Abdominals & Lower Back Pain

Abdominals & Lower
                                      Back Pain
        PilatesWorks Australia

                                         Effectiveness Of Abdominal
                                      Hollowing And Abdominal Bracing
                                       Techniques In Rehabilitation Of
                                      Chronic Lower Back Pain and Core
                                                  Training
PilatesWorks Australia
                                       Written by Suzie Kennedy
CNR GWH & Russell Street
Emu Plains
www.pilatesworkspenrith.com.au

T   4727 7710
F   4727 7720
E   info@pilatesworkspenrith.com.au

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                                        INTRODUCTION

There have been many studies conducted over the last decade examining various components
of lumbo-pelvic stabilisation exercise techniques on the rehabilitation of lower back pain pa-
tients. In 2006, Ferreira, P., Ferreira M., Maher, C., Herbert ,R. and Refshauge, K. conducted a
systematic review as to the efficacy of specific stabilisation exercises for spinal and pelvic pain.
They concluded that specific stabilisation exercises reduce pain and disability in chronic, but not
acute low back pain, and that this mode of exercise is an effective treatment for many forms of
spinal pain. However, this review did not evaluate which type of stabilisation exercises are best
or whether a combination progressing from isolated to integrated trunk musculature exercise is
preferable.

It is widely acknowledged that trunk stabilisation is essential for spinal protection during move-
ment - this stemmed from research conducted by Panjabi in 1992. Hodges, P. and Richardson,
C.A. (1998) further established that the onset of all trunk muscles precedes that of the muscles
responsible for lower limb movement, thus contributing to feed-forward postural response. They
noted that in patients with lower back pain (LBP) the onset of transversus abdominis was de-
layed providing evidence that people with LBP have compromised trunk postural control.

The muscles that contribute to trunk lumbo-pelvic stability include; Multifidis (M), Transversus
Abdominis (TrA), Internal Obliques (IO), External Obliques (EO), Rectus Abdominis (RA) and
the Erector Spinae group (ES). TrA has a limited ability to control movement of the spine
(McGill, S.A. 1996) but it does have an important role in reduction of abdominal circumference
increasing intra abdominal pressure, increasing tension in the thoracolumbar facia and in stiffen-
ing the lumbar spine-pelvic complex to provide stability. Hodges has determined that TrA is
controlled independently of other trunk muscles and he believes it should be trained in isolation.
Hodges also states that TrA is the principle abdominal muscle affected in LBP, that it loses is
tonic function in persons with LBP and therefore needs to be trained to regain function. He also
advises that there is a close relationship between the TrA, Multifidus, Pelvic Floor and thoracic
diaphragm. He also notes that as TrA has a similar function in most movement patterns it may
not need to be trained in functional positions initially.

Hodges, P.W and Richardson, CA(1999) examined the relationship between TrA and the super-
ficial abdominal muscles in motor command and co-ordination concluding that TrA may be con-
trolled independently of the motor commands for limb movements .

Neuromuscular patterning of trunk muscle activation and coordination be-
came established together with evidence of incorrect patterning in indi-
viduals with LBP (Hungerford, B, Gilleard W & Hodges P, (2003)),

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(Hodges & Richardson (1998)). The evidence presented from the Hodges & Richardson review
in 1998 is extremely convincing. They clearly show that TrA activation was delayed in respect
to IO, EO, RA in flexion, IO, EO in abduction, IO, EO, RA in extension, for persons with LBP. In
all cases individuals with LBP recruited TrA a substantial time post initiation of movement and
the onset of ES was prior to individuals without back pain.

It is clear from investigations to date that all the trunk musculature are important in spine stabli-
zation, however, it could be hypothosised from studies looking at patients with LBP that the or-
der in which these muscles are activated is of vital importance in maintaining back and spinal
health.

Based on this information investigations began into the importance of core musculature, core
training and whether motor control training of these deep stabilisers was effective treatment for
persons with LBP. Research looked at two types of lumbo-pelvic exercises – abdominal hol-
lowing and abdominal bracing. This report examines both these techniques to investigate which
is a more effective treatment or whether both exercise methods have a place in clinical rehabili-
tation practice.

                                 PART A: BACKGROUND

Two forms of core muscle activation have been investigated over the past 15 years - abdominal
hollowing and abdominal bracing. Both forms have been integrated into exercise technique –
particularly in pilates (more focused on hollowing integrating through to bracing “stabilisation
before mobilisation”), Yoga (more focused on meditation breathing and bracing “integrating mind
and body”), general fitness training and in rehabilitation clinics.

