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A comparison of training methods to increase neck muscle strength

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To compare two neck strength training modalities. Neck injury in pilots flying high performance aircraft is a concern in aviation medicine. Strength training may be an effective means to strengthen the neck and decrease injury risk. The cohort consisted of 32 age-height-weight matched participants, divided into two experimental groups; the Multi-Cervical Unit (MCU) and Thera-Band tubing groups (THER), and a control (CTRL) group. Ten weeks of training were undertaken and pre-and post isometric strength testing for all groups was performed on the MCU. Comparisons between the three groups were made using a Kruskal-Wallis test and effect sizes between the MCU and the THER groups and the THER and CTRL groups were also calculated. The MCU group displayed the greatest increase in isometric strength (flexion 64.4%, extension 62.9%, left lateral flexion 53.3%, right lateral flexion 49.1%) and differences were only statistically significant (p<0.05) when compared to the CTRL group. Increases in neck strength for the THER group were lower than that shown in the MCU group (flexion 42.0%, extension 29.9%, left lateral flexion 26.7%, right lateral flexion 24.1%). Moderate to large effect sizes were found between the MCU and THER as well as the THER and CTRL groups. This study demonstrated that the MCU was the most effective training modality to increase isometric cervical muscle strength. Thera-Band tubing did however, produce moderate gains in isometric neck strength.
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Edith Cowan University
Research Online
ECU Publications
2005
A comparison of training methods to increase neck
muscle strength
Angus Burnett
Edith Cowan University
Fiona Naumann
Edith Cowan University
Ryan Price
Edith Cowan University
Ross Sanders
Edith Cowan University
This article was originally published as: Burnett, A. F., Naumann, F. , Price, R. , & Sanders, R. H. (2005). A comparison of training methods to increase
neck muscle strength. Work: A Journal of Assessment, Prevention and Rehabilitation, 25(3), 205-210. Original article available here
This Journal Article is posted at Research Online.
http://ro.ecu.edu.au/ecuworks/2802
Work 25 (2005) 205–210 205
IOS Press
A comparison of training methods to increase
neck muscle strength
Angus F. Burnett
a,b,
, Fiona L. Naumann
b
, Ryan S. Price
b
and Ross H. Sanders
c
a
School of Physiotherapy, Curtin University of Technology, Perth, Western Australia
b
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, Western Australia
c
Physical Education Sport and Leisure Studies, The University of Edinburgh, Scotland, UK
Received 2 December 2003
Accepted 29 December 2003
Abstract. Objective: To compare two neck strength training modalities.
Background: Neck injury in pilots flying high performance aircraft is a concern in aviation medicine. Strength training may be
an effective means to strengthen the neck and decrease injury risk.
Methods: The cohort consisted of 32 age-height-weight matched participants, divided into two experimental groups; the Multi-
CervicalUnit(MCU)andThera-Band tubing groups (THER),and a control (CTRL)group. Tenweeksoftrainingwereundertaken
and pre-and post isometric strength testing for all groups was performed on the MCU. Comparisons between the three groups
were made using a Kruskal-Wallis test and effect sizes between the MCU and the THER groups and the THER and CTRL groups
were also calculated.
Results: TheMCU group displayed the greatestincrease in isometric strength(flexion 64.4%, extension 62.9%, leftlateral flexion
53.3%, right lateral flexion 49.1%) and differences were only statistically significant (p<0.05) when compared to the CTRL
group. Increases in neck strength for the THER group were lower than that shown in the MCU group (flexion 42.0%, extension
29.9%, left lateral flexion 26.7%, right lateral flexion 24.1%). Moderate to large effect sizes were found between the MCU and
THER as well as the THER and CTRL groups.
Conclusions: This study demonstrated that the MCU was the most effective training modality to increase isometric cervical
muscle strength. Thera-Band tubing did however, produce moderate gains in isometric neck strength.
Keywords: Neck, strength training, isometric, +Gz force, high performance pilots
1. Introduction
Neck pain and injuries are becoming more promi-
nent in Western countries, with neck complaints being
reported as one of the major causes for long-term sick
leave [3,12]. Individuals exposed to the extreme posi-
tive acceleration forces produced by current high per-
formanceaircraft are also at a substantial risk of injury.
This is a major concern in aviation medicine [9–11,21,
Address for correspondence: Dr. Angus Burnett, Research Fel-
low, School of Physiotherapy, Curtin University of Technology, GPO
Box1987, Perth,WA6485, Australia. E-mail: a.burnett@curtin.edu.
au.
25]. Eighty-five percent of F/A-18 pilots in the Royal
Australian Air Force (RAAF) reported experiencing
acute G-induced neck pain during their career [20].
Similarly, 85% of pilots in the US Air Force had ex-
perienced at least one acute neck pain episode during
their career, with the yearly prevalenceof neck pain for
all pilots being approximately 57% [1]. This figure is
a markedly higher incidence than the 5.7% to 16.6%
yearly prevalence of neck pain for men reported in the
general population [21].
Strengthening the cervical musculature has been
used to decrease pain in clinical patients [3,12,13,17,
28,31] in addition to being suggested as a method to
prevent neck complaints in high performance pilots [2,
1051-9815/05/$17.00 © 2005 – IOS Press and the authors. All rights reserved
206 A.F. Burnett et al. / A comparison of training methods to increase neck muscle strength
15,24]. Neck strength may be increased through ac-
tivities that make a high demand on the neck muscula-
ture such as wrestling [30] and may also be increased
in a non-significant manner through flying high perfor-
mance aircraft [4,24]. However, there may be a period
of time prior to this activity-specific adaptation where
the spinal structures are injured due to the exposure to
excessive external forces.
To date, there has been little research conducted
into the use of neck strengthening exercises in asymp-
tomatic individuals. To increase neck strength it is
known that area-specific training is required [2,7,22,
31] and that supervision of individuals during training
will increase the potential of a training effect [2]. The
magnitude of neck strength is known to be direction
dependent, for example, it has been found in previous
research studies that cervical muscle strength in exten-
sion is greater than that found in flexion [2,3,16,23,27,
29]which can be explainedbythe relationshipbetween
muscle cross sectional area and strength [14,26].
