Pilates and Core Stability?

[Guest guest]

The following discussion on Pilates may be of interest to you.

Romany-Ruby wrote:

<< Hi Dr. Siff, I was forwarded your email by Dr. Bill Biddington and have

been doing Pilates now for 5 years. I own a training organization called

PowerHouse Pilates and have been trying to make some sense of the changes

that occur with Pilates. Some thoughts on your email:

There are essentially 2-3 strains of Pilates now. The traditionals in the New

York style do their exercises in a posterior pelvic tilt, which continually

fires the rectus abdominis and I believe limits the action of the TV. I am

not sure which style of Pilates was used for the information in your email.

The more contemporary approaches of Pilates use a neutral spine similar to

what is used by PT's. I believe the exercises done with this neutral

approach not only do more for the TV, but create balance in the abdominal

musculature. This prevents the over development of the internal oblique as

in traditional fitness programs. The external oblique actually does not get

enough recognition in its ability to stabilize the lumbosacral area.

Mel Siff:

*** I am aware of the different approaches to Pilates and have had many

Pilates teachers like Moira Stott writing to me confirming that quite a bit

of Pilates material is outdated and unscientific. Posterior pelvic tilt,

whether is activates or deactivates TvA or not, is a very risky and

inefficient way of lifting a load, pushing a load overhead or stabilising the

body when exposed to sudden perturbation. In heavy lifting and powerful

contact sports, it is not always possible or desirable for maximum force

production throughout range of action to be produced with a " neutral " spine.

If you study powerlifters in particular and any movements where the trunk of

the person is at some significant angle to the direction of the gravitational

field, then functional deviations from neutrality may take place.

CRR:

I agree that classical Pilates (what I call traditional Pilates) may not be

the best alignment for functional performance. It will truly be the

combination of the wide range of Pilates exercises and the knowledge base of

skilled healthcare professionals that will bring this to a level that will

significantly improve core stability.

I am appending an article (see below) that I recently wrote on the Pilates

roll-up (straight leg sit-up) for IDEA that discusses my thoughts on muscle

balance in the abdomen. Most of the information is taken from Sahrmann and

Kendall. To me it raises the question that maybe core stability is not about

just the strength of the TV, but about muscle balance.

Mel Siff:

*** The straight leg situp has been in the PNF " Bible " written about 50

years ago and I have tried to stress the myths about straight-legged crunches

or sit-ups for many years, so I am surprised that so many fitness

professionals and therapists still seem to believe that straight-legged

sit-ups are " bad " for you. Anyway, unloaded supine crunches or sit-ups do

not elicit anything like the same level of abdominal activation as various

standing trunk exercises such as the cable crunch and the old standing

Olympic Press.

Incidentally, the work of people such as Kendall is very out of date, not

adequately based upon any definitive research and not applicable to the real

world of multi-articular movement in dynamic and ballistic sporting actions.

I will be speaking at the 2003 IDEA Personal Trainer Interantional Summit on

functional, balance and core training and will be examining many of the

myths in this field of trendy training.

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The Pilates Roll-up (Straight leg sit-up)

Romany-Ruby

Strengthening the abdominal muscles has interested the general population and

fitness professionals for years. This interest stems from the desire to have

the appearance of a flat abdomen, and the abdominal muscles' assumed ability

to protect the spine. Over the years, fitness has progressed from the sit-up

to the crunch, to the pelvic tilt, and now the roll up. Unfortunately, many

of the programs developed to strengthen abdominal muscles have contributed to

muscle imbalances and pain syndromes (3). For these reasons there has been

conflicting information in the media concerning methods and effects of

abdominal strengthening.

An understanding of the role of each abdominal muscle in both the sit up or

crunch and in healthy posture is vital to the evaluation of abdominal muscle

performance. A study by Juker and colleagues indicates that there is a

greater percentage of rectus abdominis activity (68%) during the performance

of sit-ups than there is external oblique activity (19%) or internal oblique

activity (14%) (1). The problem with this is that the rectus abdominis is

not the preferred muscle to strengthen in the abdominal area. The rectus

abdominus is not effective at preventing rotation (needed to protect the

lumbar spine) and shortening of the rectus abdominis, actually contributes to

a thoracic kyphosis2.

Examining a sit-up, legs bent or extended, there are two component motions.

There is a trunk curl and then a sit-up (hip flexion). The internal oblique

and rectus abdominis are most active in the trunk curl. As the trunk curls

and is pulled toward the pelvis, there is a simultaneous posterior tilt of

the pelvis. The sit-up is then performed by the hip flexors (rectus femoris,

illiacus, psoas). With this in mind, it is not surprising that the most

common imbalance encountered in an individual that has performed abdominal

exercises is an over development of the internal oblique and rectus abdominis

muscles (3).

The greatest risk of injury during the sit-up is hip flexion without the

trunk curl. This may happen because of lack of abdominal strength, hip

flexor dominance, or a stiff spine. Hip flexor contraction without trunk

curl causes dangerous anterior shear forces from hyperextension of the lumbar

spine (2). Because of the hip flexor attachment to the front of the lumbar

spine, the sit up phase will actually lift the torso by pulling on the u

nstable extended spine.

