Depending on which part of the foot takes maximum load at the time of landing, a runner can be classified in three broad categories - heel striker, forefoot striker and midfoot striker. Numerous studies have indicated that midfoot strike is the most efficient form and it can considerably help improve running form, while also reducing the risk of injury. When one achieves a midfoot strike, the pressure of impact is distributed across the entire foot – a major share of this load is borne by the mid-foot and forefoot, and relatively small share of load is borne by the toes and heel (see figure below).
So, let’s examine this a little closely - why is
midfoot strike considered the most efficient form?
Reason 1: Midfoot strike helps
distribute the load over a larger area, thereby reducing the pressure of impact
All other
things being constant, a midfoot strike allows the load to be distributed over
a larger surface area, thereby leading to a lower impact per unit area of foot
surface. This uniform distribution of load feels much more comfortable on the
foot as compared to a somewhat concentrated load impact that one feels during a
heel strike or forefoot strike.
As an
analogy, think of it like this – if you were given the option of being nudged
by one of the two objects – a sharp needle or a blunt object - which one would you
choose? You would most likely choose a blunt object as sharp needle creates a
highly concentrated force (i.e. high pressure) due to its very low
area of impact. This is an extreme illustration of how reducing area of contact
at the point of impact can lead to a feeling of discomfort; however, it’s the same
laws of physics which warrant the load of foot impact to be distributed over a
larger surface area through a midfoot strike.
Reason 2: Midfoot
strike helps prevent braking motion, which significantly reduces the risk of
injury
The proponents of
Chi-running suggest that midfoot strike allows the runner to ‘cooperate’ with
the natural force of impact. Essentially, in a midfoot strike the movement of
foot (at the time of impact) is in the direction of the force exerted by the
ground – this ‘cooperation’ with the natural force of impact facilitates shock
absorption. As compared to this, when one strikes with the heel, there is a ‘bang’
at the time of impact (due to opposing direction of foot movement and force of
impact). This impact passes through the runner’s lower body and can be a cause
of various running related injuries (especially the knee injury).
Reason 3: Midfoot strike helps prevent bouncing motion,
thereby minimizing “energy leakage”
It is quite
intuitive that when a runner is trying to move straight ahead, all possible
energy should be deployed to create the forward motion. Any energy which doesn’t
create this forward motion is an unnecessary dissipation, which can lead to
sub-optimal running pace.
Now, how is
this relevant in the context of our discussion related to midfoot strike?
If one traces
the trajectory of the center of mass of the running body and compares the
pattern for a runner with heel strike vis-à-vis a runner with midfoot strike,
it is observed that the runner with heel strike tends to exhibit small cyclic
vertical movements (see figure below).
These
vertical movements, (often referred to as the “bouncing” motion of a runner) are
quite small as compared to the predominant forward movement and may not
be visible to the naked eye. However, these vertical movements require the body
to spend some energy overcoming the force of gravity with each step. When
aggregated across a large number of steps, this results in a significant loss of
energy, thereby leading to sub-optimal performance.
Now that we
understand the advantages of midfoot strike, the next important question is - how
does one practice this running form? Like all proper running forms, proper foot
strike may feel awkward to begin with. However, someone keen to practice this
running form may focus on the following:
- Shorten the stride length – Longer stride length tends to land the foot ahead of the body, thereby leading to a heel strike.
- Try to lean – Tilting the body forward (from the ankle and not from the waist) places your center of gravity ahead of the foot strike and makes it easier to achieve midfoot strike.
- Listen to your footsteps – The ideal foot strike feels soft and gentle on landing and is barely audible (as compared to the loud thumping sound for hard strikers).
“A good runner leaves no footprints” – (Chi Running, by Danny Dreyer)
Sundeep Singh
(+91 - 98181 19794)
(+91 - 98181 19794)
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About the Author: By background, Sundeep Singh is a Mechanical Engineer from IIT Delhi and holds an MBA from IIM Kozhikode. Given his flair for mechanics and passion for running, he loves to analyze and write about the finer nuances of running techniques / strategies.
