Download Effects of Lumbar Stabilization Using a Pressure Biofeedback Unit

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ORIGINAL ARTICLE
Effects of Lumbar Stabilization Using a Pressure Biofeedback
Unit on Muscle Activity and Lateral Pelvic Tilt During Hip
Abduction in Sidelying
Heon-Seock Cynn, PT, MA, Jae-Seop Oh, PT, MSc, Oh-Yun Kwon, PT, PhD, Chung-Hwi Yi, PT, PhD
ABSTRACT. Cynn H-S, Oh J-S, Kwon O-Y, Yi C-H. Effects of lumbar stabilization using a pressure biofeedback unit
on muscle activity and lateral pelvic tilt during hip abduction in
sidelying. Arch Phys Med Rehabil 2006;87:1454-8.
Objective: To assess the effects of lumbar spine stabilization using a pressure biofeedback unit on the electromyographic activity and angle of lateral pelvic tilt during hip
abduction in a sidelying position.
Design: Comparative, repeated-measures study.
Setting: University research laboratory.
Participants: Eighteen able-bodied volunteers (9 men, 9
women) with no history of pathology.
Intervention: Subjects were instructed to perform hip abduction in a sidelying position in both the preferred hip abduction (PHA)
and hip abduction with lumbar stabilization (HALS). A pressure
biofeedback unit was used for lumbar stabilization.
Main Outcome Measures: Surface electromyography was
recorded from the quadratus lumborum, gluteus medius, internal oblique, external oblique, rectus abdominis, and multifidus
muscles. Kinematic data for lateral pelvic tilt angle were measured using a motion analysis system. Dependent variables
were examined with 2 (PHA vs HALS) ⫻ 2 (men vs women)
analysis of variance.
Results: Significantly decreased electromyographic activity in the quadratus lumborum (PHA, 60.39%⫾15.62% of
maximum voluntary isometric contraction [MVIC]; HALS,
27.90%⫾13.03% of MVIC) and significantly increased electromyographic activity in the gluteus medius (PHA, 25.03%⫾
10.25% of MVIC; HALS, 46.06%⫾21.20% of MVIC) and internal oblique (PHA, 24.25%⫾18.10% of MVIC; HALS,
44.22%⫾20.89% of MVIC) were found when the lumbar spine
was stabilized. Lateral pelvic tilt angle (PHA, 13.86°⫾4.66°;
HALS, 5.55°⫾4.16°) was decreased significantly when the
lumbar spine was stabilized. In women the electromyographic
activity (percentage of MVIC) in gluteus medius, external
oblique, and rectus abdominis was significantly higher than
that observed in men.
Conclusions: With lumbar stabilization, the gluteus medius
and internal oblique activity was increased significantly, and
the quadratus lumborum activity was decreased significantly,
causing reduced lateral pelvic tilt in a sidelying position. These
results suggest that hip abduction with lumbar stabilization is
useful in excluding substitution by the quadratus lumborum.
From the Department of Rehabilitation Therapy, Graduate School, Yonsei University, Wonju, South Korea.
No commercial party having a direct financial interest in the results of the research
supporting this article has or will confer a benefit upon the authors or upon any
organization with which the authors are associated.
Reprint requests to Oh-Yun Kwon, PT, PhD, Dept of Rehabilitation Therapy,
Graduate School, Yonsei University, 234 Maji-li, Hungob-myon, Wonju, Kangwon-do 222-710, Republic of Korea, e-mail: [email protected].
0003-9993/06/8711-10804$32.00/0
doi:10.1016/j.apmr.2006.08.327
Arch Phys Med Rehabil Vol 87, November 2006
Key Words: Electromyography; Muscle; Rehabilitation;
Spine.
