Effect of Whole-body Photobiomodulation on Muscular Performance Enhancement.
Phase: NA
Conditions: Sports Performance, Injury Prevention, Muscle Damage, Musculoskeletal Pain
Sponsor: Universidade Federal de Sao Carlos

 
 
  
 
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Document Type: Study Protocol and Statistical Analysis Plan 
NCT number: NCT05989815 
Document Date: 20-06-2025 
Prepared by: Italo Amaral de Oliveira, PT, MSc. 
Institution: Federal University of São Carlos (UFSCar), São Paulo, Brazil 
 
Title page 
 
Whole-body photobiomodulation for muscle performance enhancement, 
attenuation of muscular damage and delayed onset muscle soreness in 
professional soccer athletes – randomized sham-controlled trial 
 
 
 
 
 
 
Abstract 
Context: Photobiomodulation (PBM) has recently been applied in sports to enhance physical 
performance and mitigate muscle damage and delayed-onset muscle soreness (DOMS). These 
effects may be particularly relevant when PBM is delivered to large body areas through whole-
body irradiation. Objective: To evaluate the effects of whole-body PBM on muscle damage, 
DOMS, and muscle performance in professional soccer athletes undergoing a muscle damage 
induction protocol. Methods: A randomized, double-blind, sham-controlled trial was 
conducted with 30 professional soccer players from a Brazilian team. Participants were 
randomly allocated into three groups (n = 10 each): (a) PBM-post, (b) PBM-pre, and (c) PBM-
sham. Outcomes included serum creatine kinase (CK) levels, DOMS (numeric rating scale 
[NRS] and pain mapping [mapDOMS]), muscle performance (squat jump [SJ] and 
countermovement jump [CMJ]), and isometric dynamometry of the knee extensors. All groups 
received PBM irradiation (active or sham), followed by the muscle damage induction protocol, 
and subsequent PBM irradiation (active or sham). Assessments were performed at baseline, 24 
h, 48 h, and 72 h post-induction. Results: CK levels significantly increased (p < 0.05) at 24–72 
h in the sham group and at 24–48 h in the PBM-post group. In contrast, the PBM-pre group 
showed no significant increase (p > 0.05) across 24–72 h. For DOMS (NRS), the sham group 

 
 
  
 
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reported significant increases (p < 0.05) from 24–72 h, the PBM-pre group only at 24 h, and 
the PBM-post group at no time point. DOMS assessed by mapDOMS showed no significant 
changes (p > 0.05) across groups or time points. No significant differences (p > 0.05) were 
observed in muscle performance outcomes among groups. Conclusion: Pre-exercise PBM 
provided protective effects against muscle damage (lower CK) and reduced DOMS at 48–72 h, 
while post-exercise PBM reduced DOMS consistently at all time points (24–72 h). Neither pre- 
nor post-exercise PBM improved or worsened muscle performance.  
 
Keywords: CK; DOMS; light-emitting diode; low-level laser therapy; recovery  
 
 
 

 
 
  
 
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Methods 
The study was characterized as a randomized, double-blind, Sham-controlled trial and 
followed CONSORT guidelines. All procedures were approved by the Research Ethics 
Committee of the Federal University of São Carlos (CAAE 62842522.2.0000.5504) and 
registered at ClinicalTrials.gov (NCT05989815). All participants were informed about the 
study's objectives and signed an informed consent form. 
 
Sample Characterization 
Criteria for Eligibility 
Male individuals between 18 and 35 years of age, practicing professional soccer and 
undergoing training at least 5 times per week, were selected. Individuals with any impediment 
to physical activity or dysfunctions affecting the neuromuscular system were excluded. Data 
collection took place at the Desportivo Brasil Football Club in Porto Feliz, SP. The sample 
consisted of team members, with a set number of 30 athletes established for the sample.  
 
