The relationship between intramuscular temperature, skin temperature, and adipose thickness during cryotherapy and rewarming

Arm cooling selectively impacts sensorimotor control

The benefits of cold have long been recognized in sport and medicine. However, it also brings costs, which have more rarely been investigated, notably in terms of sensorimotor control. We hypothesized that, in addition to peripheral effects, cold slows down the processing of proprioceptive cues, which has an impact on both feedback and feedforward control. We therefore compared the performances of participants whose right arm had been immersed in either cold water (arm temperature: 14°C) or lukewarm water (arm temperature: 34°C). In experiment 1, we administered a Fitts's pointing task and performed a kinematic analysis to determine whether sensorimotor control processes were affected by the cold. Results revealed 1) modifications in late kinematic parameters, suggesting changes in the use of proprioceptive feedback, and 2) modifications in early kinematic parameters, suggesting changes in action representations and/or feedforward processes. To explore our hypothesis further, we ran a second experiment in which no physical movement was involved, and thus no peripheral effects. Participants were administrated a hand laterality task, known to involve implicit motor imagery and assess the internal representation of the hand. They were shown left- and right-hand images randomly displayed in different orientations in the picture plane and had to identify as quickly and as accurately as possible whether each image was of the left hand or the right hand. Results revealed slower responses and more errors when participants had to mentally rotate the cooled hand in the extreme orientation of 160°, further suggesting the impact of cold on action representations.NEW & NOTEWORTHY We investigated how arm cooling modulates sensorimotor representations and sensorimotor control. Arm cooling induced changes in early kinematic parameters of pointing, suggesting an impact on feedforward processes or hand representation. Arm cooling induced changes in late kinematic parameters of pointing, suggesting an impact on feedback processes. Arm cooling also affected performance on a hand laterality task, suggesting that action representations were modified.

Acute Effects of Varied Back Squat Activation Protocols on Muscle-Tendon Stiffness and Jumping Performance

ABSTRACT

Krzysztofik, M, Wilk, M, Pisz, A, Kolinger, D, Tsoukos, A, Zając, A, Stastny, P, and Bogdanis, GC. Acute effects of varied back squat activation protocols on muscle-tendon stiffness and jumping performance. J Strength Cond Res 37(7): 1419-1427, 2023-Intensity, movement velocity, and volume are the principal factors to successfully use postactivation performance enhancement. Therefore, 15 resistance-trained volleyball players completed 3 different back squat configurations as a conditioning activity (CA) in randomized order: (a) 3 sets of 3 repetitions at 85% 1RM (HL); (b) a single set of back squats at 60% 1RM until 10% mean velocity loss (VB); (c) and 2 sets of back squats at 60% 1RM until 10% mean velocity loss (2VB) on subsequent countermovement jump performance, Achilles tendon, and vastus lateralis stiffness with concomitant front thigh skin surface temperature assessment. The measurements were performed 5 minutes before the CA and at 2, 4, 6, 8, and 10 minutes. The jump height was significantly increased in the second minute and at peak, post-CA compared with baseline for all conditions ( p = 0.049; ES = 0.23 and p < 0.001; ES = 0.37). Skin surface temperature was significantly increased for all post-CA time points compared with baseline in the 2VB condition ( p from <0.001-0.023; ES = 0.39-1.04) and in the fourth minute and at peak post-CA in HL condition ( p = 0.023; ES = 0.69 and p = 0.04; ES = 0.46), whereas for the VB condition, a significant decrease in peak post-CA was found ( p = 0.004; ES = -0.54). Achilles tendon stiffness was significantly decreased for second, fourth, eighth, 10th, and peak post-CA in comparison to baseline for all conditions ( p from p = 0.004-0.038; ES = -0.47 to -0.69). Vastus lateralis stiffness was significantly decreased for peak post-CA compared with baseline for all conditions ( p = 0.017; ES = -0.42). We recommend using a single set of barbell squats with a 10% velocity loss as a mechanism of fatigue control to acutely improve jump height performance and avoid unnecessary increases in training volume.

The Effectiveness of Active External Warming of Patient Concurrently With Ice Application on the Incision Site on Post-Thoracotomy Pain and Analgesic Consumption

The aim of study is to investigate the effects of active external warming of patient concurrently with application of ice to incision site on thoracotomy pain and analgesic consumption. The research is a quasi-experimental design with control and study groups. The study was conducted in 2018 and 2019. A total of 70 patients were included in the study: 35 in the control group and 35 in the study group. The mean verbal pain scale values were significantly lower in the intervention group (2.85 point) than in the control group (4.57 point; p < .001). Opioid consumption rate was high in control group patients (77.1% tramadol 30 mg; 45.7% morphine sulfate 5 mg) In contrast, the rate of opioid consumption was lower in patients in the intervention group (40% tramadol 30 mg; 17% morphine sulfate 5 mg). Active external warming and ice application on the incision area, could reduce the intensity of thoracotomy pain.

The Use of Cryotherapy in Cosmetology and the Influence of Cryogenic Temperatures on Selected Skin Parameters—A Review of the Literature

Cryotherapy is becoming an increasingly popular method used in medicine, physiotherapy, and cosmetology. It is used in the form of whole-body cryotherapy (WBC) and local cryotherapy. It is a tool for achieving analgesic and anti-inflammatory effects. Since the beginning of its use, its influence on the mental state has also been pointed out. The aim of this study was to analyze the available literature on the effect of cryogenic temperatures on the skin and the mechanisms induced by such a stimulus and its influence on well-being. A literature search of keywords or phrases was performed in PubMed®. Various effects of WBC on skin characteristics (hydration, pH, level of transepidermal water loss), mechanisms of anti-inflammatory effects, and effects on adipocytes were shown. Research on the impact of individual skin characteristics is not consistent. Positive effects on the reduction of inflammation and oxidative stress have been noted. Cryotherapy is also successfully used in dermatology to treat lentil spots, actinic keratosis, and ingrown toenails, remove viral warts, or relieve itching in atopic dermatitis. The results of the review also indicate the effectiveness of WBC as an adjunctive treatment for obesity. The number of papers available on the direct effects of WBC on the skin is still limited, despite the fact that it represents the first contact of the human body with cryogenic temperatures. Available data show that cold as a physical stimulus can be a safe and useful tool in cosmetology.

Relationship between Intramuscular and Skin Temperature and Anthropometric Consideration for Post-exercise Cryotherapy: Developing Prediction Models for Clinical Use

OBJECTIVES To investigate the relationships among intramuscular cooling rates during (IM cooling rate) and after cold water immersion (CWI) (Post-IM cooling rate), skin tissue cooling rate during CWI (skin cooling rate), and anthropometric characteristics, and develop prediction models to assist clinical decision making.METHODS After a 30-min cycling trial, 16 young healthy adults received a CWI treatment (10 °C) until either intramuscular thigh temperature (2 cm sub-adipose) of the rectus femoris decreased 7 °C below preexercise level or 30 minutes was reached. Temperatures were recorded using skin and implantable finewire thermocouples. Before the cycling trial, %BF, anterior thigh adipose tissue thickness, muscle thickness, total thigh volume, and thigh circumference were measured. Pearson’s correlation coefficients were used to determine significant predictors of IM and Post-IM cooling rates (cooling rate: the amount of temperature reduction per minute). All predictors, including skin cooling rate, %BF, adipose tissue thickness, muscle thickness, total thigh volume, and thigh circumference, were included in multiple linear regression models to figure out factors that best predict the IM and Post-IM cooling rates.RESULTS Correlation analysis demonstrated significant correlations between IM cooling rate and skin cooling rate (r=.85), %BF (r=-.79), and adipose tissue thickness (r=-.79), and between Post-IM cooling rate and thigh circumference (r=-.68), adipose tissue thickness (r=-.58), total thigh volume (r=-.56), and %BF (r=-.53). Regression models identified skin cooling rate and %BF to have the greatest predictability for IM cooling rate (R2 =.82) and muscle thickness and thigh circumference to have the greatest predictability for the Post-IM cooling rate (R2 =.68).CONCLUSIONS This study provides justification for the use of skin cooling rates during CWI and %BF to estimate IM cooling rate and muscle thickness and thigh circumference to estimate Post-IM cooling rate. These findings will help practitioners to determine the duration of CWI treatment after exercise.

Thermographic Evaluation of the Duration of Skin Cooling After Cryotherapy in Dogs Following Tibial Plateau Leveling Osteotomy Surgery

Objective

To evaluate the duration of cooling after cryotherapy on the skin over stifle joints in dogs after tibial plateau leveling osteotomy (TPLO) surgery using thermography.

Materials and Methods

Seventeen client-owned dogs of various breeds were enrolled in the study. Dogs underwent TPLO surgeries, and on the next day, thermal imaging was performed on the operated stifle prior to cryotherapy for baseline. Orthogonal views were repeated at 30-min intervals until the skin over the stifle had thermally equilibrated. An ice pack was applied for 20 min on the medial and lateral aspects of the stifle. Each stifle was then re-imaged every 15 min for the first 60 min then every 30 min subsequently until the temperature was within 1°C of the pre-cryotherapy temperature.

