The Science of Barefoot Running
By Steve Nearman
Daniel Lieberman, PhD, known in the run- Do what you want, have fun, avoid injury, don’t belief, the bare foot may be well suited for run-
ning community as the “Barefoot Running fix what ain’t broke.” ning long distances without requiring modern,
Professor” has his favorite motto when ad- With his extensive research on barefoot heavily cushioned, high-heeled running shoes.”
dressing his favorite topic. running, Dr. Lieberman has discovered signifi- Dr. Lieberman was joined at the AMAA
“If you think barefoot running is a fad, cant benefits to running without shoes or with panel by Irene Davis, PhD, director of the
then it’s a two-million-year-old fad,” he told minimal shoes. Some of this research refutes newly-created Spaulding National Running
the audience of 175 doctors and sports medi- what the running shoes companies have been Center at Harvard Medical School and Mark
cine professionals at the 40th Annual Sports pitching for decades about the need for padded Cucuzzela, MD, professor of family medicine at
Medicine Symposium at the Boston Marathon running shoes to reduce injuries from pound- West Virginia University, who ran a 2:37 mara-
in April, sponsored by the American Medical ing the pavement. thon this year at Boston at age 44.
Athletic Association. According to Dr. Lieberman’s research, in- Drs. Lieberman and Davis have joined forc-
Dr. Lieberman, a professor of human evo- jury rates have not declined in 30 years even es at Harvard and are researching the barefoot
lutionary biology at Harvard University, has as major advances seem to have been made in running issue together.
become a cult hero of sorts for the growing running shoe technology over that time. Some Dr. Davis is considered one of the foremost
popularity of barefoot running. While he ad- 30 to 70 percent of habitually shod (shoe-wear- experts on the biomechanics of running and is
vocates that some people might benefit from ing) runners are injured each year, he added. known for her advocacy and innovative work
running with no shoes or minimal running And with all the advances in motion-control for barefoot and minimal footwear running.
shoes, he is quick to point out that your foot- running shoes, Dr. Lieberman stated, there is A preponderance of her research came
wear should depend upon your running style. no evidence that they prevent injuries. from the years she spent as a professor in phys-
“The lesson from barefoot running,” said “About 75 percent of runners today are pre- ical therapy and as the director of the Running
Dr. Lieberman, who claims he runs barefoot at dominantly heel strikers,” Dr. Lieberman said. Injury Lab at the University of Delaware. Over
times during his training, “is not about whether “Heel strikers generate a collisional impact. the past 20 years, she has established relation-
you run with or without shoes. What’s more im- Running shoes make it comfortable to heel ships between faulty mechanics and overuse
portant is your running form. But what is on strike.” injuries such as tibial stress fractures and
your feet can affect your form.” In Dr. Lieberman’s extensive writings, he patellofemoral disorders. This has led to the
“If you run with poor form, you are better has said “Humans evolved to run millions of development of innovative interventions such
off in shoes that protect you. But if you are a years ago, and before the mid 1970s all hu- as gait retraining, aimed at altering faulty run-
forefoot striker, you might consider running mans ran in either no shoes or very minimal ning mechanics.
barefoot or in minimalist running shoes.” And footwear such as sandals, moccasins or thin Her interests also include the mechanics of
if you do decide to try barefoot running, he said, running flats. A basic prediction of evolutionary barefoot and minimal footwear running and its
“do so gradually and carefully. It is crucial to or Darwinian medicine is that the human foot effect on injury rates. A barefoot runner herself,
build up foot strength, calf strength, and learn is likely to be well adapted to running long dis- Dr. Davis serves as a consultant for patients with
good form. But most importantly, be a skeptic. tances barefoot. If so, then contrary to popular
continued on page 6
Drs. Daniel Lieberman, Irene Davis, and Mark Cucuzzella provide their expertise on barefoot running.
AMAA Journal Spring/Summer 2011 5
continued from page 5
lower extremity problems related to overuse Kinematic and kinetic analyses show that even on hard surfaces,
problems. barefoot runners who fore-foot strike generate smaller collision
Dr. Davis recounted a story about a 55-year-
forces than shod rear-foot strikers.
old male patient who suffered from stress
fractures. As a rear-foot striker, his body ex-
perienced increased impact with the ground.
