59
Journal of Exercise Physiologyonline
October 2015
Volume 18 Number 5
Editor-in-Chief
Official Research Journal of
Tommy
the American
Boone, PhD,
Society
MBA
of
Review
Board
Exercise
Physiologists
Todd Astorino, PhD
Julien Baker,
ISSN 1097-9751
PhD
Steve Brock, PhD
Lance Dalleck, PhD
Eric Goulet, PhD
Robert Gotshall, PhD
Alexander Hutchison, PhD
M. Knight-Maloney, PhD
Len Kravitz, PhD
James Laskin, PhD
Yit Aun Lim, PhD
Lonnie Lowery, PhD
Derek Marks, PhD
Cristine Mermier, PhD
Robert Robergs, PhD
Chantal Vella, PhD
Dale Wagner, PhD
Frank Wyatt, PhD
Ben Zhou, PhD
Official Research Journal
of the American Society of
Exercise Physiologists
ISSN 1097-9751
JEPonline
Cryotherapy and Laser Therapy Do Not Interfere in the
Response to Eccentric Exercise-Induced Muscle
Damage: A Randomized Clinical Trial
Liane Macedo, Daniel Borges, Caio Lins, Jamilson Brasileiro
Neuromuscular Performance Analysis Laboratory, Department of
Physiotherapy, Federal University of Rio Grande do Norte, Natal,
Brazil
ABSTRACT
Macedo LB, Borges DT, Lins CAA, Brasileiro JS. Cryotherapy
and Laser Therapy Do Not Interfere in the Response to Eccentric
Exercise-Induced Muscle Damage: A Randomized Clinical Trial.
JEPonline 2015;18(5):59-68. The purpose of this study was to
evaluate the effect of cryotherapy and laser therapy in response to
eccentric exercise-induced muscle damage on the biceps brachii
muscle. This is a randomized clinical trial with random allocation,
composed of 60 active women. All subjects underwent an eccentric
exercise protocol (2x10 maximum eccentric contractions of nondominant elbow flexors at 60°·sec-1) and three assessments (pre,
post, and 48 hrs after the intervention) of pain sensation (measured
by algometry), peak torque normalized for body weight and power
(measured by isokinetic dynamometry), and muscle activation
(measured by surface electromyography). No intergroup statistical
differences were observed for algometry (P=0.15), peak torque
normalized for body weight (P=0.77), power (P=0.70), and RMS
(P=0.76). Thus, the findings indicate that cryotherapy and low-level
laser therapy are not sufficient to stimulate and treat the eccentric
exercise-induced muscle damage.
Key Words: Exercise, Muscle, Isokinetics, Injury
60
INTRODUCTION
Exercise-induced muscle damage affects primarily individuals who resumed strenuous
exercise involving eccentric contractions (13,20,26) after a period of non-activity. Eccentric
exercise-induced mechanical stress leads to overstretching of sarcomeres, triggering a series
of events, such as microlesions in the connective tissue, misalignment of sarcomere bands
and rupture of Z lines (18,24). This break in functional unity promotes an inflammatory
process that results in the sensation of pain and discomfort (1).
Delayed onset muscle soreness (DOMS) is characterized as a painful sensation during
contraction, stretching, and/or pressure placed on the exercised muscle (27,28). Symptoms
appear in the first 24 hrs after the conclusion of the activity, the peak occurring between 24
and 72 hrs, and dissipating between 5 and 7 days (27,29). In addition to the pain, the
structural lesion provoked by exercise and the inflammatory response may result in damage
to muscle function and decreased performance (5,16). In order to avoid or reduce these
alterations, numerous interventions have been investigated and can be grouped into three
categories: (a) pharmacological treatments with non-steroid anti-inflammatory drugs; (b)
interventions using nutritional supplements; and (c) physical therapy by means of physical
modalities such as the use of ice, ultrasound, laser therapy, electrical stimulation, massage,
stretching, warm up, light exercise, immobilization, and rest (7,14,20).
