The influence of intraoral cryotherapy on postoperative pain and substance P in symptomatic apical periodontitis: randomized clinical study

Cryotherapy is widely utilized in medicine, particularly for pain management. This randomized clinical trial aimed to assess the effect of intraoral cold pack application (cryotherapy) on postoperative pain (POP) and the level of Substance P (SP) in patients with symptomatic apical periodontitis (SAP). Enrolled patients were randomly assigned to either cryotherapy or control group. After adequate anesthesia, access cavity, and biomechanical preparation of the root canal system were completed, the first apical fluid (AF) sample (S1) was obtained. A custom-made intraoral ice-gel pack was applied for 30 min in the cryotherapy group, while no intervention was performed in the control group. The second AF sample (S2) was collected 30 min later in both groups. Patients were asked to complete the Visual Analogue Scale (VAS) questionnaire to assess their POP. Quantification of SP in AF samples was performed using the enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed statistically, revealing a significant reduction in POP and SP levels in the cryotherapy group compared to the control group (P ≤ 0.05). Furthermore, a moderate positive correlation was observed between SP levels and POP (P ≤ 0.05). In conclusion, intraoral cryotherapy represents a simple and cost-effective option for controlling POP and reducing inflammation levels in patients with SAP.

Skin temperature of the knee was effectively reduced when using a new continuous cold-flow cryocompression device: a randomised controlled crossover trial

OBJECTIVE

To determine which temperature settings on a new continuous cold-flow cryocompression device effectively reduce knee skin temperature to 10-15 °C, where pain and swelling are expected to be attenuated.

DESIGN

Randomised controlled crossover trial.

SETTING

University laboratory.

PARTICIPANTS

32 healthy adult participants recruited (1 dropout) with no contraindications to cryocompressive therapy.

INTERVENTION

A k-type thermocouple was used to record skin temperature at baseline and every five minutes during a 30-minute cryocompression treatment in a control condition and when using four different device temperature settings (6 °C, 8 °C, 10 °C, and 12 °C) on a continuous cold-flow cryocompression device. Conditions were labelled Control, Con-6, Con-8, Con-10, and Con-12, respectively.

MAIN OUTCOME MEASURES

Skin temperature change (°C) throughout cryocompression; time taken (mins) to achieve skin temperature < 15 °C; and the difference between final skin temperature and device temperature setting (°C).

RESULTS

Median (IQR) skin temperature after cryocompression was 32.1 °C (29.3-33.4), 12.8 °C (12.1-14.6), 14.3 °C (13.8-15.7), 16.1 °C (15.2-17.3), and 17.7 °C (16.9-18.9) for the Control condition and Con-6, Con-8, Con-10 and Con-12, respectively. It took 20 min (Con-6) and 25 min (Con-8) for skin temperature to reach < 15 °C. A median (IQR) difference of 6.8 °C (6.1-8.6), 6.3 °C (5.8-7.7), 6.1 °C (5.2-7.3), and 5.7 °C (4.9-6.9) for Con-6, Con-8, Con-10, and Con-12, respectively was observed between device temperature setting and final skin temperature.

CONCLUSIONS

The device is recommended as it reduced skin temperature to the therapeutic range of 10-15 °C during a 30-minute treatment when using the 6 °C or 8 °C device temperature settings. Future research should determine optimal treatment lengths for cryocompression. CONTRIBUTION OF THE PAPER.

Enhanced bone healing using local cryostimulation: In vivo rat study

A short-term intense cooling through the skin causes a response of the body. Potentially, it can be used to enhance bone healing. The aim of this study is to evaluate an effectiveness of a bone defect cryostimulation in the Wistar rat model in vivo. Through holes with a diameter of 2.15 mm were formed in the cortical layer of the diaphysis of the hind paws of rats. Further animals were subjected to cryotherapy 1 and 2 times a week (up to 6 weeks). The local average skin surface temperature dropped from 28 to 14 °C. The decrease in temperature in a control point inside the biological tissue was 5.3 °C. Micro CT and histological analyses showed that cryostimulation twice a week is efficient treatment. In this case, there was an acceleration of maturation of the newly formed bone tissue replacing the defect region. In the control, the newly formed immature bone with a large number of osteocytes and vessels was detected. In the experiment, the newly formed bone had a more mature structure with signs of a compact bone (formation of Haversian canals, reduction in the number of osteocytes, appearance of gluing lines). Morphometric analysis has showed a 2-fold decrease of the relative vessels area near the defect region and an increase of 30% in the content of mast cells in the entire bone marrow and especially near the site of osteogenesis. Generally, the complete filling of the critical size defect and almost complete mineralization have been observed. This information is expected to be useful for understanding the effect-exposure correlation of the cryotherapy and in the design of the cryotherapy protocols.

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.

Comparison of 4 Different Cooldown Strategies on Lower-Leg Temperature, Blood Lactate Concentration, and Fatigue Perception After Intense Running

CONTEXT

Although active recovery (AR) and cold application is recommended, many people take a shower after exercise. Therefore, a direct comparison between a shower and other recommended methods (AR and/or cold-water immersion) is necessary. To compare immediate effects of 4 postexercise cooldown strategies after running.

