The order of joint forces describes the amount of force placed through the musculo-skeletal system during a type of exercise or test.
The higher the force the more likely the exercise will be painful and the higher the likelihood of injury during it.
Eccentric actions are always more stressful on the body's systems because more force can be generated during these actions. Isotonic comes top of the list as the inertial properties of the movements can create forces well beyond that of the system trying to control them.
Concentric actions are always lowest as the muscle must be able to generate the force required to complete the action.
There are exceptions e.g. isometric forces may be high for muscles and tendons but are actually very low for joints. Whilst concentric actions may be higher for joints but low for muscles.
(Adapted from Davies, 1984)