Results

Mean skin temperature of the medial view showed no significance difference compared to baseline value at 45 min after cryotherapy was discontinued and after 60 min for the lateral and cranial views. Mean skin temperature was overall higher in the medial view compared to the lateral and cranial during the rewarming period (except immediately after cold application). Mean skin temperatures of all views combined showed a significant decrease in temperature during cryotherapy application, with a slow increase until a plateau was reached after 45 min of rewarming.

Conclusions and Clinical Relevance

Dogs undergoing TPLO for cranial cruciate ligament injury showed quicker rewarming period of superficial tissues compared to previous studies. Cryotherapy is a beneficial modality to reduce superficial tissue temperature in dogs undergoing TPLO, acknowledging that these dogs may require more frequent cryotherapy post-operatively due to more rapid rewarming time compared to dogs without surgery.

Short-Term Skin Temperature Responses to Endurance Exercise: A Systematic Review of Methods and Future Challenges in the Use of Infrared Thermography

BACKGROUND

Body temperature is often assessed in the core and the skin. Infrared thermography has been used to measure skin temperature (Tsk) in sport research and clinical practice. This study aimed to explore the information reported to date on the use of infrared thermography to detect short-term Tsk responses to endurance exercise and to identify the methodological considerations and knowledge gaps, and propose future directions.

METHOD

A web search (PubMed, Science Direct, Google Scholar, and Web of Science) was conducted following systematic review guidelines, and 45 out of 2921 studies met the inclusion criteria (endurance sports, since 2000, English, full text available).

RESULTS

A total of 45 publications were extracted, in which most of the sample were runners (n = 457, 57.9%). Several differences between IRT imaging protocols and ROI selection could lead to potential heterogeneity of interpretations. These particularities in the methodology of the studies extracted are widely discussed in this systematic review.

CONCLUSIONS

More analyses should be made considering different sports, exercise stimuli and intensities, especially using follow-up designs. Study-derived data could clarify the underlying thermo physiological processes and assess whether Tsk could be used a reliable proxy to describe live thermal regulation in endurance athletes and reduce their risk of exertional heat illness/stroke. Also more in-depth analyses may elucidate the Tsk interactions with other tissues during exercise-related responses, such as inflammation, damage, or pain.

Cryotherapy and compression in sports injury management: a scoping review

Background/Aims

For the management of sports injury, cryotherapy is commonly applied, yet modalities differ extensively in application including levels of compression. The aim of this study was to provide a comprehensive review of the current position in the literature on contemporary cryo-compression applications for musculoskeletal sports injury management.

Methods

A total of eight databases were searched: Sport Discus, Science Direct, CINHAL, Scopus, PubMed, Cochrane, ProQuest and MEDLINE. Publications were restricted to 30 years and had to be in the English language. Medical subject headings, free-text words, and limiting descriptors for concepts related to cryotherapy and compression for sports injury were applied. Inclusion criteria determined at least one modality of cryotherapy treatment applied simultaneous to compression or as a comparison, relevant to sports injury management. Modalities included cryo-compressive devices and gel/ice packs, in association with concomitant compression. Male, female, healthy and injured participants were included. Two reviewers independently selected eligible articles, resulting in 22 studies meeting the inclusion criteria following full-text appraisal.

Results

Inconsistent methodologies, low sample sizes and variability in outcome measures provided uncertainty over optimum protocols. A lack of previous understanding in the protocols in the available literature for isolated cryotherapy/compression applications prevents understanding of the therapeutic benefits of combined cryo-compression. No definitive agreement behind optimal cryo-compression applications were identified collectively from studies other than the consensus that compression aids the magnitude of cooling.

Conclusions

Although compression appears a useful adjunct to cooling modalities for the management of sports injury, no definitive agreement on optimum compression concurrent with cooling protocols were drawn from the studies. This was because of several methodological gaps in reporting throughout studies, highlighting a lack of studies that represent applications of compression and cryotherapy within a sporting context or applied nature within the available research.

A three-dimensional model of transient bioheat transfer in the lower extremity during cryotherapy

The purpose of this research was to create a computational model of the human thigh undergoing cryotherapy. The tissue temperatures were measured for five cold pack temperatures of -8°C, -4°C, 0°C, 4°C, and 8°C in addition to six different time intervals of cold application and ice removal. The depth of cold penetration and duration of local tissue cooling were investigated at 10 points during 30 min of application and 7 h of post-application. The model was created in CATIA, using a mid-axial cut of the human thigh MRI without pathology. After validation by the available clinical data, this research applied the finite-volume discretization method to solve bioheat transfer equations. A 16°C decrease in the cold pack temperature reduced the tissue temperatures located 1 and 2 cm below the fat by almost 3.34°C and 1.4°C, respectively, after 30 min of cold application. It took the tissues 10-15 min to start cooling down, and the temperature reached its plateau after 100 min. Thirty minutes of cold application declined the superficial tissue and deep tissue temperatures near the bone by 22.59°C and 0.48°C, respectively. Intense cryotherapy led to an insignificant change in the deep tissue temperature at 2 cm and deeper below the fat tissue. After ice removal, tissues continued cooling down for about 8 min until 40 min, depending on the tissue depth. This study proposed a 100-min cold therapy with 10 min of ice removal to optimize tissue cooling.

Intramuscular Temperature Changes in the Quadriceps Femoris Muscle After Post-Exercise Cold-Water Immersion (10°C for 10 min): A Systematic Review With Meta-Analysis

Post-exercise cold-water immersion (CWI) is a widely accepted recovery strategy for maintaining physical performance output. However, existing review articles about the effects of CWI commonly pool data from very heterogenous study designs and thus, do rarely differentiate between different muscles, different CWI-protocols (duration, temperature, etc.), different forms of activating the muscles before CWI, and different thickness of the subcutaneous adipose tissue. This systematic review therefore aimed to investigate the effects of one particular post-exercise CWI protocol (10°C for 10 min) on intramuscular temperature changes in the quadriceps femoris muscle while accounting for skinfold thickness. An electronic search was conducted on PubMed, LIVIVO, Cochrane Library, and PEDro databases. Pooled data on intramuscular temperature changes were plotted with respect to intramuscular depth to visualize the influence of skinfold thickness. Spearman's rho (r_s) was used to assess a possible linear association between skinfold thickness and intramuscular temperature changes. A meta-analysis was performed to investigate the effect of CWI on pre-post intramuscular temperature for each measurement depth. A total of six articles met the inclusion criteria. Maximum intramuscular temperature reduction was 6.40°C with skinfold thickness of 6.50 mm at a depth of 1 cm, 4.50°C with skinfold thickness of 11.00 mm at a depth of 2 cm, and only 1.61°C with skinfold thickness of 10.79 mm at a depth of 3 cm. However, no significant correlations between skinfold thickness and intramuscular temperature reductions were observed at a depth of 1 cm (r _s = 0.0), at 2 cm (r _s = -0.8) and at 3 cm (r _s = -0.5; all p > 0.05). The CWI protocol resulted in significant temperature reductions in the muscle tissue layers at 1 cm (d = -1.92 [95% CI: -3.01 to -0.83] and 2 cm (d = -1.63 [95% CI: -2.20 to -1.06]) but not at 3 cm (p < 0.05). Skinfold thickness and thus, subcutaneous adipose tissue, seems to influence temperature reductions in the muscle tissue only to a small degree. These findings might be useful for practitioners as they demonstrate different intramuscular temperature reductions after a specific post-exercise CWI protocol (10°C for 10 min) in the quadriceps femoris muscle.

The cold truth: the role of cryotherapy in the treatment of injury and recovery from exercise

Cryotherapy is utilized as a physical intervention in the treatment of injury and exercise recovery. Traditionally, ice is used in the treatment of musculoskeletal injury while cold water immersion or whole-body cryotherapy is used for recovery from exercise. In humans, the primary benefit of traditional cryotherapy is reduced pain following injury or soreness following exercise. Cryotherapy-induced reductions in metabolism, inflammation, and tissue damage have been demonstrated in animal models of muscle injury; however, comparable evidence in humans is lacking. This absence is likely due to the inadequate duration of application of traditional cryotherapy modalities. Traditional cryotherapy application must be repeated to overcome this limitation. Recently, the novel application of cooling with 15 °C phase change material (PCM), has been administered for 3-6 h with success following exercise. Although evidence suggests that chronic use of cryotherapy during resistance training blunts the anabolic training effect, recovery using PCM does not compromise acute adaptation. Therefore, following exercise, cryotherapy is indicated when rapid recovery is required between exercise bouts, as opposed to after routine training. Ultimately, the effectiveness of cryotherapy as a recovery modality is dependent upon its ability to maintain a reduction in muscle temperature and on the timing of treatment with respect to when the injury occurred, or the exercise ceased. Therefore, to limit the proliferation of secondary tissue damage that occurs in the hours after an injury or a strenuous exercise bout, it is imperative that cryotherapy be applied in abundance within the first few hours of structural damage.

