I continue to read articles relating to how you should lift an object. Even in doctor’s offices I see booklets and articles with pictures depicting how the lifting should be done. In almost all cases they show the individuals with their upper body straight (vertical).
In this position they are supposed to bend the knees to get low enough to grasp the object while keeping the upper body vertical and then use the legs to rise up. Is this an effective — and safe — way of lifting? NO!
To lift correctly you should in essence do the squat exercise. In the squat you hold the back (spine) at approximately a 45° angle when you grasp a barbell or other object. You then rise up back to the vertical position lifting the object off the floor.
The same thing happens when you execute the clean. You assume the same posture on the descent inclining the back up to 45° to grasp the barbell and then execute the up phase of the squat. It may not be identical to the squat but the joint actions in the knees and hips are the same.
The trunk should never be upright (erect) when lifting off the floor. In order to maintain the forward angle you must have strong glutes and hamstrings and have the ability to maintain the arched back at all times. This means you should have strong lower back muscles in addition to the glutes and hamstrings.
For successful lifting you should have a strong posterior chain. This is the key to correct, safe and effective lifting. Trying to lift while maintaining an erect body posture leads to an unbalanced position and excessive stress on the knees. It is very dangerous — just as dangerous as lifting with your back.