This study compared two diverse neck strength
training modalities, one being the multi-cervical unit
(MCU) [6,8] as illustrated in Fig. 1, the other being
Thera-Band tubing (Pro-Med Products, Inc.) (Fig. 2).
The MCU is a pin-loaded machine that utilizes a me-
chanical pulley arrangement and has the ability to re-
strainthebodyandisolatethecervicalmusculaturedur-
ing specific exercise. The neck can be trained in flex-
ion, extension and lateral flexion using this device and
the intensity of muscular contraction can be adjusted
by altering the pin-loaded weight stack. Thera-Band
tubing consists of a stretchable latex rubber. This tub-
ing is able to be attached to a stationary structure and
can be attached to the head via a Velcro head band.
The tubing then offers resistance to head movement in
flexion, extension and lateral flexion. Resistance can
be adjusted by increasing either the thickness or length
of the tubing. Both training methods are currently used
in rehabilitation centres to treat patients with neck in-
jury such as whiplash associated disorders. The cost
of a MCU is expensive and requires a trained therapist
to supervise the session. In comparison, Thera-Band
tubing is inexpensive, lightweight and portable, which
makes accessibility to training much easier.
The purpose of this study was to compare the iso-
metric cervical muscle strength changes in response
to a supervised ten week training program using the
MCU and Thera-Band tubing. Information obtained
from this study may assist in identifying an effective
modeoftrainingcervicalmusclestrength. This will aid
professionalsinvolvedin exerciseprescriptionto select
Fig. 1. The Multi-Cervical Unit (MCU) training modality.
Fig. 2. The Thera-Band tubing training modality.
appropriatetraining methods to increaseneck strength,
with the long term goal of possibly preventing neck
injuries in pilots.
A.F. Burnett et al. / A comparison of training methods to increase neck muscle strength 207
2. Methods
2.1. Subjects
The initial subject cohort in this study consisted of
thirty-sixmale subjects. Thesesubjects wererandomly
divided into three groups: the MCU training group
(n =12); the Thera-Band tubing (THER) training
group (n =12); and a non-training control (CTRL)
group (n =12). Subjects were free of prior cervical
injury including whiplash, neurological impairment or
neck pain lasting for more than seven days. Additional
exclusioncriteria included; subjectswho sufferedfrom
headachesormigraines,ormusculardisordersthat may
be aggravated by exercise, or subjects that were cur-
rently engaged in neck strengthening programs. The
use of a health questionnaire aided in the collection
of height and weight details and the identification of
any prior injuries that would indicate exclusion from
the study. The study protocol was approved the Edith
Cowan University Human Research Ethics Commit-
tee. Written, informed consent was obtained from all
subjects prior to testing.
Four subjects, three from the dynaband group and
one from the controlgroup, failed to completethe neck
training program due to personal reasons. Therefore,
the final cohort consisted of; the MCU training group
(n =12), THER training group (n =9) and CTRL
group (n =11).
2.2. Experimental protocol
TheMCUwasusedtomeasurebothpre-andpostiso-
metric cervical muscle strength for all subjects in flex-
ion,extensionandlateral flexionin theneutral position.
All strength tests were performed in a blinded manner
by an experiencedphysiotherapistand subject data was
notidentifiablethroughname. Measurementofisomet-
ric neck strength using the MCU has previously been
found to possess very good to excellent reliability [6].
Subjects were strapped into the MCU in an upright po-
sition, to minimize any movementother than that of the
cervical area. Subjects were instructed to press maxi-
mally against a force pad for three seconds with either
the forehead, side or back of the head depending upon
the direction being tested. Three tests were performed
consecutively for eachprocedure with an average mea-
surementinpounds(lbs)beingrecorded. Theforcepad
waspositionedimmediatelyabovetheeyebrowsforthe
flexion tests, directly above the occipital protuberance
for the extension tests and under the top of the ear in
Table 1
Multi-Cervical Unit (MCU) and Thera-Band Tubing (THER)weekly
progressions for training intensity
Week Sets Reps MCU %max Dynaband
Level
1 2 10 24 1
2 2 10 33 2
3 3 10 46 2
4 2 10 60 3
5 3 10 74 3
6 2 10 88 4
7 3 10 96 4
8 2 10 102 5
9 3 10 106 5
10 3 10 114 6
Table 2
AnthropometricdatafortheMulti-CervicalUnit(MCU),Thera-Band
tubing (THER) and control (CTRL) groups (mean ± SD)
MCU (n =12) DYN (n =9) CTRL (n =11)
Age (yrs) 23.3 (4.0) 21.7 (3.1) 22.6 (4.4)
Height (cm) 182.1 (4.0) 181.3 (7.2) 181.6 (4.3)
Mass (kg) 78.8 (13.2) 75.8 (13.6) 76.4 (7.3)
alignment with the subject’s ear for the lateral flexion
tests.
Boththe MCU andTHER traininggroupsperformed
ten weeks of resistance training comprising two ses-
sions per week, each separated by 3–4 days, for ap-
proximately 30 minutes per session. This included 15
minutesfor warm-upandcool downand15 minutes for
trainingin the subject’s specified mode. For both train-
inggroupswarm-upconsistedoftheactiverangeofmo-
tionforflexion,extension,lateralflexion(left/right)and
rotation (left/right), followed by stretches for the neck
muscles. The training protocol (sets x reps) remained
constantbetweenthetwotraininggroupsandwasbased
upon an intensive-interval strength-endurance model
(Table 1). Each set commencedone minute fifteen sec-
onds after the previous had commenced and the speed
of eccentric and concentric phases remained constant
during the ten weeks with a count of -one- for contrac-
tion and -two-three- for the eccentric phase. These two
strength training modalities could not be recounted to
the same denomination as they have varying methods
of increasing intensity.