For years, fitness has advocated the trunk curl with the hips and knees

flexed as a means of minimizing the action of the hip flexors. The theory

was that the hip flexors are on slack in this position. In reality, the

benefit of the flexed hips and knees is just ease in producing a posterior

pelvic tilt. This does reduce the risk of anterior shear to the lumbar

spine. For this reason, the bent knee crunch is recommended for class

settings where there is not one- on- one training.

In the one-on-one setting the sit-up is a better choice for those that can

perform it safely. Limiting the exercise to the bent knee crunch, does not

require maximum performance of the internal oblique (3). The greatest demands

are put on the abdominal muscles as the hip flexors contract for the sit-up

phase. A full trunk curl/sit-up not only requires the abdominal muscles to

maintain the trunk curl, but also to maintain a posterior pelvic tilt. When

working with clients in small groups or one-on-one, it would be effective to

incorporate the sit-up using the guidelines listed below.

Activities such as Pilates and Yoga have re-introduced the straight leg

sit-up or roll up into the fitness environment. With the roll up, we are

able to produce greater demands on the abdominal muscles for performance, but

we produce unfortunate risks in the group setting. The most common error

made in general instruction of the trunk curl is not matching the client's

level of strength with the appropriate level of demand made by the exercise

(3). This should remind us of the personalized instruction and attention to

detail that disciplines such as Yoga and Pilates require in the fitness

setting. This type of abdominal strengthening is most successful in small

groups or one on one.

When performing a trunk curl / sit-up (legs bent or extended) with a client

the following criteria should be checked:

1. Have knowledge of the client's passive spinal flexibility. Some clients

have stiff spines and this will limit their ability to perform the trunk curl

to a point that the sit-up portion is safe. To measure this, raise the client

up into a trunk curl passively and assess trunk flexion.

2. Look for tight hip flexors. If a client has tightness of their hip

flexors, they will be unable to hold the pelvis in a posterior tilt to safely

perform the sit-up phase. The client should be able to flatten the lumbar

spine onto the floor in supine with the lower extremities extended. If they

are unable to perform this maneuver, place a roll under their knees to reduce

the pull of the hip flexors.

3. Watch for a posterior pelvic tilt. When the client initiates the trunk

curl, does the pelvis tilt posteriorly? It should. If the client is using

hip flexors for the motion the pelvis will tilt anteriorly.

4. Observe the neck position. The chin should be brought to the Adam's

apple, not to the chest. The neck should not extend either, which is the

movement that occurs when the client's face is to the ceiling.

5. Does the client have a thoracic kyphosis? This exercise will contribute

to the problem (2).

6. Can the client curl to the limit of his/her spinal flexibility with the

shortest lever of the exercise (arms reaching in front)? If the degree of

difficulty is increased with lever (arms on chest or behind head) does the

client still perform the same amount of trunk curl? If the trunk curl

diminishes, the client is not ready to progress to the more challenging

exercise.

7. Does the client maintain the lumbar curl at the initiation of the sit-up

phase? If not, the abdominals are too weak and there is anterior shear

stress on the lumbar spine.

8. During the trunk curl phase the heels should stay in contact with the

floor (2). If the feet come up, it is safe to hold them down if attention is

focused on whether the trunk maintains the curl. For best results hold the

feet only during the sit-up phase. If the feet are held down before the sit

up phase, it will cause the hip flexors to contract to initiate the trunk rais

e. It is especially dangerous to hold the feet and perform high repetitions

because, as the abdominals fatigue, the high endurance hip flexors will take

over (2).

In summary, one should remember that the sit-up, whether the legs are

extended or bent, is a strong hip flexor exercise (2). The main abdominal

muscle strengthened is the rectus abdominis and it can cause more harm than

good to the spine. It is important to incorporate other methods of

abdominal strengthening to create muscle balance and spinal stability.

Emphasis should be placed on strengthening the external oblique and the

transverse abdominis muscles.

When teaching any abdominal exercise be sure that the client obtains the

control to appropriately stabilize the spine, maintain optimal alignment and

movement relationships between the pelvis and spine, and prevent excessive

stress and compensatory motions of the pelvis during movements of the

extremities (3).

Bibliography

1. Juker D, McGill SM, Kropf P, Steffen R: Quantitative intramuscular

myoelectric activity of lumbar portions of psoas and the abdominal wall

during a wide variety of tasks, Med Sci Sports exerc 30:301, 1998.

2. Kendall, Florence, Muscles Testing and Function 4th Edition, Lippincott

and Wilkins, 1993.

3. Sahrmann, Shirley A. Diagnosis and Treatment of Movement Impairment

Syndromes , Mosby Inc., 2002

[Mel Siff: Note that Kendall has been used quite prolifically to support

several erroneous beliefs about spinal mechanics. Since Kendall has based

little or none of her work on scientific research, these beliefs differ

radically from what has been found by McGill and others regarding spinal

mechanics. Kendall's claim that " Hip flexor contraction without trunk curl

causes dangerous anterior shear forces from hyperextension of the lumbar

spine " is but one of these myths, an issue which I discussed many months ago

on this list. I would like to see any average person initiate an

unrestrained slow sit-up while keeping the spine in an hyperextended or even

neutral position - this is a very difficult movement unless one is extremely

strong. The moral: don't rely on dubious references which have involved

minimal scientific and clinical research. ]

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Any more comments from others?

Dr Mel C Siff

Denver, USA

http://groups.yahoo.com/group/Supertraining/