Stride Length
With all the rage about foot strike during
running and stride length, one might ask, ‘can we increase our stride length
without overstriding?’
The short answer is yes! Following is a short
commentary on the practical application.
The most efficient stride is one which lands
close to its centre of mass (COM), thus eliminating deceleration forces
associated with overstriding. Landing outside the centre of mass relies more on
‘muscling through’ the movement rather than letting gravity and momentum carry
you through the stride pattern. There is a deceleration followed by an
acceleration through the stride, effectively placing increased demands on the
lower limb; namely the calf musculature.
Shortening your stride may achieve a foot strike
closer to the COM, but how do you achieve an increase in speed without sending
your nervous system into overdrive?
Let’s take a closer look; If we increase a
slight forward lean from the ankles (for example a 5-10 degree lean) in
conjunction with a slight anterior tilt of the pelvis we are able to take a
bigger stride, increasing our ‘air ‘ time, thus allowing our foot to land
inside/close to our COM. The important concept here is the ‘air’ time with a
forward lean. If you simply take a larger stride without a corresponding change
in pelvic mechanics and forward lean there will be an increase in knee
extension and most likely increased heel collision forces. The second factor
here is that knee extension and overstriding increase deceleration/acceleration
time. This equates to more time on the ground – the slowest part of the gait
cycle!
A slight forward-lean increases our hip
extension and thus our corresponding hip flexion on the contralateral leg. As
the torso creates a forward-lean the hip extension drive will be in a slight
upward and horizontal motion. This motion creates movement with fewer
oscillations ie; there will be less energy going vertically and less energy
overcoming deceleration forces as you collide with the ground. In other words,
most of your energy will be going forward.
Further to this, hip extension increases
recruitment through the large gluteus maximus and hamstring muscles - this
creates stability through the sacro-iliac joint (SIJ). Better joint stiffness through the SIJ also
creates a more stable base from which to move from.
Fig 1. Two very different running examples. The pace is consistent yet not fast when compared to shorter track races. The front runner displays better hip extension and minimal overstride. You can see the second runner has greater front leg knee extension creating a large heel strike, This also creates decreased load through the hip extensors (glute max, hamstring)
Fig 1. Two very different running examples. The pace is consistent yet not fast when compared to shorter track races. The front runner displays better hip extension and minimal overstride. You can see the second runner has greater front leg knee extension creating a large heel strike, This also creates decreased load through the hip extensors (glute max, hamstring)
Will this change where I land on my foot?
A change in landing position on the foot is
often observed, however this is secondary to the change in stride length and
the mechanics leading up to this. Whether you land on the forefoot is less
important. It is more important to have an efficient stride pattern, depending
on where you start from of course. Consideration should also be given to your
relative speed with regard to where you land on your foot. To illustrate this
point, imagine running a 100m race – most, if not all would land on their
forefoot. If you stretch that out to 400m, you would probably find increases in
mid to rear foot landing in the last part of the race for slower speeds,
stretch that out 5k then 10k and you can see the point. Speed does effect your
foot position to a large degree. Where the elite differ from us is that they
run 10km at faster speeds than many of us can run for 400m. The world record
for 10km stands at 26.17, which equates to a margin over 63 sec per 400m for 25
laps!! If you or I were running at that speed we would probably be on our
forefoot too!
Fig 2. A classic example of a slight forward lean. Notice the hip extension and projected landing position (within centre of mass) and also towards the midfoot. The pace is about 55 sec per 400m during a 1500m race! The pace may well dictate whether you land on your forefoot or not!
The question might be; Do the best runners simply run in this position due to pace alone or has this position allowed them to train efficiently and adapt to this pace?
Fig 2. A classic example of a slight forward lean. Notice the hip extension and projected landing position (within centre of mass) and also towards the midfoot. The pace is about 55 sec per 400m during a 1500m race! The pace may well dictate whether you land on your forefoot or not!
The question might be; Do the best runners simply run in this position due to pace alone or has this position allowed them to train efficiently and adapt to this pace?
What do we define as efficient?
So what is efficient when it comes to running technique
and how do we define it? Consider the following points:
- · More ‘air’ time – more time in the swing phase decreases time on the ground, therefore less loading;
- · Stability – A sight anterior tilt of the pelvis will engage more of the intrinsic stabilisers and allow greater hip extension (using the powerful mobilisers off a stable base!);
- · Greater contribution from the large muscles reduces impact on the smaller muscles (calves) which generally fatigue more quickly;
- · Reduced Oscillations – Reduced oscillations with regard to energy direction. You want your energy going in the right direction – forward (not up and down)
This is one of many ways to improve running
technique. It is certainly not the only way! It is however an area of hot interest!
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