DESIGN

A crossover design.

METHODS

Seventeen young, healthy males (23 y; 174 cm; 73 kg) visited on 4 different days and performed a 10-minute intense treadmill run (5 km/h at a 1% incline, then a belt speed of 1 km/h, and an incline of 0.5% were increased every minute). Then, subjects randomly experienced 4 different 30-minute cooldown strategies each session-AR (10-min treadmill walk + 10-min static stretch + 10-min shower), cold-water walk (10-min shower + 20-min walk in cold water), cold-water sit (10-min shower + 20-min sit in cold water), and passive recovery (10-min shower + 20-min passive recovery). Across the cooldown conditions, the water temperatures for immersion and shower were set as 18 °C and 25 °C, respectively. Lower-leg muscle temperature, blood lactate concentration, and fatigue perception were statistically compared (P < .001 for all tests) and effect sizes (ES) were calculated.

RESULTS

The cold-water walk condition (F135,2928 = 69.29, P < .0001) was the most effective in reducing muscle temperature after running (-11.6 °C, ES = 9.46, P < .0001), followed by the cold-water sit (-8.4 °C, ES = 8.61, P < .0001), passive recovery (-4.5 °C, ES = 4.36, P < .0001), and AR (-4.0 °C, ES = 4.29, P < .0001) conditions. Blood lactate concentration (F6,176 = 0.86, P = .52) and fatigue perception (F6,176 = 0.18, P = .98) did not differ among the 4 conditions.

CONCLUSIONS

While the effect of lowering the lower-leg temperature was different, the effect of reducing blood lactate concentration and fatigue perception were similar in the 4 cooldown strategies. We suggest selecting the appropriate method while considering the specific goal, available time, facility, and accessibility.

The effect of cryotherapy on postural stabilization assessed by standardized horizontal perturbations of a movable platform

BACKGROUND

Cryotherapy is a frequently used therapy in the acute treatment of sports injuries, although it has possible negative effects on dynamic postural stabilization.

RESEARCH QUESTION

What is the effect of cryotherapy on the postural stabilization assessed by imposed platform perturbations?

METHODS

Twenty-four healthy participants (15 male, 9 female) performed 2 test sessions (before and after cryotherapy) consisting of 4 trials each. Each trial included 30 s single leg stance (SLS) on both legs and 4 testing blocks (2 for each leg) of 30 s for the dynamic testing. A single testing block comprised 4 perturbations. After the first session, cryotherapy was applied to the right leg by placing it in ice water at a temperature between 10 °C and 12 ° for 20 min.

OUTCOME MEASURES

We assessed the Center of Pressure speed (CoPs) and the mean force variation for both static and dynamic tests. Additionally, the Time To Stability (TTS) was calculated for the perturbations.

RESULTS

In the static trials there was an interaction between leg and session present for the mean force variation (p = 0.01) with a large η² of 0.24, which shows higher variation of vertical force after application of the cryotherapy on the right leg. During the dynamic trials we found an interaction between leg and session for the TTS suggesting increase of the TTS due to the cryotherapy (p = 0.04), with a large η² of 0.17. No interaction effect was present for the CoPs in the mediolateral and anteroposterior direction (p = 0.62 and p = 0.12, respectively).

SIGNIFICANCE

Cryotherapy applied to the lower extremity results in a worse postural stabilization when assessed by platform perturbations. This might be the result of an altered balance strategy, due to impaired proprioception from the affected body part. More research is needed to examine the duration of this effect.

LEVEL OF EVIDENCE

Level 3, associative study.

Cold for centuries: a brief history of cryotherapies to improve health, injury and post-exercise recovery

For centuries, cold temperatures have been used by humans for therapeutic, health and sporting recovery purposes. This application of cold for therapeutic purposes is regularly referred to as cryotherapy. Cryotherapies including ice, cold-water and cold air have been popularised by an ability to remove heat, reduce core and tissue temperatures, and alter blood flow in humans. The resulting downstream effects upon human physiologies providing benefits that include a reduced perception of pain, or analgesia, and an improved sensation of well-being. Ultimately, such benefits have been translated into therapies that may assist in improving post-exercise recovery, with further investigations assessing the role that cryotherapies can play in attenuating the ensuing post-exercise inflammatory response. Whilst considerable progress has been made in our understanding of the mechanistic changes associated with adopting cryotherapies, research focus tends to look towards the future rather than to the past. It has been suggested that this might be due to the notion of progress being defined as change over time from lower to higher states of knowledge. However, a historical perspective, studying a subject in light of its earliest phase and subsequent evolution, could help sharpen one's vision of the present; helping to generate new research questions as well as look at old questions in new ways. Therefore, the aim of this brief historical perspective is to highlight the origins of the many arms of this popular recovery and treatment technique, whilst further assessing the changing face of cryotherapy. We conclude by discussing what lies ahead in the future for cold-application techniques.

