By Juan Carlos Santana, MEd, CSCS

This section of the Stability Ball (SB) series will discuss the concept of Stabilization Limited Training (SLT) and consider some of the basic guidelines and safety issues surrounding Stability Ball training.  We will also address the basic training cues that will lay the groundwork for future articles that will deal with SB training and program design.

SLT is a term I coined for lack of imagination and talent coming up with cool acronyms.  It simply refers to the type of strength training that limits force production to the strength and balance of the stabilizing structures (i.e. primarily the core and peripheral joints), not the isolated force capabilities of the prime movers.   This has been called “functional training” by various conditioning specialists.  However, I believe there is a slight theoretical difference between functional training and SLT.   In order to maintain clarity, and continuity, let’s take a moment to provide some operational definitions for terms we will use.

Function – A utility or purpose.  “A specific outcome a thing/activity is intended for”.

Functional movement can be defined as,  “a movement with a specific purpose (e.g. skill, or action) as a final outcome”.  Most human movement is integrated, and multi-planar in nature, and deals with the physical elements of our operational environment (i.e. gravity, momentum, inertia, and impulse).

Functional Training can be simply defined as, “a comprehensive training approach that aims to enhance the performance parameters of a specific movement, or target activity.”  The movement usually mimics the activity targeted for improvement.  However, this is not always the case.  Functional training, like most things, is a spectrum!  There is no distinct line, or criteria, that separates functional, somewhat functional and non-functional training (if there is such a thing).  Remember, everything is functional to some degree (e.g. a preacher curl is very functional to a bodybuilder, but not to a swimmer).

SLT is one of many functional training methods used to enhance performance.  It is under the  “comprehensive training approach” umbrella.  Its focus is on structural stabilization and strength, rather than prime mover isolation or bio-motor skill acquisition.  I guess you could make an argument that most of, if not all, functional training is SLT to some degree. The main difference between the two would be that functional training would have greater specificity of movement to the target activity, thus, greater biomotor skill acquisition.  But, that is “beer and peanuts” conversation – and I don’t like either.

SLT matches the type of training performed on the stability ball perfectly.  For example, if a person can perform 8 repetitions with 45 lb. dumbbells on bench presses, they will only get a fraction of that on a stability ball.  Why? Due to the additional stabilization demands.  Therefore, the individual was limited by the stabilization requirement not by the strength of the major chest musculature.  Therefore, the name SLT applies quite nicely.

The purpose of SLT is the same as all functional training, to reduce the deficit in force production caused by the additional stabilization.  As the deficit in force production is reduced (i.e. you are able to perform as many reps on the stability ball as you do on a bench), the joint integrity and stabilization increases.  This allows one to produce more force in familiar tasks (e.g. a standard bench press) or more challenging environments (e.g. the playing field).

Stability Ball Training Safety Issues

Selecting a ball is simple.  The ball size that will allow the most amount of versatility in stability ball exercises will allow you to sit on it with your knees and hips at 90 degrees. 

However, using different size balls will allow you more flexibility and variation with your SB training. The different ball sizes allow body weight to be shifted in the appropriate direction as to remove or add weight to any exercise.  The size of the ball can also take into account for flexibility differences amongst users.

Always exercise with a shirt.  Although several Stability Ball exercise videos show their models exercising without a shirt or in tank tops, exercising with these garments increase the chances for injury.  Exercise will naturally cause sweating.  A sweaty body can easily slide off the ball causing serious injury, especially if one falls while holding weight overhead.  A shirt will also keep the spreading of germs and bacteria to a minimum.
 
If the Stability Ball is being used in the gym setting, keeping it clean with soap and water will also maintain proper sanitary conditions in the training environment and prevent the spread of germs and bacteria amongst clients and gym members. 
 
I do not use any type of support or anchors for supporting limbs when training with the Stability Ball.  The whole idea is to train in an unstable environment. The additional weight that can be handled when stabilizing the ball adds to the risk of an accident.  I recommend training in an unstable training environment that is why I use the SB.  If I need to train higher volumes with more aggressive intensities, I use the stable environment provided by a bench.
 
When using external resistance, I recommend handling lighter loads than you would when training on a standard bench.  I do not recommend using high loads to failure during SLT on the Stability Ball – it’s virtually impossible and does not promote to proper execution.  An accident due to fatigue or technique error, while on a stability ball, can happen too fast even for a spotter to correct.  The exercise should terminated at first sign of technique error or fatigue. 
 
Spotters are recommended when using external resistance on the stability ball, especially when using loads that are challenging.  However, if you are using appropriate loads and good form, minimal supervision is required.  Even moderate loads will provide significant stabilization stimuli.  Remember that training should be fun and is ultimately a process for performance enhancement – it is not a contest to see who can handle the most weight!