For training sessions on the MCU, the subjects were
strapped into the MCU in an upright position, to mini-
mize any movement other than the cervical area. Sub-
jects were instructed to adjust the pin loaded weight
stack and lift the weight stack with either the forehead,
side or back of the head. The principle of progressive
overload was employed to ensure that training loads
continuedto challenge the subjects. This was achieved
208 A.F. Burnett et al. / A comparison of training methods to increase neck muscle strength
Table 3
Mean (±SD) for isometric strength (lbs) measured pre-and post-training for Multi-
Cervical Unit (MCU), Thera-Band tubing (THER) and Control (CTRL) groups
Time Flexion Extension L/L Flexion R/L Flexion
MCU pre 13.4 (6.8) 19.5 (9.2) 16.3 (6.9) 16.0 (7.5)
(n =12) post 22.0 (9.2) 31.8 (10.3) 25.0 (9.5) 23.8 (7.4)
difference 8.6 (3.3)* 12.3 (8.8)* 8.7 (7.2)* 7.9 (7.5)
THER pre 16.9 (8.1) 20.5 (7.8) 17.1 (6.6) 18.2 (5.8)
(n =9) post 23.9 (8.1) 26.6 (9.0) 21.6 (6.0) 22.6 (7.6)
difference 7.1 (4.3)* 6.1 (6.8) 4.6 (5.0) 4.4 (5.1)
CTRL pre 16.9 (7.9) 24.0 (12.0) 17.1 (5.8) 17.7(7.1)
(n =11) post 19.0 (8.8) 24.2 (12.7) 19.0 (9.2) 20.1 (9.1)
difference 2.1 (3.9) 0.2 (6.2) 1.9 (5.1) 2.4 (4.8)
p value 0.003 0.005 0.046 0.189
d value MCU/
THER 0.40 0.79 0.62 0.52
d value THER/
CTRL 1.20 0.90 0.54 0.40
Denotes significantly different (p<0.05) when compared to the CTRL group.
d value denotes effect size between MCU and THER and between the THER and CTRL
groups.
byeitherincreasingthe numberof repetitions,the num-
ber of sets, or the weight lifted.
In the THER training group, four distinct colours
of Thera-Band tubing (red, green, blue then black)
representing differing resistances were used to allow
progressive overload in training. Training progressed
weekly in a manner pre-determined by the researchers,
through increasing the density of the Thera-Band tub-
ing. Sessions utilising the blue and black dynabandin-
cludedan extraweek of trainingwhere the length of the
theratube which was previously standardised at 70 cm
was decreased by 15 cm (i.e.55 cm) in order to provide
another method of progression. The level of resistance
progressedassuch; leveloneonthe reddynaband,level
two the green dynaband, level three the blue dynaband,
level four used the shorter blue dynaband, level five
used the black and level six the short black dynaband.
2.3. Statistical analysis
Statisticalanalysiswas performedusingSPSSV10.0
for Windows. Comparisons between the three training
groupsfor age, height and weight, and pre-trainingiso-
metric neck strength at baseline, in addition to the dif-
ferencesin isometric strength from pre-topost training,
wereanalyzed using a Kruskal-Wallis test. Thelevelof
significancewassetatp<0.05. Effectsize(d)wascal-
culated for all variables between the MCU/THER and
THER/CTRL groups as the sample size was small [5].
An effect size of 0.2 was considered small, 0.5 moder-
ate and 0.8 as large [5].
3. Results
There were no significant differences between the
two experimental groups (MCU and THER) and the
CTRL group for age, height or weight. The anthropo-
metric data for the final subject cohort are detailed in
Table 2.
There were no significant difference in baseline cer-
vical isometric strength between the training and con-
trol groups. The valuesrecorded for pre-and post train-
ing and the differences between these values are pre-
sented in Table 3.
There was a statistically significant increase in iso-
metric flexion strength for both the MCU group and
THER group when compared to the CTRL group.
These increases were 64.4% for the MCU group and
42.0% for the THER group, respectively. The MCU
group also exhibited significant increases, when com-
pared to the CTRL group, in isometric extension
strengthandisometricleft/rightlateralflexionof62.9%
and 53.3%/49.1%, respectively.
4. Discussion
This study established that there was a trend towards
the MCU being the more effective training modality in
producing increases in isometric neck strength when
compared to the THER training group. Effect size cal-
culations indicated that with larger subject numbers in
eachgroup,there mayhavebeensignificant differences
found between the MCU and THER training groups.
A.F. Burnett et al. / A comparison of training methods to increase neck muscle strength 209
Consequently, the MCU would be recommended as an
effective training methodology to increase isometric
neck strength in asymptomatic subjects.
Previousresearchhas mainlyfocussed on re-training
an injured neck back to a basic functional state. Green-
wood and DeNardis [8], studied rehabilitation patients
and found highly significant improvements in neck
strength when training with the MCU. Subjects in
Greenwood’s study experienced increases in cervical
strength,rangingfrom 69.7to 71.0%. Maeda et al. [18]
alsofoundhighlysignificant gainsin isometricstrength
of the neck musculature of injured subjects in eight
weeks. They found significant increases in isomet-
ric strength, of between approximately 38%–40%. To
our knowledge there have been few studies however,
to document isometric strength gains in non-injured
necks.
In this study the THER training group showed non-
significant increases in isometric neck strength how-
ever, these strength gains were less than what was
achieved with the MCU. This was an important finding
considering the high cost of an MCU when compared
to the very low cost and portability associated with the
Thera-Bandtubing. One limitation of the currentstudy
was that the testing protocol favoured those training
on the MCU. Morrissey et al. [19] stated when dif-
ferent modes of strength training are compared, most
improvement is usually observed from the mode that
matches the testing routine. Recommendations for fu-
ture research would be to devise an alternative testing
protocoltotestbaselineandpost-trainingneckstrength,
such as the use of a neck dynamometer.