Pre-exercise skin temperature evolution is not related with 100 m front crawl performance

During the transition between warm-up and competition there is a change in core, muscle and (eventually) skin temperature that may affect swimming performance. We have aimed to assess skin temperature evolution during transition phases of different durations before a typical front crawl effort and to investigate its relationship with performance. Following a standardized warm-up, nine adolescent male swimmers performed three maximal randomized 100 m maximum front crawl trials after 10, 20 and 45 min transition phases. Skin temperature, performance (time, stroke frequency, length and index, and propelling efficiency), heart rate, lactate and perceived effort were assessed. Data showed a skin temperature log increase over time (R² > 0.96, p < 0.01) without differences from the 15 min with the following instants. Performance and psychophysiological variables were similar between transition phases. However, skin temperature at the end of the transition periods, i.e., just before the 100 m trials, was lower in the 10 min than the 20 and 45 min transitions (32.0 ± 0.6 vs 33.0 ± 0.4 and 33.5 ± 0.5 °C, respectively). The main finding was that no relevant relationships were observed between pre-test skin temperature and performance times (|r| < 0.6, p > 0.05) for the studied transition phases. We have concluded that transitions longer than 10 min will not present thermal changes and that, within the physiologic limits studied, pre-exercise skin temperature does not influence swimming performance.

Effects of Active and Passive Warm-ups on Range of Motion, Strength, and Muscle Passive Properties in Ankle Plantarflexor Muscles

ABSTRACT

Takeuchi, K, Takemura, M, Nakamura, M, Tsukuda, F, and Miyakawa, S. Effects of active and passive warm-ups on range of motion, strength, and muscle passive properties in ankle plantarflexor muscles. J Strength Cond Res 35(1): 141-146, 2021-The purpose of this study was to examine the effects of active and passive warm-ups on flexibility and strength of calf muscles. Fourteen healthy males (age: 23.1 ± 2.6 years, height: 172.7 ± 5.6 cm, and body mass: 64.5 ± 7.0 kg) performed 3 types of warm-ups respectively for 10 minutes in a random order: an active warm-up by pedaling a cycling ergometer, an active warm-up doing repeated isometric contractions, and a passive warm-up in a hot water bath. To assess flexibility, range of motion (ROM) of ankle dorsiflexion, passive torque of ankle plantarflexion, and muscle tendon junction (MTJ) displacement were measured and then muscle tendon unit (MTU) stiffness was calculated. After the flexibility assessment, peak torque during maximum voluntary isometric contraction was measured to assess the isometric strength. These data were compared before and after each warm-up. As a result, all 3 types of warm-ups increased ROM (p < 0.05) and passive torque at terminal ROM (p < 0.01), but there were no significant changes in MTU stiffness or MTJ displacement. The active warm-up by pedaling a cycling ergometer increased peak torque during isometric contraction (p < 0.05), whereas the other warm-ups did not show significant alterations. In conclusion, the active warm-up with aerobic exercise increased flexibility and strength of the calf muscles.

Effect of environmental temperature change on the neuromechanical function of the quadriceps muscle

AbstractThis study compared neuromechanical characteristics of voluntary (maximum voluntary contraction (MVC) peak torque, rate of torque development (RTD), voluntary activation (VA)) and electrically stimulated contractions (peak torque, RTD) when performed under the same temperature conditions. Twelve physically active males performed two isometric MVCs of the quadriceps muscle group in an isokinetic dynamometer. The MVCs were performed after lower limb submersion for 20 min in hot (40°C) or cold (10°C) water. A control MVC was performed in ambient room temperature (17 ± 0.7°C). Electrical twitches were delivered at rest pre-MVC (Unpotentiated), during the plateau phase of the MVC (Superimposed) and post-MVC (Potentiated). Peak torque for MVC, Unpotentiated and Potentiated was recorded. RTD was calculated for the MVC (at 50, 100, 150, 200 ms and peak torque time points), Unpotentiated and Potentiated twitches, while VA (using the central activation ratio method) was calculated. There was no significant change between conditions in MVC peak torque, MVC RTD, VA and (averaged) twitch peak torque (p > 0.05). Twitch RTD for the hot condition (1025.0 ± 163.0 N·m·s^-1) was significantly higher (p = 0.003) than control (872.3 ± 142.9 N·m·s^-1). In conclusion, environmental temperature changes, in the range examined, do not affect the ability to generate maximum torque or any of the RTD parameters in maximum voluntary isometric contractions. In contrast, increased heat results in higher RTD in electrically stimulated contractions, most likely induced by reduced contraction time. This has practical implications for the use of electromyostimulation for injury prevention.

Effects of Ice Massage Prior to an Iontophoresis Treatment Using Dexamethasone Sodium Phosphate

CONTEXT

Low current intensity iontophoresis treatments have increased skin perfusion over 700% from baseline potentially altering drug clearance from or diffusion to the targeted area.

OBJECTIVE

To determine the effects of a preceding 10-minute ice massage on subcutaneous dexamethasone sodium phosphate (Dex-P) concentration and skin perfusion during and after a 4-mA iontophoresis treatment.

DESIGN

Controlled laboratory study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twenty-four participants (male = 12, female = 12; age = 25.6 [4.5] y, height = 173.9 [8.51] cm, mass = 76.11 [16.84] kg).

INTERVENTION(S)

Participants were randomly assigned into 2 groups: (1) pretreatment 10-minute ice massage and (2) no pretreatment ice massage. Treatment consisted of an 80-mA·minute (4 mA, 20 min) Dex-P iontophoresis treatment. Microdialysis probes (3 mm deep in the forearm) were used to assess Dex-P, dexamethasone (Dex), and its metabolite (Dex-Met) concentrations. Skin perfusion was measured using laser Doppler flowmetry.

MAIN OUTCOME MEASURE(S)

Microdialysis samples were collected at baseline, at conclusion of treatment, and every 20 minutes posttreatment for 60 minutes. Samples were analyzed to determine Dex-Total (Dex-Total = Dex-P + Dex + Dex-Met). Skin perfusion was calculated as a percentage change from baseline. A mixed-design analysis of variance was used to determine Dex-Total and skin perfusion difference between groups overtime.

RESULTS

There was no difference between groups (P = .476), but [Dex-Total] significantly increased over the course of the iontophoresis and posttreatment time (P < .001). Dex-P was measured in 18 of 24 participants with a mean concentration of 0.67 (1.09) μg/mL. Skin perfusion was significantly greater in the no ice treatment group (P = .002). Peak skin perfusion reached 27.74% (47.49%) and 117.39% (103.45%) from baseline for the ice and no ice groups, respectively.

CONCLUSIONS

Ice massage prior to iontophoresis does not alter the tissue [Dex-Total] even with less skin perfusion.

Changes in Muscle Contractile Properties after Cold- or Warm-Water Immersion Using Tensiomyography: A Cross-Over Randomised Trial

Muscle contractile properties in clinical practice are often measured using either subjective scales or high-cost, inaccessible equipment. In this randomised cross-over study, we aimed to explore the use of tensiomyography (TMG) to assess changes in muscle contractile properties after cold- and warm-water immersion. The muscle contractile properties of the biceps femoris (BF) were assessed using TMG in 12 healthy active men (mean age 23 ± 3 years, Body Mass Index 22.9 ± 1.3 kg/m²) before and after a 20-min warm- or cold-water immersion over a period of 40 min. Muscle displacement (Dm) and contraction time (Tc) were registered as the main variables of the study. There was a significant condition by time interaction for Dm (p < 0.01). Post hoc analysis showed that, compared to the baseline, there was an increase in Dm 40 min after warm-water immersion (p < 0.01) and a decrease at 10 min after cold-water immersion (p < 0.01). No significant effect was found for Tc. Our results indicate that muscle contractile properties are affected by water temperature and time after the immersion; therefore, these factors should be taken into account when water-immersion is used as a recovery strategy.

Volume of water added to crushed ice affects the efficacy of cryotherapy: a randomised, single-blind, crossover trial

OBJECTIVE

To compare the effects of different cryotherapeutic preparations.

DESIGN

Randomised, single-blind, crossover trial.

SETTING

University laboratory.

PARTICIPANTS

Sixteen healthy women.

INTERVENTIONS

Participants were randomised to receive three cryotherapeutic preparations: pure ice (500g), watered ice (500g of ice in 500ml of water) and wetted ice (500g of ice in 50ml of water).

MAIN OUTCOME MEASURES

The primary outcome was skin surface temperature after cryotherapy, measured at the central point of application, and the minimum temperature of the region of interest (ROI). The secondary outcome was the surface area cooled to <13.6°C, which is the recommended temperature to achieve therapeutic effects.

