MECHANICAL VARIABLES OF JUMPING DURING NAVAL ACADEMY OBSTACLE COURSE TRAINING ACTIVITIES

Abstract

Introduction•-The use of the obstacle course (O-course) activities at the U.S. Naval Academy is mandatory for all midshipmen. To reduce injuries on the 0course, research has been conducted to evaluate other methods related to specific work assignments. The purpose of this study was to determine which variables contributed to the successful jump used in jumping to clear a shelf. METHODS -Five males (age: 20.2 yrs ±1.3; hgt: 178.6 cm± 3,7; wgt: 77.4 kg±7.7) and five females (age: 20.0 yrs ±1.9; hgt: 170.64 cm±7.3; wgt: 63.8 kg ± 8.5) served as subjects. Anthropometric, strength, and video data were collected at the U.S. Naval Academy, Annapolis MD. Three-dimensional video images were collected from the sagittal and posterior views as subjects scaled a shelf. Fifteen data points were digitized, files transformed, data smoothed with a digital filter set at 10Hz and graphed with the Ariel Performance Analysis System (APAS). RESULTS -Statistical differences using two-sample t-tests were found between males and females in the variables: hgt (t=2.193); wgt (t=2.639); percent body fat (t=5.028); leg length (t=2.128); knee flexion peak torque % BW(t=4.459); knee extension peak % BW (t=2.128); knee flexion (t=1.937); and hip extension (t=3.207). All subjects cleared the shelf. However, several subjects used additional time to complete the skilI. Because differences were noted in anthropometric, strength, and kinematic variables, the skill of jumping to c1eartheshelfseemsto favor the taller, stronger individuals. CONCLUSIONS -Because the Navy is incorporating gender neutral standards into their physical training standards, the 0course may not be the most appropriate way of measuring these standards.