It is a widespread proposition on multiple fitness websites that joints are better able to withstand compressive forces than shear forces.
For example: Precision Nutrition and Boot Camp Military Fitness.
But I can't find any evidence that this is true.
From first-hand experience I do believe it to be true. Take the leg extension, a commonly used isolation (single-joint) exercise that involves extension of a weight. All I've gotten from the leg extensions were joint pains.
For those who have exercised using these machines vs a squat/push-up, I think we can agree the latter is less harmful on the joints.
So where is the scientific evidence for this claim?