© 2006 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and
Rehabilitation
URING THE PAST DECADE, in the field of physical
D
therapy, the concept of lumbar stabilization has emerged
to prevent musculoskeletal injuries, to rehabilitate, and to improve performance. Lumbar stabilization refers to internal stabilization achieved by the isometric contraction of abdominal
and lumbar muscles to maintain stability.1 It has also been
referred to in the literature as core strengthening, motor control
training, and dynamic stabilization.2 Panjabi3 theorized that spine
stability is dependent on 3 subsystems: passive (spinal column), active (spinal muscles), and control (neural control)
subsystems. Panjabi4 also defined a neutral zone as being a
midrange position with minimal resistance to displacement
owing to minimal tension in the passive subsystem. In this
midrange position, deep intersegmental muscle contraction
should be provided to control excessive motion and to compensate for instability because passive restraints cannot control
the spinal movement. Two deep muscles, the transversus abdominis and lumbar multifidus, are important for this spinal
segment stabilization. It was also suggested that cocontraction
of these deep muscles must be performed without involvement
of the rectus abdominis or external oblique muscles, which are
overactive in patients with low back pain.5
A pressure biofeedback unit,a originally developed for assessing the ability of abdominal muscles to actively stabilize
the lumbar spine, has been used to examine lumbar stabilization in various studies.6-10 It is a reliable and valid clinical
instrument for assessing deep abdominal muscle function, and
has been used to develop a method for the careful monitoring
of lumbar stabilization.11,12 The pressure biofeedback unit consists of an inflatable cushion connected to a pressure gauge and
an inflation device. When the pressure biofeedback unit is
placed and inflated, the subject is required to maintain the
desired pressure and a constant lumbar position during lowerextremity movement under external loads. Changes in the
pressure during hip movement reflect an inability to maintain
isometric contraction of the abdominal muscles, resulting in
uncontrolled movement and instability of the lumbar spine.
According to Janda,13 hip abduction has failed if hip flexion,
hip external rotation, or lateral pelvic tilt is observed before 40°
of abduction is achieved. Lateral pelvic tilt can occur when the
quadratus lumborum substitutes for a weakened gluteus medius.14 The lateral portion of the quadratus lumborum originates
on the lateral ilium and inserts into the 12th rib without attachment
to any vertebrae and produces primarily a lateral bending moment,
whereas the medial portion of the muscle provides segmental
stability through its segmental attachments.5 Substitution by the
lateral portion of the quadratus lumborum leads to pelvic obliquity
LUMBAR STABILIZATION DURING HIP ABDUCTION, Cynn
(lateral pelvic tilt), and the lumbar spine undergoes lateral flexion
resulting in lateral instability and impaired movement.15
Although many studies assessing lumbar stabilization have
been conducted with subjects in the supine position,7,10 no
studies on lumbar stabilization with subjects in the sidelying
position were found in the literature. In addition, we know of
no study confirming the effect of lumbar stabilization on the
selective recruitment of the gluteus medius and the inhibition
of the quadratus lumborum in the sidelying position. Given that
hip abduction in the sidelying position is the appropriate movement for testing the range of motion and strength of the gluteus
medius and is commonly prescribed as an exercise, investigating the role of lumbar stabilization during sidelying will provide the clinician with useful information for designing and
implementing exercise protocols.
Based on published reports and clinical experience, we hypothesized that increased gluteus medius activity and reduced
quadratus lumborum activity would result in decreased ipsilateral lateral tilt during hip abduction in the sidelying position
while the lumbar spine is stabilized with a pressure biofeedback unit. The aims of this study were to assess the effect of
lumbar stabilization using a pressure biofeedback unit on the
electromyographic activity and angle of lateral pelvic tilt and to
investigate the difference of muscle activation between men
and women during hip abduction in the sidelying position.
METHODS
Participants
We recruited 18 able-bodied young subjects (9 men, 9 women)
from university students who volunteered to participate in this
study. Subjects’ characteristics are shown in table 1. The exclusion criteria were past or present neurologic, musculoskeletal,
or cardiopulmonary diseases that could interfere with hip abduction. Each subject signed informed consent approved by the
university institutional review board before entering the study.
