The viscosity and particle size distribution of the bolus were different between solid foods that have different physical properties. Based on this result, the mastication process and food bolus formation were affected by the physical properties of the food.
Adhesiveness ; Deglutition ; Hardness ; Mastication ; Musa ; Particle Size ; Rheology ; Soy Foods ; Viscosity