Training Routine Description 
The athletes underwent daily training sessions throughout the week, following the club's 
training routine as described on Table 1. 
Table 1 – Weekly Training Routine 
Period 
Monday 
Tuesday 
Wednesday 
Thursday 
Friday 
Saturday 
Morning 
Rest/Downtime 
Gym 
(strength 
training 
– 30 
min) + 
Field 
(aerobic 
activity 
60 min) 
Gym (strength 
training – 30 
min) + Field 
(aerobic 
activity 90 
min) 
Gym 
(strength 
training – 
30 min) 
Field (aerobic 
activity 45 - 60 
min) 
Training 
game or 
Official 
Game  
Afternoon 
Gym (strength 
training 30 
min) + Field 
(aerobic 
Field 
(aerobic 
activity 
60 min) 
Rest/Downtime 
Field 
(aerobic 
activity 
60 min) 
Downtime/Rest 
Rest 

 
 
  
 
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activity 45 
min) 
 
Randomization and Allocation Concealment 
The randomization was conducted using the website randomization.com, and the 
participants were allocated into three groups of ten individuals each. To ensure allocation 
concealment, sealed opaque envelopes were used, containing the randomly assigned 
interventions: PBM-post, PBM-pre, and PBM-Sham. Only one researcher (therapist 1) was 
involved in this process, being responsible for applying PBM to all participants. This researcher 
was blinded to the other assessments in the study, which were conducted by therapist 2. 
Participants were unaware of which intervention was applied during the study. 
 
Study Design 
The selected individuals were allocated into 3 equal groups and randomized according 
to the type of intervention: 
• PBM Post-Exercise Group (PBM-Post): Submitted to the protocol of muscle 
damage induction and Sham photobiomodulation pre-exercise, followed by 
active post-exercise photobiomodulation. 
• PBM Pre-Exercise Group (PBM-Pre): Submitted to the protocol of muscle 
damage induction and active pre-exercise photobiomodulation, followed by 
Sham post-exercise photobiomodulation. 
• PBM Sham Group (PBM-Sham): Submitted to the protocol of muscle damage 
induction and Sham photobiomodulation both pre and post-exercise. 
 
On the 1st day, all individuals were assessed using the one-repetition maximum (1RM) 
test to measure the loads for the muscle damage induction protocol. On the 2nd day (24 hours 
after the 1RM test), all groups underwent initial assessment tests (T1), which included: a) 
Anamnesis through a questionnaire. b) Measurement of blood levels of creatine phosphokinase 
(CK) using the Roche Hitachi 917 biochemical analyzer. c) Delayed onset muscle soreness 
(DOMS) using the numeric rating scale (NRS) and the pain location area using the pain map 
(mapDOMS). d) Muscle performance tests on a jump platform (Squat Jump test – SJ and 
Counter Movement Jump - CMJ). e) Dynamometry of the dominant knee extensor muscles with 
the Manual Muscle Test equipment (Lafayette Instrument). 

 
 
  
 
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Also on the 2nd day, the groups were irradiated with whole-body PBM (Sham or active) 
followed by the muscle damage induction protocol. Sequentially, participants underwent 
vertical jump and dynamometry tests (T2). Ten minutes after T2, participants were irradiated 
with active PBM or Sham according to their allocation in the groups. 
Finally, on the 3rd, 4th, and 5th days, participants were reassessed (T3) for CK, DOMS, 
SJ/CMJ, and Dynamometry at 24h, 48h, and 72h after the muscle damage induction protocol. 
The study design is summarized in Figure 1. 

