Each year in the United States, fifty percent of adults suffer from low back pain leading to an estimated $50 to $100 billion a year in compensatory costs (1). Those who are affected the most include operators and laborers, comprising up to 42 percent of all injuries, while service professions make up 20 percent (1). For these reasons it is important to identify the causes of low back pain so that their effects can be minimized. This study will analyze two biomechanical motions and compare the torques acting upon the lower back and hip joints in both cases.
The first motion will involve lifting a load from the ground when bending from the knees ("squat lift"). The second motion will require lifting the same load when bending only at the hip joints ("back lift"). We hypothesize that the squat lift reduces the amount of stress acting upon the lumbar vertebrae compared to the back lift. We will use digital video analysis to identify differences in joint angles and body segment position to discuss angular and linear kinematics.