Surface Electromyographic Recording and Data Analysis
We collected electromyographic data using a data acquisition system (Biopac MP100WSWb) and a Bagnoli electromyography system.c The skin was cleansed with rubbing alcohol,
and disposable Ag-AgCl surface electrodes were positioned at
an interelectrode distance of 2cm. The reference electrode was
attached to the styloid process of the ulna on the dominant
upper extremity. Electromyographic data were collected for the
following muscles on the same side as the dominant lower extremity: quadratus lumborum (⬇4cm lateral from the vertebral
ridge or belly of the erector spinae muscle, and at a slightly
oblique angle at half the distance between the 12th rib and the iliac
crest), gluteus medius (parallel to the muscle fibers, over the
proximal one third of the distance between the iliac crest and
the greater trochanter), external oblique (on the inferior edge
of the 8th rib, superolateral to the costal margin), internal oblique
(in the horizontal plane, 2cm medial to the anterior superior iliac
spine), rectus abdominis (2cm lateral to the umbricus),16,17 and
Table 1: Subject Characteristics
Parameters
Subjects (N⫽18)
Age (y)
Weight (kg)
Height (cm)
23.5⫾3.5
59.3⫾5.1
167.7⫾4.3
NOTE. Values are mean ⫾ standard deviation (SD).
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multifidus (parallel to the muscle fibers, 2cm lateral to the midline
running through the L5 spinal process).18
We amplified and digitized the electromyographic signals with
AcqKnowledge software (version 3.7.2).b Bandpass (20⫺450Hz)
and bandstop filters (60Hz) were used. The raw data were processed into the root mean square (RMS) and were converted to
ASCII files for analysis. For normalization, the mean RMS of 3
trials of maximal voluntary isometric contraction (MVIC) was
calculated for each muscle. The manual muscle testing position
was used, as described by Kendall et al.19 The electromyographic signals collected during hip abduction were expressed
as a percentage of the calculated mean RMS of the MVIC
(% MVIC).
Kinematic Study of Lateral Pelvic Tilt
We used a 3-dimensional ultrasonic motion analysis system
(CMS-HSd) to measure the lateral pelvic tilt during hip abduction in sidelying. One triplet bearing 3 active markers that emit
an ultrasonic signal was secured to the pelvis on the side of the
lower extremity to be lifted. Three markers were positioned to
face the measuring sensor by a fastening belt passing around at
the level of anterior superior iliac spines. The measuring sensor
consisting of 3 microphones was positioned in front of the
subject to record the ultrasonic signal from the markers. The
measuring plane was set and aligned according the markers.
The angle of the lateral pelvic tilt measured before hip abduction was calibrated to 0° as a reference position, and the
relative angle of the lateral pelvic tilt during hip abduction was
calculated from this reference position.20,21 The sampling rate was
20Hz. After data collection angular displacements for lateral
pelvic tilt were low-pass filtered with a cutoff frequency of
8Hz. The kinematic data were analyzed by the Windata software (version 2.19).d The mean angle of 3 trials was determined for comparison.
Procedure
Each subject was required to assume a sidelying position
with the nondominant lower extremity contacting a firm mattress. The upper trunk, pelvis, and dominant lower extremity
were aligned in a straight line. The nondominant lower extremity could be flexed at both the hip and knee joints for comfort
and stability. While sidelying, the subject was asked to perform
hip abduction with the dominant lower extremity in both the
preferred condition and the stabilized-lumbar condition, in
random order. An inclinometer was used to determine when the
hip was in 35° of abduction. A bar was placed at this level and
provided feedback to the subject as they were instructed to
abduct their hip until the side of their knee touched the bar and
to hold the position for 5 seconds. The electromyographic
signal was recorded during this 5-second period. In the stabilized-lumbar condition, the pressure biofeedback unit was
placed between the firm mattress and the subject’s lumbar
spine in the sidelying position. The elastic bag was inflated
until the lumbar curve was straight, at which point the target
pressure was determined. The spinous processes in lumbar
region were palpated and a rigid ruler was used to visually
establish that the lumbar curve was straight. Subjects were
instructed to use the visual feedback provided by the analog
gauge of the pressure biofeedback unit in order to maintain the
determined target pressure during hip abduction. A researcher
monitored the pressure fluctuations. Pressure changes of
⫾5mmHg from the target pressure were allowed to accommodate changes induced by breathing.