Whilst these forms of core training have been practiced for thousands of years, as in the case of
Yoga, it is only recently that their effectiveness has been analysed, in particular their effective-
ness in relation to prevention of and recovery from back pain.

                                ABDOMINAL HOLLOWING

Abdominal Hollowing is a technique utilised for motor pattern retraining (Jull GA & Richardson
CA. 2000). It involves the ‘hollowing’ or ‘drawing in’ of the TrA and IO muscles with as much
limitation or inactivation of EO and RA as possible. The theory behind this is that the TrA should
activate first, then IO, followed by EO and RA when full bracing occurs
with all muscles working to stabilise the spine during movement in healthy
individuals (Davidson KL, Hubley-Kozey CL 2005). As noted previously in
individuals with LBP this sequence of muscle activation is not occurring,
primarily with TrA being delayed or hindered in its onset. The philosophy

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of abdominal hollowing is to isolate the TrA as much as possible and strengthen and retrain until
‘normal’ neuromuscular patterning occurs.

It should also be noted that the pelvic floor muscles are also closely related to TrA activation
and that in healthy populations the activation of the pelvic floor muscles occurs with activation of
the TrA (Sapsford RR, Hodges PW, Richarson CA, Cooper DH, Markwll SJ & Jull GA 2001).

Does Abdominal Hollowing work? Hides, Wilson, Stanton, McMahn, Keto, McMahon, Byrant &
Richardson 2006 used an MRI to investigate the functioning of TrA during abdominal hollowing.
They found that as a result of drawing-in, there was a significant increase in thickness of the
TrA and the IO muscles. They concluded that during abdominal hollowing the TrA contracts bi-
laterally to form a musculofasical band which acts like a corset to improve the stability of the
lumbo-pelvic reation.

             TEACHING THE ABDOMINAL HOLLOWING EXERCISE

There are a number of methods available to the practitioner with which to teach TrA activation
exercises, in particular, abdominal hollowing exercises. They include utilising an Electromyog-
raph (EMG), real time ultrasound, bio-feedback stabiliser, palpitation and verbal instruction. The
choice of teaching vehicle by the practitioner will depend on access to equipment, financial
costs, motor learning ability of the patient, severity of the patients injury in relation to the CNS
function, comfort level of patient being trained and patient history.

People learn by a combination of visual, audio and kinestic means, often being stronger in one
form of motor learning than another. Therefore it would make sense for the practitioner to use
all these teaching modes when helping a patient activate such a deep muscle as TrA.

Electromyograph

The electromyography (EMG) is routinely used in research when evaluating muscle activation
and percentage of voluntary contraction. But is it a good teaching tool? Allison, Godfrey & Rob-
inson (1996) concluded that using the EMG signal profile requires special attention regarding
reliability and validity.

In 2004 Drysdale, Earl & Hertel found that the EMG provided solid evidence that abdominal hol-
lowing may be performed with minimal activation of the larger global muscles such as RA and
EO. It would be acceptable to conclude that at this stage a EMG reading
can provide the best understanding of what muscle is activating, but out-
side a research facility or hospital it seems totally impractical method of
training core strength and stability in normal patients – either with or with-
out back pain (Monfort-Panego, M., Vera-Garcia, FJ., Sanchez-Zuriaga,

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D., Sarti-Martinex, MA., 2009). The area of tester experience and reliability and understanding
has been further highlighted by Brown & McGill (2007) who investigated the effect of both ago-
nist and antagonist activity on result conclusions. They concluded that antagonist muscle co-
activation must be included when determining EMG moment relationship of trunk muscles.

Whilst it could be argued that the EMG is the ‘gold standard’ when it comes to researchers and
practitioners evaluating what is happening muscularly with a patient, it would be impractical to
assume that the patient would understand the feedback being provided by the machine and
therefore it is probably not an effective teaching tool.

Real Time Ultrasound

Real Time Ultrasound has become a popular tool in many physiotherapy and rehabilitation clin-
ics. It provides a safe, relatively cost effective and easily accessible method of examination
(Hides, JA, Richardson CA & Jull GA, 1998) and has therefore been utilised to train the trans-
versus abdominus and multifidus muscles in people with LBP. It allows immediate visualization
of the contraction of the deep lumbo-pelivic stabilisers, is non invasive and is a great modality
for the facilitation of diagnosis and teaching of muscular retraining (Hides, Richarson & Jull,
1998).

Henry & Westervelt (2005) investigating the use of real time ultrasound in teaching abdominal
hollowing to healthy subjects, concluded that using real time ultrasound can decrease the num-
ber of trials needed to consistently perform these exercises however they had inconclusive data
as to the retention of skill post training in their subjects.

