Thermal Imaging of Exercise-Associated Skin Temperature Changes in Trained and Untrained Female Subjects

Preliminary Application of Infrared Thermography to Monitoring of Skin Temperature Asymmetries in Professional Padel Players

The aim of the present study was to evaluate skin temperature (Tsk) asymmetries, using infrared thermography, in professional padel players before (PRE), after (POST) and 10 min after training (POST10), and their relationship with perceptual variables and training characteristics. Thermal images were taken of 10 players before, after and 10 min after a standardized technical training. After training, Tsk of the dominant side was higher than before training in the anterior forearm (30.8 ± 0.4 °C vs. 29.1 ± 1.2 °C, p < 0.01; ES = 1.9), anterior shoulder (31.6 ± 0.6 °C vs. 30.9 ± 0.6 °C, p < 0.05; ES = 1.0) posterior arm (29.5 ± 1.0 °C vs. 28.3 ± 1.2 °C, p < 0.05; ES = 1.0), and posterior forearm (30.8 ± 0.9 °C vs. 29.3 ± 1.6 °C, p < 0.05; ES = 1.1). Likewise, these differences were significant POST10 in the anterior arm, anterior forearm, anterior shoulder, posterior arm and posterior forearm. Comparing the different moments of measurement (PRE, POST and POST10), the temperature was higher POST10 in all the regions analyzed except for the shoulder, abdominals, and lower back. Also, correlations were found between fatigue variation and temperature variation between limbs (Tsk dominance), and no correlation was found except between age and posterior thigh (|r| = 0.69; p < 0.05), and between the racket mass and anterior knee (|r| = 0.81; p < 0.01). In conclusion, infrared thermography allows monitoring of skin asymmetries between limbs in professional padel players, but these asymmetries were not related to overall fatigue variation, overall pain variation, years of experience and training hours.

Respiratory muscles's thermographic analysis in asthmatic youth with and without bronchospasm induced by eucapnic voluntary hyperpnea

OBJECTIVE

To compare the thermographic pattern of regions of interest (ROI) of respiratory muscles in young asthmatics with and without bronchospasm induced by eucapnic voluntary hyperpnea (EVH).

MATERIALS AND METHODS

Cross-sectional study carried out with 55 young (55% male and 45% females) aged 12.5 ± 3.3 years, divided in nine nonasthmatics, 22 asthmatics without exercise-induced bronchospasm compatible response (EIB-cr) and 24 asthmatics with EIB-cr. The diagnosis of EIB was given to subjects with a fall in forced expiratory volume in the first second (FEV1) ≥ 10% compared to baseline. Thermographic recordings of respiratory muscles were delimited in ROI of the sternocleidomastoid (SCM), pectoral, and rectus abdominis intention area. Thermal captures and FEV1 were taken before and 5, 10, 15 and 30 min after EVH.

RESULTS

Twenty-four (52.1%) of asthmatics had EIB-cr. There was a decrease in temperature at 10 min after EVH test in the SCM, pectoral and rectus abdominis ROIs in all groups (both with p < 0.05). There was a decrease in temperature (% basal) in asthmatic with EIB-cr compared to nonasthmatics in the rectus abdominis area (p < 0.05).

CONCLUSION

There was a decrease in temperature in the ROIs of different muscle groups, especially in asthmatics. The greater drop in FEV1 observed in individuals with EIB-cr was initially associated with a decrease in skin temperature, with a difference between the nonasthmatics in the abdominal muscle area. It is likely that this decrease in temperature occurred due to a temporary displacement of blood flow to the most used muscle groups, with a decrease in the region of the skin evaluated in the thermography.

Response of skin temperature, blood ammonia and lactate during incremental exercise until exhaustion in elite athletes

The study aimed to evaluate the lower limb skin temperature (Tsk) and blood concentrations of lactate (LA) and ammonia (NH3) during exercise and recovery. Eleven elite sprint athletes (25 ± 3.4 yrs) and 11 elite endurance athletes (24.45 ± 5.4 yrs) performed an incremental running test until exhaustion. Body composition was estimated using the DXA method. Thermograms of the anterior and posterior surfaces of the lower limbs were recorded at rest, before each test stage (every 3 min, starting from 10 km h-1 and increasing by 2 km h-1), and in the 5th, 10th, 15th, 20th, and 30th minute of recovery. Endurance athletes had a higher maximum oxygen uptake than sprint athletes (5.0 ± 0.7 vs 4.3 ± 0.4 l·kg-1, p = 0.018), lower percentage of lean content (79 ± 2 vs 83 ± 2%, p < 0.001), and a higher percentage of fat content in the lower limbs (17 ± 2 vs 12 ± 2%, p < 0.001). In both groups, a significant decrease in Tsk was observed compared to resting value (endurance athletes-31.5 ± 0.6 °C; sprint athletes-32.3 ± 0.6 °C), during exercise (p < 0.001) and rewarming during recovery (p < 0.001). However, endurance athletes had a lower Tsk than sprint athletes at the exhaustion point (30.0 ± 1.1 vs 31.6 ± 0.8 °C, p < 0.05) and the pattern of change in Tsk differed between groups (p < 0.001). Tsk in the endurance athletes group decreased throughout the exercise protocol and returned more rapidly to initial values during recovery, while Tsk in the sprint group stabilised between moderate intensity and exhaustion, recovering more slowly after exercise. Both LA (endurance athletes-max 10.2 ± 1.5; sprint athletes-max 10.1 ± 1.4 mmol⋅L-1, p < 0.001) and NH3 (endurance athletes-max 75.6 ± 11.5; sprint athletes-max 76.7 ± 9.0 mmol⋅L-1, p < 0.001) increased during exercise and decreased during recovery (p < 0.001). During exercise, lower levels and slower increases in LA were observed during exercise in the endurance athletes' group (p < 0.05). A negative correlation was revealed between Tsk and fat percentage (r = -0.43 to -0.71, p < 0.05). Tsk was positively correlated with LA during recovery (r = 0.43 to 0.48, p < 0.05), and negatively during recovery (r = -0.45 to -0.54, p < 0.05). Differences between groups in maximum aerobic capacity, the pattern of change in Tsk, and the correlation between Tsk and LA suggest that individuals who decrease less Tsk during exercise and higher Tsk during recovery are those with better aerobic capacity. In addition, athletes with less body fat dissipate heat from their tissues more efficiently.

The back body temperatures of patients with idiopathic scoliosis measured through exercise

BACKGROUND

Aerobic exercise is closely associated with the vital functions of patients with scoliosis. Infrared thermography (IRT) has been increasingly applied in physiological measurements in recent years.

OBJECTIVE

This observational study aimed to use IRT to examine the back body surface temperatures of patients with idiopathic scoliosis during aerobic exercise.

METHODS

Forty-two participants who completed a pre-test were divided into a scoliotic group and a non-scoliotic group. Both groups completed a 30-minute cycling exercise, during which their back body temperature was measured using IRT, and the root-mean-square of the back electromyography value after 30 minutes of aerobic exercise was analyzed.

RESULTS

The back body temperature decreased significantly after 30 minutes of exercise in the non-scoliotic group. In contrast, the back body temperature (at the trapezius and quadratus lumborum muscles) was asymmetric or increased after exercise in the scoliotic group.

