There are various ways to measure physical strength of a person or population. Strength capability analysis is usually done in the field of ergonomics where a particular task (e.g. lifting a load, pushing a cart, etc.) and/or a posture is evaluated and compared to the capabilities of the section of the population that the task is intended towards. The external reactive moments and forces on the joints are usually used in such cases. The strength capability of the joint is denoted by the amount of moment that the muscle force can create at the joint to counter the external moment.