Objectives: 1. Find the optimal posture for lifting a load. 2. Apply the conditions of equilibrium to determine the amount of force that is exerted by the person’s Erector Spinae muscle FES when the person is bending over to support a load. 3. Calculate the magnitude of the Joint Reaction Force JRF. 4. Find out how the force on the person’s erector spinae muscle and the joint reaction force depend on postures.
The simulation is based on a normally proportioned person. You can adjust the postures of the person by inputting different values of ΘTNH and ΘAH. For example, ΘTNH=0˚ and ΘAH=90˚ when a person stands with arms leveled.
When you try to find the optimal posture for lifting a load to avoid potential injury, you aim to find low values on erector spinae muscle and the joint reaction force. (Hint: in order to achieve the goal, please control variables by keeping weight and height of the person, weight of the load fixed and changing ΘTNH and ΘAH values.)