RESULTS

After application of ice, mean skin surface temperature at the central point was 4.6 [standard deviation (SD) 1.9] °C for the pure ice preparation, 4.9 (SD 2.5) °C for the wetted ice preparation, and 9.6 (SD 1.8) °C for the watered ice preparation. When compared with the watered ice preparation, this represented a mean difference (MD) of 5.0°C for the pure ice preparation [95% confidence interval (CI) 4.0 to 6.0; P<0.001] and an MD of 4.7°C for the wetted ice preparation (95% CI 2.5 to 6.8; P<0.001). The minimum temperatures in the ROI were also lower for the pure ice preparation 3.0 (SD 0.9) °C and the wetted ice preparation 2.8 (SD 0.6) °C than the watered ice preparation 7.9 (SD 1.5) °C. This represented an MD of 4.8°C for the pure ice preparation (95% CI 4.0 to 5.7; P<0.001) and 5.1°C for the wetted ice preparation (95% CI 4.0 to 6.2; P<0.001].

CONCLUSIONS

Application of pure ice or wetted ice led to a greater decrease in skin surface temperature compared with watered ice. For clinical purposes, combining equal parts of water and ice could decrease this effect.

CLINICAL TRIAL REGISTRATION NUMBER

Clinicaltrials.gov (NCT03414346).

Cooling of Lower Extremity Muscles According to Subcutaneous Tissue Thickness

CONTEXT

When using an ice bag, previous researchers recommended cooling times based on the amount of subcutaneous tissue. Unfortunately, many clinicians are unaware of these recommendations or whether they can be applied to other muscles.

OBJECTIVE

To examine if muscles of the lower extremity cool similarly based on recommended cooling times.

DESIGN

Crossover study.

SETTING

Athletic training laboratory.

PATIENTS OR OTHER PARTICIPANTS

Fourteen healthy participants volunteered (8 men, 6 women; age = 21.1 ± 2.2 years, height = 174.2 ± 4.5 cm, weight = 74.0 ± 7.5 kg).

INTERVENTION(S)

Subcutaneous tissue thickness was measured at the largest girth of the thigh, medial gastrocnemius, and medial hamstring. Participants were randomized to have either the rectus femoris or medial gastrocnemius and medial hamstring tested first. Using sterile techniques, the examiner inserted a thermocouple 1 cm into the muscle after accounting for subcutaneous tissue thickness. After the temperature stabilized, a 750-g ice bag was applied for 10 to 60 minutes to the area(s) for the recommended length of time based on subcutaneous adipose thickness (0 to 5 mm [10 minutes]; 5.5 to 10 mm (25 minutes]; 10.5 to 15 mm [40 minutes]; 15.5 to 20 mm [60 minutes)]. After the ice bag was removed, temperature was monitored for 30 minutes. At least 1 week later, each participant returned to complete testing of the other muscle(s).

MAIN OUTCOME MEASURE(S)

Intramuscular temperature (°C) at baseline, end of treatment time (0 minutes), and posttreatment recovery (10, 20, and 30 minutes postintervention).

RESULTS

At the end of treatment, temperature did not differ by subcutaneous tissue thickness (10 minutes = 29.0°C ± 3.8°C, 25 minutes = 28.7°C ± 3.2°C, 40 minutes = 28.7°C ± 6.0°C, 60 minutes = 30.0°C ± 2.9°C) or muscle (rectus femoris = 30.1°C ± 3.8°C, gastrocnemius = 28.6°C ± 5.4°C, hamstrings = 28.1°C ± 2.5°C). No significant interaction was present for subcutaneous tissue thickness or muscle (P ≥ .126).

CONCLUSIONS

Lower extremity muscles seemed to cool similarly based on the recommended cooling times for subcutaneous tissue thickness. Clinicians should move away from standardized treatment times and adjust the amount of cooling time by ice-bag application based on subcutaneous tissue thickness.

Kinesio® Tape Barrier Does Not Inhibit Intramuscular Cooling During Cryotherapy

CONTEXT

Allied health care professionals commonly apply cryotherapy as treatment for acute musculoskeletal trauma and the associated symptoms. Understanding the impact of a tape barrier on intramuscular temperature can assist in determining treatment duration for effective cryotherapy.

OBJECTIVE

To determine whether Kinesio® Tape acts as a barrier that affects intramuscular temperature during cryotherapy application.

DESIGN

A repeated-measures, counterbalanced design in which the independent variable was tape application and the dependent variable was muscle temperature as measured by thermocouples placed 1 cm beneath the adipose layer. Additional covariates for robustness were body mass index and adipose thickness.

SETTING

University research laboratory.

PARTICIPANTS

Nineteen male college students with no contraindications to cryotherapy, no known sensitivity to Kinesio® Tape, and no reported quadriceps injury within the past 6 months.

INTERVENTION

Topical cryotherapy: cubed ice bags of 1 kg and 0.5 kg.

MAIN OUTCOME MEASURES

Intramuscular temperature.

RESULTS

The tape barrier had no statistically significant effect on muscle temperature. The pattern of temperature change was indistinguishable between participants with and without tape application.

CONCLUSIONS

Findings suggest that health care professionals can combine cryotherapy with a Kinesio® Tape application without any need for adjustments to cryotherapy duration.

Cross-sectional study of quadriceps properties and postural stability in patients with chronic stroke and limited vs. non-limited community ambulation

Background: Changes in the paretic-side metabolism post-stroke and quadriceps muscle mechanical properties favour muscle wasting, affecting postural instability and walking impairment. Further clarification is needed in subjects post-stroke who show limited or non-limited community ambulation. Objectives: To analyze between-limb differences in quadriceps muscle thickness, strength and thigh cutaneous temperature, as well as investigate postural stability in subjects with chronic stroke and limited vs. non-limited community ambulation and compared against healthy controls. Methods: In this controlled cross-sectional study, 26 participants with chronic hemiparesis post-stroke (divided in a slow gait group (SG<0.8 m/s) (n = 13) and a fast gait group with full community ambulation speed (FG≥0.8 m/s)) and 18 healthy people were recruited. Thigh surface temperature, rectus femoris (RF) and vastus intermedius (VI) muscles thickness, quadriceps' isometric maximal voluntary contraction and postural stability were measured. Results: The SG presented significantly lower RF (P = .019) and VI (P = .006) muscle thickness, less peak force (P < .001) and lower temperature (P = .002) in the paretic vs the non-paretic limb. The FG showed significantly lower VI thickness (P = .036) and peak force (P < .001) in the paretic vs the non-paretic limb. Regarding balance, all indices were worse in the SG versus the FG and CG. Conclusions: Subjects of the FG, despite showing full community ambulation speed, had less quadriceps strength and VI muscle thickness but not RF muscle wasting in the paretic limb. The paretic VI muscle wasting may be an important factor to reach normal walking. The SG showed between-limb differences in all the studied variables and the worst postural stability.

The effect of varying degrees of compression from elastic vs plastic wrap on quadriceps intramuscular temperature during wetted ice application

The aim of this study was to evaluate and compare the effectiveness of wetted ice bag, applied with high compression elastic wrap or held in place with low compression plastic wrap, on reducing vastus lateralis intramuscular temperature and skin surface temperature. Ten healthy male participants had wetted ice packs applied to a standardized area on the anterior aspect of the quadriceps simultaneously to both legs for 30 minutes. The ice pack was secured with high compression (elastic wrap) to the left anterior thigh (60.6 ± 8.1 mm Hg) and low compression (plastic wrap) to the right anterior thigh (15.5 ± 4.0 mm Hg). Intramuscular temperature (1 and 3 cm) and skin temperature of the vastus lateralis were measured continuously during a 10-minute baseline period, 30-minute treatment period, and a 60-minute recovery period. No difference was observed between treatments in terms of the magnitude of reduction in intramuscular temperature at both 1 and 3 cm and skin temperature regardless of compression pressure (P > 0.05). Temperature upon conclusion of elastic wrap treatment was as follows: 17.8 ± 5.2°C at 1 cm and 23.1 ± 4.9°C at 3 cm; plastic wrap treatment: 17.9 ± 4.4°C at 1 cm and 24.5 ± 6.7°C at 3 cm. Plastic wraps may offer a practical alternative to elastic wraps for clinicians as they may be disposed of by the patient or athlete without having to stay at the treatment facility.

Cryotherapy in reducing pain, trismus, and facial swelling after third-molar surgery: Systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The aim of this systematic review and meta-analysis was to evaluate the efficacy of cryotherapy in reducing pain, trismus, and facial swelling in patients undergoing third-molar surgery.

TYPES OF STUDIES REVIEWED

The authors searched for randomized clinical trials in PubMed, Web of Science, SCOPUS, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Google Scholar, and OpenThesis. Eligibility criteria were population: patients submitted to removal of impacted third molars; intervention and comparison: postoperative cryotherapy versus no cold therapy; and outcomes: primary outcome was postoperative pain, and secondary outcomes were facial swelling and trismus. Eligible studies must have reported at least 1 of the outcomes of interest. After extracting data and assessing quality, the authors performed the meta-analyses.