Cryotherapy has been used in sports to help recover from exercise-induced muscle damage
(EIMD) that often results from strenuous training and/or competition (3,22). Its effects on
damaged tissue help to relieve pain and lowers the inflammatory response and edema, since
it provokes local vasoconstriction that reduces capillary, lymphatic, and cell permeability,
(2,3,9,24). It has been observed that cooling decreases secondary hypoxia with a
consequent decline in muscle necrosis. Furthermore, deceleration of cell metabolism and
nerve conduction velocity occurs that limits injury secondary to lesion and pain (2,9). Thus, it
is suggested that due to the positive effects caused by cooling, athletes are able to continue
training with no decrease in performance during the days following the injury (24).
Another resource that has attracted attention for reducing pain and inducing tissue repair is
laser therapy. Low-level laser therapy (LLLT) uses low-power lasers to exert a regulatory
action on the inflammatory response, which appears to reduce pain symptoms and stimulates
tissue repair (17). Moreover, it is suggested that its effects on biological tissue may reduce
DOMS and prevent muscle damage. This is because LLLT may promote a biostimulating
effect that increases ATP and collagen synthesis, stimulates angiogenesis and fibroblast
proliferation, inhibits pain and oxidative stress, and modulates inflammatory reactions
(5,11,12). Thus, the purpose of the present study is to determine if the cryotherapy and laser
therapy alter the response to eccentric exercise-induced muscle damage.
METHODS
Subjects
This was a non-probability sample composed of 60 women (22.6 ± 2.5 yrs). Study power was
calculated prospectively, obtaining a type 1 error of 0.05 and type 2 of 0.20. It was estimated
that 20 subjects would be needed in each group to detect a difference around 10% with
power of 80%. The subjects’ torque values for the elbow flexors were statistically compared
before, immediately after, and 48 hrs after the interventions.
61
The inclusion criteria were: female sex, aged between 18 and 28 yrs, healthy, considered
active according to the International Physical Activity Questionnaire – Short Form (IPAQ),
engaged in physical activity involving upper limbs at least 2 times·wk-1, exhibited shoulder
joint, elbow, and non-dominant hand integrity, no history of osteo-myoarticular injuries in the
assessed limb during the 6-month period prior to the study, or neurological, visual and/or
non-corrected auditory impairments. Also, they could not be allergic to ice or any absolute
contraindication to the use of laser (cancer and pregnancy). Exclusion criteria were: not
understanding the commands given in the protocols and/or inadequate performance during
assessments.
Procedures
This study was a randomized clinical trial that conducted at the Laboratory of Neuromuscular
Performance Analysis (LAPERN) at the Department of Physiotherapy of Federal University of
Rio Grande do Norte (UFRN). The subjects were recruited by non-probability, convenience
sampling, and randomly distributed (using the website, www.randomization.com) into three
groups: (a) the control group; (b) the cryotherapy group; and (c) the laser therapy group. All
groups underwent three assessments: pre, immediately after, and 48 hrs after intervention.
This study was approved by the local Research Ethics Committee under protocol number
387.826. The present study complied with ethical aspects based on Resolution 466/12 of the
National Health Council and Declaration of Helsinki. All the subjects volunteered to take part in
the study. Each subject gave informed consent after being advised of the objectives, risks, and
benefits of the research. All subjects underwent three assessments (pre, post, and 48 hrs) that
consisted of algometry, dynamometry, and electromyography.
A digital pressure algometer (Wagner Force TenTM FDX50, USA) was used to assess pain,
measured in Newton (N). The accuracy of the device is ± 0.3% of full scale. Calibration was
certified by the manufacturer before the test procedures (serial number 10441). Each subject
was positioned in the dynamometer chair with arm supported, relaxed, and elbow extended.
The algometer was placed one-third the distance between the cubital fossa and medial
acromion of the non-dominant limb, and the assessor applied progressive perpendicular force
at a rate of 10 N·sec-1 (23). All the subjects were instructed to inform the assessor at the
onset of pain, thereby registering pain threshold. Then, the subjects’ skin was prepared with
trichotomy and cleaned with 70% alcohol before fixing the electrodes to assess the
electromyography. Electrodes were positioned according to SENIAM guidelines (10).