CONCLUSIONS

These findings suggest that when patients with scoliosis exercise, their back body temperature should be assessed thoroughly to prevent adverse physiological reactions potentially caused by back body temperature imbalances as well as the potential health problems caused by poor heat dissipation. In addition, such observations can be useful in the early screening of scoliosis.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 2: physiological measurements

In this, the second of four historical reviews on human thermoregulation during exercise, we examine the research techniques developed by our forebears. We emphasise calorimetry and thermometry, and measurements of vasomotor and sudomotor function. Since its first human use (1899), direct calorimetry has provided the foundation for modern respirometric methods for quantifying metabolic rate, and remains the most precise index of whole-body heat exchange and storage. Its alternative, biophysical modelling, relies upon many, often dubious assumptions. Thermometry, used for >300 y to assess deep-body temperatures, provides only an instantaneous snapshot of the thermal status of tissues in contact with any thermometer. Seemingly unbeknownst to some, thermal time delays at some surrogate sites preclude valid measurements during non-steady state conditions. To assess cutaneous blood flow, immersion plethysmography was introduced (1875), followed by strain-gauge plethysmography (1949) and then laser-Doppler velocimetry (1964). Those techniques allow only local flow measurements, which may not reflect whole-body blood flows. Sudomotor function has been estimated from body-mass losses since the 1600s, but using mass losses to assess evaporation rates requires precise measures of non-evaporated sweat, which are rarely obtained. Hygrometric methods provide data for local sweat rates, but not local evaporation rates, and most local sweat rates cannot be extrapolated to reflect whole-body sweating. The objective of these methodological overviews and critiques is to provide a deeper understanding of how modern measurement techniques were developed, their underlying assumptions, and the strengths and weaknesses of the measurements used for humans exercising and working in thermally challenging conditions.

Relationship between aerobic fitness and lower limb skin temperature during cycling exercise testing among well-trained athletes and nonathletes: a cross-sectional study

Background

During prolonged physical exercise, the skin plays an important role in thermoregulation by dissipating heat to maintain core temperature. Moreover, thermal variation may be influenced by the physical fitness level of an individual. The aim of the present study was to determine the relationship between aerobic fitness and lower limb skin temperature during graded cycling exercise testing in well-trained athletes and nonathletes.

Methods

Twelve trained athletes (mean ± SD maximal oxygen consumption [VO2max], 52.44 ± 4.5 ml/kg/min) and 12 nonathletes (VO2max, 36.95 ± 4.9 ml/kg/min) participated in this study. The regional skin temperature over the lower limbs was monitored continuously during incremental exercise testing using a thermal camera, and cardio-respiratory parameters were assessed and recorded using a metabolic analyzer (K5, COSMED, Rome, Italy).

Results

The mean skin temperature of athletes at a high intensity of exercise was 27.23 ± 0.3 °C while that of nonathletes was 29.03 ± 0.44 °C, a difference that was statistically significant (p < 0.05). A negative correlation was observed between skin temperature and cardiovascular parameters (VO2max and heart rate) in athletes, while no such correlation was found among nonathletes.

Conclusion

The present study demonstrated a negative correlation between oxygen consumption and lower limb skin temperature in athletes, while the correlation was poor in nonathletes. This suggests that physical fitness level may influence the pattern of alterations in lower limb skin temperature, which supports the hypothesis that athletes exhibit better heat dissipation mechanisms than nonathletes.

Myotendinous Thermoregulation in National Level Sprinters after a Unilateral Fatigue Acute Bout-A Descriptive Study

In the last decade there has been a growing interest in infrared thermography in the field of sports medicine in order to elucidate the mechanisms of thermoregulation. The aim of this study was to describe bilateral variations in skin temperature of the anterior thigh and patellar tendon in healthy athletes and to provide a model of baseline tendon and muscle thermoregulation in healthy sprinters following a unilateral isokinetic fatigue protocol. Fifteen healthy national-level sprinters (eleven men and four women), with at least 3 years of athletic training experience of 10-12 h/week and competing in national-level competitions, underwent unilateral isokinetic force testing and electrostimulation in which their body temperature was measured before, during, and after the protocol using an infrared thermographic camera. ANOVA detected a significant difference in the time × side interaction for patellar temperature changes (p ≤ 0.001) and a significant difference in the time/side interaction for quadriceps temperature changes (p ≤ 0.001). The thermal challenge produces homogeneous changes evident in quadriceps areas, but not homogeneous in tendon areas. These data show that metabolic and blood flow changes may depend on the physical and mechanical properties of each tissue. Future research could be conducted to evaluate the predictive value of neuromuscular fatigue in the patellar tendon and quadriceps after exercise in order to optimize post-exercise recovery strategies.

A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 1: Foundational principles and theories of regulation

This contribution is the first of a four-part, historical series encompassing foundational principles, mechanistic hypotheses and supported facts concerning human thermoregulation during athletic and occupational pursuits, as understood 100 years ago and now. Herein, the emphasis is upon the physical and physiological principles underlying thermoregulation, the goal of which is thermal homeostasis (homeothermy). As one of many homeostatic processes affected by exercise, thermoregulation shares, and competes for, physiological resources. The impact of that sharing is revealed through the physiological measurements that we take (Part 2), in the physiological responses to the thermal stresses to which we are exposed (Part 3) and in the adaptations that increase our tolerance to those stresses (Part 4). Exercising muscles impose our most-powerful heat stress, and the physiological avenues for redistributing heat, and for balancing heat exchange with the environment, must adhere to the laws of physics. The first principles of internal and external heat exchange were established before 1900, yet their full significance is not always recognised. Those physiological processes are governed by a thermoregulatory centre, which employs feedback and feedforward control, and which functions as far more than a thermostat with a set-point, as once was thought. The hypothalamus, today established firmly as the neural seat of thermoregulation, does not regulate deep-body temperature alone, but an integrated temperature to which thermoreceptors from all over the body contribute, including the skin and probably the muscles. No work factor needs to be invoked to explain how body temperature is stabilised during exercise.

Determination of the Effects of a Series of Ten Whole-Body Cryostimulation Sessions on Physiological Responses to Exercise and Skin Temperature Behavior following Exercise in Elite Athletes

The present study investigated the effects of a series of 10 whole-body cryostimulation (WBC) sessions (3 min; -110 °C) on physiological and thermal responses to a submaximal exercise test in 17 elite athletes. Participants performed an exercise test twice at similar levels of intensity before and after a series of ten WBC sessions. Before and during the test, each participant's oxygen uptake (VO2), heart rate (HR), internal temperature (Ti), and skin temperature in selected areas of the skin were measured, and the mean arterial pressure (MAP), physiological strain index (PSI), and mean skin temperature (Tsk) were calculated. The results show that during exercise, increases in Ti and the PSI were significantly lower after the WBC sessions, and although there were no significant changes in HR or the MAP, the Tsk was significantly higher. Following exercise, an increase in skin temperature asymmetry over the lower-body muscles was detected. A series of WBC sessions induced a tendency toward a decrease in temperature asymmetry over the thigh muscles. In conclusion, a series of ten WBC sessions does not induce significant modifications in physiological variables but does influence the PSI and Ti during exercise. Moreover, a series of ten WBC sessions influences the distribution of skin temperature and the magnitude of temperature asymmetries in the early phase of recovery.