RESULTS

The authors included 6 studies in the quantitative synthesis analysis. Differences in pain intensity were found on postoperative day 2 (weighted mean difference, -0.72; 95% confidence interval, -1.45 to 0.01; P = .05) and postoperative day 3 (weighted mean difference, -0.36; 95% confidence interval, -0.59 to -0.13; P = .002). No evidence was found that cryotherapy was effective in reducing trismus and facial swelling. The quality of evidence was graded as low.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Evidence suggests that cryotherapy may have a small benefit in reducing pain after third-molar surgery, but it is not effective on facial swelling and trismus. Owing to the lack of standardization of cold application, effective evidence-based treatment protocols for cryotherapy after third-molar surgery still need to be established.

Development of Body-Tissue Temperature-Control Transducer

The aim of this study was to develop a transducer for non-invasive temperature measurement in deeper tissue layers during tissue cooling. Simulation of the temperature field distribution in human tissues and the transducer were done, and the influence of transducer structure and material properties were studied. Using simulation results, the experimental transducer was designed for temperature measurement in deeper tissue layers during cooling. The temperature measurements with the needle thermometer and the transducer were well correlated at both before tissue cooling r = 0.723 and after cooling r = 0.945, and the temperature difference was no more than ±0.2 °C.

The Effect of Elevation on Intramuscular Tissue Temperatures

Context: Ice, compression, and elevation, or ICE, is a widely used treatment for acute musculoskeletal injuries. The effects of ice and compression on tissue temperatures have been established, but whether elevation during cryotherapy affects temperature change has not. Elevation has potential to alter local perfusion and thereby alter the balance of heat loss/heat gain, potentially impacting tissue cooling during cryotherapy. Objective: To measure the effect and interaction of ice, compression, and elevation on intramuscular temperatures. We hypothesized that elevation would not have an effect on intramuscular tissue temperature. Design: Randomized crossover study design. Setting: University athletic training facility. Patients or Other Participants: A total of 15 healthy volunteers (age 20.93 [1.67] y) provided informed consent and participated. Interventions: Participants completed 8 treatment conditions: no treatment (control), ice only (I), compression only (C), elevation only (E), ice and compression (IC), ice and elevation (IE), compression and elevation (CE), or ice, compression, and elevation (ICE). All conditions were tested on each participant with a minimum of 48 hours between each condition. Intramuscular temperatures were recorded every 30 seconds during a 1-minute preapplication, 30-minute treatment, and 20-minute postapplication period. Main Outcome Measures: The temperature difference between the mean treatment temperature and the mean preapplication temperature was compared across each measurement depth and treatment condition. Results: Non-ice treatments (control, C, E, and CE; means 33.4, 34.5, 33.7, and 34.6, respectively) had warmer intramuscular temperatures than any treatment that included ice (I, IC, IE, and ICE; means 28.4, 19.8, 28.0, and 19.3, respectively). There were no differences between IC and ICE (means 19.8 and 19.3, respectively). Ice alone was different from everything (Control, C, E, IC, CE, and ICE) except IE Conclusions: Elevation does not appear to play a role in temperature changes during cryotherapy treatments.

Examination of Intramuscular and Skin Temperature Decreases Produced by the PowerPlay Intermittent Compression Cryotherapy

CONTEXT

Previous research has found ice bags are more effective at lowering intramuscular temperature than gel packs. Recent studies have evaluated intramuscular temperature cooling decreases with ice bag versus Game Ready and with the PowerPlay system wetted ice bag inserts; however, intramuscular temperature decreases elicited by PowerPlay with the standard frozen gel pack inserts have not been examined.

OBJECTIVE

Evaluate the rate and magnitude of cooling using PowerPlay with frozen gel pack (PP-gel) option, PowerPlay with wetted ice bag (PP-ice) option, and control (no treatment) on skin and intramuscular temperature (2 cm subadipose).

DESIGN

Repeated-measures counterbalanced study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twelve healthy college-aged participants (4 men and 8 women; age = 23.08 (1.93) y, height = 171.66 (9.47) cm, mass = 73.67 (13.46) kg, and subcutaneous thickness = 0.90 (0.35) cm).

INTERVENTION(S)

PowerPlay (70 mm Hg) with either wetted ice bag or frozen gel pack was applied to posterior aspect of nondominant calf for 30 minutes; control lay prone for 30 minutes. Participants underwent each treatment in counterbalanced order (minimum 4 d, maximum 10 d between).

MAIN OUTCOME MEASURE(S)

Muscle temperature was measured via 21-gauge catheter thermocouple (IT-21; Physitemp Instruments, Inc). Skin temperature was measured via surface thermocouple (SST-1; Physitemp Instruments, Inc).

RESULTS

Significant treatment-by-time interaction for muscle cooling (F_10,80 = 11.262, P = .01, [Formula: see text], observed β = 0.905) was observed. PP-ice cooled faster than both PP-gel and control from minutes 12 to 30 (all Ps < .05); PP-gel cooled faster than control from minutes 18 to 30 (all Ps < .05). Mean decreases from baseline: PP-ice = 4.8°C (2.8°C), PP-gel = 2.3°C (0.8°C), and control = 1.1°C (0.4°C). Significant treatment-by-time interaction for skin cooling (F_10,80 = 23.920, P = .001, [Formula: see text], observed β = 0.998) was observed. PP-ice cooled faster than both PP-gel and control from minutes 6 to 30 (all Ps < .05); PP-gel cooled faster than control from minutes 12 to 30 (all Ps < .05). Mean decreases from baseline: PP-ice = 14.6°C (4.8°C), PP-gel = 4.0°C (0.9°C), and control = 1.0°C (1.0°C).

CONCLUSIONS

PP-ice produces clinically and statistically greater muscle and skin cooling compared with PP-gel and control.

Delayed effects of a 20-min crushed ice application on knee joint position sense assessed by a functional task during a re-warming period

Delayed effects of a 20-min crushed ice application on knee joint position sense assessed by a functional task during a re-warming period.

INTRODUCTION

The effect of cryotherapy on joint positioning presents conflicting debates as to whether individuals are at an increased risk of injury when returning to play following cryotherapy application at the lower limb.

OBJECTIVES

The aim of this study was to investigate whether a 20 min application of crushed ice at the knee affects knee joint kinematics immediately post and up to 20 mins post ice removal, during a small knee bend.

METHOD

17 healthy male participants took part in the study performing a functional task. Using three-dimensional motion analysis (Qualisys Medical AB Gothenburg, Sweden), kinematics of the knee were measured during a weight bearing functional task pre and immediately post, 5, 10, 15 and 20 min post cryotherapy intervention. Skin surface temperature (T_sk) cooling was measured via infrared non-contact thermal imaging (Flir Systems, Danderyd, Sweden) over the anterior and medial aspect of the knee.

RESULTS

Results demonstrated significant reductions in the ability to accurately replicate knee joint positioning. A significant increase (P ≧ 0.05) in rotational movement in the transverse plane occurred, 20 min post ice removal.

DISCUSSION

A 20-min application of crushed ice to the anterior aspect of the non-dominant knee has an adverse effect on knee joint repositioning and dynamic stability, 20 min after ice is removed. In consideration of returning a land-based athlete to dynamic functional activities, post cryotherapeutic intervention at the knee, clinicians should consider these findings due to the potential increase risk of injury.

Motor and sensory effects of ipsilesional upper extremity hypothermia and contralesional sensory training for chronic stroke patients

As hypothermia by immersion can reduce the sensory nerve conduction velocity, this study hypothesized that the reduction of sensory input to the ipsilesional upper extremity (UE) using cryotherapy would reduce the inhibitory activity of the contralesional hemisphere in chronic stroke subjects.

OBJECTIVE

In this study, hypothermia was applied by immersing the ipsilesional UE in association with sensory training of the contralesional UE of stroke patients to assess the immediate (e.g. sensorimotor function, hemodynamics, and levels of comfort) and long-term (sensory and motor performances of the UEs) effects.

METHODS

The sample included 27 stroke patients allocated into group 1 (n = 14), which received conventional physiotherapy for the affected UE, and group 2 (n = 13), which underwent 10 sessions of immersion hypothermia of the ipsilesional wrist and hand. Assessments were performed pre- and post-treatment and at follow-up using esthesiometry, the Fugl-Meyer Assessment (FMA), the Nottingham Sensory Assessment, functional tests, tactile and weight discrimination, motor sequence, level of comfort, and hemodynamic parameters.

