ABDOMINAL/ADDUCTOR STRENGTH IMBALANCE IN SOCCER PLAYERS WITH OSTEITIS PUBIS
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Original Article
DOI: 10.22374/1875-6859.14.3.5
ABDOMINAL/ADDUCTOR STRENGTH IMBALANCE IN SOCCER PLAYERS WITH
OSTEITIS PUBIS
Walaa S. Mohammad1 and Walaa M. Elsais2
1
Department of Biomechanics, Faculty of Physical Therapy, Cairo University, Giza, Egypt,
2
School of Health Sciences, PhD candidate, Salford University, UK.
Corresponding Author: walaa.sayed@pt.cu.edu.eg
Submitted: April 14, 2018. Accepted: June, 2018. Published: June 18, 2018.
ABSTRACT
Background and Objective
The muscle imbalance between abdominal and hip adductor muscles as an etiology for osteitis pubis is not
well understood. The concept of a relationship between eccentric/concentric ratios at the pelvis and osteitis
pubis in athletes is limited. This study aimed to compare the eccentric/concentric ratios for abdominal/
adductor, abdominal/back, and hip adductor muscles as well as eccentric abdominal/eccentric adductor
muscles in soccer players suffering from osteitis pubis with those in healthy athletes.
Material and Methods
Twenty male soccer athletes with osteitis pubis were recruited to participate and 20 healthy male soccer
athletes were recruited to participate. Peak torque/body weight (PT/BW) for the hip adductor, abdominal,
and back muscles during isokinetic concentric and eccentric contraction modes at a speed of 180°/s was
recorded for healthy players and soccer athletes with osteitis pubis. Eccentric/concentric ratios for the
abdominal/adductor, abdominal/back, and hip adductor muscles and the eccentric abdominal/eccentric
adductor muscles were measured for both groups.
Results
There was a significant decrease in the eccentric abdominal/concentric hip adductor muscles ratio
(p = 0.000) and in the eccentric/concentric hip adductor muscles ratio (p = 0.016) between the osteitis pubis
group and the healthy control group.
Conclusion
Soccer players with osteitis pubis present with strength imbalance. The osteitis pubis group displayed ec-
centric weakness of the abdominal and adductor muscles, resulting in imbalances in the normal eccentric
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e33Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
abdominal/concentric adductor and eccentric/concentric adductor ratios. Therefore, exercises that increase
the eccentric strength of abdominal and hip adductor muscles may be beneficial to include in rehabilitation
programs of patients with osteitis pubis.
Osteitis pubis (OP) refers to a painful, inflamma- have a central point of attachment – the “pivot point”
tory, non-infectious condition of the symphysis pubis – on the symphysis pubis. However, these muscles
and surrounding structures.1 OP may present as acute act antagonistically toward each other during kicking
abdominal, pelvic, or groin pain.2 The natural history activity, predisposing the pubic symphysis to opposing
of OP is one of progressive deterioration with con- forces.11 Muscle imbalance across the pubic symphysis
tinued activity, requiring a prolonged rehabilitation occurs because of eccentric loading and overloading
period and time away from the sport.3 In addition, OP from abdominal muscle pulling superiorly and hip
is one of the most common causes for groin pain in adductor muscles pulling inferiorly. When an athlete
athletes.4 The initial presentation of OP often includes kicks, the kicking limb is hyperextended at the hip
the insidious onset of hip adductor pain and abdominal while the trunk is rotated laterally in the opposite
discomfort, along with pain in the pubic symphysis.5,6 direction.2,11 To estimate the balance or imbalance
In soccer, the incidence of groin pain has been of muscle forces acting on a joint, the torque ratios
demonstrated to be as high as 5–13%.7 OP is a potential of muscles around the joint must be determined. The
cause of groin pain that can lead to missed playing appropriate ratio is important for reducing the risk
time during training and competition for the soccer of athletic injuries. If unbalanced forces exist, the
athlete and can potentially be a career-ending condi- weaker group of muscles may be subjected to abnormal
tion.6,8 Playing soccer involves sprinting, twisting, mechanical stress.12
turning, cutting, and kicking; the pathomechanics Eccentric muscle contraction plays a significant role
of these activities produce forces leading to severe in the activities of daily living and athletic exercise,
biomechanical strain on the symphysis pubis and such as when the body is decelerating during walking,
its associated supporting structures.2,9 In OP, a mi- running and lifting.13 Dvir, Keating 14 have suggested
crotear may occur at the pubic attachment of the that the eccentric strength of the trunk extensors was
adductor longus. This tear is frequently a primary higher than the concentric strength at the same an-
event, followed by the development of osteitis. The gular velocity by a factor of 11–60%. Moreover, the
induced muscular instability, laxity, and impaction importance of eccentric strength testing is derived
of surfaces at the symphysis may also produce OP. from the fact that the eccentric deficiency may be
Why a microtear at the adductor attachment occurs different from its concentric counterparts and hence
so frequently in soccer players is unclear. The small may constitute an additional risk factor.