Assessing aerobic physical efficiency through temple surface temperature measurements during light, heavy exercise, and recovery

The study was conducted to determine thecorrelation between the selected measures of aerobic physical efficiency and changes in the temple surface temperature in response to light and heavy exercise. 25 physically active men aged 19-25 were recruited for the study. They performed a graded exercise test on a cycle ergometer to measure maximum power (Pmax) and a test verifying the value of maximum oxygen uptake (VO2max). Then, two 3-min submaximal efforts with constant-intensity of 2.2 W·kgLBM-1 and 5 W·kgLBM-1, respectively were performed. During the constant-intensity efforts, the temperature of the temple surface was measured. Then, the difference between the temperature of the temple measured at the end of the exercise and the temperature measured at the beginning of the exercise was calculated (ΔT1-2.2, ΔT1-5, respectively). It was shown that ΔT1-2.2 correlated statistically significantly with VO2max (ml·min-1·kg-1) (r = 0.49; p = 0.01) and Pmax (W·kg-1) (r = 0.41, p = 0.04). Moreover, ΔT1-5 correlated statistically significantly with VO2max (l·min-1) (r = - 0.41; p = 0.04). Changes in body surface temperature in response to light exercise positively correlate with measurements of aerobic physical efficiency, such as VO2max and Pmax. When the exercise intensity is high (5 W·kgLBM-1), the correlation between exercise body temperature changes and VO2max becomes negative.

Joint Response to Exercise Is Affected by Knee Osteoarthritis: An Infrared Thermography Analysis

Infrared thermography can be used to evaluate the inflammation characterizing the joint environment of OA knees, but there is limited evidence on the response to physical exercise. Identifying the response to exercise of OA knees and the influencing variables could provide important information to better profile patients with different knee OA patterns. Sixty consecutive patients (38 men/22 women, 61.4 ± 9.2 years) with symptomatic knee OA were enrolled. Patients were evaluated with a standardized protocol using a thermographic camera (FLIR-T1020) positioned at 1 m with image acquisition of an anterior view at baseline, immediately after, and at 5 min after a 2-min knee flexion-extension exercise with a 2 kg anklet. Patients' demographic and clinical characteristics were documented and correlated with the thermographic changes. This study demonstrated that the temperature response to exercise in symptomatic knee OA was affected by some demographic and clinical characteristics of the assessed patients. Patients with a poor clinical knee status presented with a lower response to exercise, and women showed a greater temperature decrease than men. Not all evaluated ROIs showed the same trend, which underlines the need to specifically study the different joint subareas to identify the inflammatory component and joint response while investigating knee OA patterns.

Effect of Whole-, Upper-, and Lower-Body High-Intensity Rowing Exercise on Skin Temperature Measured by Thermography

Purpose: Despite the growing works analyzing exercise-induced thermoregulatory adjustments through thermography, the skin temperature (Tsk) response of the same muscle groups underwent to different exercise demands has not been investigated. This study analyzed the behavior of Tsk of the same muscle groups when exercised with different demands in rowing. Methods: Eighteen men underwent three performance tests on a rowing ergometer: whole-body 2,000 m test (RT_WB), upper-body (RT_UB), and lower-body (RT_LB) tests. In each condition, thermograms were recorded before (pre), immediately after test (post), and at 10 (REC₁₀), 20 (REC₂₀), and 30 (REC₃₀) minutes post-exercise recovery. Tsk was measured at the pectoral (control body region), upper back, quadriceps, brachial biceps, and forearm. Results: Pectoral-Tsk reduced comparably in response to all testing conditions (p < .05). Upper back-Tsk decreased post (p < .001) and returned to baseline in the RT_UB (REC₁₀, p = 1.0) and RT_WB (REC₃₀, p = .128), while remained reduced in the RT_LB (p < .001). Quadriceps-Tsk reduced post (p < .05) and returned to baseline in the RT_WB and RT_LB at REC₁₀ (p = 1.0), remaining reduced in the RT_UB during recovery (p < .05). Regarding the upper limbs, Tsk increased more markedly in the RT_UB versus RT_WB during the recovery period (p < .05); in the RT_LB, biceps-Tsk remained below baseline over time (p < .05), whereas the forearm-Tsk was restored at REC₁₀ (p = 1.0). Conclusion: Manipulating the muscle groups involved in rowing alters the Tsk response within equal ROI. Exercise-induced Tsk changes can reflect local hemodynamic and thermoregulatory adjustments.

An exploratory, intra- and interindividual comparison of the deep neural network automatically measured calf surface radiation temperature during cardiopulmonary running and cycling exercise testing: A preliminary study

Non-invasive and contactless infrared thermography (IRT) measurements have been claimed to indicate acute neural, cardiovascular, and thermoregulatory adaptations during exercise. Due to challenging comparability, reproducibility, and objectivity, investigations considering different exercise types and intensities, and automatic ROI analysis are currently needed. Thus, we aimed to examine surface radiation temperature (T_sr) variations during different exercise types and intensities in the same individuals, ROI, and environmental conditions. Ten healthy, active males performed a cardiopulmonary exercise test on a treadmill in the first week and on a cycling ergometer the following week. Respiration, heart rate, lactate, rated perceived exertion, the mean, minimum, and maximum T_sr of the right calf (CT_sr (°C)), and the surface radiation temperature pattern (CP_sr) were explored. We executed two-way rmANOVA and Spearman's rho correlation analyses. Across all IRT parameters, mean CT_sr showed the highest association to cardiopulmonary parameters (E.g., oxygen consumption: r_s = -0.612 (running); -0.663 (cycling); p < .001). A global significant difference of CT_sr was identified between all relevant exercise test increments for both exercise-types (p < .001; η²_p = .842) and between both exercise-types (p = .045; η²_p = .205). Differences in CT_sr between running and cycling significantly appeared after a 3-min recovery period, whereas lactate, heart rate, and oxygen consumption were not different. High correlations between the CT_sr values extracted manually and the CT_sr values processed automatically by a deep neural network were identified. The applied objective time series analysis enables crucial insights into intra- and interindividual differences between both tests. CT_sr variations indicate different physiological demands between incremental running and cycling exercise testing. Further studies applying automatic ROI analyses are needed to enable the extensive analysis of inter- and intraindividual factors influencing the CT_sr variation during exercise to allow determine the criterion and predictive validity of IRT parameters in exercise physiology.

Skin temperature normalizes faster than pressure pain thresholds, pain intensity, and pain distribution during recovery from eccentric exercise

INTRODUCTION

Acute musculoskeletal injuries have diverse symptomatology and a multidimensional recovery process, including changes in swelling, redness, hyperalgesia, and expanded pain distribution. In a small proportion of cases, the tissue heals, although these symptoms persist, reflecting altered peripheral and central pain mechanisms. However, the otherwise healthy multidimensional recovery process following damage and pain is less than clear. The objective was to assess mechanical muscle hyperalgesia, skin temperature, and pain intensity and distribution during the recovery process in response to eccentric exercise in the hamstring muscles.

METHODS

Twenty-four healthy males participated in four sessions (Day-0, Day-2, Day-4, and Day-7). Exercise-induced muscle soreness was induced on Day-0 by five sets of 20 repetitions of an eccentric exercise involving the hamstrings on the dominant leg. Each session included assessments of thermography, pressure pain thresholds (PPTs), pain intensity, and area of exercise-induced pain.