An isokinetic dynamometer (Biodex Multi-Joint System 3®, Biodex Biomedical System Inc,
New York, USA) calibrated monthly, according to manufacturer’s recommendations, was
used to assess the peak torque normalized for body weight (%) and power (Watts). The
subjects were secured with belts in the isokinetic dynamometer chair for dynamometric
assessment of the elbow. The rotation axis of the dynamometer was aligned with the lateral
epicondyle of the humerus and the lever arm was adjusted to the distal part of the upper limb
assessed, maintaining the forearm in the supine position. The range of motion performed
during the tests was 90°, initiating with the dynamometer arm in the horizontal position and
ending in the vertical position. Adjustments for gravity were carried out at 30° flexion of the
dynamometer lever and calculated using equipment software.
62
Electromyographic assessment was conducted simultaneously with dynamometric evaluation
and Root Mean Square (RMS) was analyzed. The electromyographic signal was captured by
a four-channel signal conditioner module (EMG System do Brazil®) with a 12-bits analogicaldigital (A/D) converter (CAD, 12/36-60K). The device has a common-mode rejection ratio
(CMRR) >80 dB, with sampling frequency configured at 2000 Hz and the signal was filtered
between 20 and 500 Hz. Signals were amplified 1000 times, 20 times in the electrodes and
50 times in the converter. The electromyography was linked by a battery and connected to a
laptop, which received the signal and stored it in a file. EMGLab software (EMG System do
Brazil®) was used for digital analysis of the signals.
To normalize the electromyographic signal, the subjects were asked to perform two maximum
voluntary isometric contractions (MVIC) at 90° elbow flexion for 5 sec with a 1-min interval
between each repetition. Of the two contractions, the electromyographic signal that exhibited
the greatest isometric torque was used for normalization (8). Then, the subjects executed two
eccentric contractions at 60°·sec-1 to familiarize themselves with the test. After a 2-min rest, 5
maximum eccentric contractions of the elbow flexors were performed at an angular velocity of
60°·sec-1 to assess muscle performance. The electromyographic signal with the greatest
torque among the 5 recorded by the dynamometric graph was used to analyze RMS (%).
During assessments, a standard verbal command and a visual feedback through the monitor
of the isokinetic dynamometer were used to encourage the subjects.
After the initial assessment, the subjects were submitted to an eccentric exercise protocol on
an isokinetic dynamometer (2 series of 10 maximum eccentric contractions of non-dominant
elbow flexors at 60°·sec-1). A 2-min rest period was allowed between each series and the
ROM performed was 90° of flexion at 0° extension of the dynamometer lever.
The subjects in the control group did not undergo any intervention. They remained at rest for
25 min. The cryotherapy group remained seated on the isokinetic dynamometer and a 1 kg
ice pack was strapped over the entire biceps brachii muscle and adjacent muscles of the arm
under study using a bandage. The application lasted 25 min. A digital thermometer
(Salvterm® 1200K, Brazil) with interface was used to measure cutaneous temperature and to
ensure the cooling level (4). The interface of the thermometer was isolated from the ice pack
to ensure that the temperature was recorded specifically on the skin surface.
A laser device (DMC®, Photon Laser III, Brazil) was used by the laser therapy group. This
group received laser application to the muscle belly of the non-dominant biceps brachii
muscle at four different points. These points were determined based on the distance between
the cubital fossa and the acromion, corresponding to 20%, 30%, 40%, and 50% of the length
of the arm, thereby excluding the tendinous region (15). Low-level laser therapy was used
with the following parameters: wavelength of 808 nm, power of 100 mW, irradiance of 35.7
W/cm2, total energy of 20 J, 4 points (5 J per point) and application time of 49 sec at each
point.
The laser probe was applied perpendicularly to the skin. The subjects and the researcher
used eye protection against laser irradiation. After application, the individual remained at rest
for 25 min to ensure that reassessment was conducted after the same time period in each
group. After the interventions each subject underwent two assessments: Immediately (post)
and 48 hrs after the interventions, identical to the first assessment.