This study also found that the neck musculature can
demonstratelargeincreasesin strength overarelatively
short period of time. This successful adaptation was
conditional on an adequate training stimulus and that
the mode of training was highly specific to the cervical
musculature since general whole-body strengthening
programshavenot producedcomparablegainsincervi-
cal strength [7,19]. Recommendations from this study
are that pilots that begin flight training engage in cervi-
cal neck training 10 weeks prior to the commencement
of flying high performanceaircraft, to more adequately
prepare the neck for the stress of flying high perfor-
mance aircraft. Additionally a neck-strengtheningpro-
gram should be in place for those returning to service
after a break in flying to increase neck strength.
A further limitation of this study when considering
application to high performance pilots, was the sub-
jects volunteering for this study were not currently fly-
ing high performance aircraft. Neck training may be
impaired by simultaneous +Gz exposure during aerial
combat sorties. Thus, application of these programs
would require greater care in periodising training so
that the development of neck strength does not impede
the current flight activities of the pilots.
5. Conclusions
The application of a 10 week, twice-weekly neck
muscle resistance-training program resulted in in-
creased cervical muscular strength. It was also sug-
gested that training on the MCU may elicit a greater in-
crease in isometric cervical muscle strength than train-
ing with the Thera-Band tubing. Larger subject num-
bers may have produced a significant difference be-
tween the two training groups. Future research is
needed to establish if increasing neck strength is an
effective way to combat +Gz induced neck injuries in
pilots flying high performance aircraft.
Acknowledgements
The authors would like to thank Mark Tregurtha and
ChrisChessonofTheWhiplashCentreofWesternAus-
tralia who supervised the MCU training group, and
tested and re-tested all subjects.
References
[1] J.J. Albano and J.B. Stanford, Prevention of minor neck
injuries in F-16 pilots, Aviation Space and Environmental
Medicine 69 (1998), 119–139.
[2] M.Alricsson, K.Harms-Ringdahl, B. Larsson,J.LinderandS.
Werner, Neck muscle strength and endurance in fighter pilots:
effects of a supervised training program, Aviation Space and
Environmental Medicine 75 (2004), 23–28.
[3] H.E.Berg,G.BerggrenandP.A.Tesch, Dynamicneckstrength
training effect on pain and function, Archives of Physical
Medicine and Rehabilitation 75 (1994), 661–665.
[4] A.F. Burnett, F.L. Naumann and E.J. Burton, Flight training
effect on the cervical muscle isometric strength of trainee
pilots, Aviation Space and Environmental Medicine 75 (2004),
611–615.
[5] J. Cohen, Statistical Analysis for the Behavioural Sciences,
2nd ed., New Jersey: Erlbaum Associates, 1988.
[6] T.T.W. Chiu and S.K. Lo, Evaluation of cervical range of
motion and isometric neck muscle strength: reliability and
validity, Clinical Rehabilitation 16 (2002), 851–858.
[7] M.S. Conley, M.H. Stone, M. Nimmons and G.A. Dudley,
Resistance training and human cervical muscle recruitment
plasticity, Journal of Applied Physiology 83 (1997), 2105–
2115.
210 A.F. Burnett et al. / A comparison of training methods to increase neck muscle strength
[8] K.M. Greenwood and R. DeNardis, An assessment of the re-
liability of measurements made using the Melbourne proto-
col and the Hanoun Multi-Cervical Unit, Technical Report,
LaTrobe University, Melbourne, 2000.
[9] O. Hamalainen and H. Vanharanta, Effect of Gz forces and
head movements on cervical erector spinae muscle strain, Avi-
ation Space and Environmental Medicine 63 (1992), 709–716.
[10] O. Hamalainen, S.K. Toivakka-Hamalainen and P. Kuronen,
+Gz Associated stenosis of the cervical spinal canal in fighter
pilots, Aviation Space and Environmental Medicine 70 (1999),
330–334.
[11] I.J.M. Hendriksen and M. Holewijn, Degenerative changes of
the spine of fighter pilots of the Royal Netherlands Air Force
(RNLAF), Aviation Space and Environmental Medicine 70
(1999), 1057–1063.
[12] T.R. Highland, T.E. Dreisinger, L.L. Vie and G.S. Russell,
Changes in isometric strength and range of motion of the iso-
lated cervical spine after eight weeks of clinical rehabilitation,
Spine 17 (1992), 77–82.
[13] A. Jordan, J. Mehlsen, P.M. Bulow, K. Ostergaard and B.
Danneskiold-Samsoe, Maximal isometric strength of the cer-
vical musculature in 100 healthy volunteers, Spine 24 (1999),
1343–1348.
[14] L.K. Kamibayashi and F.J.R. Richmond, Morphometry of hu-
man neck muscles, Spine 23 (1998), 1314–1323.
[15] A. Kikukawa, S. Tachibana and S. Yagura, G-related muscu-
loskeletal spine symptoms in Japan Air Self Defense Force
F-15 pilots, Aviation Space and Environmental Medicine 65
(1994), 269–272.
[16] S.Kumar, Y.NarayanandT.Amell, Cervicalstrengthofyoung
adults in sagittal, coronal, and intermediate planes, Clinical
Biomechanics 16 (2001), 380–388.
[17] S.H. Leggett, J.E. Graves, M.L. Pollock, M. Shank, D.M.
Carpenter, B. Holmes and M. Fulton, Quantitative assessment
andtrainingofisometriccervicalextensionstrength, American
Journal of Sports Medicine 19 (1991), 653–659.
[18] A. Maeda, T. Nakashima and H. Shibayama, The effect of
training on the strength of cervical muscle, Annals of Physio-
logical Anthropology 13 (1994), 59–67.
[19] M.C. Morrissey, E.A. Harman and M.J. Johnson, Resistance
training modes specificity and effectiveness, Medicine and
Science in Sports and Exercise 27 (1995), 648–660.
[20] D.G.Newman, +Gz-induced neckinjures in Royal Australian
Air Force fighter pilots, Aviation Space and Environmental
Medicine 68 (1997), 520–524.
[21] J. Oksa, O. Hamalainen, S. Rissanen, J. Myllyniemi and P.
Kuronen, Muscle strain during aerial combat manoeuvring ex-
ercise, Aviation Space and Environmental Medicine 67(1996),
1138–1143.