Effects of 7 Consecutive Systematic Applications of Cryotherapy With Compression

CONTEXT

Postsurgical and acute orthopedic patients are frequently treated with consecutive systematic cryotherapy despite the void of data to support treatment safety or effectiveness. The purpose of this study was to examine the occurrence of frostbite and measure skin temperatures during the systematic application of 2 cryocompression protocols.

DESIGN

A repeated-measures design guided this study.

METHODS

Nine healthy, college-aged participants (4 men and 5 women; age = 20.7 [1.2] y; height = 174 [11.01] cm; mass = 74 [14] kg) received both cryocompression protocols separated by ≥ 1 week. The static cryocompression protocol consisted of seven 40-minute "on" cycles of cryotherapy (4.4°C) with 45 mm Hg of compression, each followed by a 30-minute "off" cycle (no cryotherapy, compression set at 5 mm Hg). The intermittent cryocompression protocol consisted of seven 40-minute "on" cycles of cryotherapy (4.4°C) with compression alternating between 5 and 45 mm Hg, each followed by a 30-minute "off" cycle (no cryotherapy, compression set at 5 mmHg). At the end of each "on" and "off" cycle, we used a checklist to assess for frostbite, a PT-6 thermocouple to measure skin temperature (in degrees Celsius), and a 10-cm Likert scale to assess comfort.

RESULTS

None of the participants experienced any signs or symptoms of frostbite. There were no differences in skin temperature between the compression conditions over time (F14,112 = 1.43; P = .149) nor were there any differences between the 2 compression conditions (F1,8 = 3.75; P = .087; 1-β = 0.40). The skin temperatures were statistically different over the course of all 7 "on" and "off" cycles (F14,112 = 95.12; P < .001). There was no difference between the skin temperatures produced at the end of each "on" cycle.

CONCLUSIONS

The application of 7 consecutive cryotherapy treatments with compression did not result in any signs or symptoms of frostbite and produced similar skin temperatures with each "on" cycle.

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.

Assessment of the Dynamics of Temperature Changes in the Knee Joint Area in Response to Selected Cooling Agents in Thermographic Tests

Although local cryotherapy (LC) is performed with various cooling agents (C_Ag) such as ice, water, and gasses, in clinical practice, it is mostly performed with cooling gasses. Presently, LC with cooling gasses is very popular but the inference about the thermal (stimulus) effect on the tissues is mainly based on research carried out using ice packs. The proposed objective of the study was to evaluate the dynamics of temperature changes in the knee joint area in response to a 3-min exposure to liquid nitrogen vapors (LNVs), cold air (CA) and ice bag (IB). The study group included 23 healthy volunteers with an average age of 26.67 ± 4.56. The exposed (ROI_E) and contralateral (ROI_NE) areas of the knee joint after exposure to C_Ag were observed. Immediately after 3 min of LC, the ROI_E temperature dropped by 10.11 ± 0.91 °C after LNV, 7.59 ± 0.14 °C after IB and 6.76 ± 1.3 °C after CA. Significant tissue cooling was maintained up to 15 min after LNV (p < 0.01), 10 min after IB (p < 0.05) and 5 min after CA (p < 0.05). LC causes significant temperature changes both in ROI_E and ROI_NE. The greatest cooling potential was demonstrated for LNV and the lowest for CA.

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.

Don't Lose Your Cool With Cryotherapy: The Application of Phase Change Material for Prolonged Cooling in Athletic Recovery and Beyond

Strenuous exercise can result in muscle damage in both recreational and elite athletes, and is accompanied by strength loss, and increases in soreness, oxidative stress, and inflammation. If the aforementioned signs and symptoms associated with exercise-induced muscle damage are excessive or unabated, the recovery process becomes prolonged and can result in performance decrements; consequently, there has been a great deal of research focussing on accelerating recovery following exercise. A popular recovery modality is cryotherapy which results in a reduction of tissue temperature by the withdrawal of heat from the body. Cryotherapy is advantageous because of its ability to reduce tissue temperature at the site of muscle damage. However, there are logistical limitations to traditional cryotherapy modalities, such as cold-water immersion or whole-body cryotherapy, because they are limited by the duration for which they can be administered in a single dose. Phase change material (PCM) at a temperature of 15°C can deliver a single dose of cooling for a prolonged duration in a practical, efficacious, and safe way; hence overcoming the limitations of traditional cryotherapy modalities. Recently, 15°C PCM has been locally administered following isolated eccentric exercise, a soccer match, and baseball pitching, for durations of 3-6 h with no adverse effects. These data showed that using 15°C PCM to prolong the duration of cooling successfully reduced strength loss and soreness following exercise. Extending the positive effects associated with cryotherapy by prolonging the duration of cooling can enhance recovery following exercise and give athletes a competitive advantage.

Is the whole-body cryotherapy a beneficial supplement to exercise therapy for patients with ankylosing spondylitis?

BACKGROUND

The treatment of ankylosing spondylitis (AS) patients requires a combination of non-pharmacological (education, exercise and physical therapy), as well as pharmacological treatment modalities. The optimal management of AS still remains unresolved.