RESULTS

The immediate effects of hypothermia using immersion of the ipsilesional UE in association with sensory training of the contralesional UE were hemodynamic stability during and after hypothermia, the absence of sensory abnormalities in the contralesional UE, hypoesthesia in the ipsilesional extremity (dermatomes C6 and C8) (P < 0.05), the maintenance of acceptable levels of comfort, and good patient compliance to the technique. The long-term effects included significant increases in scores on tests performed without functional vision, in scores on blindfolded functional tests, and in tactile localization and joint position sense for the contralesional hand in group 2 as well as the maintenance of these gains at long-term follow-up (5 weeks). Improvement was also found in the tactile function of the C6 and C7 dermatomes of the contralesional hand (P < 0.05).

CONCLUSIONS

The use of immersion hypothermia on the ipsilesional UE in association with sensory training of the contralesional UE improved motor function and sensitivity in the contralesional UE of individuals with chronic stroke. Immersion hypothermia of the ipsilesional UE in chronic stroke patients is a safe, practical, inexpensive, and easily applied technique.

[The feasibility of the application of cryotherapy and radonotherapy for the treatment of the patients presenting with osteoarthritis]

Osteoarthritis (OA) is currently considered to be one of the most widespread diseases. Its main clinical symptoms include pain and dysfunction of joints. In the present review of the foreign and domestic literature, the questions of pathogenesis and risk factors underlying the development of osteoarthritis are discussed. The understanding of OA pathogenesis have altered essentially in the recent years which made necessary the search for the novel approaches to the treatment of this pathology. According to the modern views of OA origin and progression, its therapy should be based on the application of the combination of medicamentous and non-medicamentous modalities including, in particular, collective and individual activities focused on the implementation of the programs of therapeutic physical training as an obligatory component of ОА prophylaxis and treatment. The present review gives evidence of the feasibility of the application of the methods of cryotherapy and radonotherapy for the management of the patients suffering from osteoarthritis. It is emphasized that many recent publications report extensive investigations of the clinical and pathogenetic aspects of the application of these methods for the combined regenerative treatment of the patients presenting with gonarthrosis. The influence of cryotherapy and radonotherapy on the neuroendocrine and immune systems is discussed with special reference to the possibility of regulation of the metabolic processes and retardation of inflammation. It is concluded that the introduction of the above methods into the compulsory individual program for the regenerative treatment of patients presenting with osteoarthritis is pathologically substantiated since it greatly contributes to the reduction of pain and retardation of the progress of the disease. The main pharmaceutical preparations for the OA treatment remain to be slow-acting symptomatic medicines possessed of the chondro-protective effect.

Expected accuracy of proximal and distal temperature estimated by wireless sensors, in relation to their number and position on the skin

A popular method to estimate proximal/distal temperature (T_PROX and T_DIST) consists in calculating a weighted average of nine wireless sensors placed on pre-defined skin locations. Specifically, T_PROX is derived from five sensors placed on the infra-clavicular and mid-thigh area (left and right) and abdomen, and T_DIST from four sensors located on the hands and feet. In clinical practice, the loss/removal of one or more sensors is a common occurrence, but limited information is available on how this affects the accuracy of temperature estimates. The aim of this study was to determine the accuracy of temperature estimates in relation to number/position of sensors removed. Thirteen healthy subjects wore all nine sensors for 24 hours and reference T_PROX and T_DIST time-courses were calculated using all sensors. Then, all possible combinations of reduced subsets of sensors were simulated and suitable weights for each sensor calculated. The accuracy of T_PROX and T_DIST estimates resulting from the reduced subsets of sensors, compared to reference values, was assessed by the mean squared error, the mean absolute error (MAE), the cross-validation error and the 25^th and 75^th percentiles of the reconstruction error. Tables of the accuracy and sensor weights for all possible combinations of sensors are provided. For instance, in relation to T_PROX, a subset of three sensors placed in any combination of three non-homologous areas (abdominal, right or left infra-clavicular, right or left mid-thigh) produced an error of 0.13°C MAE, while the loss/removal of the abdominal sensor resulted in an error of 0.25°C MAE, with the greater impact on the quality of the reconstruction. This information may help researchers/clinicians: i) evaluate the expected goodness of their T_PROX and T_DIST estimates based on the number of available sensors; ii) select the most appropriate subset of sensors, depending on goals and operational constraints.

Local cryotherapy minimally impacts the metabolome and transcriptome of human skeletal muscle

Cryotherapy is commonly used in the treatment of skeletal muscle injuries. However, the data to support the use of cryotherapy is inconclusive, and the biochemical etiology of cryotherapy in human skeletal muscle remains largely unknown. We therefore sought to determine how a clinically-relevant dose of cryotherapy would impact the transcriptome and metabolome of skeletal muscle. Eight healthy male subjects (age 24.7 ± 4.5 years, BMI 22.2 ± 1.6) received a 15 minute bout of local cryotherapy, delivered via ice cup massage over the anterolateral thigh. This resulted in an 85% decrease in skin temperature and a predicted 27% reduction in intramuscular temperature. The contralateral side served as a non-treated control. Two hours after cryotherapy, muscle biopsies were obtained to analyze changes in the transcriptome, metabolome, and activation of p38 MAPK, ERK1/2, Akt, and p70S6K proteins. No changes were detected in the transcriptome between control and cooled muscles. Cryotherapy reduced levels of hexose sugars and hypoxanthine by 1.3%, but no statistically different changes were observed in 60 additional metabolites. Overall, no differences in phosphorylated p38 MAPK, ERK1/2, Akt, and p70S6K were observed. A clinically relevant dose of cryotherapy produced negligible acute biochemical and molecular changes in the skeletal muscle of human subjects.

The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial

The central- and peripheral mechanisms by which heat strain limits physical performance are not fully elucidated. Nevertheless, pre-cooling is often used in an attempt to improve subsequent performance. This study compared the effects of pre-cooling vs. a pre-thermoneutral application on central- and peripheral fatigue during 60% of isometric maximum voluntary contraction (MVC) of the right quadriceps femoris muscle. Furthermore, the effects between a pre-cooling and a pre-thermoneutral application on isometric MVC of the right quadriceps femoris muscle and subjective ratings of perceived exertion (RPE) were investigated. In this randomized controlled trial, 18 healthy adults voluntarily participated. The participants received either a cold (experimental) application (+8°C) or a thermoneutral (control) application (+32°C) for 20min on their right thigh (one cuff). After the application, central (fractal dimension - FD) and peripheral (muscle fiber conduction velocity - CV) fatigue was estimated using sEMG parameters during 60% of isometric MVC. Surface EMG signals were detected from the vastus medialis and lateralis using bidimensional arrays. Immediately after the submaximal contraction, isometric MVC and RPE were assessed. Participants receiving the cold application were able to maintain a 60% isometric MVC significantly longer when compared to the thermoneutral group (mean time: 78 vs. 46s; p=0.04). The thermoneutral application had no significant impact on central fatigue (p>0.05) compared to the cold application (p=0.03). However, signs of peripheral fatigue were significantly higher in the cold group compared to the thermoneutral group (p=0.008). Pre-cooling had no effect on isometric MVC of the right quadriceps muscle and ratings of perceived exertion. Pre-cooling attenuated central fatigue and led to significantly longer submaximal contraction times compared to the pre-thermoneutral application. These findings support the use of pre-cooling procedures prior to submaximal exercises of the quadriceps muscle compared to pre-thermoneutral applications.

The effect of local cryotherapy on subjective and objective recovery characteristics following an exhaustive jump protocol

The purpose of this controlled trial was to investigate the effects of a single local cryotherapy session on the recovery characteristics over a period of 72 hours. Twenty-two young and healthy female (n=17; mean age: 21.9±1.1 years) and male (n=5;mean age: 25.4±2.8 years) adults participated in this study. Following an exhaustive jump protocol (3×30 countermovement jumps), half of the participants received either a single local cryotherapy application (+8°C) or a single local thermoneutral application (+32°C) of 20-minute duration using two thigh cuffs. Subjective measures of recovery (delayed-onset muscle soreness and ratings of perceived exertion) and objective measures of recovery (vertical jump performance and peak power output) were assessed immediately following the postexercise applications (0 hours) and at 24 hours, 48 hours, and 72 hours after the jump protocol. Local cryotherapy failed to significantly affect any subjective recovery variable during the 72-hour recovery period (P>0.05). After 72 hours, the ratings of perceived exertion were significantly lower in the thermoneutral group compared to that in the cryotherapy group (P=0.002). No significant differences were observed between the cryotherapy and the thermoneutral groups with respect to any of the objective recovery variables. In this experimental study, a 20-minute cryotherapy cuff application failed to demonstrate a positive effect on any objective measures of recovery. The effects of local thermoneutral application on subjective recovery characteristics were superior when compared to the effects of local cryotherapy application at 72 hours postapplication.

An exploratory study into the effects of a 20 minute crushed ice application on knee joint position sense during a small knee bend

OBJECTIVES

The effect of cryotherapy on joint positioning presents conflicting debates as to whether individuals are at an increased risk of injury when returning to play or activity immediately following cryotherapy application at the knee. The aim of this study was to investigate whether a 20 min application of crushed ice at the knee immediately affects knee joint position sense during a small knee bend.