adductor attachment may increase the susceptibility The pathogenesis of OP remains obscure; previous
of the adductor longus muscle to strain/overuse, and studies1,15,16 were restricted to specific issues, such
a microtear might occur as a consequence of tendon as demonstrating the clinical picture of patients and
stretching and applied traction due to twisting and the radiographic findings of the symphysis pubis in
turning or, more likely, secondary to both.9 OP. Other studies5,7 the effects of specific treatment
The most likely mechanism of OP development is protocols on OP recovery, and one study17 found hip
repetitive stress from increased shearing forces on the muscle imbalances in athletes with OP during con-
pubic symphysis or from increased stress placed on the centric contraction. There is a paucity of literature on
joint from traction exerted by the pelvic musculature, isokinetic evaluation of the abdominal and adductor
especially in the presence of muscle imbalance.10 muscles ratios in athletes with OP. Therefore, the pur-
Muscle imbalance between the abdominal muscles pose of our study was to determine and compare the
and hip adductors has been suggested as an etiologic eccentric/concentric (E/C) ratios for the abdominal/
factor in OP. The abdominal and adductor muscles adductor, abdominal/back, and hip adductor muscles
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright
e34Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
and for the eccentric abdominal/eccentric adductor performed for 10 min (10 seconds hold stretch/10
muscles in soccer players suffering from OP with seconds relax). The muscle groups (trunk and hip
those in healthy soccer players. muscles) for all subjects were tested in a randomized
METHODS order to prevent a dependent ordering effect. Rest
periods of 5 min were provided between each muscle
Participants group test. Throughout testing, the participants were
Twenty male soccer athletes suffering from OP were verbally encouraged to perform maximal contractions
recruited to participate as volunteers in this study. A through their range of motion (ROM).
sports medicine specialist and a team of orthopedic For hip adductor muscle testing, the involved
surgeons, who referred the OP patients to our isokinetic (affected) side of the OP group was tested; such
lab, conducted the clinical examinations. The criterion as in the injured athletes, the kicking side was that
for diagnosing OP was that the athlete complained of with unilateral inguinal and adductor pain, whereas
pain combined with tenderness over the symphysis the dominant limb was tested in the healthy athlete
area that radiated inferiorly (adductors area) and/or (control) group. Leg dominance was demonstrated
superiorly (lower abdominal area). The diagnosis was according to the preferred kicking leg. Testing was
confirmed by magnetic resonance imaging (MRI). performed with the participants in the standing posi-
Another group of 20 healthy (control) male soccer tion, which is the most functional position despite
athletes were matched with the OP patient group ac- being associated with less stabilization. To allow hip
cording to age, body weight, body height, and years movement tests to be performed from the standing
of playing (both groups were collected from youth and position, the hip attachment was inserted into the
first teams). They had no history of lower extremity knee adaptor and secured to the dynamometer. The
surgery or trauma to the back or hip. The uninjured participants performed isokinetic concentric and ec-
athletes and the athletes with OP were right-leg domi- centric hip adduction at an angular velocity of 180°/s,
nant. The number of subjects was determined a priori as previously recommended in the literature.18 During
based on statistical power analysis to ensure type I hip abduction and adduction, the player was placed
error did not exceed 0.05 and type II error did not in the standing position facing away from the dyna-
exceed 0.20. This analysis indicated that 36 subjects mometer, with the axis of the dynamometer aligned
were required to find a power of 96% and level of with the anterior superior iliac spine. The ROM for
significance of 95%. Table 1 presents the demographic hip abduction/adduction was 65° (recorded from 20°
data of the participants in this study. Prior to undergo- adduction to 45° abduction).