 
 
  
 
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Figure 1.  Study Flowchart 
 

 
 
  
 
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Assessments/Measurement Instruments 
a) Anamnesis: 
In the initial assessment, the volunteer's name, age, medical history, duration of sports 
practice, weight, height, and calculation of Body Mass Index (BMI) were collected. 
Additionally, the participants' skin phototype (Fitzpatrick scale) was determined.  
 
b) Measurement of Blood Levels of Creatine Phosphokinase (CK):  
The analyses were carried out by a clinical analysis laboratory (LabCenter Diagnostics 
Integrates, Itu, SP, Brazil) in a blinded manner, meaning they were unaware of the therapies 
applied to each participant. Briefly, the athletes rested for about 10 minutes in a seated position 
before blood collection. The material was labeled, and the forearm was aseptically cleaned with 
70% alcohol. Using a 25x8 multiple collection needle, a vein in the antecubital fossa was 
punctured, and a 5 ml vacuum collection gel tube was inserted for CK analysis. Subsequently, 
the measurement was performed on a Roche Hitachi 917 biochemical analyzer using enzymatic 
methodology. A biomedical professional from the laboratory, not involved in the study, 
assessed the results in U/L. This analysis was conducted at baseline (T1), i.e., before the muscle 
damage induction protocol, and at 24h, 48h, and 72h after (T3). 
 
c) Delayed Onset Muscle Soreness (DOMS):  
The perception of Delayed Onset Muscle Soreness (DOMS) was assessed using the 
Numeric Rating Scale (NRS). The scale was numbered from 0 to 10, where 0 indicated the 
absence of muscle pain, and 10 indicated maximum muscle pain during a maximum voluntary 
contraction for knee extension in a seated position. The choice of NRS was based on its 
reliability and responsiveness, as reported by 26, 27. 
The location and extent (percentage area) of DOMS were assessed using a pain map 
(mapDOMS) using a body chart representing the human body from different views (frontal, 
lateral, and dorsal). Two variables, the extent and location of pain, were used following the 
approach proposed by 28. Briefly, the areas where athletes reported pain were marked and later 
measured in cm. The painted area was then calculated using ImageJ software, an open-source 
software created by Wayne Rasband at the National Institutes of Health (NIH) in 1987 29. 
Finally, the painted area was calculated as a percentage (%) of the total area related to the lower 
limbs. 
d) Muscle Performance Tests on Jump Platform: 

 
 
  
 
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Vertical jumps were performed twice, and the mean value was used for the analyses. 
Initially, the athletes warmed up on a cycle ergometer for 5 minutes at over 90 rpm. To perform 
the vertical jumps on a jump platform (Cefise, SP, Brazil), participants kept their hands on their 
hips and received verbal commands to initiate the jumps. For the Squat Jump (SJ) test, the 
athlete started from a semi-squat position, maintaining this position for approximately 3 
seconds before takeoff. For the Counter Movement Jump (CMJ) test, the athlete was instructed 
to initiate a downward movement (squatting) from a standing position, which was immediately 
followed by an upward movement leading to takeoff 30. The mean value of two jumps was used 
for subsequent analyses. 
 
e) Muscle Performance Test of Knee Extensors by Dynamometry: 
The manual dynamometry test was performed on the individual's dominant leg, as 
indicated by a previous study 31, using a portable dynamometer (Manual Muscle Test - 
Lafayette Instrument). The athlete was positioned in a seated position with legs hanging off the 
edge of a table, keeping the knee at approximately 90° of flexion, as illustrated in figure 2. All 
participants performed two maximum voluntary contractions, verbally encouraged during 
execution for five seconds, with a one-minute interval between contractions. The mean value, 
in kilogram-force (kgf), of the two contractions was used for analysis. 
 
 
Figure 2. Positioning of the adapted test from 31. A) The test was conducted with the participant in a seated 
position, legs hanging off the edge of a table, maintaining the knee at approximately 90° of flexion. To minimize 
posterior thigh discomfort, a small wedge-shaped cushion was placed on the posterior aspect of the distal thigh, 
and a standard gait belt was used to stabilize the thighs on the table. During the test, participants kept their arms 
crossed to isolate the quadriceps muscle. A foam pad was positioned on the anterior aspect of the leg, where the 
dynamometer was placed, situated 5 cm proximal to the lateral malleolus, with the strap wrapped around a pad 
and the dynamometer secured against the leg of the table (B). Additionally, a small elastic wrap was placed 
between the leg of the table and the triceps surae muscle to minimize belt slack (A).  