RESULTS

Decreased PPTs (P < 0.005), higher pain intensity (P < 0.001), and a larger area of pain (P < 0.001) were displayed on Day-2 and Day-4 than Day-0. Skin temperature decreased on Day-2 than Day-0 (P < 0.01) and returned to baseline assessments by Day-4, despite lower temperature than the contralateral tight (P < 0.01). Further, there was a positive correlation between pain intensity and area on Day-2 and Day-4 (P < 0.005), but no for changes in skin temperature.

CONCLUSION

Thermographic changes and pain-related variables altered following eccentric exercise demonstrate different recovery times. These results provide insights into potential mechanisms and measures that can be used to assess recovery from exercise-induced damage.

Can Skin Temperature Be Altered After Different Magnitudes of Eccentric Exercise-Induced Muscle Damage?

Purpose: This study aimed to assess skin temperature (Tsk) changes after different magnitudes of exercise-induced muscle damage (EIMD) of the elbow flexor muscles and investigate whether Tsk is related to indirect markers of EIMD. Methods: Thirty healthy active men were randomly allocated to the mild (MiDG) (n = 15) or moderate (MoDG) (n = 15) muscle damage group. Muscle damage in elbow flexor muscles was induced by 10 (for MiDG) or 30 (for MoDG) maximal eccentric isokinetic contractions at 60 degrees/s. Tsk, maximal voluntary isometric contraction (MVIC), delayed-onset muscle soreness (DOMS), plasma creatine kinase (CK) activity, range of motion (ROM), and pressure pain threshold (PPT) were measured before and up to 72 hr after EIMD. Results: Tsk increased only immediately after EIMD (p < .05; f = 1.44) in the MoDG (4.2%) and MiDG (4.6%), returning to near baseline values 30 min after EIMD and remaining so thereafter. In addition, there was no intergroup difference (p > .05) at any of the times analyzed, or correlation between Tsk and most indirect markers of EIMD. Conclusions: In conclusion, Tsk should not be considered an indirect marker of mild or moderate muscle damage in active men, since alterations in this variable last less than 30 min after damaging exercise and showed no correlation with most indirect markers of EIMD.

Wirkmechanismen körperlicher Aktivität auf den Schlaf bei Patienten mit Depression: Ein Narratives Review

Insomnie ist eines der Kardinalsymptome einer unipolaren Depression. Insomnie hat dabei einen negativen Einfluss auf den Krankheitsverlauf, ist eines der häufigsten Residualsymptome und ein Risikofaktor für ein Rezidiv. Im vorliegenden Überblick werden mögliche Wirkmechanismen von körperlichem Training auf den Schlaf bei Patienten mit Depression zusammengefasst. Die vorgestellten Mechanismen beruhen auf Daten aus In-vitro‑, Tier- und Humanstudien, welche die Effekte von Kraft‑, Ausdauer- und Mind-Body-Training untersuchen. Sowohl akutes Training als auch über mehrere Wochen regelmäßig absolviertes Training kann über verschiedene Signalwege positive Effekte auf den Schlaf bei Patienten mit Depression haben. Folgende Mechanismen sind dabei relevant: Zeitgebereffekte, Energiekonservierung, Regeration, Thermoregulation, psychophysiologische Effekte und „tissue–brain crosstalk“. Diese Befunde sind relevant, um die Therapie von nichtorganischen Schlafstörungen im Rahmen einer depressiven Episode besser zu verstehen, weiterzuentwickeln und auf individuelle Patienten anzupassen.

Infrared thermal imaging-based skin temperature response during cupping at two different negative pressures

Cupping therapy can relieve muscle fatigue and pain after exercise by increasing blood flow at the treatment site, which may lead to dynamic changes of the local skin temperature. This study aimed to analyze the effect of cupping on local skin temperature under two different negative pressures using infrared thermography (IRT). Cupping therapy was performed on the forearms of 22 healthy subjects using the negative pressures of − 0.03 and − 0.04 MPa. IRT was used to record the dynamic changes in skin temperature before, during, and after cupping. Both cupping pressures induced a non-linear skin temperature response: temperature decreased first and then increased during cupping, while it first increased and then decreased after cupping. A significant difference was noted between the two negative pressure groups in the maximum temperature increment after cupping (P < 0.001). Compared with the basal temperature before cupping, the maximum increase in skin temperature after cupping in the − 0.03 and − 0.04 MPa groups was 0.92 and 1.42 °C, respectively. The findings of this study can lay the foundation evaluating the curative effect of cupping based on IRT and provide an objective reference for selecting the cupping negative pressure.

Infrared Thermography with High Accuracy in a Neonatal Incubator

As the accuracy of body temperature measurement is especially critical in premature infants on admission to the neonatal intensive care unit (NICU), noninvasive measurement using infrared thermography (IRT) has not been widely adopted in the NICU due to a lack of evidence regarding its accuracy. We have established a new calibration method for IRT in an incubator, and evaluated its accuracy and reliability at different incubator settings using a variable-temperature blackbody furnace. This method improved the accuracy and reliability of IRT with an increase in percentage of data with mean absolute error (MAE) < 0.3 °C to 93.1% compared to 4.2% using the standard method. Two of three IRTs had MAE < 0.1 °C under all conditions examined. This method provided high accuracy not only for measurements at specific times but also for continuous monitoring. It will also contribute to avoiding the risk of neonates' skin trouble caused by attaching a thermistor. This study will facilitate the development of novel means of administering neonatal body temperature.

Effects of Resistance Training on Skin Temperature and Its Relationship with Central Nervous System (CNS) Activation

The aim of this work was to relate the activation of the sympathetic and parasympathetic nervous systems with the skin temperature (Tsk) of the lower limbs after a resistance training exercise. Under controlled conditions, the average Tsk in the areas of the anterior and posterior thighs, knees and legs was obtained with a thermal imager and the parasympathetic and sympathetic activation was registered with an Omegawave^® device on 20 healthy and trained male volunteers (25.39 ± 8.21 years) before exercise, immediately after standard resistance training (3 exercises (2 quadriceps + 1 hamstrings) × 4 sets × 10 repetitions (70% 1RM), 90-sec recovery) and after 20 min of recovery. The results showed a significant effect of exercise and recovery on Tsk in all regions of interest (ROIs) considered (p < 0.05) and strong inverse relationships between sympathetic and parasympathetic activation values. Significant results were found for the total variation of Tsk (p < 0.05) with highly positive values for subjects with lower sympathetic activation and almost null or even negative values for those with higher sympathetic activation. Sympathetic activity was a significant predictor of total Tsk variation in the anterior thigh, posterior thigh and anterior knee but not in the posterior knee, anterior leg, and posterior leg. Baseline Tsk was a significant predictor of total Tsk variation the all ROIs except in the posterior knee. Tsk measured by thermography could be used to estimate the level of participation of muscle areas in exercise and registering the level of sympathetic activation before exercise could be interesting in predicting the athlete’s physiological response to strength training.

