SubscribeI 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.
For more information see Kinesiology of Exercise
by Mark, on June 16 2010 @ 12:45 pm
That’s interesting I have only seen the golfers pick up or going down to one knee. Unfortunately most people probably don’t have enough glute strength for picking something up off the floor while maintaining a neutral spine.
by DrYessis, on June 16 2010 @ 4:40 pm
Right on!
by Chris, on August 1 2010 @ 1:37 pm
“Trying to lift while maintaining an erect body posture leads to an unbalanced position and excessive stress on the knees. It is very dangerous.”
This is a strange statement since many lifts are done with a near vertical spinal position. Front squats and overhead squats both try to maintain a vertical torso position during the lift. This allows for the hips (movers) to remain under the load while keeping the bar over the centre of the foot. These movements are both used extensively in Olympic Weightlifting (snacth and clean) and casue no ill effects when performed properly.
Furthermore movements such as the sumo-deadlift are commonly used to lift extreme amounts of weight and can be performed both with a near vertical torso as well as an inclined one (45 degrees).
In theory, as well as practice, torso angle during lifting is dependent upon the dimensions of the object being lifted whether from the ground or from a standing position. If you are lifting a 4 foot high box from the ground that weights a considerable amount, you will first place yourself as close to the object as possible and then establish a torso angle which best facilitates the lift (most likely not a 45 degree angle especially if lifting the object alone). Though the knee angle may be considerably larger during this lift the potential for injury is substantially less likely than that indicated. Basic mathematics (and biomechanics) both indicate that the greatest amount of force placed on a fulcrum or point of axis is at a 90 degree angle, which indicates that a greater angle at the knee during lifting does not increase the potential for injury due to force but to pre-existing ailments (i.e. imbalances in agonist/antagonist activity or weak connective tissue).
by DrYessis, on August 6 2010 @ 11:15 am
Chris, my statement that an erect body position can lead to injuries still stands. If you look closely at the Olympic lifts as well as the powerlifting squat, you’ll see that the trunk inclines forward, up to about a 45° angle. Maintaining an erect position with the hips under the shoulders and the bar over the feet means that the knees will protrude way out in front. This is how many athletes blow out their knees.
In the front and overhead squats the trunk is more erect in order to maintain balance, but never perfectly erect. Also there are two factors to consider in regard to angles: the mechanical advantage and the angle of muscle pull. Both of these must be considered to find the optimal angle.