OBJECTIVE

The aim was to measure and compare the effects of whole-body cryotherapy (WBC) at -110∘C and at -60∘C and exercise therapy alone on disease activity and the functional parameters of patients with AS.

METHODS

Ninety-two patients were allocated to three groups: with WBC at -110∘C or at -60∘C (each concurrent with exercise therapy), or exercise therapy alone. Disease activity and the functional parameters of the patients were measured at study entry and at the end of the 8-day treatment.

RESULTS

Supervised therapy, irrespective of the program, led to a significant reduction in disease activity (Bath Ankylosing Spondylitis Disease Activity Index: BASDAI, Ankylosing Spondylitis Disease Activity Score: ASDAS-CRP), disease-related back pain, fatigue, duration and intensity of morning stiffness and a significant improvement in the patient's functional capacity (Bath Ankylosing Spondylitis Functional Index: BASFI), spine mobility (Bath Ankylosing Spondylitis Metrology Index: BASMI) and chest expandability, with no changes in the levels of CRP. It has been demonstrated that following therapy, the group that underwent cryotherapy at -110∘C manifested significantly reduced disease activity (BASDAI) compared with exercise therapy only (p= 0.024).

CONCLUSION

Adding cryotherapy at -110∘C to exercise therapy led to significantly reduced disease activity expressed in BASDAI, compared with exercise therapy alone.

The Effect of Cryotherapy Application to the Knee Joint on Dynamic Postural Stability

CONTEXT

Decreased postural balance is a primary risk factor for lower-limb injuries. Cryotherapy is commonly utilized by clinicians to provide local analgesia for minor acute knee joint musculoskeletal injuries during breaks in play or at halftime. Its effect on dynamic postural balance remains unclear.

OBJECTIVE

To investigate the acute effects of a 15-minute knee joint cryotherapy application on dynamic postural balance, as assessed primarily via a clinically oriented outcome measure.

DESIGN

Experimental study.

SETTING

University biomechanics laboratory.

PATIENTS OR PARTICIPANTS

A total of 28 elite-level college male field-sport athletes.

INTERVENTION

Participants were tested on the anterior, posteromedial, and posterolateral reach directions of the Star Excursion Balance Test both before and after a 15-minute knee joint cryotherapy application.

MAIN OUTCOME MEASURE(S)

Normalized reach distances, 3-dimensional knee joint kinematics, sagittal plane hip and ankle joint kinematics, as well as fractal dimension of the center-of-pressure path during the performance of the anterior, posteromedial, and posterolateral reach directions of the Star Excursion Balance Test.

RESULTS

There was a statistically significant decrease in reach distance scores achieved on anterior, posteromedial, and posterolateral directions of the Star Excursion Balance Test from precryotherapy to postcryotherapy (P < .05). None of the decreases in reach distance scores exceeded the reported smallest detectable difference values. No significant differences were observed in hip, knee, or ankle joint kinematics (P > .05). No significant change in fractal dimension was observed for any reach direction following cryotherapy application (P > .05).

CONCLUSIONS

The results of the present study indicate that dynamic postural balance is unlikely to be adversely affected immediately following cryotherapy application to the knee joint.

Partial-body cryotherapy (-135°C) and cold-water immersion (10°C) after muscle damage in females

This randomized controlled trial examined the effects of cold‐water immersion (CWI), partial‐body cryotherapy (PBC), or a passive control (CON) on physiological and recovery variables following exercise‐induced muscle damage (EIMD, 5 × 20 drop jumps) in females. Twenty‐eight females were allocated to PBC (30 seconds at −60°C, 2 minutes at −135°C), CWI (10 minutes at 10°C), or CON (10 minutes resting). Muscle oxygen saturation (SmO₂), cutaneous vascular conductance (CVC), mean arterial pressure (MAP), and local skin temperature were assessed at baseline and through 60 minutes (10‐minute intervals), while delayed onset of muscle soreness (DOMS), muscle swelling, maximum voluntary isometric contraction (MVIC), and vertical jump performance (VJP) were assessed up to 72 hours (24‐hour intervals) following treatments. SmO₂ was lower in PBC (Δ‐2.77 ± 13.08%) and CWI (Δ‐5.91 ± 11.80%) compared with CON (Δ18.96 ± 1.46%) throughout the 60‐minute follow‐up period (P < .001). CVC was lower from PBC (92.7 ± 25.0%, 90.5 ± 23.4%) and CWI (90.3 ± 23.5%, 88.1 ± 22.9%) compared with CON (119.0 ± 5.1 and 116.1 ± 6.6%, respectively) between 20 and 30 minutes (P < .05). Mean skin temperature was lower from CWI vs PBC (between 10 and 40 minutes, P < .05). Mean skin temperature was higher in CON compared with CWI up to 60 minutes and compared with PBC up to 30 minutes (P < .05). DOMS was lower following both PBC and CWI compared with CON through 72‐hour (P < .05), with no difference between groups. No main group differences for swelling, MVIC, and VJP were observed. In conclusion, CWI elicited generally greater physiological effects compared with PBC while both interventions were more effective than CON in reducing DOMS in females, but had no effect on functional measures or swelling.