Effect of fatigue strength exercise on anterior thigh skin temperature rewarming after cold stress test

Although dynamic thermography skin temperature assessment has been used in medical field, scientific evidence in sports is scarce. The aim of the study was to assess changes in anterior thigh skin temperature in response to a cold stress test after a strength exercise fatiguing protocol. Ten physically active adults performed a familiarization session and two strength exercise sessions, one with dominant and the other with non-dominant lower limb. Participants performed bouts of 10 concentric and eccentric contractions of leg extensions in an isokinetic device until reaching around 30% of force loss. Infrared thermographic images were taken at baseline conditions and after the fatigue level from both thighs after being cooled using a cryotherapy system. ROIs included vastus medialis, rectus femoris, adductor and vastus lateralis. Skin temperature rewarming was assessed during 180s after the cooling process obtaining the coefficients of the following equation: ΔSkin temperature = β₀ + β_{1 *} ln(T), being β₀ and β₁ the constant and slope coefficients, respectively, T the time elapsed following the cold stress in seconds, and ΔSkin temperature the difference between the skin temperature at T respect and the pre-cooling moment. Lower β₀ and higher β₁ were found for vastus lateralis and rectus femoris in the intervention lower limb compared with baseline conditions (p < 0.05 and ES > 0.6). Adductor only showed differences in β₀ (p = 0.01 and ES = 0.92). The regressions models obtained showed that β₀ and β₁ had a direct relationship with age and muscle mass, but an inverse relationship with the number of series performed until 30% of fatigue (R² = 0.8). In conclusion, fatigue strength exercise results in a lower skin temperature and a faster thermal increase after a cold stress test.

Relationship between exercise-induced muscle soreness, pain thresholds, and skin temperature in men and women

Infrared thermography (IRT) has gained popularity in sports medicine for determining whether changes in skin temperature relate to pain and muscle damage. Such a relationship would support IRT as a non-invasive method to monitor these physiological responses. However, the literature remains controversial. Here, we determine the relationship between exercise-induced muscle soreness (DOMS), pain, and skin temperature in men and women before and after exercise. Twenty-two physically active adults (10 men and 12 women) completed a squat exercise protocol to induce muscle damage. Skin temperature, DOMS, and pressure pain threshold (PPT) were assessed in the quadriceps pre, post-exercise, and 48 h post-exercise. DOMS increased similarly in men and women post-exercise and 48 h post-exercise. PPT was lower in women compared to men. PPT decreased 48 h post-exercise for men but did not differ between the moments for women. Skin temperature responses were sex-dependent. Mean and maximum temperatures increased post-exercise for men, and maximum temperature reduced 48 h post-exercise. In women, the minimum temperature increased 48 h post-exercise. DOMS was not predicted by skin temperature but showed a direct association between pre and 48 h post-exercise variation of maximum skin temperature and PPT. We conclude that there is a sex-dependent effect in analyzing skin temperature changes in response to exercise, something that seems to not have been addressed in previous studies. To date, inferences are generally assumed as similar for both men and women, which we show may not be the case.

Regions of interest selection and thermal imaging data analysis in sports and exercise science: a narrative review

OBJECTIVE

Infrared thermography (IRT) is a non-invasive, contactless and low-cost technology that allows recording of the radiating energy that is released from a body, providing an estimate of its superficial temperature. Thanks to the improvement of infrared thermal detectors, this technique is widely used in the biomedical field to monitor the skin temperature for different purposes (e.g. assessing circulatory diseases, psychophysiological state, affective computing). Particularly, in sports and exercise science, thermography is extensively used to assess sports performance, to investigate superficial vascular changes induced by physical exercise, and to monitor injuries. However, the methods of analysis employed to treat IRT data are not standardized, and hence introduce variability in the results.

APPROACH

This review focuses on the methods of analysis currently used for thermal imaging in sports and exercise science.

MAIN RESULTS

Firstly, the procedures employed for the selection of regions of interest (ROIs) from anatomical body districts are reviewed, paying attention also to the potentialities of morphing algorithms to increase the reproducibility of thermal results. Secondly, the statistical approaches utilized to characterize the temperature frequency and spatial distributions within ROIs are investigated, showing their strengths and weaknesses. Moreover, the importance of employing tracking methods to analyze the temporal thermal oscillations within ROIs is discussed. Thirdly, the capability of employing procedures of investigation based on machine learning frameworks on thermal imaging in sports science is examined.

SIGNIFICANCE

Finally, some proposals to improve the standardization and the reproducibility of IRT data analysis are provided, in order to facilitate the development of a common database of thermal images and to improve the effectiveness of IRT in sports science.

Footwear outsole temperature may be more related to plantar pressure during a prolonged run than foot temperature

Objective. The temperature of the sole of the foot has been suggested as an alternative to the measurement of plantar pressure during running despite the scarce evidence about their relationship. The temperature of the footwear outsole could also be representative of plantar pressure distribution due to its less multifactorial dependence. The aim of the study was to determine if plantar pressure during a prolonged run could be related to plantar temperature, either of the sole of the foot or the footwear outsole.Approach. Thirty recreational runners (15 males and 15 females) performed a 30 min running test on a treadmill. Thermographic images of the sole of the foot and the footwear outsole were taken before and immediately after the test, and dynamic plantar pressure was measured at the end of the test. Pearson correlations and stepwise multiple linear regressions were performed.Main results.Plantar pressure percentage was related to a moderate correlation with plantar temperature percentage in forefoot and rearfoot (P < 0.05), showing a greater relationship with the footwear outsole than with the sole of the foot (r = 0.52-0.73 versusr = 0.40-0.61, respectively). Moreover, moderate correlations were also observed between footwear outsole and sole of the foot temperature variables, especially in rearfoot.Significance. Footwear outsole temperature may be better related to plantar pressure distribution than sole of the foot temperature, in the forefoot and rearfoot. The midfoot is the most sensitive and variable region to analyze, as it does not seem to have any relationship with plantar pressure.

Detection of Muscle Activation during Resistance Training Using Infrared Thermal Imaging

Infrared thermal imaging has been widely used to show the correlation between thermal characteristics of the body and muscle activation. This study aims to investigate a method using thermal imaging to visualize and differentiate target muscles during resistance training. Thermal images were acquired to monitor three target muscles (i.e., biceps brachii, triceps brachii, and deltoid muscle) in the brachium while varying the training weight, duration, and order of training. The acquired thermal images were segmented and converted to heat maps. By generating difference heat maps from pairs of heat maps during training, the target muscles were clearly visualized, with an average temperature difference of 0.86 °C. It was observed that training order had no significant effect on skin surface temperature. The difference heat maps were also used to train a convolutional neural network (CNN) to show the feasibility of target muscle classification, with an accuracy of 92.3%. This study demonstrated that infrared thermal imaging could be effectively utilized to locate and differentiate target muscle activation during resistance training.

Thermal Imaging of Exercise-Associated Skin Temperature Changes in Swimmers Subjected to 2-min Intensive Exercise on a VASA Swim Bench Ergometer

An important element of swimming training is the improvement of muscle strength and the technique of swimming movements on dry land. The heat generated by the muscles involved in the effort contributes to a change in the temperature of the skin surface, which can be assessed by the IRT method. The aim of the study was to assess the symmetry and dynamics of changes in surface temperatures of selected areas of the body in swimmers after exercise on a swimming ergometer with the use of IRT. A total of 12 swimmers (aged 19 ± 1.3 years) completed a two-minute stress test (front crawl swimming movements) using a VASA Swim Ergometer, with a load of 5. Using an IRT camera (FLIR E60), postexercise changes in back and upper limbs surface temperature in relation to the resting values were observed. After exercise, the temperature value of all assessed areas decreased, apparently in the area of the back and the back of the arms, returning to the baseline values after 12 min of observation. There was no asymmetry in mean temperature values between the right and left upper limbs. IRT is a noninvasive and sensitive tool for the individual analysis of changes in body surface temperature in swimmers after training on dry land.

