Tips to avoid compressing the spinal discs or straining your lower back when lifting:
Keep your feet shoulder-width apart, with one foot slightly ahead of the other
Squat down, bending at the hips and knees only. If necessary, put one knee to the floor and your other knee in front of you, bent at a right angle (half kneeling).
To maintain good posture. Look straight ahead, and keep your back straight, your chest out, and your shoulders back. This will keep your upper back straight while maintaining the proper curve in your lower back.
Slowly lift by straightening your hips and knees (not your back). Keep your back straight, and never twist as you lift.
Hold the load as close to your body as possible, at waist level..
Use your feet to change direction, taking small steps.
Lead with your hips as you change direction. Keep your shoulders in line with your hips as you move.
Set down your load carefully, squatting with the knees and hips only.
Never attempt to lift or pick anything up off the floor by bending forward. Always bend your hips and knees to squat down and keep the load close to your body, straighten your legs to lift, do not use your back muscles. Never lift a heavy object above shoulder level. Avoid turning or twisting your body while lifting or holding heavy objects. Make sure your nose and toes always point in the same direction.