Temporal Patterns of Knee-Extensor Isokinetic Torque Strength in Male and Female Athletes Following Comparison of Anterior Thigh and Knee Cooling Over a Rewarming Period

CONTEXT

The effect of local cooling on muscle strength presents conflicting debates, with literature undecided as to the potential implications for injury, when returning to play following cryotherapy application.

OBJECTIVE

To investigate concentric muscle strength following local cooling over the anterior thigh compared with the knee joint in males and females and the temporal pattern over a 30-minute rewarming period.

DESIGN

Repeated-measures crossover design.

METHOD

Twelve healthy participants randomly assigned to receive cooling intervention on one location, directly over either the anterior thigh or the knee, returning 1 week later to receive the cooling intervention on opposite location. Muscle strength measured via an isokinetic dynamometer at multiple time points (immediately post, 10-, 20-, and 30-min post) coincided with measurement of skin surface temperature (Tsk) using a noninvasive infrared camera.

RESULTS

Significant main effects for time (P ≤ .001, η2 = .126) with preice application higher than all other time points (P ≤ .05) were demonstrated for both peak torque and average torque. There were also significant main effects for isokinetic testing speed, sex of the participant, and position of the ice application for both peak torque and average torque (P ≤ .05). Statistically significant decreases in Tsk were reported in both gender groups across all time points compared with preintervention Tsk for the anterior thigh and knee (P < .05).

CONCLUSIONS

Reductions reported for concentric peak torque and average torque knee-extensor strength in males and females did not fully recover to baseline measures at 30-minute postcryotherapy interventions. Sports medicine practitioners should consider strength deficits of the quadriceps after wetted ice applications, regardless of cooling location (joint/muscle) or gender.

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.

Cold water immersion settings for reducing muscle tissue temperature: a linear dose-response relationship

BACKGROUND

Although cold water immersion (CWI) is widely accepted and integrated as a recovery modality in sports practice, questions regarding its proposed working mechanisms remain. This study systematically reviews the existing literature on one the proposed mechanisms of CWI, its effect on muscle tissue temperature, and subsequently tries to identify a dose-response relationship in order to describe an optimal dose.

EVIDENCE ACQUISITION

A systematic literature search (PubMed and Sport Discus) was conducted in October 2017. Dose-response relationships were analyzed using linear regression while controlling for possible confounders (muscle measurement depth and immersion position).

EVIDENCE SYNTHESIS

A total of 10 studies, with a total of 104 participants, were included utilizing 26 different CWI protocols. Muscle tissue temperatures were reduced significantly by 24 CWI protocols. A significant, relationship with a medium effect size (r=0.51) was identified between muscle tissue temperature and CWI. The most optimal dose-response relationship, with a large effect size, (r=0.87) was described for CWI protocols using full-body immersion at a measurement depth of 30 mm (y = 4.051 x + 0.535).

CONCLUSIONS

CWI can decrease muscle tissue temperature significantly if a minimum CWI dose of 1.1 is applied, corresponding with an immersion of 11 minutes with a water temperature of 10 °C.

Efficacy of Endo-Ice followed by intrapulpal ice application as an adjunct to inferior alveolar nerve block in patients with symptomatic irreversible pulpitis-a randomized controlled trial

OBJECTIVE

The purpose of the present study was to evaluate the effect of Endo-Ice followed by intrapulpal ice application for reducing pain during pulp extirpation in mandibular molars with symptomatic irreversible pulpitis.

MATERIALS AND METHODS

Sixty patients diagnosed with symptomatic irreversible pulpitis participated in the present study. Subjects were randomly allocated to any one of the following groups: control group-inferior alveolar nerve block with lignocaine (2%) adrenaline (1:80000), articaine group-inferior alveolar nerve block with lignocaine (2%) adrenaline (1:80000) + Buccal infiltration with articaine (4%) with adrenaline (1:100000); or cold group-inferior alveolar nerve block with lignocaine (2%) adrenaline (1:80000) + cold application. The outcome assessor measured the level of pain during access opening and pulp extirpation using the visual analogue scale. The anxiety level of the patient was also measured.

RESULTS

During access opening, there was a significant difference in the pain reduction in the articaine group when compared to cold and control group (p value = 0.02). During pulp extirpation, cold group and articaine group showed a significant reduction in pain levels as compared to the control group (p value = 0.001). There was no difference in the pain level during pulp extirpation among the two test arms (articaine and cold) (p value = 0.99). Further, cold significantly reduced the level of anxiety when compared to the articaine or control group (p value = 0.001).

CONCLUSION

Hence, cold is a simple, supplementary technique in reducing pain during pulp extirpation.

CLINICAL RELEVANCE

Application of cold may help in minimizing the fear of additional injection in managing pain during endodontic treatment.