Eight-week high-intensity interval training is associated with improved sleep quality and cardiorespiratory fitness in patients with depressive disorders

PURPOSE

This study aimed to examine the effect of high-intensity interval training (HIIT) on both sleep and cardiorespiratory fitness in patients with depression.

METHODS

Using a single pre- and post-test study design with no control group, 82 patients diagnosed with depressive disorders underwent HIIT comprising a total of 24 15-min sessions, three times per week for 8 weeks. Depressive symptoms, sleep quality, and cardiorespiratory fitness were evaluated using the Beck depression inventory-II, the Pittsburgh sleep quality index (PSQI), and cardiopulmonary exercise testing (CPET) in the form of maximum oxygen uptake (VO₂ max), respectively.

RESULTS

All 82 patients completed the intervention. HIIT training was associated with significant improvements in BDI-II score (diff =  - 1.57 [95% CI - 2.40 to - 0.73], P = 0.001), PSQI score (diff =  - 1.20 [95% CI - 2.10 to - 0.32], P = 0.008), and CPET VO₂ max (diff = 0.95 [95% CI 0.62-1.28], P = 0.001). Effect size calculations revealed that the greatest improvement occurred in CPET VO₂ max (Cohen's d = 0.64) and that improvements in the BDI-II and PSQI scores were somewhat smaller in magnitude (Cohen's d =  - 0.41 and - 0.30, respectively). Sleep quality improvements were observed in sleep latency, habitual sleep efficiency, and the use of sleep-promoting medications (Cohen's d = 0.18, 0.19, and 0.25, respectively). Change in cardiorespiratory fitness successfully predicted change in sleep quality but not in depressive symptoms. Adverse effects were limited to minor injuries which did not interfere with completion of training.

CONCLUSIONS

HIIT training delivered over 8 weeks was associated with improvements in depression symptoms, sleep quality, and cardiorespiratory fitness in patients with depressive disorders.

An Overview of Thermal Infrared Imaging-Based Screenings during Pandemic Emergencies

Infrared thermal imaging (IRI) is a contact-less technology able to monitor human skin temperature for biomedical applications and in real-life contexts. Its capacity to detect fever was exploited for mass screening during past epidemic emergencies as well as for the current COVID-19 pandemic. However, the only assessment of fever may not be selective for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Hence, novel approaches for IRI data analysis have been investigated. The present review aims to describe how IRI have been employed during the last epidemics, highlighting the potentialities and the limitations of this technology to contain the contagions. Specifically, the methods employed for automatic face recognition and fever assessment and IRI's performances in mass screening at airports and hospitals are reviewed. Moreover, an overview of novel machine learning methods for IRI data analysis, aimed to identify respiratory diseases, is provided. In addition, IRI-based smart technologies developed to support the healthcare during the COVID-19 pandemic are described. Finally, relevant guidelines to fully exploit IRI for COVID-19 identification are defined, to improve the effectiveness of IRI in the detection of the SARS-CoV-2 infection.

Physical therapy to address fall risk in an individual with neurofibromatosis

Background: While physical therapy may help improve function and quality of life in patients with neurofibromatosis (NF), a standard of care remains to be established. This case report describes the physical therapy management of an individual with NF who was at high fall risk.Case Description: A 61-year-old male with NF and multiple comorbidities was determined to be at high fall risk by the Dynamic Gait Index, Berg Balance Scale, and Modified Falls Efficacy Scale. Deficits included coordination and strength which limited his ability to ascend and descend stairs or walk on uneven terrain. This reduced his independence at home and in his rural community. Interventions incorporated components of hip and trunk coordination, and addressed balance, strength, and functional mobility.Outcomes: The patient scored above the cutoff for high fall risk on all outcome assessments.Discussion: This case report describes physical therapy management to reduce fall risk for an individual with NF. Due to the limited research on NF, the treatment plan was developed using evidence-based practice for fall-risk reduction in other neurological disorders.

The effects of exercise on sleep in unipolar depression: A systematic review and network meta-analysis

Insomnia predicts the onset, course, and reoccurrence of unipolar depression. However, systematic reviews of treatment options for insomnia in unipolar depression are lacking. After screening 7725 records, 17 trials comprising 1645 patients randomized to 13 treatments were included for quantitative synthesis. Network meta-analysis showed that compared to a passive control condition, all exercise interventions except moderate aerobic exercise alone resulted in significantly better sleep outcomes. Compared with treatment as usual, mind-body exercise plus treatment as usual (SMD: -0.46; 95% CI: -0.80, -0.12) and vigorous strength exercise (SMD: -0.61; 95% CI: -1.12, -0.10) were significantly more effective. Pairwise meta-analyses showed that mind-body exercise (SMD: -0.54; 95% CI: -0.85, -0.23) had beneficial effects compared to passive control. The network meta-analysis is statistically very robust with low heterogeneity, incoherence, and indirectness. However, confidence in the findings was moderate to very low, primarily due to within-study bias. This is the first network meta-analysis to assess exercise's efficacy to improve sleep quality in patients with depression. The findings confirm the benefits of exercise as an add-on treatment for depression. This consolidation of the current state of evidence can help clinicians make evidence-based decisions.

The immediate effect of whole-body vibration on rectus abdominis muscle activity and cutaneous temperature: A randomized controlled trial

OBJECTIVES

To compare acute effects of isometric abdominal exercises performed with or without vibration on the electromyographic activity and cutaneous temperature in the abdominal region of physically active individuals.

METHODS

A randomized controlled crossover clinical trial was undertaken in thirty volunteers who completed one unique session of two different protocols of interventions apart from a week from each other, in a two-week study protocol. The subjects were randomly divided in to two groups of 15 volunteers; both were assigned to perform board exercise (30 s on the front, right and left lateral boards, with a rest interval of 2 min). The first group performed it on a vibrating platform at a frequency of 30 Hz for the first week, while the remaining participants executed the same exercise without stimulates vibration. In the second week the protocol was inverted. The outcome were surface electromyography (EMG) data for the rectus abdominis muscle (RAM) and cutaneous temperature (CT) of the abdominal region. Normality was accepted, and Student's t-tests were used to compare the measurements for dependents variables (P < 0.05).

RESULTS

There were no differences in RAM activation and CT between protocols with or without vibration (P > 0.05). CT increased (P = 0.001) after both the exercises with and without vibration.

CONCLUSION

The results suggest that there were no effects in cutaneous temperature or muscle activation through the use of vibration associated with isometric abdominal exercises.

Relationship between Skin Temperature, Electrical Manifestations of Muscle Fatigue, and Exercise-Induced Delayed Onset Muscle Soreness for Dynamic Contractions: A Preliminary Study

Delayed onset muscle soreness (DOMS) indicates the presence of muscle damage and impairs force production and control. Monitorization of DOMS is useful to improving recovery intervention plans. The magnitude of DOMS may relate to muscle fatigue, which can be monitored by surface electromyography (EMG). Additionally, growing interest has been expressed in determining whether the skin temperature over a muscle group during exercise to fatigue could be a non-invasive marker for DOMS. Here we determine whether skin temperature and manifestations of muscle fatigue during exercise are correlated and can predict DOMS after concentric-eccentric bicep curl exercises. We tested 10 young adults who performed concentric-eccentric bicep curl exercises to induce muscle damage in the biceps brachialis to investigate the relationship between skin temperature and fatigue during exercise and DOMS after exercise. Muscle activation and skin temperature were recorded during exercise. DOMS was evaluated 24 h after exercise. Data analysis was performed using Bayesian regression models with regularizing priors. We found significant muscle fatigue and an increase in skin temperature during exercise. DOMS was observed 24 h after exercise. The regression models showed no correlation of changes in skin temperature and muscle fatigue during exercise with DOMS 24 h after exercise. In conclusion, our preliminary results do not support a relationship between skin temperature measured during exercise and either muscle fatigue during exercise or the ability to predict DOMS 24 h after exercise.