 
 
  
 
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f) 1RM Test 
The 1RM (One Repetition Maximum) Test aimed to assess the maximum load an 
individual could use during the execution of a specific exercise. This test was conducted for the 
exercises included in the muscle damage induction protocol. Initially, a maximum load close to 
what was expected for the participant to endure was chosen. The test concluded when the 
individual completed only one full repetition of the movement with the determined load 32. Five 
attempts were made, with a 3-minute interval between each attempt.  
 
Photobiomodulation (PBM) Protocol 
Photobiomodulation (PBM) was performed using a whole-body irradiation system 
(Joovv Elite System), consisting of 6 panels with 76 red LEDs (660±10nm) and 74 infrared 
LEDs (850±10nm), totaling 900 LEDs in an area of 12,193 cm² (Figure 3). Athletes were 
positioned in front of the device (20 cm away from the thigh region), wearing only swim shorts 
to expose the muscle area of the lower limbs, trunk, and arms, with a total irradiation time of 
20 minutes (600 seconds for the anterior region, 600 seconds for the posterior region). The 
effective PBM dose applied to each region (anterior and posterior) was 48.97 J/cm², with an 
irradiance of 81.62 mW/cm². The Sham condition consisted of irradiation with the device 
without effective light emission. An investigator not involved in data collection and analysis 
performed all irradiations (Sham and effective). The order of treatments was determined 
through simple balanced randomization, as shown in Figure 1. 
The application of PBM (effective and/or Sham) was performed after the muscle 
performance tests (protocol T1), in the pre and post-protocol of muscle damage induction, as 
illustrated in Figure 1. In all conditions, participants were blindfolded during treatments. All 
PBM parameters were measured beforehand using a power and energy meter (PM100D, 
Thorlabs Inc.) equipped with the S130C light sensor (area of 0.70 cm²) and are described in 
Table 2. 
 

 
 
  
 
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Figure 3. Whole-Body Photobiomodulation using the Joovv Elite System, containing LEDs (light-emitting diodes) 
in the infrared range (850±10nm) and red range (660±10nm). A. Frontal irradiation; B. Dorsal irradiation.  
 
Table 2 – Irradiation Parameters 
Table 2. Irradiation Parameters 
Manufacturer 
Joovv 
Wavelength 
Red 
Infrared 
Central wavelength (nm) 
660 ±10 
850 ± 10 
Number of LEDs (6 panels) 
456 
444 
Beam area (cm2) per LED 
2.54 
2.54 
Operational mode 
Continuous 
Continuous 
Body distance (cm) 
20 
20 
Radiant power (mW): 
31.85 
25.29 
Power density (mW/cm2) 
45.50 
36.13 
Irradiation time (front) (s) 
600 
600 
Irradiation time (back) (s) 
600 
600 
Energy density (front) (J/cm2) 
27.30 
21.67 
Energy density (back) (J/cm2) 
27.30 
21.67 
Total average radiant power (mW) 
(31.85 + 25.29) = 57.14 
Total average power density (mW/cm2) 
(45.50 + 36.13) = 81.62 
Total average energy density (J/cm2) 
(27.30 + 21.67) = 48.97 
Total area of six panels (cm2) 
12,193 

 
 
  
 
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Distance from power meter (cm) 
20 
20 
Area sensor power meter (cm2) 
0.70 
0.70 
 
 
Muscle Damage Induction Protocol 
The adopted muscle damage induction protocol followed the recommendations of 
ACSM 33 for trained individuals, which consists of 8-12 repetitions above 70% of the one-
repetition maximum (1RM) with 1 minute of rest between sets and 2 minutes between exercises. 
The protocol consisted of 3 sets of 10 repetitions for each exercise, with emphasis on the 
eccentric phase of the exercise to induce microlesions in the muscle tissue, and it is described 
in Table 3. 
 
