In vivo attenuation profile of 660 nm and 830 nm wavelengths on human elbow skin and calcaneus tendon of different phototypes.

Physical factors and tissue characteristics determine the transmission of light through tissues. One of the significant clinical limitations of photobiomodulation is the quantification of fluence delivered at application sites and optical penetration depth in vivo. There is also the difficulty of determining the distances of the application points to cover a uniformly irradiated area. Thus, the aim was to evaluate in vivo the influence of melanin on light transmission of the 660 nm and 830 nm laser wavelengths on skin and tendon. Thirty young individuals of both sexes were recruited, divided into two groups based on melanin index, and submitted to photobiomodulation protocols in the posterior region of the elbow (skin-skin) and the calcaneus tendon (skin-tendon-skin). The irradiation area was evaluated using a homemade linear array of five sensors. We found significant transmission power values for different melanin indexes and wavelengths (p<0.0001). Also, different equipment can generate significant differences in the transmitted power at an 830-nm wavelength. Average scattering values are 14 mm and 21 mm for 660 nm, in higher and lower melanin index, respectively. For 830 nm, values of 20 mm and 26 mm are indicated. Laser light transmission in vivo tissues is related to wavelength, beam diameter, tissue thickness, and composition, as well as melanin index. The 830-nm laser presents higher light transmission on the skin than 660 nm. The distances between the application points can be different, with higher values for 830 nm than 660 nm.

15-item Roland-Morris disability questionnaire for general pain (RMDQ-g): Structural validity and criterion validity on Brazilian patients with chronic pain.

BACKGROUND: Roland-Morris Disability Questionnaire for general pain (RMDQ-g) is an instrument adapted to assess disability in patients with pain in any region of the body. OBJECTIVE: To perform the structural and criterion validity of the RMDQ-g in Brazilian patients with chronic pain. DESIGN: A cross-sectional study. METHODS: We included native speakers of Brazilian Portuguese, of both sexes, aged ≥18 years, with pain for at least 3 months in any region of the body. Participants eligible for the study responded to an online form containing personal and clinical data, and assessment instruments. We used the confirmatory factor analysis and considered the following fit indices: chi-square/degree of freedom (DF), comparative fit index (CFI), Tucker-Lewis index (TLI), root mean square error of approximation (RMSEA). In the comparison between models, we considered the structure with the lowest values of the Akaike information criterion (AIC) and sample-size adjusted Bayesian information criterion (SABIC). We assessed criterion validity via Spearman's correlation coefficient (rho) to correlate the long and short versions. RESULTS: The study consisted of 297 participants with chronic pain. The main sites of pain were the lumbar region (40.7%), thoracic (21.5%), and neck (19.5%). Mean pain intensity was greater than 5 points. The 24-item long version and the 15-item short version had adequate fit indices (chi-square/DF ≤ 1.77, CFI ≥0.97, TLI ≥0.96, and RMSEA ≤0.05). However, when comparing structures, the short version was the most appropriate because it had the lowest values of AIC (2562.05) and SABIC (2577.72). Criterion validity was acceptable (rho = 0.94) and internal consistency as well (Cronbach's alpha = 0.87). CONCLUSION: The structural validity and criterion validity of the RMDQ-g with one domain and 15 items is the most appropriate version and should be considered in the clinical environment and in research for measuring disability in patients with chronic pain in any region of the body.

Intrareliability and Interreliability of Low-Cost Devices to Measure Skin Tone, Moisture, and Oiliness.

OBJECTIVE: To evaluate the intraexaminer and interexaminer reliability of low-cost commercial devices to measure skin tone, moisture, and oiliness; determine associations with the Fitzpatrick Scale; and compare results with those of widely used commercial equipment. METHODS: Researchers bilaterally collected a total of 36 samples from 18 participants. For data acquisition, two experienced raters were considered for skin index assessment. Evaluations were conducted independently, with measurements taken at two different times with an interval between them, thus enabling intrarater and interrater reliability measures. The measurements were made with two low-cost devices and compared with those acquired using standard equipment for such analyses. RESULTS: For the intraexaminer reliability results, the authors observed intraclass correlation coefficient ranging from moderate to high reliability between these tools (0.747-0.971). Regarding interexaminer reliability, intraclass correlation coefficient ranging from moderate to high (0.541-0.939) were observed. For the results of the correlations, a moderate to a large association was observed for skin tone. However, a small association for moisture was observed among the tools. CONCLUSIONS: Evaluations of skin tonality, oiliness, and moisture showed moderate to excellent intrareliability and interreliability. These methods can be applied in different environments, especially clinics, because of their low cost and ease of use.

Optical Properties of Human Skin Phototypes and Their Correlation with Individual Angle Typology.

