Anyway, still thinking of the upcoming Hillfit articles, he had a good piece on the walking gait the other day:
I'll copy all of it here but all his articles are worth checking out.
More on Gait
Dr. Phil Maffetone
The two-part article on gait (May 2011) was very popular. Among the reader’s questions were those about walking gait. Walking is an ideal workout for fat burning and overall fitness for millions of people. Runners often walk too, as warm up or cool down, as a method to develop more endurance (i.e., longer runs), and even during marathons, often unplanned. It’s actually not unusual to see the walking gait of runners as abnormal.
As discussed in the article on gait, there’s an obvious difference between walking and proper running, especially in how the foot strikes the ground (on the heel for walkers and more forward in runners). The walking body, which always has one foot in contract with the ground, functions like an inverted pendulum, swinging along step-by-step, literally vaulting over stiff legs with locked knees. Running should not involve locking the knee, as each is always slightly flexed while the foot is on the ground. Herein lies one problem with many runners who walk, and even those who don’t run. When walking, many people keep their knee slightly flexed instead of locked. It’s as if their knee is in a running gait pattern while the rest of the body is walking. This poses a potential physical problem—stress on the knee joint and in the muscles around it.
When walking, you should gently be locking your knee with each step, as you “vault over your foot and start pushing off. That doesn’t mean thrusting the knee joint into extension. But naturally allowing it to go into full extension and lock momentarily before continuing the normal gait cycle. This should never cause pain in the knee—if it does it means something is wrong somewhere (such as muscle imbalance, poor foot mechanics, or bad shoes).
In competitors performing the Olympic walk, in addition to making sure there is always contact with the ground, locking the knee is a requirement—otherwise they may be disqualified.
All other walkers need not be so concerned other than to avoid unnatural gait movements. Improper shoes promote this more than anything else. For runners, the problem may be they’re used to a slightly flexed knee during running and somehow this gets translated into a walking gait.
Many other factors discussed in the running gait article also apply to walkers. These include an upright posture, which promotes the use of the abdominal and gluteus maximus muscles, a slightly forward center of gravity (but not bending forward), allowing the pelvis to lead the way, and a level head. And, the wearing of flat shoes, which, while landing on your heels, you don’t remain there very long as your muscles and body’s forward motion quickly move you through the mid-foot and toe-off phase of gait.
Another question about gait was regarding children, and how shoes can interfere with it. This requires more discussion and is the topic of an upcoming article.
Phil's piece on hiking is also worth reflecting on.