Table 3 – Muscle damage induction protocol 
Table 3. Muscle damage induction protocol 
Exercise 
Illustration 
Sets 
Repetitions 
Total 
Repetitions 
Squat 
 
3 
10 
30 
Leg Extension 
 
3 
10 
30 
Stiff 
 
3 
10 
30 
Hip Extension 
(Cable) 
 
3 
10 
30 

 
 
  
 
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Deadlift 
 
3 
10 
30 
Copenhagen 
 
3 
10 
30 
Nordic Curl 
 
3 
10 
30 
Leg Press 45° 
 
3 
10 
30 
3.7 Sample Size Calculation 
The sample size (n=30) was calculated a priori using GPower 3.1 software. It considered 
3 groups, 4 assessment time points (immediately after the muscle damage induction protocol, 
and at 24h, 48h, and 72h after), a minimum effect size of 0.25, a test power of 80%, and a 
significance level of 5%, for comparisons through two-way repeated measures analysis of 
variance. 
 
STATISTICAL ANALYSIS PLAN (SUMMARY) 
Primary endpoint: Serum CK levels (U/L) over time. 
Secondary endpoints: DOMS (NRS and mapDOMS), SJ and CMJ jump heights (cm), 
and isometric knee extensor force (kgf). 
Statistical tests: 
- Normality (Shapiro–Wilk) and homogeneity (Levene). 
- Two-way repeated measures ANOVA with Tukey post hoc (parametric). 
- Friedman and Kruskal–Wallis (nonparametric when assumptions not met). 
- Significance level: α = 0.05. 
Software: IBM SPSS Statistics v20.0. 

 
 
  
 
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Data Analysis 
Data analysis was conducted by a researcher blinded to participant group allocation. The 
primary outcome of the study was considered the muscle damage measured by CK levels. 
The data were descriptively analyzed using mean and standard deviation. The 
independent variables were the experimental conditions (Sham, PBM-pre, and PBM-post) and 
assessment times pre, 24h, 48h, 72h after the muscle damage induction protocol. Normality and 
homoscedasticity assumptions were tested beforehand using the Shapiro-Wilk W Test and 
Levene test, respectively. The dependent variables included CK, DOMS, height of jumps in 
Squat Jump (SJ) and Counter Movement Jump (CMJ), and isometric manual dynamometry of 
the femoral quadriceps (kgf). 
Two-way repeated measures analysis of variance (ANOVA) was conducted 
(considering pre, 24h, 48h, and 72h after the muscle damage induction protocol) followed by 
Tukey's post hoc test when the data showed normal distribution and variance homogeneity. In 
cases where the data did not present normal distribution, a logarithmic transformation (log10) 
was adopted, and normality and variance homogeneity were verified again for parametric tests. 
If the data did not meet the assumptions of normality and variance homogeneity, non-parametric 
tests such as Friedman's ANOVA (intragroup analyses) and Kruskal-Wallis (intergroup 
analyses) were employed. The significance level was set at 5%. Statistical analysis was 
performed using a statistical software (SPSS Statistics for Windows version 20.0, IBM, 
Chicago, IL, United States). 
 
RESULTS  
Thirty male professional football players (high level) from the same team were recruited 
and completed all procedures of this study. Therefore, there were no dropouts, and intention-
to-treat analysis was not necessary. Anthropometric data are described in Table 4. No adverse 
effects were reported during the study. 
Table 4. Anthropometric data of the investigated athlete sample. Values in mean (± standard deviation): 
Groups Age (years) 
Body Mass (kg)  BMI 
(kg/m2) 
Years of Practice 
Fitzpatrick 
Phototype 
Sham 
18.70 (±0.82) 76.03 (±13.27) 
22.62 (±2.10) 9.60 (±1.77) 
Type I: 2, 
Type II: 0, 
Type III: 3, 

 
 
