WHY Your Core is Useless Without This Stability First

September 12, 2012

The myth of core stability is popular for one reason; its visual association with chiseled abs and a thin waistline. In fact, foot stability is significantly more important, but not many people would prefer a better looking foot to six pack abs. Part of the reason your foot isn't sexy is the large number of structures jammed into a very small space. The human foot and ankle contains 26 bones, 33 joints, and more than a hundred muscles, tendons, and ligaments. With all of those pieces, there has to have been some stimulus or need for such intricacy. Since your ground reaction force (GRF) is the most important characteristic, it would make perfect sense that the most necessary stability comes from the first interaction with the earth, which is the foot.

Foot Stability > Core stability

Stability is your ability to resist movement, especially at the end ranges of motion (see Sparta Point). One of the best ways to enhance foot stability, or any movement that challenges your balance, is to increase the surface area. The more area in contact with the ground, the easier it is to move quickly or resist movement. Perhaps the easiest example is how much more stable you are standing on two feet versus one. For those of you who have had too many concussions, you have half the surface area when on just one foot.

Off-Center Signature

We mentioned stability being exposed at end ranges of motion, and a great example occurs when you are jumping and have to finish off your toes to move in the desired direction. If the foot is unstable, that toe off period is shortened or directed in a less desirable direction. The movement signatureTM  we see among these athletes is shown to the right, called “off-center.” We see plantar fasciitis, stress fractures of the foot, and ACL injuries with this movement signatureTM .


The athlete can generate substantial force initially (LOAD, see Sparta Point) and use trunk strength to transfer that force within the trunk to minimize transitions, or the amortization phase (EXPLODE, see Sparta Point). However, when it comes to finishing the movement, the athlete is unable to prolong his DRIVE of force production.

Prescription is Non-Vertical

The best way to improve the DRIVE within this movement signatureTM  is to provide movements that just take longer for each rep such as heavy, single leg movements (lunges, split squats, etc.). Loaded carries like sled pulls/pushes or jumping require you to move in different directions than vertical, and as such, require a longer amount of DRIVE to complete. As mentioned last week, the myth of measuring barbell velocity would be even more hurtful for those with foot instability needing more DRIVE. Or, as my friend and fellow coach Jim Steel says, if we keep doing what we always have done, we need to bring back leeches and start bleeding people out.

Fatigue and the Jump Shot

Evidence Based Training - What Are You Measuring?

Train for quality not quantity