The answer to this should be:
<span>introduction</span>
For items over 50 pounds, squat down and firmly grasp the object. If necessary use gloves. When lifting, lift with the knees, not the back.
Walking briskly (3 miles per hour or faster, but not race-walking)
Water aerobics.
Bicycling slower than 10 miles per hour.
Tennis (doubles)
Ballroom dancing.
General gardening.