Hides, Richardson & Jull (1998) do acknowledge that good clinical skills with this machine are
also of extreme importance. This is supported by Hides, Miokovic, Belavy, Stanton & Richard-
son 2007, who established that novice assessors displayed inconsistancies in measurements of
reliability for recapturing the image and repetition of that task.

Taking tester inconsistancies aside it appears that utilising real time ultrasound as a method of
teaching abdominal hollowing exercises is highly successful. However, again whilst possibly
affordable in a physiotherapy clinic or hospital situation they may still be beyond the financial
reach of many private practitioners, sporting teams and exercise physiologists. Solid training of
the practitioner also has to be factored into the purchase equation.

Like the EMG it could be difficult for the patient to understand and compre-
hend the feedback shown on the monitor. Patients can not be assumed to
have the understanding of the tester, and with the fact that novice testers
can provide incorrect or inconsistent evaluations it also would seem an
impractical tool to use in many cases.

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Manual Bio-Feedback Stabilisers

There have not been many studies to verify the efficacy of the utilising the bio-feedback unit has
a tool for assisting corrected muscular recruitment in patients or of patient reduction in chronic
lower back pain. Of those studies done there is very positive results. Donaldson, Romney,
Donaldson & Skubick (1994) ran a randomised study using the biofeedback stabiliser as a train-
ing tool in recovery from chronic lower back pain (CLBP). They separated trial groups into a)
using biofeedback stabiliser, b) using relaxation techniques and c) using education about pain
management and postural control. Assesment was compiled using a combination of EMG read-
ings, pain scale and re-current injury or pain. The biofeedback group reported a decrease in
pain within 6 training sessions which was maintained at 90 days post treatment, the relaxation
group showed no changes and the education group reported some decrease in pain at 90 days.
A 4 year follow up was conducted. At this time only the biofeedback group remained symptom
free. This study implies that using a biofeedback stabiliser is a very effective treatment teaching
tool and the exercise adaptations were positive in relation to patients returning to normal func-
tion.

A further study was conducted in 2009 by Von Garnier, Koveker, Rackwitz, Kober, WilkeEwert &
Stucki. They determined that using a biofeedback stabilser in a prone test had relatively low
inter-observer reliability but high test-re-test reliability. They concluded that by providing visual
feedback the biofeedback stabiliser allows patients insight into what their deep abdominal mus-
cles are doing and that this facilitates learning and increases motivation to exercise.

Currently in Australia a “Chatanooga” biofeedback stabiliser costs between $145-$190 per unit.
This makes it a very affordable tool for the practitioner. It is easy for the patient to use and once
intense practitioner instruction is completed it is a tool that can be self-managed by the patient
for training purposes. There are also digital versions ranging between $350-$500.00. This
makes a biofeedback stabiliser extremely affordable, not just for the practitioner but also for the
patient who may be requested to practise exercise outside of treatment appointment times.

Verbal Instruction with Instructor Palpitation

This would be the most common method of teaching abdominal hollowing. The practitioner
gives verbal instructions for the patient to follow and can confirm correctness of manouver by
palpitation. Whilst there is little scientific evidence as to the efficacy of this teaching tool it is
widely practised and has good qualitative evidence. The problem with this
teaching method is neither the patient or instructor can be really sure that
activation felt by palpitation is by the TrA and not significantly IO, EO or
even Psoas. An experienced instructor may have the ability to determine
which muscles are activating but it leads to questionable practice for

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reliability and validity. While this may never be a concern for a healthy subject, the practitioner
treating a patient with either non-specifiic LBP, chronic LBP or other diagnosed lower back injury
must question the effectiveness of this as the only tool of teaching.

RECOMMENDED TEACHING METHODS FOR THE CLINICAN

Choosing a teaching tool is dependent upon equipment available and the educated judgement
of the clinican as to which method the patient will respond to best. For the reasons outlined
above I would recommend the use of a biofeedback stabiliser in conjunction with verbal instruc-
tion and palpitation. Testing of effectiveness could then be done on either a real time ultrasound
or EMG if available.

Once the patient understands the concept and can repeatedly perform the movement correctly
then removal of the stabiliser is necessary so the patient can ensure correct performance in nor-
mal circumstances. The biofeedback stabiliser can then be used as a test and measure tool or
for re-training if technique lapses.

If no equipment is available then the instructor must rely on correct demonstration of technique,
verbal correction for what they are observing, cueing throughout movements and utilising palpi-
tation to ensure patient is performing correctly and not bearing down on the pelvic floor.