[22] P. Portero, A.X. Bigard, D. Gamet, J.R. Flageat and C.Y.
Guezennec, Effects of resistance training in humans on neck
muscle performance, and electromyogram power spectrum
changes, European Journal of Applied Physiology 84 (2001),
540–546.
[23] K.Y. Seng, V.S. Lee and P.M. Lam, Neck muscle strength
changes across the sagittal and coronal planes: an isometric
study, Clinical Biomechanics 17 (2002), 545–547.
[24] K.Y. Seng, P.M. Lam and V.S. Lee, Acceleration effects on
neck muscle strength: pilots vs. non-pilots, Aviation Space
and Environmental Medicine
74 (2003), 164–168.
[25] R.D. Vanderbeek, Period prevalence of acute neck injury in
US Air Force pilots exposed to high G forces, Aviation Space
and Environmental Medicine 59 (1988), 1176–1180.
[26] A.N. Vasavada, S. Li and S.L. Delp, Influence of muscle mor-
phometry and moment arms on the moment generating capac-
ity of human neck muscles, Spine 23 (1998), 412–422.
[27] A.N. Vasavada, S. Li and S.L. Delp, Three-dimensional iso-
metric strength of neck muscles in humans, Spine 26 (2001),
1904–1909.
[28] J.Ylinen andJ. Ruuska, Clinicaluseofneckisometricstrength
measurement in rehabilitation, Archives of Physical Medicine
and Rehabilitation 75 (1994), 465–469.
[29] J.J. Ylinen, A. Rezasoltani, M.V. Julin, H.A. Virtapohja and
E.A. Malkia, Reproducibility of isometric strength: measure-
ment of neck muscles, Clinical Biomechanics 14 (1999), 217–
219.
[30] J.J. Ylinen, M. Julin, A. Rezasoltani, H. Virtapohja, H. Kau-
tiainen, T. Karila and E. Malkia, Effect of training in Greco-
roman wrestling on neck strength at the elite level, Journal of
Strength and Conditioning Research 17 (2003), 755–759.
[31] J. Ylinen, E.P. Takala, M. Nykanen, A. Hakkinen, E. Malkia,
T.Pohjolainen, S.L.Karppi, H. Kautiainen and O.Airaksinen,
Active neck muscle training in the treatment of chronic neck
pain in women: A randomized control trial, Journal of the
American Medical Association 289 (2003), 2509–2516.
... There have been a number of studies on the effectiveness of training programmes on neck muscle strength or endurance ( Table 2). Half of these studies have involved healthy non-athletes including college students [16][17][18][19][20][21][22][23]. ...
... All but one study [17] conducted the training programme for at least 8 weeks and two studies went for up to 12 weeks [18,19]. Most programmes utilised dynamic neck extension exercises and some included flexion and lateral flexion exercises [21][22][23]; three studies used isometric exercises [17,18,20]. Neck rotation and proprioceptive resistance training were incorporated in one study [23]. ...
... Studies that reported modest increases of around 10 % used relatively low intensity or frequency [16,22]; training twice a week was more effective than just once a week [18]. When comparing the effectiveness of different training equipment, no significant difference was found between the use of a pin-load neck exercise machine or elastic resistance bands [21]. General strength training involving standard multi-joint exercises such as squat and deadlift incur isometric neck stabilisation but appear to provide insufficient stimulus to enhance dynamic neck strength [19], highlighting the importance of specificity of training. ...
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The neck musculature has an essential role in positioning and stabilising the head and may influence sport performance and injury risk. The objectives of this review are to (1) compare the neck strength of different athletes; (2) report on the outcomes of training programmes; (3) explore the association between neck strength and head stabilisation; (4) examine the relationship between neck strength and sport injury risk; and (5) identify areas for future research. There was a difference in strength between different player positions in football codes, gender and age. Detected differences were partly attributed to variation in neck muscle mass. Neck strength training programmes were generally shown to be effective for untrained and trained participants using dynamic or isometric actions and various types of resistance devices. There was a wide range of reported increases in neck strength; the smallest gains were usually for programmes that utilised lower intensity or frequency. There was limited evidence that greater isometric strength or dynamic training was associated with better head stabilisation during low-level force application, while there is direct evidence of an association between neck isometric training or strength and injury risk. A retrospective analysis of professional rugby union players revealed that isometric training reduced match-related cervical spine injuries and a prospective study found that greater overall isometric neck strength reduced concussion risk in high school athletes. Recommendations for future research include substantiating the link between neck strength and sport injury risk and assessing the effectiveness of neck plyometric and perturbation training on stabilisation and injury risk.
... Previous literature supports the concept that enhanced dynamic neck force is related to exercise intensity and muscle recruitment patterns that are developed through specific strength training [3,4]. In comparing two dynamic cervical training modalities, including a pin-loaded machine and Thera-Band tubing, it was proposed that the increased intensity of the pin-loaded machine would be more effective for developing static neck strength [4]. ...
... Previous literature supports the concept that enhanced dynamic neck force is related to exercise intensity and muscle recruitment patterns that are developed through specific strength training [3,4]. In comparing two dynamic cervical training modalities, including a pin-loaded machine and Thera-Band tubing, it was proposed that the increased intensity of the pin-loaded machine would be more effective for developing static neck strength [4]. The pin-loaded machine was also associated with significantly greater EMG activations in comparison to the Thera-Bands, which would explain the greater training effect produced by the machine [3]. ...
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The purpose of this study was to compare maximal static and dynamic neck strength between hockey players and wrestlers. Athletes were recruited from the university men's hockey and wrestling teams, with active male university students serving as a control group. Each group consisted of eight participants between the ages of eighteen and twenty-four. Anthropometric measurements, including height, mass, neck length, and neck girth were taken prior to testing. Static and dynamic cervical strength testing was completed using a modified Nautilus neck strengthening machine. Maximal static neck flexion and extension strength were measured using a load cell attached to the arm of the Nautilus machine, which was set in a neutral neck position. To measure dynamic neck strength, a 6-Repetition Max (RM) submaximal test was completed for cervical flexion and extension, from which 1-RM values were predicted. Mean normalized strength values were significantly higher among all participants for neck extension (M = .32, SD = .12) than for neck flexion (M = .20, SD = .07). Mean neck strength was significantly greater for dynamic muscle contractions (M = .31, SD = .13) than for static muscle contractions (M = .22, SD = .08). When comparing among groups, mean normalized static neck strength of the wrestlers was significantly greater than that of the hockey players in both the flexion and extension directions, with no differences seen between the hockey players and the controls. Differences in static and dynamic neck strength between hockey players and wrestlers are likely associated with the demands of each sport and their sport-specific strength training.