DESIGN

Pre- and post-intervention.

SETTING

University movement analysis laboratory.

PARTICIPANTS

Eleven healthy male participants.

MAIN OUTCOME MEASURES

Kinematics of the knee were measured during a weight bearing functional task pre and post cryotherapy intervention using three-dimensional motion analysis (Qualisys Medical AB Gothenburg, Sweden). Tissue cooling was measured via a digital thermometer at the knee.

RESULTS

Results demonstrated significant reductions in the ability to accurately replicate knee joint positioning in both sagittal (P = .035) and coronal (P = .011) planes during the descent phase of a small knee bend following cryotherapy.

CONCLUSION

In conclusion a 20 min application of crushed ice to the knee has an adverse effect on knee joint repositioning. Team doctors, clinicians, therapists and athletes should consider these findings when deciding to return an athlete to functional weight bearing tasks immediately following ice application at the knee, due to the potential increase risk of injury.

Effects of cold water immersion on variables of balance in healthy subjects with open and closed eyes

AbstractIntroduction Cryotherapy is the use of cold as therapeutic approach. Although often used, its impact on the postural balance is not well-known.Objectives To analyze the effects of cold water immersion in the postural balance on single-leg balance in healthy subjects through the variables of center-of-pressure, velocity anteroposterior and medial-lateral oscillations, comparing conditions open and closed eyes in the moments before, immediately, 20 and 40 minutes after cold water immersion.Material and methods Cross-sectional study with 30 male subjects, cold water immersion at 5 °C during 15 minutes assessed in a force platform, protocol of 3 trials of 30 seconds each with 10 seconds of rest, the average of the 3 trials was used for analysis. The software GraphPad Prisma 5.0 was used for statistical analysis, with the ANOVA test for repeated measures and comparisons with test of Friedman and post-test of Dunn.Results It was observed improvement of the balance by the results of the following variables: in the condition Open Eyes (OE) it was observed significant difference only in the velocity anteroposterior (AP) in the moment before immersion when compared to the 40-minute moment. Significant differences were observed in the condition Closed Eyes (CE) in the following comparisons: in the Center-of-Pressure (COP) only at the immediate moment when compared to the 40-minute moment; in the velocity AP in the moment before when compared to the 40-minute moment, in the immediate moment when compared to the 20-minute and 40-minute moments; and in the medial-lateral velocity (Vel-ML) in two comparisons: in the moment before immersion when compared to the 20-minute and 40-minute moments after cryotherapy. Results show safety in performing activities after cryotherapy.Conclusion Improvement of the postural balance after cold water immersion on the predetermined conditions of this study.

Subcutaneous and Intramuscular Hemodynamics and Oxygenation After Cold-Spray Application as Monitored by Near-Infrared Spectroscopy

CONTEXT

Vapocoolant spray, commonly known as cold spray (CS), is a cryotherapy modality used in sports medicine, athletic training, and rehabilitation settings. Proposed physiologic effects of cryotherapy modalities include reductions in tissue blood flow, oxygenation, and cell metabolism in addition to attenuation of pain perception attributed to reduced superficial nerve conduction velocity.

OBJECTIVE

To examine the effects of CS on subcutaneous and intramuscular blood flow and oxygenation on the thigh muscle using near-infrared spectroscopy, an optical method to monitor changes in tissue oxygenated (O2Hb), deoxygenated (HHb), and total (tHb) hemoglobin.

DESIGN

Cross-sectional study.

SETTING

Muscle Biophysics Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Participants were 13 healthy adults (8 men, 5 women; age = 37.4 ± 6 years, body mass index = 27.4 ± 2.6, adipose tissue thickness = 7.2 ± 1.8 mm).

INTERVENTION(S)

Conventional CS was applied to the vastus medialis muscles.

MAIN OUTCOME MEASURE(S)

Changes in chromophore concentrations of O2Hb, HHb, and tHb at superficial and deep layers were monitored for 5 minutes using a 2-channel near-infrared spectroscopy.

RESULTS

Thirty seconds after CS application, we observed a decrease from baseline in O2Hb and tHb only in the superficial layer that was maintained for 3 minutes.

CONCLUSIONS

Application of CS induced a transient change in blood flow and oxygenation of the superficial tissues with no change in deeper tissues over the healthy vastus medialis muscle. The limited physiologic effect of CS on the superficial hemodynamics and oxygenation of limb muscles may limit the therapeutic benefit of this cryotherapy modality to a temporary analgesic effect, a hypothesis that warrants a clinical trial on traumatized muscles.

Lower limb ice application alters ground reaction force during gait initiation

BACKGROUND:

Cryotherapy is a widely used technique in physical therapy clinics and sports. However, the effects of cryotherapy on dynamic neuromuscular control are incompletely explained.

OBJECTIVES:

To evaluate the effects of cryotherapy applied to the calf, ankle and sole of the foot in healthy young adults on ground reaction forces during gait initiation.

METHOD:

This study evaluated the gait initiation forces, maximum propulsion, braking forces and impulses of 21 women volunteers through a force platform, which provided maximum and minimum ground reaction force values. To assess the effects of cooling, the task - gait initiation - was performed before ice application, immediately after and 30 minutes after removal of the ice pack. Ice was randomly applied on separate days to the calf, ankle and sole of the foot of the participants.

RESULTS:

It was demonstrated that ice application for 30 minutes to the sole of the foot and calf resulted in significant changes in the vertical force variables, which returned to their pre-application values 30 minutes after the removal of the ice pack. Ice application to the ankle only reduced propulsion impulse.

CONCLUSIONS:

These results suggest that although caution is necessary when performing activities that require good gait control, the application of ice to the ankle, sole of the foot or calf in 30-minute intervals may be safe even preceding such activities.

Effect of cryotherapy on the ankle temperature in athletes: ice pack and cold water immersion

Introduction Cryotherapy is often used for rehabilitation of injured athletes. Objective To compare the effectiveness of ice pack (IP) and cold water immersion (CWI) on lowering the ankle skin surface temperature in athletes. Materials and methods Thirteen athletes (seven women and six men), age 19.53 (± 2.9) years. IP and CWI were applied on the anterior talofibular ligament (ATFL) of the dominant leg for 30 minutes. The skin surface temperature was measured with an infrared digital thermometer prior to the application and during cryotherapy (10, 15, 20, 25 and 30 minutes) and up to two hours of rewarming. During rewarming, the athletes remained at rest and the temperature was measured every 1 minute until 10 minutes, every 5 minutes for up to an hour and every 15 minutes until 2 hours. Results The two types of cold application were effective in lowering the skin surface temperature after the 30-minute procedure. Significant differences were observed among the following temperatures: pre-application (IP = 29.8 ± 2.4 °C and CWI = 27.5 ± 3 °C – P < 0.05); after 30 minutes (IP = 5 ± 2.4 °C and CWI = 7.8 ± 3 °C – P < 0.01). For rewarming, after 25 minutes (IP = 20.8 ± 3.3 °C and CWI = 18.2 ± 2.7 °C – P < 0.04); after 45 minutes (IP = 24.5 ± 2.3 °C and IP = 22.1 ± 3.5 °C – P < 0.05); after 75 minutes (IP = 26.4 ± 2.2 °C and CWI = 24 ± 2.7 °C – P < 0.02). Conclusion After the 30-minute application, both IP and CWI produced the appropriate temperature; however the application of CWI produced the lowest temperature during rewarming.

Whole-body cryotherapy: empirical evidence and theoretical perspectives

Whole-body cryotherapy (WBC) involves short exposures to air temperatures below −100°C. WBC is increasingly accessible to athletes, and is purported to enhance recovery after exercise and facilitate rehabilitation postinjury. Our objective was to review the efficacy and effectiveness of WBC using empirical evidence from controlled trials. We found ten relevant reports; the majority were based on small numbers of active athletes aged less than 35 years. Although WBC produces a large temperature gradient for tissue cooling, the relatively poor thermal conductivity of air prevents significant subcutaneous and core body cooling. There is weak evidence from controlled studies that WBC enhances antioxidant capacity and parasympathetic reactivation, and alters inflammatory pathways relevant to sports recovery. A series of small randomized studies found WBC offers improvements in subjective recovery and muscle soreness following metabolic or mechanical overload, but little benefit towards functional recovery. There is evidence from one study only that WBC may assist rehabilitation for adhesive capsulitis of the shoulder. There were no adverse events associated with WBC; however, studies did not seem to undertake active surveillance of predefined adverse events. Until further research is available, athletes should remain cognizant that less expensive modes of cryotherapy, such as local ice-pack application or cold-water immersion, offer comparable physiological and clinical effects to WBC.

Nerve enlargement after cold exposure: a pilot study with ultrasound imaging

INTRODUCTION

Changes of electrophysiogical parameters with regard to cold have been studied intensively but not the morphology of nerves. We explored the effects of cold exposure on median nerve morphology.