So the man changed his form into a forefoot
striker and he subsequently developed Achilles (mid-foot strike) or, less often, on the heel their center of body mass. eventually, he found
tendonitis. When he returned to his old rear- (rear-foot strike). In contrast, habitually shod ChiRunning.
foot strike ways, the stress fractures returned. runners mostly rear-foot strike, facilitated by He presented the audience with a video of
“The impact-related loading was greater the elevated and cushioned heel of the modern himself running barefoot in the historic roads
in those with histories of stress fractures,” running shoe. Kinematic and kinetic analy- of the Antietam National Battlefield, illustrating
Dr. Davis concluded. “Unless the underlying ses show that even on hard surfaces, barefoot from behind as his feet met the hard surface
mechanics are addressed, injury rates may runners who fore-foot strike generate smaller with the soft landing he has perfected.
increase.” To that end, Dr. Davis said she “re- collision forces than shod rear-foot strikers. The panel discussed the pros and cons of
trains” runners in a two-week course consisting This difference results primarily from a more forefoot striking barefoot or in minimalist
of eight sessions in her office. Her retraining plantarflexed foot at landing and more ankle footwear.
teaches athletes to land softer on their forefeet compliance during impact, decreasing the ef-
rather than harder on their heels. “Tibial shock fective mass of the body that collides with the Advantages:
is reduced by 30 percent,” she said, thus reduc- ground. Fore-foot- and mid-foot-strike gaits • Forefoot striking strengthens the muscles in
ing impact-related injuries to the ankles, bones were probably more common when humans the foot, especially in the arch. A stronger
and knees. She further added that by running ran barefoot or in minimal shoes, and may pro- foot will pronate less;
on your forefoot, “injury risk is reduced by tak- tect the feet and lower limbs from some of the • Barefoot running can feel comfortable be-
ing shorter strides.” impact-related injuries now experienced by a cause of minimal impact forces provided
Dr. Davis also cited a study conducted in high percentage of runners.” the feet are properly callused;
1989 by Dr. Bernard Marti. He looked at 5,026 The take-away on Dr. Davis’ presentation: • With the natural spring of the stride, you
runners who participated in a marathon and “we don’t listen to our bodies, we were not may expend less energy to forefoot strike.
discovered that runners in shoes costing $95 built for the speeds we are running, we push
or more were twice as likely to get injured ourselves too hard, we were not meant to land Disadvantages:
as runners in shoes which cost under $40. on our heels and we’ve taken away the function • Thick-soled shoes are much more forgiv-
Interestingly, pronation tendency appears to be of our feet by putting them in shoes.” ing and protecting when running over glass,
greater in motion control shoes, something that Dr. Cucuzella agreed with Drs. Lieberman sharp objects, ice, roots, etc.;
counters conventional logic. and Davis that educating people about running • If you have been a heel striker, it takes some
We also are now finding that “static and dy- in proper form is crucial. “The science is behind time and much work to train your body
namic stability decreased in running shoes,” a this, and I agree 100 percent,” said Cucuzella, to forefoot or mid-foot strike, especially
conclusion Dr. Davis said she has just reached. who frequently performs injury-prevention because you need stronger feet and calf
She will be announcing more results of her re- seminars. He even owns the first running store muscles. Runners should be careful not to
search on this topic soon. to sell only minimalist running shoes. He is develop Achilles tendonitis when they switch
Dr. Davis also referenced her and Dr. not alone in his vision of increasing minimal- from heel striking to forefoot or mid-foot
Lieberman’s research as published in Nature ist shoe sales: at this year’s Boston Marathon striking.
last year. In the abstract of that article, it states: expo, quite a number of vendors were selling
“Humans have engaged in endurance running minimalist running shoes, including several of Steve Nearman has been a running writer
for millions of years, but the modern running the major running shoe manufacturers. for 30 years and is the event director and
shoe was not invented until the 1970s. For most As a Lieutenant Colonel in the Air Force founder of the Woodrow Wilson Bridge Half
of human evolutionary history, runners were ei- Reserves, he is coach and captain of their mar- Marathon in Alexandria, VA.
ther barefoot or wore minimal footwear such athon team and designs programs to reduce
as sandals or moccasins with smaller heels and running injuries in military personnel.
little cushioning relative to modern running His passion for injury prevention is highly
shoes. We wondered how runners coped with personal. After he was diagnosed with arthritis
the impact caused by the foot colliding with in his toe joint, Cucuzella was told by several
the ground before the invention of the modern specialists to stop running. But Cucuzzella
shoe. was determined keep going, so he used his
“Here we show that habitually barefoot en- research skills and knowledge as a physician
durance runners often land on the fore-foot to develop low-impact techniques so as not to
(fore-foot strike) before bringing down the further damage his joint. He also observed the
heel, but they sometimes land with a flat foot elite runners, and the way they landed under
6 AMAA Journal Spring/Summer 2011