Category Archives: Biomechanics

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Technique Threshold, the key to unlocking run potential?

I feel a little like I’m getting a little repetitive with blogs relating to run technique, but I don’t think I stressed the ‘technique threshold’ significantly in previous blogs. Based on that,  I decided to give it an article all to itself..

What is the technique threshold?

The technique threshold is the running speed at which good running technique starts to falter. The simplest way to understand this concept is to find a flat 100m stretch and conduct this simple test. Start by jogging the first 10 metres and then gradually increase running speed every 10 metres, getting faster and faster. The key to this test is starting slow and making gradual increases every 10 metres, most people just sprint flat out and by 30 metres, it’s all gone very ugly..

At some point your ‘good technique’ will start to falter and you may feel the following changes:

1. Tension rather than being relaxed, things start to feel ‘strained’ rather than ‘effortless’.
2. Changes in general posture (some people twist, other lean back and stick their chest out.. to name but a few).
3. The arms start ‘pumping like a sprinter’ rather than being ‘relaxed like a distance runner’.
4. Your stride starts to feel uncomfortable and uncoordinated (however you wish to describe, it certainly isn’t smooth and fluid).

Examine a little deeper..

Try the test and see how far you get, if you have a ‘high technique threshold’ you’ll be able to run very fast and still remain relaxed and smooth. If your technique threshold is ‘low’ then you’ll have a ‘technique wobble’ at a relatively slow speed. The main impact of a low technique threshold is that runners simply are not able to change pace whatsoever. They commonly increase their speed over the first 30 metres and then hit a ceiling, with no further increases in speed. They simply can’t run fast.

What’s the meaning of all this..?

Consider this simple fact: ‘It doesn’t matter how big your car engine is when you’ve got flat tyres’

What if you’re engine was actually pretty big by comparison with other runners who beat you in races? All this time you thought those other runners were ‘fitter’ than you, had a bigger VO2 max, and actually that was never the case at all. It is very possible that you have a bigger engine than many of the other runners ahead of you, but unfortunately, you just can’t move your legs properly. Your flat tyres mean that you just can’t roll along efficiently, no matter how hard the engine tries.

*Fact: the above scenario is 100% realistic as we’ve tested hundreds of runners in the lab and there are plenty of people with high VO2, poor running style and subsequent poor 10k time.

How does this impact upon my running?

If you can’t move your legs properly and you run with an uncoordinated style then it has 2 negative consequences:

1. It stops you running quickly as explained above
2. It’s uneconomical and leads to greater fuel usage

Its important to point out that if your technique threshold is low, it will impact on all distances ranging from 800m runners right through to ultra runners. It limits you moving quickly but it also impacts significantly upon your economy when running at slower speeds. It will come as no surprise to hear that if you spend lots of time running at slow speeds, your technique threshold will drop, impairing your ability to run at faster paces.

Coordination and speed just don’t go together..

Any skill which require coordination is easy to do when it’s done slow. Hitting the right notes on a piano keyboard, playing a computer game, or learning new dance moves are much simpler when you do them at a slow, step by step speed. It’s when you try to speed up those movements that your coordination tends to let you down. Running is no different, placing one foot in front of the other at jogging speed is simple, but it’s an altogether different challenge coordinating limb movements when running at top speed. Even if you are able to coordinate your limbs at speed, can you actually make them move fast enough? Does your neurological system fire a nerve signal to the muscles and create movement fast enough for you to run quickly?

2 simple questions:

1. Can you physically move your limbs quick enough?
2. Can you coordinate them when doing so?

I’d stick my neck out and say that technique threshold is perhaps the key to unlocking running potential for the majority of ‘stuck in the rut’ club runners. All runners, no matter what their ability should spend some time developing technique threshold if they aspire to improve their performances.

previous blogs and video posts have discussed correct running technique so I don’t intend to discuss that again. What you shouldn’t do in response to this blog is traditional speed work (1 mile repetitions etc) as that’s not the point. If your technique threshold is poor you’ll run them slowly, whilst still working that big engine and nothing will change. The answer is more simple, you just need to learn the skill of running fast before you attempt intervals. Start with ‘acceleration strides’ after 10 minutes of warming up, do them before and after each session. Find a 50m flat stretch and gradually build your pace (as during the test described earlier) and learn to run quickly whilst remaining smooth, efficient and in control.

It may well open a whole new world of personal bests!!

Please share if you found this useful.

Regards
Marc Laithwaite
The Endurance Coach.com

Lower limb injuries part 2..