Parabrachial neuron types categorically encode thermoregulation variables during heat defense

Heat defense is crucial for survival and fitness. Transmission of thermosensory signals into hypothalamic thermoregulation centers represents a key layer of regulation in heat defense. Yet, how these signals are transmitted into the hypothalamus remains poorly understood. Here, we reveal that lateral parabrachial nucleus (LPB) glutamatergic prodynorphin and cholecystokinin neuron populations are progressively recruited to defend elevated body temperature. These two nonoverlapping neuron types form circuits with downstream preoptic hypothalamic neurons to inhibit the thermogenesis of brown adipose tissues (BATs) and activate tail vasodilation, respectively. Both circuits are activated by warmth and can limit fever development. The prodynorphin circuit is further required for regulating energy expenditure and body weight homeostasis. Thus, these findings establish that the genetic and functional specificity of heat defense neurons occurs as early as in the LPB and uncover categorical neuron types for encoding two heat defense variables, inhibition of BAT thermogenesis and activation of vasodilation.

A computer aided diagnostic method for the evaluation of type II diabetes mellitus in facial thermograms

Almost 50% of individuals around the globe are unaware of diabetes and its complications. So, an early screening of diabetes is very important at this current situation. To overcome the difficulties such as pain and discomfort to the subjects obtained from the biochemical diagnostic procedures; an infrared thermography is the diagnostic technique which measures the skin surface temperature noninvasively. Thus, the aim of our proposed study was to evaluate the type II diabetes in facial thermograms and to develop a computer aided diagnosis (CAD) system to classify the normal and diabetes. The facial thermograms (n = 160) including male (n = 79) and female (n = 81) were captured using FLIR A 305sc infrared thermal camera. The Haralick textural features were extracted from the facial thermograms based on gray level co-occurrence matrix algorithm. The T_ROI, T_MAX, and T_TOT are the statistical temperature parameters exhibited a significant negative correlation with HbA1c (r = - 0.421, - 0.411, - 0.242, p < 0.01 (T_ROI); r = - 0.259, p < 0.01(T_MAX) and - 0.173, p < 0.05 (T_TOT)). An optimal regression equation has been constructed by using the significant facial variables and standard HbA1c values. The model has achieved sensitivity, specificity, and accuracy rate as 91.42%, 88.57%, and 90% respectively. The anthropometrical variables, extracted textural features and temperature parameters were fed into the classifiers and their performances were compared. The Support Vector Machine outperformed the Linear Discriminant Analysis (84.37%) and k-Nearest Neighbor (81.25%) classifiers with the maximum accuracy rate of 89.37%. The developed CAD system has achieved 89.37% of accuracy rate for the classification of diabetes. Thus, the facial thermography could be used as the basic non-invasive prognostic tool for the evaluation of type II diabetes mellitus.

Functional Infrared Thermal Imaging: A Contemporary Tool in Soft Tissue Screening

Soft tissue injury screening faces two main diagnostic challenges. One is the perceptual bias of the athlete in terms of referred pain and second injury assessment tools are not only in need of highly specialized personal but they are also financially demanding. Since ankle sprains is one of the leading soft tissue injuries, the current study was set to examine the suitability of functional infrared thermal imaging (fITI) in evaluating physiological alteration on the ankle as a result of exercise or injury. The current study consists of a case report of a patient with an ankle sprain and the behavior of temperature after a series of physiotherapy sessions. Moreover to strengthen the communication of the report, results from a healthy population sample were added to draw a deeper understanding on physiological temperature manifestations on soft tissue. Twenty participants underwent a 30-minute treadmill run with pictures of their ankles being taken during rest and after exercise. In addition the case of a patient is reported that has suffered an ankle sprain followed for a period of over a month. It was observed that the temperature of the ankles of participants that underwent physical exercise rose on average by 2.4 °C after taking into account both the medial and lateral sides of the both ankles. In addition the patient's left ankle appeared to be 2.5 °C above the temperature of the non-affected right ankle. This phenomenon of unilateral hyperthermia of the left injured side seems to start to dissipate by the 21st day following the injury, completely resolving by the 42nd day achieving bilateral isothermia in both ankles. Thermal imaging provides a reliable tool for the screening of soft tissue strain and injury. The current study further expands the literature on soft tissue screening with the use of thermal imaging, adding a quantifiable way for assessing the extend of tissue damage. The implemented method of analyses offers a suggested simple way not only in visualizing trauma but also physical strain. Nevertheless further investigations with a variety in the severity of ankle sprains need to be applied in order for thermal imaging to be used as a first line tool for the assessment and recovery of ankle sprains.

Evaluation of Thermographic Imaging in Canine Hindlimb Muscles After 6 Min of Walking-A Pilot Study

Objective: To evaluate changes in superficial temperature of hindlimb muscles before and after a 6-min walk in healthy dogs.

Methods: Two infrared thermographic images were captured of the proximal and distal hindlimbs of 11 healthy dogs before and after a 6-min walk. Orthopedic exam and objective gait analysis confirmed the healthy status of study subjects. Superficial temperatures of the gastrocnemius, biceps femoris, and gracilis were assessed. Analysis of images was performed using 2 different methods of region of interest (ROI) selection. ROI were selected first using one point (single pixel) in the muscle and then separately by selecting a line (LN) corresponding to many points of each muscle belly from which an average was taken. P < 0.05 was considered significant.

Results: There was no significant change in temperature using point ROI before and after 6 min of walking of the gastrocnemius, gracilis, and biceps femoris muscles (p = 0.273, p = 0.349, p = 0.351, respectively). Using linear ROI, both biceps femoris and gracilis muscles exhibited significant increases in temperature (p < 0.0001, p = 0.032, respectively). There was no significant increase in temperature of gastrocnemius muscle for both point and linear ROI selection (p = 0.273, p = 0.448, respectively). The right biceps femoris temperatures were higher compared to left biceps femoris using the linear ROI before and after walks (p < 0.0001). The overall (left and right limbs pooled) standard deviation of point selected values were greater than LN selected values of the biceps femoris (1.35 and 1.11) and gastrocnemius (1.51 and 1.23). In contrast, standard deviation for the gracilis measurements were decreased using point selection vs. LN selection (1.09 and 1.3).

Conclusions: The biceps femoris and gracilis muscles demonstrated significant increases in surface temperature after 6 min of walking using the linear method of ROI. Measurement of numerous points along the entire length of the biceps femoris and gastrocnemius muscles may provide a more accurate assessment of the increased vascularity within the tissues resulting from work compared to single point selection.

Clinical Significance: Prior activity and ROI selection method should be considered when interpreting thermography results.