63
Statistical Analyses
The sample size of this study was determined by a priori analysis of power, demonstrating
the need for at least 20 subjects per group. SPSS for Windows (version 20.0) was used for all
statistical analyses. One-way ANOVA was used to investigate baseline differences between
groups. A mixed design ANOVA (3x3) was used to investigate changes in algometry, peak
torque normalised for body weight, power, and RMS with one between-subjects variable,
group, with three levels (control, cryotherapy, and laser therapy), and one within-subject
variable, time, with three levels (pre intervention, post intervention, and 48 hrs after
intervention). The effect of group, time, and group by time interactions were tested. When the
assumption of sphericity was violated, significance was adjusted using the GreenhouseGeisser method. When the effect of test was significant, the analysis using the multiple
comparison Bonferroni post hoc test was applied. A 5% significance level was used (P<
0.05).
RESULTS
No initial differences in anthropometric measures or variables analysed were observed
between the groups (Table 1).
Table 1. Baseline Characteristics of the Subjects.
Variables/Groups
Control Group
(n = 20)
Cryotherapy
Group
(n = 20)
Laser Therapy
Group
(n = 20)
P value
22.6  2.1
23.0  2.4
22.3  30
0.67
22.2  2.4
22.5  2.9
22.2  20
0.95
Algometry (N)
28.8  11.3
32.2  15.9
33.8  4.4
0.51
PT/BW (%)
52.5  7.2
49.6  7.6
55.7  11.1
0.10
Power (Watts)
18.5  4.8
17.4  2.8
20.8  5.8
0.06
106.5  26.3
97.2  21.7
94.5  23.3
0.25
Age (yr)
BMI (Kg·m-2)
RMS (%)
BMI: body mass index; PT/BW: peak torque normalised by body weight; RMS: root mean square
In relation to algometry, a significant difference was observed in the laser therapy group
between the three times of intervention (pre, post, and 48 hrs). For the control and
cryotherapy groups, we found similar responses with a statistical difference at 48 hrs
compared to pre and immediate post. However, no intergroup difference was observed
(P=0.15) (Figure 1).
64
Analysis of dynamometric variables showed that peak torque normalized for body weight had
altered values in the three groups analyzed, demonstrating a difference between pre and
immediate post and 48 hrs. With respect to power, there was a significant difference between
pre and immediate post and 48 hrs, in addition to a significant difference between immediate
post and 48 hrs for all the groups. The two variables showed no intergroup differences
(P=0.77 and P=0.70, respectively) (Figure 1).
Analysis of normalized electromyographic amplitude revealed no significant pre, immediate
post, and 48 hrs difference after intervention in the three groups assessed for RMS or any
intergroup variation (P=0.76) (Figure 1).
Figure 1. Means and Standard Deviation of Algometry, Root Mean Square (RMS), Peak Torque
Normalized by Body Weight (PT/BW), Power and Comparison Between and Within-Group. *P<0.05
**P<0.01
DISCUSSION
The results of the present study show that the use of cryotherapy and laser therapy, as
employed in this protocol, does not alter the response to muscle damage for any of the
variables analyzed.
The literature has documented that exercise-induced muscle injury causes DOMS (19,26).
Pressure algometry is used to assess the threshold and limit of this pain, since it is
65
characterized as a painful sensation during contraction, stretching, and when pressure is
placed on the exercised muscle (27,28). According to the findings of this study, algometric
values reached their lowest values after 48 hrs, demonstrating that peak pressure-induced
pain occurred two days after exercise, irrespective of the application of cryotherapy or laser
therapy. This peak pain may be related to a structural lesion provoked by eccentric exercise,
which develops into a series of inflammatory reactions. During this process there is a release
of inflammatory mediators that sensitize peripheral nociceptors, thus reducing the threshold
of mechanic stimulation (28).
To date, no literatures studies have been found that used a pressure algometer to assess
DOMS in subjects that used cryotherapy or laser therapy. We observed only assessment of
muscle sensitivity using palpation associated to Visual Analogue Scale (VAS) (24). Although
peak pain occurs 48 hrs after activity, dynamometric variables show that the reduction in
muscle strength begins in the first 24 hrs in response to the cell lesion provoked by eccentric
actions (6,16). This damage would be responsible for the rupture of the sarcolemma and t
tubules and the consequent failure of action potential conduction and excitation-contraction
coupling, which are the mechanisms responsible for the loss of muscle strength (21,25).
Furthermore, a difference was also observed between normalized peak torque and power.
Although the two variables decreased in the first 24 hrs, normalized peak torque remained
stable in the following 48 hrs, while power declined even more two days after intervention.