ing actual measurements, the participants received an For trunk muscle testing, each subject was allowed
explanation of the study procedures and provided their to sit on the adjustable seat of the Biodex isokinetic
written informed consent. This study was approved dynamometer system. This sitting position was pre-
by the university’s institutional review board. ferred, as the lower extremity muscles could influence
trunk muscle strength.19,20 The subjects were secured
Instrumentation
in place using the available straps to prevent unwanted
A Biodex 3 Multi-Joint Testing and Rehabilitation motion. Two curved anterior leg pads were positioned
System (Biodex Medical Systems, Shirley, NY, USA) to adjust the knee block position. In addition, a lumbar
was used. Torque values were gravity adjusted. Cali- support pad was positioned against the lower spine.
bration of the Biodex dynamometer was automatically The pelvis was stabilized to minimize contributions
performed at the beginning of each session. from the hip muscles and to prevent as much motion
Procedures from the pelvis as possible, allowing for lumbar mo-
Participants executed a 10-minute warm-up proce- tion only. Both thighs were stabilized by two straps,
dure prior to entering the laboratory and undergoing and the feet were held in a dorsiflexed position above
hip and trunk strength measures. The warm-up pro- the foot support of the dynamometer chair. The axis
cedure consisted of stretching exercises, which were of the dynamometer was aligned at the intersection of
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e34Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
the mid-axillary line and the L5/S1 disc space in the Statistical Analysis
vertebral column. The dynamometer’s ROM during Data were analyzed using SPSS (version 20.0 for
trunk flexion/extension was 80° (20° hyperextension Windows; SPSS Inc., Chicago, IL, USA). A two-way
to 60° flexion).21–23 Participants performed isokinetic multivariate analysis of variance (MANOVA) was
concentric and eccentric trunk flexion and extension conducted for the abdominal/adductor, abdominal/
at a speed of 180°/s.24,25 back, and hip adductor muscle E/C ratios and for
The subjects were instructed to perform three to the eccentric abdominal/eccentric adductor muscle
four submaximal contractions through the predeter- ratios to compare the groups. In case the F ratio was
mined ROM to familiarize them with the dynamometer significant, the differences between peak torque/body
before the actual test. Maximum voluntary efforts weight (PT/BW) were examined using Tukey’s test.
were recorded when the subjects were instructed to The level of significance was set at p < 0.05 for all
perform trunk flexion and extension in both concen- statistical tests.
tric and eccentric modes for a total of 5 repetitions/ RESULTS
set, and 2 sets were performed. All the subjects were
encouraged to exert maximum effort during the tests. For this study, 30 male soccer athletes suffering
In the same manner, maximum voluntary efforts were from OP were identified as potential participants
recorded from the hip adductor muscles when the (Figure 1), 7 athletes from screened participants were
subjects performed two sets of adductions at the same excluded because they failed to fulfill the inclusion
angular velocity and in the same contraction mode. criteria and three athletes refused to participate in the
The highest value of the five repetitions in one set study. Thus, 20 athletes with OP were included in the
was recorded, and the mean value of the two sets was study (Table 1).
used for statistical analysis. The outcome parameter The values for PT and PT/BW for the hip adductor,
was the peak torque (PT; expressed in Nm), which abdominal, and back muscles at 180°/s angular velocity
was normalized to each participant’s body weight are shown in Table 2. MANOVA was conducted for
(expressed in Nm/kg) in an effort to reduce inter- the hip adductor, abdominal and back muscle ratios of
subject variability in the raw scores of the quantitative the healthy athlete and OP groups in both concentric
muscle tests. and eccentric modes.
FIG. 1 Study flowchart of the OP soccer players participants.