  
 
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Type IV: 3, 
Type V: 2 
PBM-
pre 
20.50 (±4.30) 70.43 (±4.90) 
23.07 (± 
0.94) 
11.30 (±3.74) 
Type I: 2, 
Type II: 2, 
Type III: 3, 
Type IV: 2, 
Type V: 1 
PBM-
post 
21.22 (±7.44) 76.13 (±8.03) 
23.48 (±1.73)  11.44 (±3.46) 
Type I: 3, 
Type II: 5, 
Type III: 1, 
Type IV: 1, 
Type V: 0 
 
Creatine Kinase (CK) 
The CK data in U/L did not follow a normal distribution, and a logarithmic 
transformation (log10) was applied. After the transformation, the data showed a normal 
distribution and homogeneity of variances for conducting parametric tests. Repeated measures 
ANOVA revealed a moment interaction (F2,27 < 0.001) and a moment versus treatment 
interaction (F2,27 < 0.001). Tukey's post hoc test identified significant differences as shown in 
the table below:    
Table 5. Mean values (±standard deviation) of creatine phosphokinase (CK) in U/L for the Sham, PBM-pre, and 
PBM-post groups at pre, 24h, 48h, and 72h after the muscle damage induction protocol: 
Groups 
CK pre 
CK 24h 
CK 48h 
CK 72h 
Sham 
289.2 (±209.94) 
661.5 (±477.24)* 
491.6 (±285.44)* 
523.2 (±343.15)* 
PBM-pre 
249.2 (±112.28) 
372.7 (±190.58) 
424.2 (±248.90) 
392.6 (±215.23) 
PBM-post 
287.8 (±199.09) 
794.5 (±763.80)* 
631.2 (±512.08)* 
271.44 (±133.27) 
Abbreviations: PBM (photobiomodulation); CK (creatine phosphokinase). * p-value < 0.05 in two-way repeated 
measures ANOVA followed by Tukey's post hoc analysis. 
 
Compared to the pre-moment of the muscle damage induction protocol, there was a 
significant increase in CK levels in the Sham group (p = 0.001) and PBM-post group (p = 0.001) 
at the moment 24h after, while in the PBM-pre group the increase was not significant (p = 
0.285). When comparing the pre-moment of the muscle damage induction protocol to 48h after, 
the Sham group had a significant increase in CK (p = 0.028), as well as the PBM-post group (p 
= 0.015), while the PBM-pre group did not show a significant increase (p = 0.131). In the 

 
 
  
 
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comparison between the pre-moment of the muscle damage induction protocol and 72h after, 
only the Sham group had a significant increase in CK (p = 0.010), while the PBM-pre and PBM-
post groups did not show significant increases (p = 0.506; p = 1.000, respectively). In the 
comparison between groups for the respective CK assessment moments, there were no 
significant differences (p > 0.05). The graphical representation of these results is in Figure 4. 
 
Figure 4. Results for creatine phosphokinase (CK) at the evaluated time points (pre-moment of muscle damage 
induction protocol, 24h, 48h, and 72h after), and experimental groups (Sham, PBM-pre, PBM-post). Values 
presented in both log10-transformed and raw formats. Data expressed as mean (± standard error).  
 
Delayed Onset Muscle Soreness (DOMS) measured by the Numeric Rating Scale (NRS). 
Repeated measures ANOVA revealed a moment interaction (F2,27 < 0.001) and a moment 
versus treatment interaction (F2,27 = 0.044). Tukey's post hoc analysis identified significant 
differences as shown in Table 6. 
Table 6. Mean values (± standard deviation) of Delayed Onset Muscle Soreness (DOMS) measured by the 
Numeric Rating Scale (NRS) for the Sham, PBM-pre, and PBM-post groups at pre, 24h, 48h, and 72h after the 
muscle damage induction protocol: 
Groups 
DOMS (NRS) 
pre 
DOMS (NRS) 
24h 
DOMS (NRS) 
48h 
DOMS (NRS) 
72h 
Sham 
0.60 (±1.26) 
5.70 (±2.05)* 
4.20 (±2.39)* 
3.20 (±2.78)* 