We hypothesize that power would be more sensitive in the assessment of muscle injury than
peak torque, given that alterations in any part of the dynamometric curve would alter its
values. Thus, although eccentric exercise caused muscle damage with the presence of pain
and a reduction in performance, there were no alterations in the electromyographic variable
(i.e., no differences in normalized RMS value between assessments or between groups).
The literature contains varied results in relation to electromyography after eccentric exercise.
Some studies demonstrate an increase in these variables while others show a decline
(21,25). Our findings, however, show no alterations, leading us to conclude that surface
electromyography is not sensitive enough to reveal alterations in injured muscle fibers (which
is likely due to their greater depth). It is also reasonable that the eccentric exercise damages
the non-contractile structures of the muscle that are not be detected by surface EMG.
CONCLUSIONS
Based on these findings, we conclude that cryotherapy and low-level laser therapy are not
sufficient to stimulate and treat the eccentric exercise-induced muscle damage. We
underscore that the results of the present study are limited to healthy, young and active
women who underwent eccentric exercise-induced muscle damage. In addition, we suggest
that future studies should include a longer period of intervention and a greater number of
revaluations.
66
ACKNOWLEDGMENTS
We thank all the volunteers that participated in this study, the CNPq and CAPES (National
Research Council) for financial support.
Address for correspondence: Jamilson S. Brasileiro, PhD, Universidade Federal do Rio
Grande do Norte, Departamento de Fisioterapia, Av. Senador Salgado Filho, 3000, Campos
Universitário, Lagoa Nova, Natal/RN, Brasil, CEP: 59078-970. Email:brasileiro@ufrnet.br
REFERENCES
1. Abad CCC, Ito LT, Barroso R, Ugrinowitsch C, Tricoli V. Effect of classical massage
on subjective perceived soreness, edema, range of motion and maximum strength
after delayed onset muscle soreness induced by exercise. Rev Bras Med Esporte.
2010;16:36-40. (In Portuguese: English abstract).
2. Ascensão A, Leite M. Rebelo AN, Magalhães S, Magalhães J. Effects of cold water
immersion on the recovery of physical performance and muscle damage following a
one-off soccer match. J Sports Sci. 2011;29(3):217-225.
3. Bailey DM, Erith SJ, Griffin PJ, Dowson A, Brewer DS, Gant N, Williams C. Influence
of cold-water immersion on indices of muscle damage following prolonged intermittent
shuttle running. J Sports Sci. 2007;25:1163-1170.
4. Bleakley CM, Hopkins JT. Is it possible to achieve optimal levels of tissue cooling in
cryotherapy? Phys Ther Rev. 2010;15(4):344-350.
5. Camargo MZ, Siqueira CPCM, Petri MCP, Nakamura FY, Lima FM, Dias IFL, Toginho
Filho DO, Ramos SP. Effects of light emitting diode (LED) therapy and cold water
immersion therapy on exercise-induced muscle damage in rats. Lasers Med Sci.
2012;27:1051-1058.
6. Clarkson PM, Hubal MJ. Exercise-induced muscle damage in humans. Am J Phys
Med Rehabil. 2002;81:52-69.
7. Connolly DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed onset
muscle soreness. J Strength Cond Res. 2003;17:197-208.
8. DeLuca CJ. The use of surface electromyography in biomechanics. J Appl Biomech.
1997;13:135-163.
9. Gregson W, Black MA, Jones H, Milson J, Morton J, Dawson B, Atkinson G, Green
DJ. Influence of cold water immersion on limb and cutaneous blood flow at rest. Am J
Sports Med. 2011;39:1316-1323.
67
10. Hermens, H.J., Freriks, B., Disselhorst-Klug, C. and Rau, G. Development of
recommendations for SEMG sensors and sensor placement procedures. J
Electromyogr Kinesiol. 2000;10(5):361-374.
11. Huang YY, Chen AC, Carroll JD, Hamblin MR. Biphasic dose response in low level
light therapy. Dose Response. 2009;7(4):358-383.
12. Huang YY, Sharma SK, Carroll J, Hamblin MR. Biphasic dose response in low level
light therapy - An update. Dose Response. 2011;9(4):602-618.