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e35Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
TABLE 1 Demographic Data for Healthy and Athletes with Osteitis Pubis Groups
Healthy athletes group Osteitis Pubis group
Groups
Mean ± SD Mean ± SD
Age (years) 20.78 ± 3.35 19.94 ± 3.51
Height (cm) 176.00 ± 4.15 176.16 ± 4.93
Weight (kg) 71.33 ± 7.35 70.91 ± 7.26
Body mass
22.92 ± 1.33 22.78 ± 1.07
index
TABLE 2 The Peak Torque (Nm) and the Peak Torque/Body Weight (Nm/kg) of Hip Adductors, Abdominal,
and Back Muscles of Healthy and Athletes with Osteitis Pubis Groups
Healthy athletes Osteitis Pubis
Test statistics
PT PT/BW PT PT/BW
Mean ± SD Mean ± SD Mean ± SD Mean ± SD
Abdominal (Eccentric) 73.04 ± 12.55 1.01 ± 0.11 45.77 ± 11.34 0.65 ± 0.15
Back (Concentric) 181.36 ± 23.19 2.26 ± 0.18 100.85 ± 23.90 1.44 ± 0.33
Hip adductors (Concentric) 124.11 ± 7.24 1.79 ± 0.19 120.06 ± 5.44 1.74 ± 0.14
Hip adductors (Eccentric) 89.94 ± 15.61 1.12 ± 0.16 57.68 ± 14.62 0.74 ± 0.11
PT = peak torque; PT/BW = peak torque/body weight; SD = standard deviation.
There were no significant differences between the OP and healthy soccer players. An angular velocity of
healthy and injured groups for the eccentric abdominal/ 180°/s was chosen to imitate the muscular performance
concentric back and eccentric abdominal/eccentric hip during high-speed sports-specific activities such as
adductor muscle ratios (p > 0.05). However, there were sprinting, kicking, and cutting, which were reported
significant decreases in both the eccentric abdominal/ to be provocative.26
concentric hip adductor muscle ratio (p = 0.000) and Historically, clinicians and researchers have used
the eccentric/concentric hip adductors muscle ratio comparisons of the concentric strength values from
(p = 0.016) in the OP group, as shown in Table 3. the same muscle groups in opposite extremities to
DISCUSSION evaluate the differences in muscle activity between
normal athletes and OP.17 However, isokinetic as-
Our study was conducted to compare the E/C ratios sessment provides technological advances to improve
for the abdominal/adductor, abdominal/back, and hip the evaluation of many sports problems by using
adductor muscles and the eccentric abdominal/ec- the eccentric mode of contraction, given that many
centric adductor muscles between soccer players with muscles work concentrically and eccentrically while
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e36Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
TABLE 3 The Hip Adductors, Abdominal, and Back Muscle Ratios of Healthy Athletes and Athletes with
Osteitis Pubis
Healthy athletes ratios Osteitis Pubis ratios
Test statistics p value
Mean ± SD Mean ± SD
Eccentric Abdominal/Concentric Back 0.77 ± 0.19 0.83 ± 0.12 0.216
Eccentric Abdominal/Eccentric Adductor 1.04 ± 0.27 1.24 ± 0.39 0.311
Eccentric Abdominal/Concentric Adductor 0.61 ± 0.06 0.38 ± 0.09 0.000*
Hip adductors Eccentric/Concentric 0.64 ± 0.06 0.43 ± 0.08 0.016*
*Significant < 0.05
kicking. Consequently, any abnormalities in eccentric/ eccentric contraction, resulting in more stretch and
concentric ratios may reveal pathologies or identify shear on the symphysis pubis.
athletes who may be at risk for injury.27 The absolute PT values for the concentric strength
The high eccentric abdominal/concentric back ratio of the back muscles and the eccentric strength of the
in the OP group results from both back and abdominal abdominal muscles for healthy athletes in the current
muscles imbalances, including concentric weakness study were 181.36 and 73.04, respectively (see Table
of the back muscles and eccentric weakness of the ab- 2). These values were compared to those observed by
dominal muscles (see Table 2). Both imbalances result Müller, Müller, Stoll, Fröhlich, Baur, Mayer 31, who
in non-significant differences in eccentric abdominal/ presented a nearly identical value for the PT of back
concentric back muscle ratios between healthy and muscles in healthy adolescent athletes (187 Nm) but
OP athletes. In the same context, Mohammad, Ab- a different value for abdominal muscles (146 Nm).
delraouf, Abdel-aziem28 assessed the trunk muscles This difference may be due to their use of a different
in healthy soccer players, compared them to soccer angular velocity.