In part 1 we discussed common lower limb injuries sustained by long distance runners and also highlighted the fact that pronation is often blamed for these injuries. As a consequence, shoes are specifically marketed as anti-pronation and inserts are often encouraged. In part 2, we ask whether pronation is really such a bad thing?

The Benefits of Pronation

One of the simple benefits of pronation is shock absorbancy. As your foot strikes the ground, the inwards rolling on the foot allows the dispersion of energy, thereby reducing the shock. Aside from shock absorbancy, pronation can also assist performance by storing energy and using it to generate propulsion.

In the last blog we discussed the muscles which ‘control pronation’, these muscles can also be used in a propulsive manner, using stored energy in an elastic manner. Look at the video clip below and watch the foot movement as it strikes the ground. What you are seeing largely is ‘ankle eversion’ as opposed to pronation. Pronation is the rolling forwards from heel to big toe, ankle eversion refers to the inward collapse of the ankle which can be clearly seen in the last 2 frames..


Elastic / Plyometric Energy

Hopefully you saw clearly the inward collapse of the ankle under weight.. it looks almost uncomfortable and it looks like bad technique. However, it didn’t seem to do Samuel Wanjiru any harm as he broke the world half marathon record aged only 18 and went on to claim gold at Bejing Olympics in the marathon.

The muscles which control the pronation/eversion movement (discussed in part 1) are stretched as the foot collapses inwards and are able to store elastic energy. That stored energy can then be used to provide propulsion as the muscles ‘spring back’ to their original shape. The ability to store and generate energy in such a way is governed by individual tendon structure and it deteriorates with age as tendons lose elasticity.

Pronation the Performance Enhancer

I’ll stick my neck on the line here and state that Samuel Wanjiru would not have broken the half marathon record if we had inserted an orthotic into his shoe which prevented the pronation / eversion movement you saw in the video. The movement created the elastic energy needed to propel him at such speeds and without it, performances would have suffered.

Go Forwards and Pronate??

That’s not quite what I’m saying.. but the point I am making is that pronation is not necessarily a bad thing. Some running shops and podiatrists  conducting gait analysis, upon identifying that a runner pronates, make the snap judgement that the runner requires an ‘anti-pronation shoe’.  It would be wrong to make such assumptions and will have a potentially negative impact upon performance.

Some Things to Consider

1. If a runner has no injury history (in particular lower limb) and they visit a shop to be told that they pronate and should therefore wear anti-pronation shoes, that should be seriously questioned!

2. Based on age and tendon structure (varies each individual), some runners will be capable of pronating excessively and rarely suffer injury as a consequence.

3. If you have an injury which is caused by pronation / eversion, your first port of call should be rehab and conditioning so the tissues can handle the movement, store elastic energy and provide propulsion. Don’t instantly take the easy option and purchase inserts. If your injury is chronic, there will be cases where inserts are necessary as this is your only option to continue enjoying running.

4. The video plays extremely slowly, in real time the pronation / eversion movement is ‘super quick’. The stretch and energy return occurs within hundredths of a second as the foot ‘bounces’ on the ground. When you are doing rehab you should consider this, calf raises or lowering are all well and good, but the movement is slow and controlled, unlike reality. You need to include plyometric exercises in the rehab before you return to running.

5. As part of your regular running routine you should include simple plyometric exercises which strengthen all the tissues of the lower limb and encourage energy storage and return.

Lower limb injuries part 1..

One of the most common problems with long distance running is the recurrence of lower limb injuries. By ‘lower limb’ I’m talking about the stuff that goes on below the knee and this includes (but not exclusively):

1. Achilles problems
2. Shin Splints (front or rear)
3. Plantar Fasciitis (pain under the foot / heel)

Overuse injuries are created by repeated action, hence they are common in long distance runners. In some circumstances, runners may have bio-mechanical faults which make them more susceptible to overuse injuries. In other cases, it’s simply a matter of doing too much and the tissues just can’t handle the load. Perhaps the most commonly cited reason for injury in runners in ‘over-pronation’, this describes the action of the foot landing on the outside of the heel and then rolling both forwards and inwards onto the big toe. Pronation has been blamed so frequently for running injuries that we now have specific shoes and various inserts to prevent the action, but is pronation receiving unnecessary criticism?

Pronation explained

The vast majority of runners pronate to some extent when they run. If you stand with your feet hip distance apart and then start walking, you’ll notice that you don’t walk with your feet hip distance apart. It is natural to walk and run with your foot directly underneath the centre line of your body (if you draw a line from your nose, through your belly button and down to the floor, that’s where you foot will land). This means that your leg is always at a slight angle, starting at your hip, the leg angles inwards to the point of foot strike and this means that you are likely to hit with the outside of your heel.