Basic Teaching Cues and Recommendations

Neutral Spine

Unless otherwise specified, a neutral alignment of the spine should be maintained when exercising. This is especially critical when it comes to the lumbar spine.  The key is to try to prevent the core musculature from disengaging and allowing a hyperextension of the lumbar spine during compression or flexion loading.  A “neutral spine” is preferred when exercising, although occasionally we will ask for a posteriorly tilted pelvis during specific movements, like a push-up or roll-out.  This is done to teach preferential recruitment of specific musculature and safety.  After proper core stabilization is mastered during the exercises, we no longer insist on a posterior pelvic tilt during the execution prone exercises.

Robinson defines a neutral spine as “a position or range of movement defined by the patient’s symptoms, pathology, and current musculoskeletal restrictions.  It is a position in which a vertical force exerted through the spine allows equal weight transference to the weightbearing surfaces (e.g. in sitting – the ischial tuberosities, in standing – the feet).”  It should be noted that a neutral spine is an ideal concept, defined differently by various authorities.  A neutral spine is also different from person to person, therefore don’t get too caught up the “exactness” of the definition and just use the concept! 
 
When suspended in prone positions that load flexion of the spine (e.g. push-up or roll-out position), an attempt to maintain a posterior pelvic tilt engages the lower abdominals and prevents the lumbar spine form hyper-extending.  Although maintaining a “neutral spine” position during such exercises will provide adequate protection to the lumbar spine, the position is “too close for comfort” and can easily result in lumbar hyperextension in a fatigued state.  Especially for beginners, a posterior pelvic tilt provides better stimuli to the lower abdominals and hip flexors, and affords “more room for error”.  If you look at most of our clients exercising in a prone position, you will see a natural line at their lumbar spine.

Now let’s take a close look at each body part and offer some general recommendations for positioning:

1) Head (ball under hips)        
The cervical spine, or neck, should not be hyper flexed or extended. Try to maintain it in the position used when you are standing - in a neutral position.  A general exception to this would be if the head needs to be move to avoid hitting a surface, like a push-up with your feet on the ball (i.e. the neck may extend a bit more to realize a deeper push-up and avoid your face from hitting the ground). (See above picture)

2) Core (ball under hips, knees and feet progression)    
When performing exercises where the body is suspended in the prone position between two distal support-points, it is imperative that the core be strong enough to maintain a posterior or neutral pelvic tilt. This protects the lumbar spine from hyperextension and requires exceptional abdominal and hip flexor strength.  Strive for a straight body alignment from head to toe. Ee above picture).

3) Abdominal strength and tests           
A simple method of assessing abdominal strength is to check if a person can maintain their lower back flat to the ground when lifting one knee and foot off the ground.  This test can then be advanced to two knees and eventually to extended leg (s).  A ruler can be used to assure the lumbar spine is in contact with the ground at all times.  Insert the ruler under the lumbar spine and have the individual pinch the ruler against the ground.  If you can pull the ruler out during the test the lower abdominals have not been able to maintain a posterior pelvic tilt (i.e. has not maintained a flat lower back) – this means lower abdominals are relatively weak.  If an individual cannot maintain a flat lower back during this test, they should not to perform exercises that risk lumbar hyperextension, such as the rollouts (i.e. loaded flexion in a prone position). 

4) Protraction/Retraction     
Finally, exercises requiring the arms to support the weight of the body demand optimal integrity of the shoulder complex.  The key element to look for is proper stabilization of the scapula and thoracic complexes.  An individual should be able to prevent scapular “collapse”.  Holding a slightly, retracted (i.e. pre-stretched) position will allow more force production on a bench press, especially since the bench supports the scapulas and prevent their separation from the rib cage.  During pronated -SLT on the stability ball, the ability to produce maximum force is superceded by joint stabilization.  Therefore, a stable sacpular complex is needed for optimal performance.  Retraction and protraction can be emphasized in an isolated manner to teach recruitment patterns and can then be incorporated in normal pressing mechanics.

5) Standing Exercises
When exercising in a standing position, there are a few teaching cues, which will help make the learning and training process flow smoothly.  During wall slides, the middle of the stability ball should be at about the belt line.  This ball position will provide adequate support when in the bottom position of a squat. 
When performing free-standing, single leg exercises smaller balls require less flexibility on the part of the trailing leg’s hip flexors. However, a deeper squat is possible with the smaller balls, placing a higher strength demand on the part of the ground-leg hip extensors.  Larger balls require greater hip flexor flexibility but reduce the range of motion, placing less emphasis on strength.
Obviously, a two-leg position of any exercise should be mastered before a one-leg version is attempted.

The next article will address the lever system inherent to Stability Ball training.  We will explore the progressive nature of this lever system and how to apply it to increase intensity to Stability Ball training.  The next section will also look at some of the complimentary equipment we have used over the year to make SB training more versatile. 

Until then –stay on the ball!

- JC