If neuromuscular pattern and TrA strength and endurance is the goal of the training and if it is
agreed with Hoges that TrA should be trained initially in isolation before integration of other
trunk muscles, then teaching abdominal hollowing from supine position first is recommended
(Urquhart, D.M., Hodges P.W., Allen T.J., & Story I.H, 2004).

                                  ABDOMINAL BRACING

A coactivation of all trunk muscles (TrA, PF, M, IO, EO, RA, ES) is termed abdominal bracing
(Vera-Garcia, FJ., Elvira JLL., Brown, SHM. & McGill SM., 2006). This a global maneuver that
provides a brace or corset-like tightening of the trunk muscles to stiffen and support the spine.
As discussed earlier there is a correct activation sequence and timing for this bracing movement
(Vera-Garcia et al 2006) and in patients with LBP the correct sequence is not occurring
(Hungerford et al 2003). There is evidence that abdominal bracing provides better spine stabili-
sation against trunk pertubations (Brown SMH, Vera-Garcia FJ, & McGill SM, 2006). This was
also concluded by Vera-Garcia et al 2006.

Vera-Garcia, Brown & McGill, 2006 note that, stiffness equates to stability.
Therefore if the goal of training is spinal stability or the movement being
performed places external forces upon the spine – such as lifting, jumping,
pushing and pulling actions seen in sport and some activities of daily liv-

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ing, they argue that abdominal bracing is a preferable training method to abdominal hollowing.
This is opposed to the recommendations of Richardson & Jull 2000) who concluded that
strengthening of TrA lead to stability of the spine and recommended using the abdominal hol-
lowing method.

Again it must be reiterated that this is only if the correct muscle activation sequence occurs and
adequate endurance in all muscles is possible – as concluded by Hall, L., Tsao, H., MacDonal
D, Coppieters, M., & Hodges, PW 2007). From their study they determined that ‘unlike isolated
voluntary training, co-contraction training of the trunk muscles does not restore the motor control
of the deep abdominal muscles in people with LBP”. Therefore whilst abdominal bracing is im-
portant for trunk stabilisation it needs to be performed only in patients who have correct muscle
patterning. Until they do, it would appear that abdominal hollowing would be more appropriate
training to bring about correct co-contraction sequence.

TEACHING ABDOMINAL BRACING

Assuming that the patient can activate the trunk musculature in the correct order, teaching of the
abdominal bracing manoeuvre can be done using any of the tools outlined in teaching of ab-
dominal hollowing (EMG, Ultrasound, Biofeedback Stabiliser, Instructor demonstration, cueing
and palpitation).

Considerations for the best choice of tool are also the same, however, use of the biofeedback
stabiliser may not be particularly effective as patients could move out of neutral position when
initiating the brace. Bracing is also not as effective in supine or prone positions where the pa-
tient is supported by the floor or table.     It is very effective in positions such as 4-point
(quadruped), side bridging and plank positions and standing balance.

Teaching of this manoeuvre can simply involve instructor demonstration, verbal instruction, ver-
bal correction from observations and palpitation of torso to ensure patient is contracting all mus-
cles. Cues like ‘’squeeze your tummy, back, sides, front”, “tighten a large belt or corset around
your abdomen’ etc, can be used to help patient’s visualise the action required.

Again, like abdominal hollowing using an EMG or real time ultrasound would identify if muscular
action was occurring correctly, but may not be a suitable teaching tool for all cases due to pa-
tient comprehension.

                           AUTHORS OPINION.

Based on all evidence outlined it this author’s opinion that a combination
of both techniques would be ideal in many situations where a progressive
training program was involved. This would allow the clinician to ensure

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correct motor control and patterning, strengthen the deep abdominal muscles and increase their
endurance then lead into co-activation movements to further enhance spinal stability and stiff-
ness in the lumbo-pelvic region.

The time spent on abdominal hollowing before progressing to abdominal bracing should be de-
termined on a case-by-case basis. It is very clear from research by Hodges, Tsao and McGill
that progressing to bracing manoeuvres before correct neural muscular patterning is achieved
will not make any improvement for people with lower back pain.

Tsao,. Overs, ME., Wu, JC., Galea, MP and Hodges, PW (2008) made an interesting finding
that there is a longer reaction time during bilateral activation of the trunk muscles – they surmise
that this is due to variations in postural demand.

                                                References

1. Allison, GT., Godfrey P., & Robinson G. 1996. EMG signal amplitude

        assessment during abdominal bracing and hollowing. Journal of electromyography and Kinesiology. 8: 51-
        57

2. Brown SHM., Vera-Garcia FJ., & McGill, SM. 2006. Effects of abdominal

        muscle co-activation on the externally pre-loaded trunk: variations in motor control and its effect on spine
        stability. Spine 13: 387-393.

