An Examination of Whether Heel Strike is Dangerous or Safe for Running
I remember back in high school, I tried out for the track team. I was a lanky, out-of-shape freshman but I fell in love with running. Lo-and-behold, it only took a few weeks to run into injuries (no pun intended). It was shin splints, and I soon became known as the shin-splints-kid.
You know what I was told would fix it? Bigger, more cushion-y running shoes. The big cinder blocks that I wore helped, until they didn’t. Next solution? Strengthen my “shin muscle”, the anterior tibialis, because that’s what was supposedly injured (or so my coaches said so). This is the story of numerous runners out there.
Back then, I naturally ran using a “heel strike”. Heel strike is a technique that involves landing on the heel during each stride. This was further compounded by the thicker shoes I was recommended to use. Yet, there is another running technique that I never knew about back then, and it’s called “toe strike”. Toe strike is when the runner lands on the toes between each stride. Nowadays, there is much discussion and debate over heel strike and toe strike.
Toe strike has been touted as “safer” and more “natural” than heel strike. But is the heel strike truly the devil its been claimed as? Would toe strike running prevented my injuries in the past? (I already know the answer, but let’s continue this discussion anyway.)
The Foot is Designed to Transfer Load
The foot is an interesting piece of anatomical ingenuity. Given that it is the first part of our bodies touch the ground while running, it may be worth examining how the foot is built.
The foot has 20-something bones, each being part of some joint, with numerous muscles attaching to various points throughout. Most importantly, these bones and their joints form an arch along the foot, which has a band of connective tissue on either end underneath it. This band is called the plantar fascia.
What’s interesting is that the plantar fascia can slightly flatten out and stretch when it undergoes load-bearing. For example, check out your bare feet while doing calf raises. As your prop up on your toes, the “arch” supports some of the load and stretches a little. While this happens, the muscles in your feet contract to further support transferring the load
Coincidentally, this same action occurs when the body is engaged in toe strike running. With toe strike, the structures/muscles of the foot transfers force from the toes to the ankle. Meanwhile, heel strike delivers the force to the heel bone, which is passively transferred up the ankle to the rest of the body.
Calves Are Your Shock Absorbers
As I stated before, heel strike and toe strike will change how the body absorbs the “shock” of the body landing with each step.
Heel strike transfers the force through the bones, while toe strike actively transfers it. Similarly, as the force travels through the foot with or without the help of the muscles, it transfers up through the leg without or without the help of muscles, as well.
What happens with heel strike, is that the bones of the lower limb take a nice chunk of the impact from running, while during toe strike, a lot of it is absorbed by the calves.
Why is this so? Well, it’s because that toe strike running requires the foot to be plantar flexed. Meaning, we must be “on our toes”. Doing this actively engages the calf muscles. As you can see in the picture above, if the calf muscles contract, the Achilles’ tendon will yank on the heel to prop us up on our toes.
Anyone with a basic understanding of muscles will know that muscles can contract concentrically (to shorten) or eccentrically (to lengthen). Either contraction is an act of load-bearing. We see both types of contractions in the calves during toe strike running, actually.
When the runner is in stride and the landing-foot first makes contact with the ground, the foot is plantar-flexed. So, it starts out propped up on its toes. As the stride continues, the foot “rolls” flat on to the ground, until the heel gently touches the ground. Immediately after is the “push-off”, and the foot plantar-flexes again, while the other foot is in front and about to make contact with the ground. What we have here are essentially springs that bounce our feet off of the ground.
During the heel strike, there is only concentric contraction of the calf muscles. As the landing-foot first makes contact with the ground, it touches with the heel first, rolls flat, and then is on its toes as it pushes off. While heel strike delivers impact to the bones and then uses the muscles of the foot/ankle to push-off, toe strike uses muscles the entire time. This is important, because the human body is designed to deal with impact using its MUSCLES.
Consider the shin splints injury I discussed earlier. The pain in shin splints comes from the interosseous membrane. This structure is the connective tissue that spans the length of the two bones in your shin, the tibia and fibula, and connects the two. It prevents excessive movement of the two bones, and transfers load between the two as well. When you heel strike and the impact travels through your heel, it transfers through the tibia as well. When it travels through the tibia, the fibula experiences impact as well, via the interosseous membrane. This connective tissue becomes damaged as it repetitively transfers the force between the two shin bones.
Meanwhile, this can all be avoided if toe strike is used. The calf muscle acts as a shock absorber, sparing the bones and interosseous membrane from excessive impact. Think about what else can be stressed by heel strike. The knees and hips must certainly take a pounding, as they’re further up the bony-chain.
Given that toe strike stresses muscles (a readily healing tissue-organ) and heel strike stresses bones and connective tissue (both slowly healing tissue-organs), heel strike appears to be dangerous. Period.
But isn’t Heel Strike More Efficient?
Earlier this year, a study was released that found heel strike running to be more economical than toe strike running. Basically, heel strike was found to use less energy (Ogueta-Alday A).
Fantastic. My entire discussion on the role of the muscles/bones in different running styles is scrapped. We can all keep running in our ugly training shoes.
Energy consumption, or running economy, doesn’t mean much in the heel strike vs. toe strike debate. In fact, it actually proves more-so that heel strike is in fact dangerous. Why? Because letting your bones absorb impact takes no energy to do, while using your muscles to slow down the impact DOES require energy to do.
Using up more energy during a run is an after-thought, because it preserves the health of the lower limbs and joints. Muscles can take much more of a beating than bones, connective tissue, and cartilage can. If it makes the run more tiring, so be it. At the cost of a slightly slower run and sore muscles, toe strike running prevents excessive trauma to the passive structures in the legs.
Heel Strike Running is Dangerous, and is Inferior to Toe Strike Running
Heel strike involves delivering impact to the bones of the legs, while toe strike uses muscles to transfer the impact. Because the muscles can readily heal itself from damage, unlike the bones and connective tissue, toe strike is a safer and more logical form of running.
After understanding this on my own years ago, I decided to purchase a pair of Vibram FiveFingers shoes. It was official – I jumped on the barefoot bandwagon. Given that barefoot-style shoes are conducive for toe strike running, it made sense to get myself a pair. I don’t consider myself a runner, but my training-sessions/walks/sprints/whatever are all awesome with these shoes. I’ve been insanely satisfied with my Abrams, and recommend them to anyone. If you’re interested, you can buy a pair of Vibram FiveFingers from Amazon.
1. Ogueta-Alday A. Rearfoot striking runners are more economical than midfoot strikers. Medicine and Science in Sports and Exercise. 46.3 (2014): 580-585. Pubmed. Web.