A cooling cuff compared to a moist ice pack on radial artery blood flow and lumen diameter in healthy participants

Background

Cryotherapy is a favourable treatment for post-traumatic injuries in the acute stage because of its effect on inflammation and pain. A novel cooling cuff, which can be easily used and can be wrapped around the injured area that does not require freezing, has been developed. Its efficacy compared to traditional ice therapy has not been established.

Aim

To establish the effect of a cooling cuff on radial artery blood flow and lumen diameter compared to moist ice.

Setting

Chiropractic clinic and radiographic laboratory.

Method

A controlled laboratory pre-test post-test investigation assessed asymptomatic participants who were randomly allocated into a moist ice pack (n = 22) or the cooling cuff (n = 21) group. The intervention was placed on the participants forearm over the radial artery for 15 min. Data was collected by a qualified diagnostic radiographer using Doppler ultrasound. Data was analysed, using repeated measures analysis of variance to assess changes in blood flow and lumen diameter pre- and post-intervention. A p-value of less than 0.05 was considered significant.

Results

Both groups showed a significant decrease in radial artery blood flow (p < 0.001) after 15 min with no significant changes being observed in diameter size. No significant differences were observed between the groups for radial artery blood flow or diameter.

Conclusion

The cooling cuff resulted in a similar effect on radial artery blood flow and lumen diameter as moist ice, indicating that patients and practitioners may utilise the cooling cuff in the acute phases of an injury to alter blood flow.

Thermal Sensations during a Partial-Body Cryostimulation Exposure in Elite Basketball Players

Partial-body cryostimulation is used to improve recovery after exercise, especially during competitions or heavy training; however, a limited number of studies have been conducted with international-level athletes in situ during competitions. This study was undertaken to assess the thermal sensation ratings during 3 min of cold exposure (at –130°C) in 24 international-level athletes during the European Basketball Championship. The mean thermal sensation score, measured using a perceptive scale, increased significantly (p < 0.05) during partial-body cryostimulation exposure in athletes from 3.0 ± 1.7 at 30 s to 5.7 ± 2.3 at 3 min (maximal observed value = 10.0). The mean value of 5.7 is considered a “cold” sensation on the scale (ranging from 0 = neutral sensation to 10 = very cold). However, we observed a large inter-individual variation in the perceived thermal sensations. The body mass index was significantly and negatively correlated with the thermal sensation value after 2 min 30 s and 3 min of exposure in females (r = –0.61, n = 13, p < 0.05; r = –0.56, n = 13, p = 0.054, respectively). Three participants reported high perceived thermal sensation after 30 s of exposure and their cold-induced discomfort worsened as the exposure continued. In conclusion, a 3-min exposure is globally well tolerated by athletes and can be used during a heavy competition period and/or during a training period. However, special attention should be given to female athletes with a low body mass index as they seem to be much more sensitive to cold.

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.

Intracanal Cryotherapy Reduces Postoperative Pain in Teeth with Symptomatic Apical Periodontitis: A Randomized Multicenter Clinical Trial

INTRODUCTION

A prospective, multicentered, randomized clinical trial was designed to assess if controlled irrigation with cold saline could result in less incidence and intensity of postoperative pain in patients presenting with pulp necrosis and symptomatic apical periodontitis.

METHODS

A total of 210 patients (presenting with necrotic uniradicular teeth with a diagnosis of symptomatic apical periodontitis and a preoperative visual analog scale (VAS) score higher than 7) were randomly allocated in the control or experimental group after the completion of shaping and cleaning procedures. The experimental group received a final irrigation with 20 mL sterile cold (2.5°C) saline solution delivered to the working length with a sterile, cold (2.5°C) Endovac microcannula (Kerr Endo, Orange Country, CA) for 5 minutes. The same protocol was used in the control group with room temperature saline solution. Patients were instructed to record the presence, duration and level of postoperative pain, and analgesic medication intake. A logistic regression was used to compare the incidence of postoperative pain and the need for painkillers between groups. Differences in general pain intensity between groups were analyzed using the ordinal (linear) chi-square test. Postoperative pain after 6, 24, and 72 hours (recorded in a VAS scale) and the need for analgesic medication intake between the 2 groups were assessed using the Mann-Whitney U test.

RESULTS

Patients in the control group presented a significantly higher incidence of postoperative pain, intensity, and need for medication intake (P < .05).

CONCLUSIONS

Cryotherapy reduced the incidence of postoperative pain and the need for medication intake in patients presenting with a diagnosis of necrotic pulp and symptomatic apical periodontitis.