Objective: This study aims to correlate human skin phototypes with complete optical characterization (absorption, scattering, effective attenuation, optical penetration, and albedo coefficients) based on individual typology angle (ITA) values and colorimetric parameters. Methods: A colorimeter was used to group 12, fresh, ex vivo human skin samples according to their phototype; the CIELAB color scale and ITA values were employed. An integrating sphere system and the inverse adding-doubling algorithm were applied during optical characterization, conducted from 500 to 1300 nm. Results: On the basis of ITA values and their classification, the skin samples were separated into six groups: two intermediates, two tan, and two brown. In the visible range, for lower ITA values (darker skins), the absorption and effective attenuation coefficient parameters increased, whereas the albedo and depth penetration parameters decreased. In the infrared region, all the phototypes had similar parameters. The scattering coefficient was similar for all the samples and did not change with ITA values. Conclusions: ITA analysis, a quantitative method, showed that the human skin tissue's optical properties and pigmentation colors were highly correlated.

Laser light sources for photobiomodulation: The role of power and beam characterization in treatment accuracy and reliability.

PURPOSE: Daily clinical use of therapeutic light sources can lead to changes in light emission stability with potentially significant consequences for usage in photomedicine treatment. The aim of this study was to evaluate the average and maximum power and to describe the beam diameter of different low-power laser photobiomodulation devices in clinical use in Brazil. METHODS: The power and light-emitting beam diameter of twenty-four therapeutic devices with an average age of 11±5 years, with an average weekly use of fewer than thirty minutes, were measured. RESULTS: The analyzed power varied between 2% to 134% of the values declared by the manufacturers. Differences in beam diameter of between 38% and 543% of the nominal values were also observed. It is also noteworthy that even between the same brand and model, differences in diameter were obtained. Finally, differences were observed in the power output after one and three minutes of sequential emission for 830 nm and 904 nm (p < 0.05), but not when comparing the difference between wavelengths in factor time. CONCLUSION: There is a need for a shared effort on the part of laser manufacturers to improve standardization and consistency of laser output power and beam diameters. At the same time, medical laser operators should also consider development of standardized protocols for maintenance and monitoring equipment performance over time to correct for fluctuations that could ultimately impact on treatment outcomes.

Correlation between skin temperature in the lower limbs and biochemical marker, performance data, and clinical recovery scales.

The aim of this study was to evaluate the correlation between tools commonly used in the detection of physiological changes, such as clinical complaints, a biochemical marker of muscle injury, and performance data during official matches, with infrared thermography, which has been commonly used in the possible tracking of musculoskeletal injuries in athletes. Twenty-two athletes from a professional soccer club (age 27.7 ± 3.93 years; BMI 24.35 ± 1.80 kg/cm2) were followed during the season of a national championship, totaling 19 matches with an interval of 7 days between matches. At each match, the athletes used a Global Positioning System (GPS) device to collect performance data. Forty-eight hours after each match, every athlete's perception of recovery, fatigue, and pain was documented. Blood was collected for creatine kinase (CK) analysis, and infrared thermography was applied. Only athletes who presented pain above 4 in either limb were included for thermographic analysis. Each thermographic image was divided into 14 regions of interest. For statistical analysis, we included only the images that showed differences ≥ 1° C. Data normality was verified by the Kolmogorov-Smirnov test with Dallal-Wilkinson-Lilliefors correction. We used the Pearson correlation coefficient to verify the correlation between infrared thermography and the biochemical marker, performance data, and clinical recovery scales. No correlation was observed between mean skin temperature and blood CK levels, pain level, perception of recovery, and fatigue perception (r <0.2, p>0.05). Thus, infrared thermography did not correlate with CK level, pain, fatigue perception, or recovery, nor with performance variables within the field.

Photobiomodulation in Sciatic Nerve Crush Injuries in Rodents: A Systematic Review of the Literature and Perspectives for Clinical Treatment.

Objective : The aim of the study was to perform a literature review to analyze the effect of photobiomodulation in experimental studies on peripheral nerve regeneration after sciatic nerve crush injury in rodents. Methods: A bibliographic search was performed in the electronic databases, including MEDLINE (PubMed), SCOPUS, and SciELO, from 2008 to 2018. Results: A total of 1912 articles were identified in the search, and only 19 fulfilled all the inclusion criteria. Along with the parameters most found in the manuscripts, the most used wavelengths were 660 nm and 830 nm, power of 30 and 40 mW, and energy density of 4 and 10 J/cm2 . For total energy throughout the intervention period, the lowest energy found with positive effects was 0.70 J, and the highest 1.141 J. Seventeen studies reported positive effects on nerve regeneration. The variables selected to analyze the effect were: Sciatic Functional Index (SFI), Static Sciatic Index (SSI), morphometric, morphological, histological, zymographic, electrophysiological, resistance mechanics and range of motion (ROM). The variety of parameters used in the studies demonstrated that there is yet no pre-determined protocol for treating peripheral nerve regeneration. Only two studies by different authors used the same power, energy density, beam area, and power density. Conclusion: It was concluded that the therapeutic window of the photobiomodulation presents a high variability of parameters with the wavelength (632.8 to 940 nm), power (5 to 170 mW) and energy density (3 to 280 J /cm2 ), promoting nerve regeneration through the expression of cytokines and growth factors that aid in modulating the inflammatory process, improving morphological aspects, restoring the functionality to the animals in a brief period.