Prior to testing all subjects were familiarized with the standard
position and movement and with the use of the pressure biofeedback unit and felt comfortable at the time of data collection.
Arch Phys Med Rehabil Vol 87, November 2006
1456
LUMBAR STABILIZATION DURING HIP ABDUCTION, Cynn
Statistical Analysis
The data are expressed as the mean ⫾ standard deviation
(SD). A 2⫻2 analysis of variance with 1 within-subject factor
(condition) and 1 between-factor (sex) was used to determine
the main effects and their interaction in each muscle with the
significance level set at P equal to or less than .05.
RESULTS
The electromyographic activity and the angle of lateral pelvic tilt during preferred hip abduction (PHA) and hip abduction
with lumbar stabilization (HALS) is shown in table 2. There
were significant main effects for condition (PHA vs HALS) in
quadratus lumborum (F1,16⫽54.51, P⫽.000), gluteus medius
(F1,16⫽46.29, P⫽.000), internal oblique (F1,16⫽23.92, P⫽.000),
and for angle of the lateral pelvic tilt (F1,16⫽73.79, P⫽.000).
There were significant main effects for sex in gluteus medius
(F1,16⫽4.98, P⫽.040), external oblique (F1,16⫽20.10, P⫽.000),
and rectus abdominis (F1,16⫽14.25, P⫽.002). There were also
significant condition by sex interactions in gluteus medius
(F1,16⫽7.30, P⫽.016), external oblique (F1,16⫽11.55, P⫽
.004), and multifidus (F1,16⫽10.37, P⫽.005). With lumbar
spine stabilization, the electromyographic activity was decreased significantly in the quadratus lumborum and increased
significantly in the gluteus medius and internal oblique. The
angle of lateral pelvic tilt was decreased significantly with
lumbar spine stabilization. In women the electromyographic
activity in gluteus medius, external oblique, and rectus abdominis was higher than that observed in men.
Table 2: Electromyographic Activity in Muscles and Angle of
Lateral Pelvic Tilt During Preferred Hip Abduction and Hip
Abduction With Lumbar Stabilization
Parameters
Muscle activity (% MVIC)
Quadratus lumborum
Men
Women
All
Gluteus medius
Men
Women
All
Internal oblique
Men
Women
All
External oblique
Men
Women
All
Rectus abdominis
Men
Women
All
Multifidus
Men
Women
All
Angle of lateral pelvic tilt (deg)
Men
Women
All
PHA
HALS
56.08⫾21.46
64.70⫾9.78
60.39⫾15.62
32.23⫾15.34
23.57⫾10.72
27.90⫾13.03
22.37⫾10.67
27.73⫾9.83
25.03⫾10.25
36.98⫾18.05
55.14⫾24.35
46.06⫾21.20
20.26⫾17.34
28.24⫾18.86
24.25⫾18.10
31.15⫾25.70
57.29⫾16.08
44.22⫾20.89
19.93⫾8.24
39.67⫾19.74
29.80⫾13.99
16.94⫾12.54
50.08⫾34.04
33.51⫾23.29
14.53⫾7.60
30.97⫾22.82
22.75⫾15.21
12.57⫾9.18
32.93⫾26.96
22.75⫾18.07
41.19⫾16.51
43.29⫾23.97
42.24⫾20.74
25.42⫾15.20
40.82⫾24.75
33.12⫾19.99
11.99⫾4.15
15.73⫾4.58
13.86⫾4.66
4.36⫾3.14
6.73⫾4.87
5.55⫾4.16
NOTE. Values are mean ⫾ SD.
Arch Phys Med Rehabil Vol 87, November 2006
DISCUSSION
Lumbar stabilization can be achieved by the cocontraction of
the transversus abdominis and lumbar multifidus. When the
transversus abdominis contracts, the intra-abdominal pressure
(IAP) increases, and the tension of the thoracolumbar fascia
increases. Consequently, stabilization of the spine is maintained by the IAP in the abdominal cavity and the stiffness of
the lumbar spine.22 Furthermore, the activation of the transversus abdominis is independent of the direction of limb movement and is continuous throughout lower limb movement,23,24
suggesting a stabilizing function of the abdominal pressure.