players with OP and found significant decreases in It has been suggested in the literature that OP in
concentric and eccentric contractions of the back and soccer players is related to the repetitive stress on the
abdominal muscles, respectively. A possible expla- abdominal and hip adductor muscles during kicking,32
nation they proposed for these observations was an without clarification or substantiation of the phase of
increased anterior pelvic tilt produced by decreased kicking or the type of contraction during which this
hip flexor length 29 and an increased PT/BW value stress occurs. Our finding of a decreased eccentric
of the hip flexor muscles in OP.17 Conneely, Sullivan, abdominal/concentric hip adductor ratio observed in
Edmondston 30 reported excessive extension of the OP athletes compared to healthy athletes may have
lumbar spine and anterior pelvic tilt in OP patients clinical relevance to this injury pattern. When an athlete
during hip extension due to their inability to actively kicks, the kicking limb is hyperextended at the hip
isolate these movements. This excessive anterior pelvic in the backswing phase of kicking, while the trunk is
tilt puts a strain/passive tension on the insertion of rotated laterally in the opposite direction,11,33 which
the abdominal muscles. Stretching of the abdominal results in eccentric loading and possibly overloading
muscles may lead to pain and to reflex inhibition of back from abdominal muscles, which pull superiorly, while
muscles rather than to actual weakness. In addition, the adductor muscles pull inferiorly.
eccentric weakness of the abdominal muscles leads to The backswing phase of kicking is followed by the
less effective stabilization capacity and uncontrolled acceleration phase, where the angular velocity of the
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e37Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
thigh is positive until ball impact,33 and during which athletes in the eccentric/concentric ratios of the hip
concentric contraction of the adductor muscles occurs. adductors at high velocity supports our hypothesis.
Regarding the eccentric abdominal/concentric adductor The eccentric/concentric hip adductor strength ratio
ratio, as this ratio decreases, either the eccentric force of 64% or lower shown in our study may be one of
has decreased compared to the concentric force or the the greatest risk factors for OP.
concentric torque has increased compared to the eccentric Neural control of the lengthening contraction can
torque. If one reconsiders the force-velocity relation- be explained by two mechanisms: neural inhibition39 or
ship, the capacity of the abdominal muscles in the OP incomplete voluntary activation.40 Duchateau, Enoka39
athletes to maintain eccentric torque production at the suggested that during lengthening contractions, the
velocity used here was inadequate compared with the augmented feedback from peripheral sensory receptors
concentric torque of the hip adductors. These findings seems to be suppressed by centrally and peripherally
may help to explain the high incidence of OP and the mediated presynaptic inhibition of Ia afferents, which
susceptibility of healthy soccer players to injury. This may explain the depression of voluntary activation
observation may constitute the basis for the finding that occurs during maximal lengthening contractions
that persons with OP have fracture lines described as to prevent tissue damage. Additionally, this neural
tension stress fractures when their pubic symphysis inhibitory control could be greatly reduced after a
is scanned using MRI. These fractures may have formal resistance training program, increasing the
been caused by excessive tensile or torsional stresses chance for overuse injuries to occur in response to the
across the pelvis secondary to muscle imbalances,34 erratic pulling of eccentrically weak muscles. Serner,
which would then suggest that rehabilitation should et al. concluded that specific hip adduction exercises
include not only concentric muscle strengthening but can be used during different phases of groin injury
also eccentric muscle strengthening, particularly for prevention and treatment in soccer players.
the abdominal muscles. CONCLUSION
The eccentric PT values of hip muscles for OP
soccer players are unique to this study. However, This study revealed that eccentric/concentric ratios
several studies have reported PT values of hip adduc- may help to predict the development of OP in soccer
tor muscles in normal athletes18,35–37 or the effects of athletes. This information may help clarify the role of
specific training programs on the symptoms of OP.9 A trunk and hip adductor muscles in the development
reduced eccentric/concentric hip adductor muscle ratio of OP and may allow these muscle strength assess-
was observed in the OP cases in this study. Since the ments to guide return-to-play decisions. Exercises that
magnitude of the moments produced by the concentric increase the eccentric strength of the abdominal and
and eccentric modes are velocity dependent,27 the adductor muscles should be included in rehabilitation
eccentric/concentric ratio is velocity dependent and programs developed for patients with OP. Moreover,
increases proportionately to the test velocity, which restoring the correct eccentric abdominal/concentric
is relevant to soccer given that it is a high-speed sport adductor and eccentric/concentric hip adductor ratios
requiring sudden directional changes. The higher might be an important measure for preventing pos-
eccentric strength in normal athletes may reflect the sible muscle imbalances, consequent instability of the
role of hip adductor contraction during the backswing pelvic region, and the subsequent risk of OP.