2. Brown SHM & McGill SM., 2007. Co-activation alters the linear versus non-

        linear impressionof the EMG-torque relationship of trunk muscles.

        Journal of Biomechanics 41: 491-497.

3. Davidson KL, Hubley-Kozey CL 2005. Trunk muscle responses to demands

        of an exercise progression to improve dynamic spinal stability. Archives of Physical Medicine and Reha-
        bilitation 86: 216-823

4. Donaldson, S., Romney, D., Donaldson, M and Subick, D 1994.

        Randomised study of the application of a single motor unit biofeedback training to chronic lower back pain.
        Journal of Occupational Rehabilitation. 4 (1):23-37

5. Ferreira PH, Ferreira ML, Maher CG, Herbert RD & Refshaug K 2006.

        Specific stabilisation exercise for spinal and pelvic pain: A systematic review.
        Australian Journal of Physiotherapy 52: 79-88

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6. Jull GA & Richardson CA. 2000. Motor control problems in patients with

        spinal pain: a new direction for therapeutic exercise. Journal of Manipulative Physiological Therapy 23:
        115-117

7. Henry, SM. & Westervelt, K.C. 2005. The use of real-time ultrasound

        feedback in teaching abdominal hollowing exercises to healthy subjects. Journal of orthopaedic and sports
        physical therapy. 35 (6): 338-345

8. Hides, JA., Richardson CA. & Jull GA. 1998. Use of real-time ultrasound

        imaging for feedback in rehabilitation. Manual Therapy 3 (3): 125-131

9. Hides J., Wilson, S., Stanton W., McMahon, S., Keto, H., McMahon, K.,

        Bryant M. & Richardson C. 2006. An MRI investigation into the function of the transversus abdominis mus-
        cle during ‘drawing-in’ of the abdominal wall. Spine 31 (6): 175-178

10. Hides JA., Miokovic, T., Belavy, DL., Stanton, WR. & Richardson, CA.

        2007. Ultrasound imaging assessment of abdominal muscle function during drawing-in of the abdominal
        wall: an intrarater reliability study. Journal of orthopaedic and sports physical therapy. 37 (8): 480-486

11. Hodges PW & Richardson CA 1998. Delayed Postural Contraction of

        Transversus Abdominis in Low Back Pain Associated with Movement of the Lower Limb. Journal of Spinal
        Disorders 11: 46-56

12. Hodges PW & Richardson CA 1999. Transversus abdominis and the

        superficial abdominal muscles are controlled independently in a postural task. Neuroscience Letters 265:
        91-94

13. Hodges PW. 1999. Is there a role for transversus abdominis in lumbo-

        pelvic stability? Journal of Manual Therapy 4(2): 74-86

14. Hungerford B, Gilleard W & Hodges P. 2003. Evidence of altered

        lumbopelvic muscle recruitment in the presence of sacrioiliac joint pain. Spine 28 (14): 1593-1600

15. Monfort-Panego, M. Vera-Garcia FK., Sachez-Zuriaga, D., Sarti-Martinez

        MA. 2009. Electormyographic studies inabdominal exercises: A literature synthesis. National University of
        Health Sciences

16. Panjabi MM 1992a. The stabilising system of the spine, Part 1. Function,

        dysfunction, adaptation and enhancement. Journal of Spinal Disorders 5: 383-
        389

17. Panjabi MM 1992b. The stabilizing system of the spine. Part 2. Neutral

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         zone and instability hypothesis. Journal of Spinal Disorders 5: 390-397

18. Sapsford RR, Hodges PW, Richardson CA, Cooper DH, Markwell SK &

         Jull GA. 2001.    Co-activation of the abdominal and pelvic floor muscles during voluntary exercises.
         Neurourology and Urodynamics 20 (1): 31-42

19. Urquhart DM, Hodges PW., Allen TJ. & Story IH. 2004. Abdominal

         muscle recruitment during a range of voluntary exercises. Manual Therapy 10: 144-153

20. Vera-Garcia, FJ., Elvira, JLL., Brown, SHM & McGill, SM. 2006. Effects of

         abdominal stabilisation maneuvers on the control of spine motion and stability against sudden trunk pertur-
         bations. Journal of Electromyography and Kinesiology 17: 556-567

19. Von Garnier, K., Koveker, K., Rackwitz, B., Kober, U., Wilke, S., Ewert, T.,

         Stucki, G. 2009. Reliability of a test measuring transversus abdominis muscle recruitment with a pressure
         biofeedback unit. Charted Society of Physiotherapy 95: 8-14

put in Alan’s book, Basi books and strong to the core book as reference for statement about different ex rx.