Panjabi4 determined that the lumbar multifidus acts as a stabilizer in the lumbar spine because it is a deep, segmentally
attached muscle. The role of the multifidus as a segmental
stabilizer has been also demonstrated previously.25-27
We found significantly increased internal oblique activities with lumbar stabilization. The internal oblique was
thought to enhance the stability of the spine in previous
studies,23,28,29 and this is consistent with our results, suggesting
that increased internal oblique muscle activity contributed to
lumbar stabilization. In this study, however, the activity of the
external oblique, rectus abdominis, and multifidus did not show
significant changes with the use of a pressure biofeedback unit.
Lumbar stabilization during hip abduction in sidelying does not
seem to affect the activity of these muscles. Unlike the internal
oblique muscle, the external oblique and rectus abdominis do
not blend at the lateral raphe of the thoracolumbar fascia,1 so
that the external oblique does not contribute to lumbar stabilization. The rectus abdominis runs longitudinally from pubic
crest and symphysis to costal cartilages and sternum. Thus, this
muscle could have led to sagittal plane stabilization with the
multifidus that runs relatively longitudinally. Our findings are
consistent with those of Arokoski et al18 who reported that it
was difficult to contract the paraspinal muscles independently
from the external oblique during stabilization exercise in the
sidelying position. In addition, Jull et al7 found no RMS
amplitude difference in rectus abdominis and the lumbar erector spinae with abdominal setting action during leg lifting in
supine position.
In women a higher percentage of MVIC in gluteus medius,
external oblique, and rectus abdominis was observed. This
higher percentage of MVIC in women is thought to result from
the need to maintain lumbopelvic stability required during hip
abduction in sidelying position. The sex-dependent differences
exist affecting the lumbopelvic stability between men and
women, even though we did not measure the differences. First,
less skeletal muscle mass, thickness of lateral abdominal muscles, and physiologic cross-sectional area of abdominal region
in women were reported from the previous studies.30-32 As muscle mass increases, so does amount of titin. Passive muscle
stiffness will increase as amount of titin increases, because titin
contribute to passive muscle stiffness.15 Thus, passive muscle
stiffness in women will be lower than that in men. This lower
passive stiffness can result in less lumbopelvic stability while
assuming hip abduction in sidelying position. Second, the
wider pelvic size in women,31 as an anthropometric difference,
may be one of the causes inducing lower lumbopelvic stability
in women. The center of gravity in sidelying position in women
would be positioned relatively higher than men secondary to
the wider pelvis, possibly threatening the lumbopelvic stability
of maintaining hip abduction in sidelying position. For these
possible reasons, it is presumed that the higher percentage of
MVIC in gluteus medius, external oblique, and rectus abdominis was required in women to overcome the lower lumbopelvic
stability during hip abduction in sidelying position. Further
LUMBAR STABILIZATION DURING HIP ABDUCTION, Cynn
studies should address the relation between the neuromuscular
control in the lumbopelvic region during hip abduction in sidelying position and the sex-specific differences.
Janda13 also identified an abnormal recruitment sequence for
hip abduction in symptomatic subjects compared with nonsymptomatic subjects. In patients with low back pain, gluteus
medius activity was delayed, whereas gluteus medius activity
was observed before the ipsilateral quadratus lumborum in
normal subjects. The recruitment imbalance between the gluteus medius and quadratus lumborum can induce movement
impairment. For this reason, the gluteus medius and quadratus
lumborum should be closely monitored for lumbar stability and
joint support.15 Clinicians often report overactivity and trigger
points for the quadratus lumborum with gluteus medius insufficiency in patients with back pain.14 In addition, increased
tension in the quadratus lumborum was implicated in pelvic
upward movement and rotational malalignment.33 Care should
be taken to prevent an overactive quadratus lumborum from
substituting for the gluteus medius.