A tailored, electronic textile conformable suit for large-scale spatiotemporal physiological sensing in vivo

The rapid advancement of electronic devices and fabrication technologies has further promoted the field of wearables and smart textiles. However, most of the current efforts in textile electronics focus on a single modality and cover a small area. Here, we have developed a tailored, electronic textile conformable suit (E-TeCS) to perform large-scale, multimodal physiological (temperature, heart rate, and respiration) sensing in vivo. This platform can be customized for various forms, sizes and functions using standard, accessible and high-throughput textile manufacturing and garment patterning techniques. Similar to a compression shirt, the soft and stretchable nature of the tailored E-TeCS allows intimate contact between electronics and the skin with a pressure value of around ~25 mmHg, allowing for physical comfort and improved precision of sensor readings on skin. The E-TeCS can detect skin temperature with an accuracy of 0.1 °C and a precision of 0.01 °C, as well as heart rate and respiration with a precision of 0.0012 m/s2 through mechano-acoustic inertial sensing. The knit textile electronics can be stretched up to 30% under 1000 cycles of stretching without significant degradation in mechanical and electrical performance. Experimental and theoretical investigations are conducted for each sensor modality along with performing the robustness of sensor-interconnects, washability, and breathability of the suit. Collective results suggest that our E-TeCS can simultaneously and wirelessly monitor 30 skin temperature nodes across the human body over an area of 1500 cm2, during seismocardiac events and respiration, as well as physical activity through inertial dynamics.

Effects of intermittent negative pressure and active recovery therapies in the post-match period in elite soccer players: A randomized, parallel arm, comparative study

Study aim: This study compared the effects of intermittent negative pressure therapy (INPT) vs. active recovery therapy (ART) on post-match physiological parameters such as serum CK level and skin temperature of the lower limbs in elite soccer players.

Material and methods: Twenty healthy male professional soccer players from a Brazilian first division soccer club were enrolled in this randomized, parallel arm, open label, comparative study. After participating in 2 soccer matches, they were randomly assigned to two groups (n = 10) to receive a 30-min session of INPT (intermittent exchange of hypobaric pressure range 33 to 51 mmHg) or ART (self-myofascial release, mobility and stability exercises, and cycle ergometer exercise). The intervention was conducted after a match with assessments immediately before and after the intervention and again 24 h after the intervention.

Results: A significant interaction effect (F2,36 = 4.503, p = 0.018, η2 = 0.130) was observed, indicating that the decrease of CK from pre-intervention to 24 h post-intervention was greater in the INPT than in the ART group. Lower limb skin temperature was significantly lower after INPT than after ART (p < 0.003).

Conclusions: Serum CK level and skin temperature of lower limbs showed better recovery up to 24 h after the intervention with INPT in elite soccer players.

The effects of aerobic, resistance, and meditative movement exercise on sleep in individuals with depression: protocol for a systematic review and network meta-analysis

BACKGROUND

The main objective of this review is to assess the effects of aerobic, resistance, and meditative movement exercise on sleep quality in patients with unipolar depression. A secondary goal is to ascertain the effects on sleep duration, sleepiness, daytime functioning, use of hypnotics, and adverse events.

METHODS

A systematic computerized search will be performed in the following online databases: PubMed, EMBASE (on Ovid), Cochrane Library, PsycINFO (on Ovid), SPORTDiscus (on EBSCOhost), CINHAL (on EBSCOhost), Clinicaltrials.gov , WHO International Clinical Trials Registry, OpenGrey, and ProQuest Dissertations and Theses. Bibliographies of all included studies as well as any other relevant reviews identified via the search will be screened. Randomized trials using aerobic, resistance, or meditative movement exercise interventions which target sleep as a primary or secondary outcome will be included. The primary outcome will be differences in sleep quality at post-intervention. Secondary outcomes will be adverse events, differences in sleep duration, daytime sleepiness and functioning, and the use of hypnotics at post-intervention. Two authors will independently screen the identified records. Disagreement will be resolved by consensus or if no consensus can be reached by adjudication of a designated third reviewer. Data extraction will be done independently by two authors using a standardized and piloted data extraction sheet. Bias in individual studies will be assessed using the revised Cochrane risk of bias tool. The certainty of evidence across all outcomes will be evaluated using the CINeMA (Confidence in Network Meta-Analysis) framework. A frequentist network meta-analysis will be conducted. The systematic review and network meta-analysis will be presented according to the PRISMA for Network Meta-Analyses (PRISMA-NMA) guideline.

DISCUSSION

This systematic review and network meta-analysis will provide a synthesis of the currently available evidence concerning the effects of aerobic, resistance, and meditative movement exercises on sleep in patients with unipolar depression. Thereby, we hope to accelerate the consolidation of evidence and inform decision-makers on potential benefits and harms.

SYSTEMATIC REVIEW REGISTRATION

The protocol has been registered at the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42019115705).

Changes in local skin temperature after the application of a pulsed Nd:YAG laser to healthy subjects: a prospective crossover controlled trial

Pulsed Nd:YAG laser (1064 nm) is a recent modality that is used for the rehabilitation of musculoskeletal disorders, but there is no evidence about its thermal effects. The aim of the study was to investigate the changes in local skin temperature (LST) after the application of a pulsed Nd:YAG laser to healthy subjects. The study participants were 30 male subjects with an average age of 21.96 (± 0.92) years. A rectangular area (15 × 10 cm²) was marked at the front of the dominant thigh and scanned with a laser beam at 3000 J with 20 J/cm² for 15 min. The other thigh was considered as a control side. The minimum, average, and maximum LSTs were measured using a thermographic camera. The measurements were performed before laser application, immediately after, and then every minute until the LST returned to the pre-treatment value. An independent t test and repeated measures ANOVA were used to analyze the changes in LST. The level of significance was set at p < 0.05. The pulsed Nd:YAG laser significantly increased the minimum, average, and maximum LSTs in comparison with the control. The increase was significant for up to 5 min after the application, and it took 10 min to reach the baseline values. The level of increase was 1.23-4.03 °C, and the average increase was 2.6 °C. The pulsed Nd:YAG laser significantly increased the minimum, average, and maximum LSTs of the thigh area in normal subjects, and the thermal effect lasted for 5 min after application.

Can infrared thermography be used to monitor fatigue during exercise? A case study

BACKGROUND

Infrared thermographic imaging (IRTG) is a safe and reliable technology used to monitor skin temperature. The main aim of our study was to evaluate the relationship between skin temperature changes and muscle fatigue in order to answer the main research question if IRTG can be used to monitor muscle fatigue.

METHODS

This was a case study performed on a 23-year-old trained middle distance runner. After warm-up the subject was exercising on the dynamometer for 7.5 min at 120°/s performing only concentric contractions of quadriceps. At the same time IRTG recording of both (exercising and non-exercising) quadriceps was performed.

RESULTS

A correlational analysis that was performed in order to quantify the relationship between power and temperature change over time has shown that there is a significant negative correlation between skin temperature increase and power decrease (r = -0.543, p = 0.036) of exercising quadriceps. In linear regression model the exercising quadriceps power could be predicted from skin temperature. No such relationships were noted for the non-exercising limb that served as a control.

CONCLUSION

We believe that correlation between skin temperature change and muscle power output as described in this case study deserves further analysis on the larger sample including subjects of the different ages, health status, and physical abilities in order to create a new tool for monitoring the muscle fatigue.