Correlation Between Skin Temperature Over Myofascial Trigger Points in the Upper Trapezius Muscle and Range of Motion, Electromyographic Activity, and Pain in Chronic Neck Pain Patients.

OBJECTIVE: The purpose of this study was to assess the correlation between skin temperature over a myofascial trigger point in the upper trapezius muscle and range of motion of the cervical spine, electromyographic activity, and pain in patients with chronic neck pain. METHODS: This is a single-blind cross-sectional study. Forty participants of both sexes, aged 18 to 45 years, with chronic neck pain and myofascial trigger points in the upper trapezius muscle were included in the study. The participants were assessed using the Numeric Rating Scale, the Neck Disability Index, infrared thermography, algometry, fleximetry, and electromyographic activity. RESULTS: A positive association was observed between skin temperature to the right with the range of motion of cervical flexion (r = 0.322, P = .043), the median frequency of isometrics to the right (r = 0.341, P = .032), and the median frequency of rest to the left (rs = 0.427, P = .006); as were a negative association between skin temperature to the right and the root mean square of rest to the right (rs = -0.447, P = .004), and a positive association of skin temperature to the left with the median frequency of isometrics to the right (r = 0.365, P = .020), and the median frequency of rest to the left (rs = 0.573, P < .001). CONCLUSION: Patients with chronic neck pain who had reduction of skin temperature over myofascial trigger points in the upper trapezius muscle had reduced cervical range of motion for flexion, reduced median frequency at rest and during isometric contraction, and increased root mean square at rest.

Additional Effect of Static Ultrasound and Diadynamic Currents on Myofascial Trigger Points in a Manual Therapy Program for Patients With Chronic Neck Pain: A Randomized Clinical Trial.

OBJECTIVE: To assess the additional effect of static ultrasound and diadynamic currents on myofascial trigger points in a manual therapy program to treat individuals with chronic neck pain. DESIGN: A single-blind randomized trial was conducted. Both men and women, between ages 18 and 45, with chronic neck pain and active myofascial trigger points in the upper trapezius were included in the study. Subjects were assigned to 3 different groups: group 1 (n = 20) was treated with manual therapy; group 2 (n = 20) was treated with manual therapy and static ultrasound; group 3 (n = 20) was treated with manual therapy and diadynamic currents. Individuals were assessed before the first treatment session, 48 hours after the first treatment session, 48 hours after the tenth treatment session, and 4 weeks after the last session. RESULTS: There was no group-versus-time interaction for Numeric Rating Scale, Neck Disability Index, Pain-Related Self-Statement Scale, pressure pain threshold, cervical range of motion, and skin temperature (F-value range, 0.089-1.961; P-value range, 0.106-0.977). Moreover, we found no differences between groups regarding electromyographic activity (P > 0.05). CONCLUSION: The use of static ultrasound or diadynamic currents on myofascial trigger points in upper trapezius associated with a manual therapy program did not generate greater benefits than manual therapy alone.

Evolution of Skin Temperature after the Application of Compressive Forces on Tendon, Muscle and Myofascial Trigger Point.

Some assessment and diagnosis methods require palpation or the application of certain forces on the skin, which affects the structures beneath, we highlight the importance of defining possible influences on skin temperature as a result of this physical contact. Thus, the aim of the present study is to determine the ideal time for performing thermographic examination after palpation based on the assessment of skin temperature evolution. Randomized and crossover study carried out with 15 computer-user volunteers of both genders, between 18 and 45 years of age, who were submitted to compressive forces of 0, 1, 2 and 3 kg/cm2 for 30 seconds with a washout period of 48 hours using a portable digital dynamometer. Compressive forces were applied on the following spots on the dominant upper limb: myofascial trigger point in the levator scapulae, biceps brachii muscle and palmaris longus tendon. Volunteers were examined by means of infrared thermography before and after the application of compressive forces (15, 30, 45 and 60 minutes). In most comparisons made over time, a significant decrease was observed 30, 45 and 60 minutes after the application of compressive forces (p < 0.05) on the palmaris longus tendon and biceps brachii muscle. However, no difference was observed when comparing the different compressive forces (p > 0.05). In conclusion, infrared thermography can be used after assessment or diagnosis methods focused on the application of forces on tendons and muscles, provided the procedure is performed 15 minutes after contact with the skin. Regarding to the myofascial trigger point, the thermographic examination can be performed within 60 minutes after the contact with the skin.