13. Kanda K, Sugama K, Hayashida H, Sakuma J, Kawakami Y, Miura S, Yoshioka H,
Mori H, Suzuki K. Eccentric exercise-induced delayed-onset muscle soreness and
changes in markers of muscle damage and inflammation. Exerc Immunol Rev. 2013;
19:72-85.
14. Law RY, Herbert RD. Warm-up reduces delayed-onset muscle soreness but cooldown does not: A randomized controlled trial. Aust J Physiother. 2007;53(2):91-95.
15. Leal Junior ECP, Lopes-Martins RAB, Vanin AA, Baroni BM, Grosselli D, De Marchi T,
Iversen VV, Bjordal JM. Effect of 830 nm low-level laser therapy in exercise-induced
skeletal muscle fatigue in humans. Lasers Med Sci. 2009;24:425-431.
16. Lewis PB, Ruby D, Bush-Joseph CA. Muscle soreness and delayed-onset muscle
soreness. Clin Sports Med. 2012;3:255-262.
17. Meireles GCS, Santos AM. Mecanismos de ação da laserterapia sobre componentes
do processo inflamatório. C&D Revista eletrônica da Fainor. 2010;3(1):30-40. (In
Portuguese: English abstract).
18. Munehiro T, Kitaoka K, Ueda Y, Maruhashi Y, Tsuchiya H. Establishment of an animal
model for delayed-onset muscle soreness after high-intensity eccentric exercise and
its application for investigating the efficacy of low-load eccentric training. J Orthop
Sci. 2012;17:244-252.
19. Nosaka K, Clarkson PM. Changes in indicators of inflammation after eccentric
exercise of the elbow flexors. Med Sci Sports Exerc. 1996;28(8):953-961.
20. Olsen O, Sjøhaug M, Beekvelt MV, Mork PJ. The effect of warm-up and cool-down
exercise on delayed onset muscle soreness in the quadriceps muscle: A randomized
controlled trial. J Hum Kinet. 2012;35:59-68.
21. Piitulainen H, Bottas R, Komi P, Linnamo V, Avela J. Impaired action potential
conduction at high force levels after eccentric exercise. J Electromyogr Kinesiol.
2010;20(5):879-887.
22. Pointon M, Duffield R, Cannon J, Marino FE. Cold application for neuromuscular
recovery following intense lower-body exercise. Eur J Appl Physiol. 2011;111:29772986.
68
23. Potter L, McCarthy C, Oldham J. Algometer reliability in measuring pain pressure
threshold over normal spinal muscles to allow quantification of anti-nociceptive
treatment effects. Int J Osteopath Med. 2006;9:113-119.
24. Sellwood KL, Brukner P, Williams D, Nicol A, Hinman R. Ice-water immersion and
delayed-onset muscle soreness: A randomised controlled trial. Br J Sports Med.
2007;41:392-397.
25. Takekura H, Fujinami N, Nishizawa T, Ogasawara H, Kasuga N. Eccentric
exercise‐ induced morphological changes in the membrane systems involved in
excitation-contraction coupling in rat skeletal muscle. J Physio. 2001;533(2):571-583.
26. Torres R, Ribeiro F, Duarte JA, Cabri JMH. Evidence of the physiotherapeutic
interventions used currently after exercise-induced muscle damage: Systematic review
and meta-analysis. Phys Ther Sport. 2012;13:101-114.
27. Uchida MC, Nosaka K, Ugrinowitsch C, Yamashita A, Martins Jr E, Moriscot AS, Aoki
MS. Effect of bench press exercise intensity on muscle soreness and inflammatory
mediators. J Sports Sci. 2009;27(5):499-507.
28. Wakefieldl E, Holtermannl A, Morkl PJ. The effect of delayed onset of muscle
soreness on habitual trapezius activity. Eur J Pain. 2011;15:577-583.
29. Zhou Y, Li Y, Wang R. Evaluation of exercise-induced muscle damage by surface
electromyography. J Electromyogr Kinesiol. 2011;21:356-362.
Disclaimer
The opinions expressed in JEPonline are those of the authors and are not attributable to
JEPonline, the editorial staff or the ASEP organization.