... 5,6 It has been suggested that isometric strength training of the neck is the most promising training method to activate and strengthen the stabilisation muscles of the head-neck segment. 7 While there is currently insufficient 15% in both sagittal and frontal planes. 9 But in elite female athletes, no neck strength program has been assessed that may benefit SRC risk reduction. ...
Article
Objectives The purpose of this study was to investigate the effectiveness of an isometric neck strengthening program to improve isometric neck strength in elite women's football-code athletes. Design Randomised controlled trial. Method Elite female soccer (n = 10) and Australian football (n = 30) players were randomised into either a control (n = 20) or experimental (n = 20) group for a 12-week intervention study during their respective seasons. While both groups undertook their prescribed strength and conditioning programs, the experimental group also performed isometric neck strengthening exercises three times per week prior to training. Isometric neck strength of the extensors, flexors, lateral flexors, and rotators were assessed pre, mid (Week 7), and post (Week 13) intervention with a hand-held dynamometer during early to mid-competition season. A mixed design analysis of variance was performed for statistical analysis. Results No significant group-by-time interactions in isometric neck strength were observed. All strength variables displayed a significant change over time throughout the 12-week period (p < 0.05). No significant between group differences in isometric neck strength variables were observed except for lateral left flexion (F(1, 38) =5.064, p = 0.030, η²p = 0.117). Conclusion The addition of isometric neck strengthening exercises did not improve neck strength beyond a standard strength and conditioning program for elite women's football-code athletes. While this specific program may not improve neck strength in elite women's football-code athletes, further investigation is needed to determine whether sport-specific neck strength exercises may improve neck strength or if lower-level competition athletes may still benefit from an isometric neck strengthening program.
... The multi-cervical unit is a commercial product (BTE Technologies) aimed at offering pain reduction by restricting the neck lateral movements; however, this device could induce a vertical continuous force which may contribute to the treatment of conical and acute pain, vertebral disks compression, and some others. This equipment requires the recurrent visits of the patient to the specialized clinical facilities [21]. ...
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The objective of this study was to design of an output based impedance adaptive controller for a special class of cervical orthoses, a class of biomedical devices for the rehabilitation of neck illnesses. The controller used the adaptive sliding mode theory to enforce the tracking of the reference trajectory if the patient was not resistant to the therapy. If the patient rejects the orthosis activity, a second impedance-based controller governs the orthosis movement allowing the patient to take the leading role in the orthosis sequence of movements. The proposed controller considers a weighted controller combining the tracking and the impedance controls in a single structure. The monitoring of the external force was evaluated on a novel weighting function defining on-line the role of each controller. The proposed orthosis was motivated by the prevalence of whiplash, which is a syndrome that is produced by forced hyperextension and hyperflexion of the neck. This study included the development of a technological prototype of the orthotic type to support the recovery of patients diagnosed with whiplash. The sections that make up the orthotic device are two independent systems that move the patient’s head in the sagittal and frontal planes. For this purpose, the mechanical structure of the cervical orthosis was made up of 7 pieces printed in 3D with polylactic acid (PLA). The operation of the cervical orthosis was evaluated in two sections: (a) using a simulation system, which consists of a spring with an artificial head and the development of a graphic interface in Matlab, and (b) evaluating the controller on the proposed orthosis. With these elements, the follow-up of the trajectory proposed by the actuators was evaluated, as well as its performance in the face of the opposition that a patient generates. The superiority of the proposed controller was confirmed by comparing the tracking efficiency with proportional-integral-derivative and first-order sliding variants.
... The Multi-Cervical Unit (MCU, BTE Technologies, Inc., Hanover, MD) is a medical device designed for neck exercises based on the Melbourne Protocol (MP) [6]. This device showed effects in alleviating cervical dysfunction and enhancing muscle strength [7]. It could also be used to quantitatively measure neck muscle strength and cervical range of motion (ROM) [8][9][10]. ...
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Objective . To compare the immediate and short term effectiveness of Shi’s Daoyin therapy (DT) rather than the Melbourne Protocol (MP) in terms of pain, mobility, and isometric strength of cervical muscles in nonacute nonspecific neck pain patients. Material and Methods . A total of 114 nonacute nonspecific neck pain patients aged 20~50 years were recruited and randomly assigned to be treated by either Shi’s DT or the MP. 56 cases and 54 cases received treatment for 3 weeks and were evaluated before and after intervention and at 3-week follow-up in Shi’s DT group and MP group, respectively. The outcome measures were Chinese version of the Neck Disability Index (NDI), cervical range of motion (ROM), maximal voluntary isometric force (MVIF), and pain intensity (Numeric Pain Rating Scale, NPRS). Results . All outcomes of both groups showed statistically significant improvements after the intervention and at 3-week follow-up ( P < 0.05), while no statistically significant difference was found in NDI between groups. When followed up after 3 weeks, the ROM in axial rotation was significantly greater in the Shi’s DT group ( P < 0.05), and the NPRS in the Shi’s DT group was significantly lower than the MP group (P < 0.05). At the end of the treatment period, the MVIF in lateral bending in the Shi’s DT group had a lower value ( P = 0.044) than in the MP group, but there was no significant difference in flexion and extension between the two groups. Conclusions . Both Shi’s DT and MP groups demonstrated an obvious reduction in pain intensity and improvements in neck mobility after a short term follow-up period. The improvement of Shi’s DT in disability and pain during functional activities is generally similar to that of the MP for the treatment of nonacute nonspecific neck pain.
