If you don't have proper form when you walk for fitness, you may be missing out on some of the benefits -- you may even be setting yourself up for injury. Los Angeles-based fitness professional Lalo Fuentes has identified some common problems people have with walking form:

• Easy gliders. Some people walk with a very relaxed/cool stride; They tend to bring their legs forward and their heels touch the ground first. This type of walk can put the body off-balance and doesn't work the hamstrings and glutes as much as it should. If this sounds like you, then straighten up -- imagine a string being pulled upward from your head -- your stride will improve and so will the effects of your walking workout.
• Tippy toes. Many people who are into sports are used to being light on their feet. This can lead to a walking stride where the middle of the feet hit the ground first and heels immediately rise, leaving the person practically on tip-toe. The calf muscles are getting a great workout, but the hamstrings are virtually ignored. When walking, you should strike the ground first with your heel and then roll through from heel to toe.
  

When you have proper walking form, your calves, hamstrings, glutes, and obliques will get a better workout. In addition, you'll have better posture -- and, remember, posture has a big impact on your appearance. See AOL Health for more tips on walking workouts.