Colin Griffin, Strength & Conditioning Coach – This is a topic that has generated plenty of recent interest and debate among runners, coaches and sports medicine practitioners. Many runners change their foot strike pattern from heel strike to mid-foot or even forefoot strike. Others claim that there is nothing wrong with a heel strike.
Let’s take a look at the mechanics of running and the impact of a heel strike from an injury and performance perspective.
In the clinic, we see many runners with anterior shin or knee pain, and in many cases, calf pain and hamstring tendinopathy, who display a heel-striking pattern. With that we usually see over-striding – the foot making contact with the ground well in front of the centre of mass with a negative shin angle. This places greater shear loading on the shin with that narrow centre of pressure point as the foot makes contact with the ground. The foot has to flatten which eccentrically loads the tibialis anterior as it absorbs high forces.
In the case of calf and knee pain, because the runner lands with lengthened and poor recruitment of ankle plantar flexors and hip extensors, there is an inability to achieve joint stiffness and stability during mid-stance at the critical moment when highest peak impact forces are absorbed. The knee and ankle continue to bend placing excessive eccentric loading on the calf muscle and at the knee.
In the case of hamstring tendinopathy – when the athlete over-strides and lands with a heel strike, it puts the hamstrings at a mechanical advantage over the gluteal muscles. But with that comes a cost. The dominant hamstrings are elongated and experience increased shear loading and compressive forces at its proximal attachment.
When running at faster speeds, it is desirable to maintain a short ground contact time and a high rate of force development repeatedly to optimise performance. A heel strike at initial contact allows the foot to stay on the ground longer with prolonged deceleration as it flattens. Athletes in short events from sprint distance up to 1500m tend to favour forefoot landing, with midfoot landing more favoured over longer distances. When an athlete fatigues, there tends to be a favoured heel strike pattern.
Changing running gait
Altering a runners gait can be difficult particularly for highly trained athletes with deeply ingrained movement patterns. Certainly for the injured athlete with heel striking being a contributing factor; it makes sense to reduce heel strike to a closer to midfoot contact position to reduce the stress on the anterior shin. The heel strike on its own may not be as big a problem, but a heel strike while over-striding and perhaps a forward trunk lean can cause problems.
In the clinic, we tend to coach a vertical shin angle at initial contact with a slightly bent knee with the foot making contact just in front of the hip. This usually results in a reduced heel strike if the foot plant is coached well. A mid-foot strike allows for a larger surface area for the foot to absorb forces and dissipate evenly from the foot up the kinetic chain to the centre of mass.
In order to achieve that, we must look at that the leg does before landing. We look for an arc-like trajectory of the foot during swing phase. A linear foot trajectory closer to the ground (or a lazy swing leg) usually results over striding and heel strike. This is common in novice and recreational runners. If we increase the arc curvature by bending the knee more and picking the foot up as the leg swings through, this will allow the athlete to achieve a vertical shin at initial contact. The higher the speed the higher that arc angle will become, as the foot needs more space over the ground to apply and generate more force.
The downward foot plant will help recruit hip extensors and ankle plantar flexors to achieve optimal loading of the limb during midstance and greater power retained for propulsion with greater hip muscle contribution.
Successful gait changes can be achieved with appropriate coaching cues, running drills that have purposeful intent and a well-designed strength-training programme. There may be a short-term sacrifice for a long-term performance benefit!
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