INTRODUCTION

For the past number of years, ergonomics and safety has been on the minds of engineers. These engineers want to build a safer environment for the average worker, so that the worker will be more productive. If the work assignment is safe, the worker is made to feel that the upper management cares about him/her. This leads to the worker saying "That makes me feel good, I am going to work harder." One ergonomic debate that has not been solved is whether lifting a heavy object with ones' legs, known as a leg lift (squat lift), is safer than lifting the objects with ones' back, known as a stoop lift. The leg lift occurs with the knees bent, while the stoop lift occurs with the knees straight. Although our first impression may be to say of course it is easier to lift with your legs, that is what everyone tells us to do. However, both methods have advantages and disadvantages. The leg lift is known to decrease the disc compression force on the L5/S1 segment, but it also increases the amount of sheer force. For the leg lift versus the stoop lift, is there a noticeable biomechanical difference?

The object of our study is going to be comparing the leg lift versus the stoop lift from a biomechanical aspect. This will involve comparing the angles in the legs, arms, and torso during each movement. Members of this group have an industrial engineering background and are interested in solving ergonomics problems through biomechanical methods.