phase of kicking. In contrast, the reduced eccentric/ DISCLOSURE
concentric ratio for the hip adductors in OP may be
related to impaired neuromotor control of the adductors The authors have no conflicts of interest to declare.
or may be due to either selective inhibition of their REFERENCES
eccentric performance as a result of pain38 or a rapid
1. Williams PR, Thomas DP, Downes EM. Osteitis pubis and
change in the mode of contraction from eccentric to
instability of the pubic symphysis. When nonoperative
concentric. The difference between normal and OP
measures fail. Am J Sports Med 2000;28(3):350–55.
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e38Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
2. Pham DV, Scott KG. Presentation of osteitis and 17. Mohammad WS, Abdelraouf OR, Elhafez SM, et al.
osteomyelitis pubis as acute abdominal pain. Perm J Isokinetic imbalance of hip muscles in soccer players
2007;11(2):65–68. with osteitis pubis. J Sports Sci 2014;32(10):934–39.
3. Wollin M, Lovell G. Osteitis pubis in four young 18. Masuda K, Kikuhara N, Demura S, et al. Relationship
football players: a case series demonstrating success- between muscle strength in various isokinetic move-
ful rehabilitation. Phys Ther Sport 2006;7(3):153–60. ments and kick performance among soccer players. J
4. Brukner P. Brukner & Khan’s clinical sports medicine. Sports Med Phys Fitness 2005;45(1):44–52.
McGraw-Hill North Ryde; 2012. 19. Cohen P, Chantraine A, Gobelet C, et al. [Influence of
5. Holt MA, Keene JS, Graf BK, et al. Treatment of osteitis testing position on lumbar isokinetic measurements].
pubis in athletes. Results of corticosteroid injections. Ann Readapt Med Phys 2002;45(1):12–18.
Am J Sports Med 1995;23(5):601–606. 20. Shirado O, Ito T, Kaneda K, et al. Concentric and
6. Elattar O, Choi HR, Dills VD, et al. Groin injuries eccentric strength of trunk muscles: influence of test
(athletic pubalgia) and return to play. Sports Health postures on strength and characteristics of patients
2016;8(4):313–23. with chronic low-back pain. Arch Phys Med Rehabil
7. Ekstrand J, Ringborg S. Surgery versus conservative 1995;76(7):604–11.
treatment in soccer players with chronic groin pain : 21. Findley BW, Brown LE, Whitehurst M, et al. Sitting vs.
A prospective randomised study in soccer players.. standing isokinetic trunk extension and flexion performance
Eur J Sports Traumatol Relat Res 2001;23(4):141–45 differences. J Strength Condit Res 2000;14(3):310–15.
(Testo stampato). 22. Williams CA, Singh M. Dynamic trunk strength of
8. McSweeney SE, Naraghi A, Salonen D, et al. Hip and Canadian football players, soccer players, and middle
groin pain in the professional athlete. Can Assoc Radiol to long distance runners. J Orthop Sports Phys Ther
J 2012;63(2):87–99. 1997;25(4):271–76.
9. Cunningham PM, Brennan D, O’Connell M, et al. Pat- 23. Donovan OO, Cheung J, Catley M, et al. An investiga-
terns of bone and soft-tissue injury at the symphysis tion of leg and trunk strength and reaction times of
pubis in soccer players: observations at MRI. AJR Am hard-style martial arts practitioners. J Sports Sci Med
J Roentgenol 2007;188(3):W291–296. 2006;5(Cssi):5–12.
10. Fricker PA. Osteitis Pubis. Sports Med Arthrosc 24. Delitto A, Crandell CE, Rose SJ. Peak torque-to-body
1997;5(4):305–12. weight ratios in the trunk: a critical analysis. Phys Ther
11. Mandelbaum B, Mora SA. Osteitis pubis. Oper Tech 1989;69(2):138–43.
Sports Med 2005;13(1):62–67. 25. Delitto A, Rose SJ, Crandell CE, et al. Reliability of
12. Pontaga I. Muscle strength imbalance in the hip isokinetic measurements of trunk muscle performance.
joint caused by fast movements. Mechan Comp Mat Spine (Phila Pa 1976) 1991;16(7):800–803.
