Note how the model is tilted forwards to get a greater range of movement. His arms are free, supported by his back.
Now he is incorrectly bending forwards from the waist. His legs are braced, and his head is pulled back.
Here the model has aligned herself nicely to make the bed. Her legs are bent, Short to long haircuts shoulder length creating a greater range of movement.
This model is lunge squatting to brush up dirt from the floor. She has maintained her good use, giving herself a maximum range of movement. She looks good and feels good.
Here, in an incorrect example of how you should sweep the floor, the model is badly restricting his range of movement. He is quite clearly unbalanced, and feels totally uncomfortable.
Note how this man is squatting sensibly to plant a rose bush in his garden. By placing himself at the same level as the rose, he is allowing himself a greater range of movement lifting and carrying A lot of back pain is the result of lifting heavy weights. To avoid back strain, stand near to the load by placing your feet either side of it, and maintain the alignment between head, neck and back. Go into the monkey or lunge monkey and squat. Then bend your arms so that your elbows are close to your body. Make sure that you widen out across the upper arms, and avoid tension in the arms and wrists.