Muscle blog series: Part 8: Core stability:

This is the next blog article in the series and will discuss core stability.

What is Core Stability?

Core stability is defined as the ability to control the position and motion of the trunk over the pelvis to allow optimum production, transfer and control of force and motion to the terminal segment in integrated athletic activities.

Core muscle activity is best understood as the pre-programmed integration of local, single-joint muscles and multi-joint muscles to provide stability and produce motion.

This results in proximal stability for distal mobility, a proximal to distal patterning of generation of force, and the creation of interactive moments that move and protect distal joints.

What is the background of core stability?

Core stability started in the late 1990’s.

It was derived from studies that demonstrated a change in timing of the trunk muscles in back injury and chronic lower back pain (CLBP) patients.

However, there have been assumptions on how this relates to injury prevention and sporting performance:

Certain muscles are more important for stabilisation of the spine, in particular transverses abdominis (TrA):

Transverse abdominis is absent or fused to the internal oblique muscle as a normal variation in some people and they don’t all have poor core stability and injury! (Gray’s Anatomy 36th edition 1980, page 555)

That weak abdominal muscles lead to back pain:

A study no correlation between sit-up performance and backache. (Fast et al., 1990)

That there is a unique group of “core” muscles working independently of other trunk muscles:

No single muscle is dominated in the enhancement of spine stability.

Their individual roles continuously change across tasks.

Clinically, if the goal is to train for stability, enhancing motor patterns that incorporate many muscles rather than targeting just a few is justifiable. (Kavic et al 2004)

If there is no proof that single muscle activation is possible so why do we try?

Overweight = Poor core stability=Lower back pain:

Weight gains and obesity are only weakly associated with Lower back pain. (Leboeuf-Yde, 2000)

So what is the importance of core stability?

Injury Prevention:

The odds of sustaining a lower back injury increased 2.8 times when a history of lower back injury was present and increased by 3% with each millisecond of abdominal muscle shut-off latency. On average, this latency was 14 milliseconds longer for athletes who sustained lower back injury in comparison to athletes who didn’t! (Cholewicki 2005)

This shows these muscles are important and they don’t work well with pain

However it isn’t strength it’s activation and co-ordination:

Standing: Co-contraction of trunk flexors and extensors are less than 1% Maximal voluntary contraction (MVC)

3% MVC with a 32 Kg weight

During bending and lifting a weight of about 15 kg co-contraction increases by only 1.5% MVC

So you would have to get very weak for any problems to arise.

Improving performance:

Evidence on Core stability training to aid performance is ambiguous!

Swiss ball training may positively affect core stability without improvements in physical performance in young athletes (Stanton et al 2004)

Core stability training for runners showed faster times in the 5000m run after 6 weeks of training (Sato & Mokha 2009)

Core stability using unstable, closed kinetic chain movements can significantly improve maximal throwing velocity (Saeterbakken et al 2011)

How should I train?

Core stability has long placed too much focus on stability, not enough on movement to be functionally better you need reciprocal strategies and coordination of movement (control of movement)

You can train with as much volume and frequency as want but 10 reps, several times per week is fine.

Core muscles are slow twitch fibre muscles and designed to work all day everyday.

Effort levels need to be below 25% to stop bracing effects.

It all about quality not quantity!

First need to learn good posture and spinal alignment awareness.(Below pic: Poor posture)

You are best starting with more stable based exercises and advance to more unstable.

Once you have improved you next will move to more sport specific exercises.

Here are some examples of generic exercises:

Swiss ball superman:

Pilates table top knee circling:

Sport Specific exercises:

Swimmer:

Swiss ball prone position arm pull through with theraband:

Netball:

Swiss ball kneeling and passing

Bowler in Cricket:

Wobble board single leg balance with theraband pulling over in bowling action

Trampolining:

Swiss ball knee tucks

High jumper:

Supine double leg flexions

So hopefully that clears up some of the mistakes made in training core stability and in doing so helps you to minimise your risk of injury and improve your performance.

If you need any further information or would like to book an appointment then call Hawkes Physiotherapy on 01782 771861 or 07866195914

WWW.HAWKESPHYSIOTHERAPY.CO.UK