METHODS

Cross-sectional area (CSA) and depth of the right median nerve were assessed at the carpal tunnel and mid-forearm levels before and after 15 min ice-pack application in 34 healthy volunteers.

RESULTS

After cooling, mean CSA measurements increased at the carpal tunnel and mid-forearm levels (from 8.00 to 8.85 and 6.64 to 7.55, respectively, P < 0.05); however, the depth values were similar.

CONCLUSIONS

These preliminary results revealed that cold exposure may cause acute nerve swelling. Further studies with larger samples will be necessary to confirm our findings, to correlate them with electrophysiological data, and to explore when/how the nerve edema resolves.

Effects of cold modality application with static and intermittent pneumatic compression on tissue temperature and systemic cardiovascular responses

Background:

In the therapeutic setting, cryotherapy with varying levels of intermittent cyclical compression often replaces an ice bag and elastic wrap. However, little is known about the cardiovascular strain and tissue temperature decreases associated with cooling and intermittent compression.

Hypothesis:

The authors hypothesized that higher levels of intermittent compression will result in greater reductions of tissue temperature and that all cold modalities will cause acute increases in cardiovascular strain.

Design:

Experimental crossover repeated measure design.

Methods:

Ten healthy subjects (23 ± 3 years) volunteered for 4 cryotherapy sessions (30-minute treatments with 30-minute passive recovery). Treatments included ice with elastic wrap and Game Ready (GR) with no, medium (5-50 mmHg), and high compression (5-75 mmHg). Throughout the experiment, oral, skin surface, and intramuscular quadriceps temperatures were measured along with mean arterial pressure, heart rate, rate pressure product, forearm blood flow, and forearm vascular conductance.

Results:

Mean arterial pressure increased up to 5 minutes (P < 0.05). Forearm blood flow and forearm vascular conductance decreased after baseline (P < 0.05), but there were no differences between treatments. Peak intramuscular changes from baseline were −14 ± 2°C (ice), −11 ± 6°C (GR_HIGH), −10 ± 5°C (GR_MED), and −7 ± 3°C (GR_NO). Ice cooled the muscle the most, while GR with medium and high compression cooled more than GR without compression (P < 0.05).

Conclusions:

The application of cold and intermittent pneumatic compression using GR did not produce acute cardiovascular strain that exceeded the strain produced by standard ice bags/elastic wrap treatment. Greater temperature decreases are achieved with medium- and high-pressure settings when using the GR system.

Clinical Relevance:

Type of cold and amount of compression affect tissue cooling in healthy lean subjects. All tested cold modalities caused acute increases in cardiovascular strain; however, these increases are no more than what healthy subjects experience with the onset of exercise.

Central and peripheral adjustments during high-intensity exercise following cold water immersion

PURPOSE

We investigated the acute effects of cold water immersion (CWI) or passive recovery (PAS) on physiological responses during high-intensity interval training (HIIT).

METHODS

In a crossover design, 14 cyclists completed 2 HIIT sessions (HIIT1 and HIIT2) separated by 30 min. Between HIIT sessions, they stood in cold water (10 °C) up to their umbilicus, or at room temperature (27 °C) for 5 min. The natural logarithm of square-root of mean squared differences of successive R-R intervals (ln rMSSD) was assessed pre- and post-HIIT1 and HIIT2. Stroke volume (SV), cardiac output (Q), O2 uptake (VO2), total muscle hemoglobin (t Hb) and oxygenation of the vastus lateralis were recorded (using near infrared spectroscopy); heart rate, Q, and VO2 on-kinetics (i.e., mean response time, MRT), muscle de-oxygenation rate, and anaerobic contribution to exercise were calculated for HIIT1 and HIIT2.

RESULTS

ln rMSSD was likely higher [between-trial difference (90% confidence interval) [+13.2% (3.3; 24.0)] after CWI compared with PAS. CWI also likely increased SV [+5.9% (-0.1; 12.1)], possibly increased Q [+4.4% (-1.0; 10.3)], possibly slowed Q MRT [+18.3% (-4.1; 46.0)], very likely slowed VO2 MRT [+16.5% (5.8; 28.4)], and likely increased the anaerobic contribution to exercise [+9.7% (-1.7; 22.5)].

CONCLUSION

CWI between HIIT slowed VO2 on-kinetics, leading to increased anaerobic contribution during HIIT2. This detrimental effect of CWI was likely related to peripheral adjustments, because the slowing of VO2 on-kinetics was twofold greater than that of central delivery of O2 (i.e., Q). CWI has detrimental effects on high-intensity aerobic exercise performance that persist for ≥ 45 min.

Cryotherapy Effects, Part 2: Time to Numbness Onset and Numbness Duration

Context:

Recommended treatment duration for cryotherapy varies, but the primary therapeutic benefit may be related to the amount of time required for changes in cutaneous sensation.

Objective:

To determine the amount of time required to induce numbness for three different modes of cryotherapy administration, and the amount of time that numbness persists after treatment.

Design:

Repeated measures.

Participants:

30 healthy adults (12 males, 18 females, age = 21.1 ± 1.9 years).

Interventions:

Crushed ice bag, ice massage, and cold water immersion.

Main Outcome Measures:

Time required to induce numbness and the amount of time numbness remained after removal of each mode of cryotherapy.

Results:

Ice massage and cold water immersion produced numbness significantly faster than the crushed ice. There were no significant differences in terms of numbness duration.

Conclusions:

Changes in cutaneous sensation can be achieved in a relatively short amount of time (6–12 minutes) with ice massage and cold water immersion. The duration of the treatment effect did not differ among the three modes of cryotherapy administration.

Skinfold thickness at 8 common cryotherapy sites in various athletic populations

CONTEXT

Researchers have observed slower cooling rates in thigh muscle with greater overlying adipose tissue, suggesting that cryotherapy duration should be based on the adipose thickness of the treatment site. Skinfold data do not exist for other common cryotherapy sites, and no one has reported how those skinfolds might vary because of physical activity level or sex.

OBJECTIVE

To determine the variability in skinfold thickness among common cryotherapy sites relative to sex and activity level (National Collegiate Athletic Association Division I athletes, recreationally active college athletes).

DESIGN

Descriptive laboratory study.

SETTING

Field.

PATIENTS OR OTHER PARTICIPANTS

Three hundred eighty-nine college students participated; 196 Division I athletes (157 men, 39 women) were recruited during preseason physicals, and 193 recreationally active college athletes (108 men, 85 women) were recruited from physical education classes.

INTERVENTION(S)

Three skinfold measurements to within 1 mm were taken at 8 sites (inferior angle of the scapula, middle deltoid, ulnar groove, midforearm, midthigh, medial collateral ligament, midcalf, and anterior talofibular ligament [ATF]) using Lange skinfold calipers.

MAIN OUTCOME MEASURE(S)

Skinfold thickness in millimeters.

RESULTS

We noted interactions among sex, activity level, and skinfold site. Male athletes had smaller skinfold measurements than female athletes at all sites except the ATF, scapula, and ulnar groove (F₇,₂₇₀₂ = 69.85, P < .001). Skinfold measurements were greater for recreationally active athletes than their Division I counterparts at all sites except the ATF, deltoid, and ulnar groove (F₇,₂₇₀₂ = 30.79, P < .001). Thigh skinfold measurements of recreationally active female athletes were the largest, and their ATF skinfolds were the smallest.

CONCLUSIONS

Skinfold thickness at common cryotherapy treatment sites varied based on level of physical activity and sex. Therefore, clinicians should measure skinfold thickness to determine an appropriate cryotherapy duration.

Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects

PURPOSE

To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects.

SUBJECTS

Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20-62) volunteered.

METHODS

A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling.

RESULTS

The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7-12.1) %, and in the compliance parameter, -7.5 (-9.8 to -5.3) %. Responses in the oscillation frequency, 6.5 (2.3-10.6) %, and stiffness parameters, 4.0 (0.8-7.1) %, were also statistically significant. The compliance still showed a -6.1 (-7.7 to -4.5) % decrease after the 15 min recovery phase, while no remaining alteration was found in the oscillation parameters.

CONCLUSION

The quadriceps muscle became tenser, stiffer, and less elastic as a result of cooling, and the mechanical properties were not fully recovered after 15 min. Careful warming-up is suggested after cooling to enable normalization of mechanical properties of the muscle and to avoid injuries.

Edema: a silent but important factor

Edema is a normal response to injury. Even the smallest injury is associated with some inflammation, and initial edema is part of the normal inflammatory process. However, edema becomes a concern when it persists beyond the inflammatory phase. Once we have progressed into the rebuilding, or fibroplastic phase of healing, edema will delay healing and contribute to complications such as pain and stiffness. Early prevention and management to prevent this progression are therefore critical. This article discusses edema in relation to stages of healing and presents the research behind techniques available to the clinician to manage localized extracellular upper extremity edema in the patient with an intact lymphatic system.