Whole-Body Cryotherapy in Athletes: From Therapy to Stimulation. An Updated Review of the Literature

Nowadays, whole-body cryotherapy is a medical physical treatment widely used in sports medicine. Recovery from injuries (e.g., trauma, overuse) and after-season recovery are the main purposes for application. However, the most recent studies confirmed the anti-inflammatory, anti-analgesic, and anti-oxidant effects of this therapy by highlighting the underlying physiological responses. In addition to its therapeutic effects, whole-body cryotherapy has been demonstrated to be a preventive strategy against the deleterious effects of exercise-induced inflammation and soreness. Novel findings have stressed the importance of fat mass on cooling effectiveness and of the starting fitness level on the final result. Exposure to the cryotherapy somehow mimics exercise, since it affects myokines expression in an exercise-like fashion, thus opening another possible window on the therapeutic strategies for metabolic diseases such as obesity and type 2 diabetes. From a biochemical point of view, whole-body cryotherapy not always induces appreciable modifications, but the final clinical output (in terms of pain, soreness, stress, and post-exercise recovery) is very often improved compared to either the starting condition or the untreated matched group. Also, the number and the frequency of sessions that should be applied in order to obtain the best therapeutic results have been deeply investigated in the last years. In this article, we reviewed the most recent literature, from 2010 until present, in order to give the most updated insight into this therapeutic strategy, whose rapidly increasing use is not always based on scientific assumptions and safety standards.

The physiological and mononuclear cell activation response to cryotherapy following a mixed martial arts contest: a pilot study

Cold water immersion is thought to reduce the inflammatory response to injury. Using cultured mononuclear cells and human subjects in a mixed martial arts (MMA) contest, we examined the effect of cryotherapy on 7,8-dihydroneopterin and neopterin generation. Urine was collected from 10 elite male mixed martial artists before, immediately post and 1, 2, 24 and 48 h following a contest. Myoglobin was analysed by reverse-phase high performance liquid chromatography, and urinary neopterin and total neopterin (neopterin+7,8-dihydroneopterin) were measured by strong cation exchange high-performance liquid chromatography. Cold water immersion and passive recovery were compared using changes in these markers, while cryotherapy tested total neopterin production in γ-interferon and phorbol myristate acetate (PMA)-stimulated blood-derived mononuclear cells (monocytes/T cells). Myoglobin significantly increased (p<0.05) at 1 h post-contest, neopterin significantly increased at 1 and 24 h (p<0.05), total neopterin significantly increased (p<0.05) at 1 h post for the passive group only, and significant individual variation was observed for all markers (p<0.01). Cold water immersion attenuated total neopterin production (p<0.05), while cryotherapy significantly reduced total neopterin production in PMA-stimulated mononuclear cells (p<0.01). Cryotherapy attenuates the post-exercise inflammatory response following an MMA contest. The evidence also suggests that the mechanisms responsible for this may be related to direct immune cell suppression.

Dynamic Postural-Stability Deficits After Cryotherapy to the Ankle Joint

CONTEXT

Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however, its effects on postural stability remain unclear.

OBJECTIVE

To investigate the acute effects of a 15-minute ankle-joint cryotherapy application on dynamic postural stability.

DESIGN

Controlled laboratory study.

SETTING

University biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 29 elite-level collegiate male field-sport athletes (age = 20.8 ± 1.12 years, height = 1.80 ± 0.06 m, mass = 81.89 ± 8.59 kg) participated.

INTERVENTION(S)

Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Star Excursion Balance Test before and after a 15-minute ankle-joint cryotherapy application.

MAIN OUTCOME MEASURE(S)

Normalized reach distances; sagittal-plane kinematics of the hip, knee, and ankle joints; and associated mean velocity of the center-of-pressure path during performance of the ANT, PL, and PM reach directions of the Star Excursion Balance Test.

RESULTS

We observed a decrease in reach-distance scores for the ANT, PL, and PM reach directions from precryotherapy to postcryotherapy (P < .05). No differences were observed in hip-, knee-, or ankle-joint sagittal-plane kinematics (P > .05). We noted a decrease in mean velocity of the center-of-pressure path from precryotherapy to postcryotherapy (P < .05) in all reach directions.

CONCLUSIONS

Dynamic postural stability was adversely affected immediately after cryotherapy to the ankle joint.

Muscle Reaction Time During a Simulated Lateral Ankle Sprain After Wet-Ice Application or Cold-Water Immersion

CONTEXT

Cryotherapy is used widely in sport and exercise medicine to manage acute injuries and facilitate rehabilitation. The analgesic effects of cryotherapy are well established; however, a potential caveat is that cooling tissue negatively affects neuromuscular control through delayed muscle reaction time. This topic is important to investigate because athletes often return to exercise, rehabilitation, or competitive activity immediately or shortly after cryotherapy.

OBJECTIVE

To compare the effects of wet-ice application, cold-water immersion, and an untreated control condition on peroneus longus and tibialis anterior muscle reaction time during a simulated lateral ankle sprain.

DESIGN

Randomized controlled clinical trial.

SETTING

University of Hertfordshire human performance laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 54 physically active individuals (age = 20.1 ± 1.5 years, height = 1.7 ± 0.07 m, mass = 66.7 ± 5.4 kg) who had no injury or history of ankle sprain.

INTERVENTION(S)

Wet-ice application, cold-water immersion, or an untreated control condition applied to the ankle for 10 minutes.