Our results confirm the hypothesis that lumbar stabilization
during hip abduction in sidelying can reduce quadratus lumborum activity and ipsilateral pelvic tilt and can recruit the
gluteus medius and internal oblique. Previous studies have
recommended a treatment protocol that included relaxation to
decrease the activity of the quadratus lumborum and exercise to
facilitate the recruitment of the gluteus medius.5,14 The lumbar
stabilization method used here could stabilize the pelvis and
recruit the gluteus medius muscle without substitution by the
quadratus lumborum. Therefore, we suggest that lumbar stabilization during sidelying is useful in treatment protocols designed to prevent motor control dysfunction by reducing quadratus lumborum activity and strengthening the gluteus medius.
Our study showed that lumbar stabilization using a pressure
biofeedback unit significantly increased gluteus medius and
internal oblique activity, while decreasing quadratus lumborum
activity and ipsilateral pelvic tilt in hip abduction during sidelying. We used surface electromyography to investigate muscle
activity and assumed that the detected signal represented each
muscle in its entirety; however, there are potential signal alterations caused by muscle movements below the surface electrode or cross-talk from adjacent muscles. We established the
predetermined hip abduction at 35° of verticality to assure hip
abduction in the frontal plane and to prevent possible hip or
pelvis movement in other planes that might affect the targeted
muscle activities. Our results cannot be generalized to other
populations because all the subjects participating in the study
were young and able-bodied. Therefore, the benefits of lumbar
stabilization used in this study should be confirmed in other
populations. The activity of the transversus abdominis was not
measured in our study. Therefore, further studies are warranted
to assess deep muscle activity during hip abduction training
while sidelying with lumbar stabilization and to determine the
direct benefit and selective muscle facilitation associated with
lumbar stabilization.
CONCLUSIONS
This study showed that the activity of the gluteus medius and
internal oblique increased significantly, the activities of the
quadratus lumborum decreased significantly, and the lateral
pelvic tilt was reduced significantly during sidelying with lumbar stabilization achieved using a pressure biofeedback unit.
Therefore, hip abduction with lumbar stabilization during sidelying can be recommended as a more effective method for
excluding unwanted substitution by the quadratus lumborum
and to facilitate gluteus medius muscle activity.
1457
References
1. Kisner C, Colby LA. Therapeutic exercise: foundations and techniques. 4th ed. Philadelphia: FA Davis; 2002.
2. Akuthota V, Nadler SF. Core strengthening. Arch Phys Med
Rehabil 2004;85(3 Suppl 1):S86-92.
3. Panjabi M. The stabilizing system of the spine. Part I, function,
dysfunction, adaptation, and enhancement. J Spinal Disord 1992;
5:383-9.
4. Panjabi M. The stabilizing system of the spine. Part II, neutral
zone and instability hypothesis. J Spinal Disord 1992;5:390-7.
5. Richardson C, Jull G, Hodges P, Hides J. Therapeutic exercise for
spinal segmental stabilization in low back pain. London: Churchill
Livingstone; 1999.
6. Herrington L, Davies R. The influence of Pilates training on the
ability to contract the transversus abdominis muscle in asymptomatic individuals. J Bodywork Mov Ther 2005;9:52-7.
7. Jull G, Richardson C, Toppenberg R, Comerford M, Bui B.
Towards a measurement of active muscle control for lumbar
stabilization. Aust J Phys 1993;39:187-93.
8. Mills JD, Taunton JE, Mills WA. The effect of a 10-week training
regimen on lumbo-pelvic stability and athletic performance in
female athletes: a randomized-controlled trial. Phys Ther Sport
2005;6:60-6.
9. Richardson C, Jull G, Toppenberg R, Comerford M. Techniques
for active lumbar stabilization for spinal protection: a pilot study.
Aust J Phys 1992;38:105-12.
10. Wohlfart D, Jull G, Richardson C. The relationship between
dynamic and static function of the abdominal muscles. Aust J
Phys 1993;39:9-13.
11. Cairns M, Harrison K, Wright C. Pressure biofeedback: a useful
tool in the quantification of abdominal muscular dysfunction?
Physiotherapy 2000;86:127-38.