2003;39(4):365–68. 26. Kachingwe AF, Grech S. Proposed algorithm for the
13. Alexander MJ. Peak torque values for antagonist management of athletes with athletic pubalgia (sports
muscle groups and concentric and eccentric contrac- hernia): a case series. J Orthop Sports Phys Ther
tion types for elite sprinters. Arch Phys Med Rehabil 2008;38(12):768–81.
1990;71(5):334–39. 27. Dvir Z. Isokinetics: muscle testing, interpretation, and
14. Dvir Z, Keating JL. Trunk extension effort in patients clinical applications. Elsevier Health Sciences; 2004.
with chronic low back dysfunction. Spine (Phila Pa 28. Mohammad WS, Abdelraouf OR, Abdel-aziem AA.
1976) 2003;28(7):685–92. Concentric and eccentric strength of trunk muscles
15. Verrall GM, Hamilton IA, Slavotinek JP, et al. Hip joint in osteitis pubis soccer players. J Back Musculoskelet
range of motion reduction in sports-related chronic Rehabil 2014;27(2):147–52.
groin injury diagnosed as pubic bone stress injury. J 29. McCarthy A, Vicenzino B. Treatment of osteitis pubis
Sci Med Sport 2005;8(1):77–84. via the pelvic muscles. Man Ther 2003;8(4):257–60.
16. Verrall GM, Slavotinek JP, Fon GT. Incidence of pubic 30. Conneely M, Sullivan KO, Edmondston S. Dissection
bone marrow oedema in Australian rules football players: of gluteus maximus and medius with respect to their
relation to groin pain. Br J Sports Med 2001;35(1):28–33.
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e39Abdominal/Adductor Strength Imbalance in Soccer Players with Osteitis Pubis
suggested roles in pelvic and hip stability: implications 37. Poulmedis P. Isokinetic maximal torque power of
for rehabilitation? Phys Ther Sport 2006;7(4):176. Greek elite soccer players. J Orthop Sports Phys Ther
31. Müller J, Müller S, Stoll J, et al. Reproducibility of 1985;6(5):293–95.
maximum isokinetic trunk strength testing in healthy 38. Thorborg K, Branci S, Nielsen MP, et al. Eccentric
adolescent athletes. Sport-Orthopädie-Sport-Traumatol- and isometric hip adduction strength in male soccer
ogie-Sports Orthopaed Traumatol 2014;30(3):229–37. players with and without adductor-related groin pain:
32. Cetin C, Sekir U, Yildiz Y, et al. Chronic groin pain in an an assessor-blinded comparison. Orthopaed J Sports
amateur soccer player. Br J Sports Med 2004;38(2):223–24. Med 2014;2(2):2325967114521778.
33. Brophy RH, Backus SI, Pansy BS, et al. Lower extrem- 39. Duchateau J, Enoka RM. Neural control of shortening
ity muscle activation and alignment during the soccer and lengthening contractions: influence of task con-
instep and side-foot kicks. J Orthop Sports Phys Ther straints. J Physiol 2008;586(24):5853–64.
2007;37(5):260–68. 40. Hahn D, Hoffman BW, Carroll TJ, et al. Cortical and
34. De Paulis F, Cacchio A, Michelini O, et al. Sports spinal excitability during and after lengthening contrac-
injuries in the pelvis and hip: diagnostic imaging. Eur tions of the human plantar flexor muscles performed with
J Radiol 1998;27:S49–S59. maximal voluntary effort. PLoS One 2012;7(11):e49907.
35. O’Connor D. Groin injuries in professional rugby 41. Serner A, Jakobsen MD, Andersen LL, et al. EMG
league players: a prospective study. J Sports Sci evaluation of hip adduction exercises for soccer play-
2004;22(7):629–36. ers: implications for exercise selection in prevention
36. Lourencin FTC, Macedo OGd, Scarpellini EdS, et and treatment of groin injuries. Br J Sports Med
al. Evaluation of hip adductor and abductor muscles 2014;48(14):1108–14.
using an isokinetic dynamometer. Acta Fisiátrica
2012;19(1):16–20.
J Mens Health Vol 14(3):e33-e40; June 18, 2018
This article is distributed under the terms of the Creative Commons Attribution-Non
Commercial 4.0 International License. Author Retained Copyright.
e40You can also read