At the point of impact, the force applied to the outside of your heel ‘flips’ your shoe (and your foot) inwards. Stand holding a running show and with your hand, strike the underside of the heel on the outside edge. The blow will flip the shoe inwards, this is what happens to your foot each time you strike the ground.

Injuries linked to pronation

As your foot flips inwards, this triggers the pronation movement. In an attempt to control both the amount and speed of pronation, there are some specific muscles  which take the majority of the strain. The tibialis posterior and anterior muscles run along the length of your shin bone. The anterior muscle is found on the front of your shin and the posterior muscle is found on the inside of the lower leg, behind the shin bone. You can generally find both quite easily with your fingers. The tendons from each pass over the inside of your ankle joint (look at the boney lump on the inside of your ankle, if you move your foot about, you’ll see the tendon moving on the boney lump).

When these 2 muscles contract, they pull up the arch of the foot and turn the ankle so the sole of the foot faces inwards, this is the opposite movement to pronation. Their main job is to control the pronation movement and as the foot rolls inwards, they are pulling back in the opposite direction to reduce and slow the pronation movement. For this reason, if your foot pronates excessively, these muscles have to work extremely hard and this may lead to inflammation of the muscle or the tendon (the tendon is the white part which attaches the muscle to the done). Inflammation of these muscles is commonly referred to as shin splints or potentially ‘compartment syndrome’.

The pronation movement can also lead to achilles problems. Generally the achilles is pretty strong when it pulls in correctly alignment, unfortunately pronation causes the achilles to twist, as if ‘wringing it out’ and this leads to damage and inflammation. Pronation can also lead to flattening of the arch and this applies stress to the tissues which are supporting the arch. one of the main structures supporting the arch is the plantar fascia, a tendon which runs from the underside of the heel bone to the forefoot, splitting into the 5 toes. If stress is applied to the plantar fascia, it can start to pull away from the underside of the heel bone, leading to a sharp pain known as plantar fasciitis.

So pronation is bad.. right?

There are various problems which are ‘potentially associated’ with pronation and these are often treated with a change of shoes or orthotic insert when they may well have been resolved with some rehab (strength and stretch). However, pronation is not a bio-mechnical fault, it is an important part of your running which has simply received a lot of bad press. Before you rush out and buy inserts for your shoes, contrary to what you might think from reading the above information, pronation can be your friend if you know how to handle it.. we’ll look at that in part 2 of the sequel.

Hip flexor length and running performance..

Short and tight hip flexors are a known problem for cyclists and distance runners, leading to a number of complications. The role of the hip flexor muscles is to flex your hip (obviously), if you stand upright and lift your left knee upwards towards waist height, you would be using your left hip flexors to do this task. During running, the knee lift action is governed by hip flexors and during cycling the upwards part of the pedal stroke is controlled by hip flexors.

Why do we get short hip flexors?

Exercising can create short hip flexors, but every time we sit down whether working, driving or relaxing, our hip flexors are in a shortened position. Short hip flexors are common amongst the general population for these reasons and can lead to a change in your posture.

How do short hip flexors change posture?

Tight hip flexors pull the pelvis forwards (known as an anterior tilt) and this condition is commonly termed lordosis. The result of lordosis is an exaggerated inward curve of the lumbar spine (lower back) and the lower abdominals will tend to ‘stick out’ as a consequence. Often people with lordosis think they have gained weight and have a ‘bit of a belly’ in the lower abdominal region, when in fact, it is purely a postural position. You can check lordosis by standing and viewing side on in mirror, tilt your pelvis backwards (this is pelvic thrust action) and see if you can hollow your abdominals and remove the arch in lower back. Better to do this when alone with curtains firmly closed..

What are the consequences of short hip flexors?

1. May feel discomfort in the front of the groin area or lower pelvic region
2. The anterior tilt stretches the hamstrings, leading to tightness
3. The lumbar region excessive curvature leads to tight lower back

How do I resolve the problem?

1. Start by releasing the hip flexors, to do this you can visit physio or complete the stretch shown. It’s important that when completing this stretch you don’t allow yourself to twist, don’t lean forwards and when don’t allow your lower back to arch (pull your stomach in). in essence, stay square, tall and neutral.

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2. Complete abdominal strengthening exercises to strengthen core. This will push the abdominal wall inwards and the lower back outwards. Unless you have completed hip flexor stretches beforehand the core work will have low impact as the pelvis will remain locked in position.