12. Richardson CA, Jull GA. Muscle control-pain control. What exercises would you prescribe? Man Ther 1995;1:2-10.
13. Janda V. Evaluation of muscle imbalance. In: Liebenson C, editor.
Rehabilitation of the spine: a practitioner’s manual. Baltimore:
Williams & Wilkins; 1996. p 97-112.
14. Chaitow L. Muscle energy techniques. London: Churchill Livingstone; 1996.
15. Sahrmann S. Diagnosis and treatment of movement impairment
syndrome. St. Louis: Mosby; 2002.
16. Cram JR, Kasman GS, Holtz J. Introduction to surface electromyography. Gaithersburg: Aspen; 1998.
17. Vera-Garcia FJ, Grenier SC, McGill SM. Abdominal muscle
response during curl-ups on both stable and labile surfaces. Phys
Ther 2000;80:564-9.
18. Arokoski JP, Valta T, Kankaanpaa M, Airaksinen O. Activation of
lumbar paraspinal and abdominal muscles during therapeutic exercises in chronic low back pain patients. Arch Phys Med Rehabil
2004;85:823-32.
19. Kendall FP, McCreary EK, Provance PG. Muscles: testing and
function with posture and pain. 5th ed. Baltimore: Williams &
Wilkins; 2005.
20. Knoll Z, Kiss RM, Kocsis L. Gait adaptation in ACL deficient
patients before and after anterior cruciate ligament reconstruction
surgery. J Electromyogr Kinesiol 2004;14:287-94.
21. Vogt L, Banzer W. Measurement of lumbar spine kinematics in
incline treadmill walking. Gait Posture 1999;9:18-23.
22. Ebenbichler GR, Oddsson LIE, Kollmitzer J, Erim Z. Sensorymotor control of the lower back: implications for rehabilitation.
Med Sci Sports Exerc 2001;33:1889-98.
23. Cresswell AG, Grundstrom A, Thorstensson A. Observations on
intra-abdominal pressure and patterns of abdominal intramuscular activity in man. Acta Physiol Scand 1992;144:409-18.
Arch Phys Med Rehabil Vol 87, November 2006
1458
LUMBAR STABILIZATION DURING HIP ABDUCTION, Cynn
24. Hodges PW, Richardson CA. Contraction of the abdominal muscles associated with movement of the lower limb. Phys Ther
1997;77:132-43.
25. Kaigle AM, Holm SH, Hansson TH. Experimental instability in
the lumbar spine. Spine 1995;20:421-30.
26. McGill SM. Kinetic potential of the lumbar trunk musculature
about three orthogonal orthopaedic axes in extreme postures.
Spine 1991;16:809-15.
27. Wilke HJ, Wolf S, Claes LE, Arand M, Wiesend A. Stability
increase of the lumbar spine with different muscle group: a biomechanical in vitro study. Spine 1995;20:192-8.
28. Tesh KM, ShawDunn J, Evans JH. The abdominal muscles and
vertebral stability. Spine 1987;12:501-8.
29. Macintosh JE, Bogduk N, Gracovetsky S. The biomechanics of
the thoracolumbar fascia. Clin Biomech 1987;2:7-83.
30. Janssen I, Heymsfield SB, Wang Z, Ross R. Skeletal muscle mass
and distribution in 468 men and women aged 18-88 yr. J Appl
Physiol 2000;89;81-8.
Arch Phys Med Rehabil Vol 87, November 2006
31. Marras WS, Jorgensen MJ, Granata KP, Wiand B. Female and
male trunk geometry: size and prediction of the spine loading
trunk muscles derived from MRI. Clin Biomech (Bristol, Avon)
2001;16:38-46.
32. Springer BA, Mielcarek BJ, Nesfield TK, Teyhen DS. Relationships among lateral abdominal muscles, gender, body mass
index, and hand dominance. J Orthop Sports Phys Ther 2006;
36:289-97.
33. Schamberger W. The malalignment syndrome: implication for
medicine and sports. London: Churchill Livingstone; 2002.
a.
b.
c.
d.
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