... In a related study on F-16 pilots, it was found that neck strengthening exercises and bracing the head prior to maneuvers reduced risk of injury(Albano and Stanford, 1998). The study ofBurnett et al. (2005) compared a multi cervical unit (MCU) group ...
Thesis
Among occupational settings an unusual, but nonetheless important job at high prevalence area of occupational neck injury (reports of up to 90% incidence during flying careers in the aviation medicine literature) that of High Performance Combat Pilots (HPCP) has received relatively less studies. In the last years, the military helmet systems have increased the amount of head-supported mass (HSM) to serve also as mounting platforms for numerous combat-essential devices. It has been hypothesized that there could be an increase of risk for neck injuries as a function of the weight of the aviator's helmet. In this thesis, a prevalence study was carried out to verify the extent of the problem among Italian Air Force (ITAF) aircrews and, afterwards it was performed a study to identify the risk factors that characterize neck pain (NP) in Eurofighter pilots. It wanted to also identify simple tools, as well as the most common tests using in clinical setting, useful to simplify the epidemiological studies on cervical injuries among ITAF. Finally, a specific Physical Exercise Training (PET) was proposed to reduce incidence or to improve neck pain condition in pilots who suffer. The subjects were 44 volunteer male pilots (age: 34.6 ± 5.5) employed on Eurofighter Typhoon aircraft. Design of the study included three main area of investigation: first, a wide survey about individual and flight related factors, lifestyle, prevention strategies, medical treatments and pain experience; second, a functional assessment through Muscular Endurance Performance and Active Cervical Range of Motion (ACROM) evaluations; third, effect of an eight-weeks of specific PET on cervical functionality. For the first two areas of investigation, the pilots were grouped together as one cohort, later 24 pilots (35.6 + 4.4 yrs.) were selected and randomly divided into 2 groups: exercise group (EG) and control group (CG). In this study, smartphone application was used in physical assessment of cervical muscles. The iPhone 5c® used showed good intra- and inter-rater reliability and good validity for movements in all planes of movement compared to a gold standard (fluid inclinometer). More than 43% of pilots reported NP in the previous year. Among them, functional assessment was worse than the healthy pilots, but only Cranio-Cervical Flexion Test (CCFT) produced significant difference between the groups (p<.05). Pilots with previous F-16 experience were selected and they seemed more correlated with NP and cervical dysfunction. They showed no significant difference in NP compared to other pilots, but reported significant limitation in some ACROM. Age of pilots showed no correlation with NP, but was negatively correlated with ACROM, with significant limitation over 34 years old. Pilots suffering NP reported heavier physical activity during occupational duties and it may suggest to investigate more thoroughly some psychological or different stress factors in NP survey. The amount of physical exercise during leisure time seemed negatively correlated with neck injuries, especially for subjects who practiced ball games and core stability training. The data about PET were inconsistent. In conclusion, associate factors to NP investigated in this dissertation did not seem to affect the incidence of neck disorders among Typhoon pilots. Only previous experience on F-16 may suggest to deserve more attention about neck disorder in this population, although the transition to Typhoon does not seem to have exacerbate their condition. A programmed functional assessment and survey in pilots with and without NP may help to prevent acceleration-induced neck injuries, especially with increasing age and flight hours.
... Several studies show that resistance training programs are capable of increasing the strength of the cervical musculature. 3,13,29,42 However, the relationship between increases in cervical isometric strength after resistance training and reductions in head acceleration remains unknown. 29,34,54 Further evidence is needed to support the widespread use of cervical strength and conditioning programs for concussion prevention. ...
Chapter
The cervical spine is an anatomically complex structure whose essential roles are to orient the head and the sensory system and to protect the spinal cord. In developed countries, sports related accidents constitute the fourth most common cause of spinal cord trauma. They are the second most frequent case of spinal cord injuries for those under the age of 30. All sports are potentially affected even though it would seem that highly kinetic physical activities or contact sports would be the most concerned. In this chapter, we will first review the anatomy of the cervical spine and then describe the biomechanical basis of the protective effect of the cervical musculature and the neurophysiological aspects of trauma prevention. We will describe how cervical muscles can be evaluated and close with a brief overview of preventative strategies of the French Rugby Federation will be described.
Chapter
Chiropractic as defined by the World Federation of Chiropractic is “a health profession concerned with the diagnosis, treatment and prevention of mechanical disorders of the musculoskeletal system, and the effects of these disorders on the functions of the nervous system and general health. There is an emphasis on manual treatments including spinal adjustment and other joint and soft-tissue manipulation.” In patients with Neurogenic Thoracic Outlet Syndrome [NTOS] there may be mechanical compression of neural structures within the brachial plexus at one of several anatomical sites, several of which may be targeted by the techniques used in Chiropractic.
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The aim of this study was to examine whether F-16 pilots are at an increased risk of (cervical) spine degeneration. Retrospectively, X-ray slides were examined of pilots of the Royal Netherlands Air Force who were systematically radiographed (at least twice). In total, 316 pilots were evaluated: 188 F-16 pilots and 128 pilots in the control group. Two radiologists, who were blinded as to whether the X-ray films were of F-16 pilots or the control group, examined these X-rays separately. In both groups, the time between the two X-rays was on average 6 yr. Though the inter-rater agreement of the X-rays was rather low, both radiologists found comparable statistically significant differences between the two groups. In the F-16 group, an increased osteophytic spurring was found at levels C4-C5 and C6-C7, and increased arthrosis deformans was found in the cervical spine. Further analysis of the data of a selected group of pilots, whereby the difference in age between both groups was minimized, showed that the higher mean age of the F-16 pilots was possibly correlated with the increased degeneration in this group. No consistent relationship was found between spinal degeneration and initial radiological status. Also, a clear relationship between spinal degeneration and flying hours could not be demonstrated. These findings suggest that frequent exposure to high +Gz forces might cause premature degeneration of the spine of F-16 pilots. Future research must demonstrate to what extent age, mission, and number of flying hours have influenced the results. An uniform international classification and coding system in combination with establishing an international database is recommended.