 
 
  
 
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PBM-pre 
1.20 (±1.61) 
3.80 (±2.74)* 
2.80 (±1.54) 
1.70 (±1.82) 
PBM-post 
1.30 (±2.11) 
3.00 (±2.00) 
2.40 (±1.83) 
2.10 (±1.72) 
Abbreviations: PBM (photobiomodulation); DOMS (Delayed Onset Muscle Soreness); NRS (Numeric Rating 
Scale); * p-value < 0.05 in two-way repeated measures ANOVA followed by Tukey's post hoc analysis. 
 
Compared to the pre-moment of the muscle damage induction protocol, there was a 
significant increase in DOMS measured by the NRS in the Sham group (p < 0.001) and PBM-
pre group (p = 0.027) at the moment 24h after, while the PBM-post group did not show a 
significant increase (p = 0.460). In the comparison between the pre-moment of the muscle 
damage induction protocol and 48h after, the Sham group had a significant increase in DOMS 
(NRS) (p < 0.001), while the PBM-pre and PBM-post groups did not show significant increases 
(p = 0.555; p = 0.933, respectively). In the comparison between the pre-moment of the muscle 
damage induction protocol and 72h after, only the Sham group had a significant increase in 
DOMS (p = 0.027), while the PBM-pre and PBM-post groups did not show significant increases 
(p = 0.999; p = 0.993, respectively). In the comparison between groups for the respective 
moments of DOMS (NRS) assessment, there were no significant differences (p > 0.05). The 
graphical representation of these results is in Figure 5. 
 
Figure 5. Results for Delayed Onset Muscle Soreness (DOMS), measured by the Numeric Rating Scale (NRS) at 
the evaluated time points (pre-moment of muscle damage induction protocol, 24h, 48h, and 72h after), and 
experimental groups (Sham, PBM-pre, PBM-post). Data expressed as mean (± standard error).  
 
DOMS measured by Pain Map (mapDOMS) 
The mapDOMS data did not follow a normal distribution, and a logarithmic 
transformation (log10) was applied. After the transformation, the data exhibited a normal 
distribution and homogeneity of variances, allowing for the use of parametric tests. Repeated 

 
 
  
 
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measures ANOVA did not reveal a moment interaction (F2,27 = 0.302) and moment versus 
treatment interaction (F2,27 = 0.423). As there was no significant interaction, Tukey's post hoc 
analysis was not conducted. The means (± percentage standard deviation) of mapDOMS are 
presented in Table 7.    
Table 7. Mean values (± percentage standard deviation) of mapDOMS for the Sham, PBM-pre, and PBM-post 
groups at pre, 24h, 48h, and 72h after the muscle damage induction protocol: 
Groups 
mapDOMS pre 
mapDOMS 24h mapDOMS 48h mapDOMS 72h 
Sham 
2.99% (±5.16%) 9.55% (±7.78%) 
8.51% (±6.55%) 5.97% (±7.16%) 
PBM-pre 
0.96% (±0.83%) 5.42% (±7.66%) 
3.73% (±3.41%) 3.85% (±3.71%) 
PBM-post 1.53% (±2.23%) 4.88% (±5.64%) 
3.54% (±2.81%) 3.08% (±3.15%) 
Abbreviations: PBM (photobiomodulation); mapDOMS (Delayed Onset Muscle Soreness Map). 
 
Figure 6 shows an example of the graphical representation of the map used during data 
collection for mapDOMS. 
 
Figure 6. Pain Map (mapDOMS) of the experimental groups at pre, 24h, 48h, and 72h after. 
 