MAIN OUTCOME MEASURE(S)

Muscle reaction time and muscle amplitude of the peroneus longus and tibialis anterior in response to a simulated lateral ankle sprain were calculated. The ankle-sprain simulation incorporated a combined inversion and plantar-flexion movement.

RESULTS

We observed no change in muscle reaction time or muscle amplitude after cryotherapy for either the peroneus longus or tibialis anterior (P > .05).

CONCLUSIONS

Ten minutes of joint cooling did not adversely affect muscle reaction time or muscle amplitude in response to a simulated lateral ankle sprain. These findings suggested that athletes can safely return to sporting activity immediately after icing. Further evidence showed that ice can be applied before ankle rehabilitation without adversely affecting dynamic neuromuscular control. Investigation in patients with acute ankle sprains is warranted to assess the clinical applicability of these interventions.

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.

Parasympathetic activity and blood catecholamine responses following a single partial-body cryostimulation and a whole-body cryostimulation

The aim of this study was to compare the effects of a single whole-body cryostimulation (WBC) and a partial-body cryostimulation (PBC) (i.e., not exposing the head to cold) on indices of parasympathetic activity and blood catecholamines. Two groups of 15 participants were assigned either to a 3-min WBC or PBC session, while 10 participants constituted a control group (CON) not receiving any cryostimulation. Changes in thermal, physiological and subjective variables were recorded before and during the 20-min after each cryostimulation. According to a qualitative statistical analysis, an almost certain decrease in skin temperature was reported for all body regions immediately after the WBC (mean decrease±90% CL, -13.7±0.7°C) and PBC (-8.3±0.3°C), which persisted up to 20-min after the session. The tympanic temperature almost certainly decreased only after the WBC session (-0.32±0.04°C). Systolic and diastolic blood pressures were very likely increased after the WBC session, whereas these changes were trivial in the other groups. In addition, heart rate almost certainly decreased after PBC (-10.9%) and WBC (-15.2%) sessions, in a likely greater proportion for WBC compared to PBC. Resting vagal-related heart rate variability indices (the root-mean square difference of successive normal R-R intervals, RMSSD, and high frequency band, HF) were very likely increased after PBC (RMSSD: +54.4%, HF: +138%) and WBC (RMSSD: +85.2%, HF: +632%) sessions without any marked difference between groups. Plasma norepinephrine concentrations were likely to very likely increased after PBC (+57.4%) and WBC (+76.2%), respectively. Finally, cold and comfort sensations were almost certainly altered after WBC and PBC, sensation of discomfort being likely more pronounced after WBC than PBC. Both acute cryostimulation techniques effectively stimulated the autonomic nervous system (ANS), with a predominance of parasympathetic tone activation. The results of this study also suggest that a whole-body cold exposure induced a larger stimulation of the ANS compared to partial-body cold exposure.

Effects of air-pulsed cryotherapy on neuromuscular recovery subsequent to exercise-induced muscle damage

BACKGROUND

Localized cooling has been proposed as an effective strategy to limit the deleterious effects of exercise-induced muscle damage on neuromuscular function. However, the literature reports conflicting results.

PURPOSE

This randomized controlled trial aimed to determine the effects of a new treatment, localized air-pulsed cryotherapy (-30°C), on the recovery time-course of neuromuscular function following a strenuous eccentric exercise.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 24 participants were included in either a control group (CONT) or a cryotherapy group (CRYO). Immediately after 3 sets of 20 maximal isokinetic eccentric contractions of elbow flexors, and then 1, 2, and 3 days after exercise, the CRYO group received a cryotherapy treatment (3 × 4 minutes at -30°C separated by 1 minute). The day before and 1, 2, 3, 7, and 14 days after exercise, several parameters were quantified: maximal isometric torque and its associated maximal electromyographic activity recorded by a 64-channel electrode, delayed-onset muscle soreness (DOMS), biceps brachii transverse relaxation time (T2) measured using magnetic resonance imaging, creatine kinase activity, interleukin-6, and C-reactive protein.

RESULTS

Maximal isometric torque decreased similarly for the CONT (-33% ± 4%) and CRYO groups (-31% ± 6%). No intergroup differences were found for DOMS, electromyographic activity, creatine kinase activity, and T2 level averaged across the whole biceps brachii. C-reactive protein significantly increased for CONT (+93% at 72 hours, P < .05) but not for CRYO. Spatial analysis showed that cryotherapy delayed the significant increase of T2 and the decrease of electromyographic activity level for CRYO compared with CONT (between day 1 and day 3) in the medio-distal part of the biceps brachii.

CONCLUSION

Although some indicators of muscle damage after severe eccentric exercise were delayed (ie, local formation of edema and decrease of muscle activity) by repeated air-pulsed cryotherapy, we provide evidence that this cooling procedure failed to improve long-term recovery of muscle performance.

CLINICAL RELEVANCE

Four applications of air-pulsed cryotherapy in the 3 days after a strenuous eccentric exercise are ineffective overall in promoting long-term muscle recovery. Further studies taking into account the amount of exercise-induced muscle damage would allow investigators to make stronger conclusions regarding the inefficiency of this recovery modality.