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There have been no reports in the literature objectively measuring changes in strength and range of motion in patients with non-spinal-cord injuries of the cervical spine. Ninety patients participated in an 8-week training study. Diagnostic groups included patients with the following: degenerative disc (n = 6), herniated disc (n = 14), and cervical strain (n = 70). Full-range isometric strength tests were performed at eight equidistant positions in a device that constrained all motion with the exception of cervical flexion and extension. Post tests were performed following training. Significant gains were seen in strength as well as range of motion. Perceived pain was significantly reduced. This kind of testing can potentially provide the clinician with objective findings to direct patient management more adequately.
Article
External stimulus/loading initiates adaptations within skeletal muscle. It has been previously found that the cervical area has the highest loading while performing flying maneuvers under +Gz. The first purpose of this study was to examine the neck muscle response to the physical environment associated with flight training, incorporating limited exposure sure to +Gz force, in a Pilatus PC-9 aircraft. The second purpose was to examine the short-term range of movement (ROM) response to flight training. Isometric cervical muscle strength and ROM was monitored in 9 RAAF pilots completing an 8-mo flight-training course at Pearce Airbase in Western Australia, and in 10 controls matched for gender, age, height, and weight. Isometric cervical muscle strength and ROM were measured at baseline and at 8 mo using the multi-cervical rehabilitation unit (Hanoun Medical, Downsview, Ontario, Canada). Results indicated that an increase in pilot neck strength was limited to flexion while in a neutral position. No strength changes were recorded in any other site in the pilots or for the controls. These findings suggest that short-term exposure to the physical environment associated with flight training had a limited significant effect on increasing isometric cervical muscle strength. No significant changes were observed in pilot ROM, indicating that short-term exposure to flight does not effect ROM.
Article
To evaluate the repeatability of an advanced method of measuring the strength of functionally different groups of neck muscles using an isometric apparatus. A repeated measures design was used within and between sessions. Chronic neck pain has been associated with poor isometric neck strength. In rehabilitation, strength measurements may thus help to evaluate the basic condition and show whether or not treatments and exercises have been beneficial for improving strength. Previous tests have concentrated on testing strength while trying to bend forwards and backwards, but no biomechanics device, able to test rotator muscles, has been presented. The new isometric measurement device was used to test flexion, extension and also rotation strengths of normal subjects (n = 33). Intratester repeatability was good with regard to all measured parameters. With both tests performed on the same day and test comparisons between days, intratest repeatability was good with regard to all measured parameters.
Article
The purpose of this study was to quantify the neuromuscular cervical adaptations to an 8week strength training programme. Seven healthy men, with no pathological conditions of the neck, performed a lateral flexion isometric resistance-training programme three times a week. The training sessions consisted of one set of ten contractions, each of 6s duration, at 60% of the predetermined maximal voluntary isometric torque (MVTim) (warm-up) and two sets of eight contractions, each of 6s duration, at 80% MVTim. The training effects were evaluated in three ways: muscle size, strength and fatigability. The cross-sectional areas (CSA) of the trapezius (TRP) and sternocleidomastoideus (SCM) muscles were determined using a computerised tomographic scanner. Results showed an increase in the CSA of TRP and SCM muscles after training, 8.8% at C5 level and 6.4% at C7 level for SCM muscle and 12.2% at C7 level for TRP muscle. Strength increased significantly under both isometric and isokinetic conditions (35% and 20%, respectively). Muscle fatigability in lateral flexion was quantified during a sustained isometric contraction at 50% of MVTim. The shift of the mean power frequency of the electromyogram power spectrum density function of SCM muscle toward lower frequencies was less after training (14.6% compared to 6.8%). These results indicate the beneficial effect of a strength-training programme which increases neck muscle size and strength during lateral flexion, and decreases the fatigability of the superficial muscles of the neck.
Article
A portable surface-integrated EMG (IEMG) device was used to investigate the strain caused by low and high Gz forces and head movements on the cervical erector spinae muscles during flight missions. The obtained IEMG activities were normalized by comparing them with activities representing maximal voluntary contraction (MVC) of the cervical erector spinae muscles in each subject. The muscular strain increased with increasing Gz forces and head movements. Under +7.0 Gz the mean muscular strain was 5.9-fold compared with +1.0 Gz and was 37.9% of the MVC. In some individuals, the muscular tolerance (100% of the MVC) was ipsilaterally reached already under +4.0 Gz with concomitant movements and twisted positions of the head. Pilots are susceptible to acute neck injury when the protection afforded by their neck muscles is insufficient.
Article
The purpose of this study was to evaluate the reliability and variability of repeated measurements of isometric cervical extension strength and determine the effect of 10 weeks of dynamic variable resistance cervical extension training on isometric cervical extension strength. Seventy-three subjects (age, 29 +/- 12 years [mean +/- SD]) completed isometric cervical extension strength tests on 4 separate days (D1, D2, D3, and D4). For each test, isometric cervical strength was measured at 126 degrees, 108 degrees, 90 degrees, 72 degrees, 54 degrees, 36 degrees, 18 degrees, and 0 degrees of cervical flexion. Between-day correlation coefficients over the eight angles of cervical flexion were high for D2 versus D3 (r = 0.90 to 0.96). Test variability (standard error of estimate) between D2 versus D3 was low (7.4% to 10.2% of mean) through the entire range of motion. Regression analysis showed that the isometric cervical extension strength curve is linear and descending from flexion to extension. In a second study, 14 subjects (age, 25 +/- 3 years) trained the cervical extensor muscles for 10 weeks while 10 subjects (age, 23 +/- 3 years) served as controls. Training included 8 to 12 cervical extensions to volitional fatigue, 1 day per week. The training group improved isometric cervical extension strength at six of eight angles before to after training (P less than or equal to 0.05). During the same time period the control group did not change. These data indicate that repeated measures of isometric cervical extension strength are highly reliable and can be used for the quantification of isometric cervical extension strength through a 126 degrees range of motion.(ABSTRACT TRUNCATED AT 250 WORDS)