Squat Jump (SJ) 
A repeated measures ANOVA did not reveal a moment interaction (F2,27 = 0.177) and 
moment versus treatment interaction (F2,27 = 0.834). As there was no significant interaction, 

 
 
  
 
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Tukey's post hoc analysis was not conducted. The means and standard deviation for SJ are 
presented in Table 8. 
Table 8. Mean values (± standard deviation) of SJ (cm) for the Sham, PBM-pre, and PBM-post groups at pre, 
immediately after, 24h, 48h, and 72h after the muscle damage induction protocol: 
Groups 
SJ pre 
SJ post 
SJ 24h 
SJ 48h 
SJ 72h 
Sham 
39.80 (±4.60) 
39.65 (±4.20) 
38.56 (±4.09) 40.10 (±3.89) 
39.12 (±4.13) 
PBM-pre 
39.96 (±7.40) 
40.42 (±7.54) 
38.91 (±5.45) 39.63 (±6.94) 
40.32 (±7.08) 
PBM-post 37.04 (±3.74) 
38.39 (±4.68) 
37.38 (±5.22) 38.18 (±4.07) 
38.20 (±3.77) 
Abbreviations: PBM (photobiomodulation); SJ (Squat Jump). 
 
Counter Movement Jump (CMJ) 
The repeated measures ANOVA did not reveal a moment interaction (F2,27 = 0.166) and 
moment versus treatment interaction (F2,27 = 0.127). As there was no significant interaction, the 
Tukey post hoc analysis was not conducted. The means and standard deviations for the Counter 
Movement Jump (CMJ) are presented in Table 9. 
Table 9. Mean values (± standard deviation) of Counter Movement Jump (CMJ) in centimeters for the Sham, 
PBM-pre, and PBM-post groups at pre, immediately after, 24h, 48h, and 72h after the muscle damage induction 
protocol: 
Groups 
CMJ pre 
CMJ post 
CMJ 24h 
CMJ 48h 
CMJ 72h 
Sham 
40.86 (±4.68) 
40.49 (±4.16) 
39.94 (±3.64) 
41.11 (±4.16) 
40.35 (±4.76) 
PBM-pre 
41.17 (±7.09) 
42.51 (±7.66) 
40.93 (±5.82) 40.21 (±6.22) 
42.98 (±6.86) 
PBM-post 38.29 (±3.55) 
39.57 (±3.89) 
39.30 (±4.59) 39.64 (±4.70) 
39.99 (±4.60) 
Abbreviations: PBM (photobiomodulation); CMJ (Counter Movement Jump). 
 
Dynamometry  
A repeated measures ANOVA revealed a significant moment interaction (F2,27 = 0.034). 
However, there was no significant interaction between moment and treatment (F2,27 = 0.486). 
Since there was a significant interaction for moment, Tukey's post hoc analysis was conducted. 
However, no significant differences were found (p > 0.05). The means and standard deviations 
for dynamometry (kgf - kilogram-force) are presented in Table 10. 
Table 10. Mean values (± standard deviation) of dynamometry (kgf) for the Sham, PBM-pre, and PBM-post 
groups at pre, immediately after, 24h, 48h, and 72h after the muscle damage induction protocol: 
Groups 
Dynamo pre 
Dynamo post 
Dynamo 24h 
Dynamo 48h 
Dynamo 72h 
Sham 
50.41 (±14.98) 
53.83 (±10.38) 
55.58 (±10.45) 
56.46 (±11.14) 
54.71 (±9.61) 
PBM-pre 
53.87 (±9.81) 
58.02 (±7.64) 
53.45 (±8.63) 
56.26 (±10.95) 
57.75 (±7.50) 

 
 
  
 
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PBM-post 
59.53 (±8.87) 
58.67 (±8.80) 
59.19 (±8.34) 
64.38 (±8.21) 
63.18 (±11.32) 
Abbreviations: PBM (photobiomodulation); Dynamo (dynamometry). 
 
 
FUNDING   
 
This study did not receive external financial support. All study expenses were self-
funded by the principal investigator.