Subcutaneous adipose tissue thickness alters cooling time during cryotherapy

Comparison of Cryotherapy Performed With Ice or Gel and Superficial Skin Cooling of Older Women: A Randomized, Crossover, Clinical Trial

BACKGROUND AND PURPOSE

Cryotherapy is an affordable and popular treatment of soft tissue injuries, which can reduce inflammation and pain. Studies have specifically addressed young adults and athletes, and these findings have been extended to older adults in clinical practice. Aging is associated with changes in the skin, including collagen degradation, decreased fat layer thickness, and reduced blood flow, which can alter the skin response to stress. Because of age-related changes, there are concerns about the direct use of ice on the skin of older individuals. Skin injuries were also observed after cryotherapy. This study aimed to assess the most effective and safe cryotherapy for superficial skin cooling among older women.

METHODS

Eighteen older women were enrolled in this blinded, randomized, crossover, clinical trial. The mean values (SD) of their age, height, and weight were 70.0 years (6.0), 156.0 cm (9.1), and 72.8 kg (19.5), respectively. The participants underwent cryotherapy using bagged ice, bagged ice plus a wet towel, or gel pack for 20 minutes. The surface temperature of the skin was measured at the end of a 20-minute cryotherapy session using an infrared thermometer. Repeated-measures analysis of variance was conducted to analyze the effect of cryotherapy modalities and time, as well as the interaction between these 2 factors. The secondary outcome was the presence of cryotherapy-induced lesions.

RESULTS AND DISCUSSION

Cryotherapy modalities had significant effects on superficial skin temperature (P = .001). Time points after application also had an effect (P = .0001), and no interaction was observed between cryotherapy modalities and time points (P = .051). Bonferroni post hoc evaluation showed that bagged ice (P = .008) and gel (P = .007) were more effective in decreasing the superficial skin temperature than bagged ice plus wet towel. No difference was observed between bagged ice and gel (P = .32). Three of the 18 patients experienced adverse effects with the gel pack.

CONCLUSION

This study of older women found that ice and gel cooled the skin more effectively than ice wrapped in towels. However, the gel pack had some adverse effects. Therefore, bagged ice is recommended for cryotherapy in older women.

Immediate Effect of Cryo-Compression Therapy on Biomechanical Properties and Perfusion of Forearm Muscles in Mixed Martial Arts Fighters

Mixed martial arts (MMA) fighters use their arms and hands for striking with the fists, grappling, and defensive techniques, which puts a high load on the forearms and hand muscles. New methods are needed to decrease the risk of injury and increase the effectiveness of regeneration. This study aimed to assess the effectiveness of cryo-compression (CC) therapy of different times (3 and 6 min) on forearm muscles in MMA fighters by investigating muscle pain, stiffness, tension, elasticity strength, and perfusion. Twenty professional male MMA fighters aged 26.5 ± 4.5 years, with training experience of 10.3 ± 5.0 years, were enrolled on an experimental within-group study design. The participants underwent CC therapy at a temperature of 3 °C and compression of 75 mmHg for 3 min and, in the second session, for 6 min. The investigated parameters were in the following order: (1) perfusion in non-reference units (PU), (2) muscle tone (T-[Hz]), (3) stiffness (S-[N/m]), (4) elasticity (E-[arb]), (5) pressure pain threshold (PPT-[N/cm]), and (6) maximum isometric force (Fmax [kgf]) at two time points: (1) at rest-2 min before CC therapy (pre) and (2) 2 min after CC therapy (post). There were significant differences between 3 and 6 min of CC therapy for PU and T. Meanwhile, F, E, PPT, and S were significantly different when comparing pre- to post-conditions. These results provide evidence that CC therapy is a stimulus that significantly affects parameters characterizing muscle biomechanical properties, pain threshold, strength, and tissue perfusion.

Mechanism involved of post-exercise cold water immersion: Blood redistribution and increase in energy expenditure during rewarming

Thermogenesis is well understood, but the relationships between cold water immersion (CWI), the post-CWI rewarming and the associated physiological changes are not. This study investigated muscle and systemic oxygenation, cardiorespiratory and hemodynamic responses, and gastrointestinal temperature during and after CWI. 21 healthy men completed randomly 2 protocols. Both protocols consisted of a 48 minutes heating cycling exercise followed by 3 recovery periods (R1-R3), but they differed in R2. R1 lasted 20 minutes in a passive semi-seated position on a physiotherapy table at ambient room temperature. Depending on the protocol, R2 lasted 15 minutes at either ambient condition (R2_AMB) or in a CWI condition at 10°C up to the iliac crest (R2_CWI). R3 lasted 40 minutes at AMB while favoring rewarming after R2_CWI. This was followed by 10 minutes of cycling. Compared to R2_AMB, R2_CWI ended at higherV ˙ O2 in the non-immersed body part due to thermogenesis (7.16(2.15) vs. 4.83(1.62) ml.min-1.kg-1) and lower femoral artery blood flow (475(165) vs. 704(257) ml.min-1) (p < 0.001). Only after CWI, R3 showed a progressive decrease in vastus and gastrocnemius medialis O2 saturation, significant after 34 minutes (p < 0.001). As blood flow did not differ from the AMB protocol, this indicated local thermogenesis in the immersed part of the body. After CWI, a lower gastrointestinal temperature on resumption of cycling compared to AMB (36.31(0.45) vs. 37.30(0.49) °C, p < 0.001) indicated incomplete muscle thermogenesis. In conclusion, the rewarming period after CWI was non-linear and metabolically costly. Immersion and rewarming should be considered as a continuum rather than separate events.

The role of a cryocompression device following total knee arthroplasty to assist in recovery: a randomised controlled trial

PURPOSE

The study sought to investigate the effectiveness of a cryocompression Game Ready™ (GR) versus usual care protocol (UC) on early post-operative recovery following total knee arthroplasty.

METHODS

This study prospectively randomised 72 total knee arthroplasties to a 2-week (from day 0) intervention of GR treatment (n = 36, 63.9% females) or UC of ice with static compression (n = 36, 45.7% females). Knee flexion and extension range of motion (ROM), a visual analogue pain scale and limb circumference were documented at day 1, 2 and 14, as well as 6 weeks post-surgery. Medication usage and length of hospital stay were documented. Patient-reported outcome measures (PROMs) included the Knee Injury and Osteoarthritis Outcome Score and a Patient Satisfaction Questionnaire. Statistical analysis using linear mixed modelling and analysis of variance table with Satterthwaite's method were used along with two-tailed t-tests.

RESULTS

There were no significant group-by-time interactions regarding any of the outcomes. The GR group had 19% lost to follow-up at 2 weeks, while the UC group had 8%. The GR group demonstrated significantly better knee extension ROM at day 1 (p = 0.048) and day 14 (p = 0.007) compared with the UC group. There were no group differences (n.s.) observed in pain, flexion ROM, limb circumference, opioid use or PROMs. Overall, higher pain levels resulted in increased opioid intake (p = 0.002), older patients used significantly less opioids (p < 0.001) and males reported significantly less pain than females (p = 0.048). No adverse effects were observed due to either protocol.

CONCLUSION

Despite patients gaining significantly more knee extension during the initial two-week intervention period when using GR compared to UC, this effect was likely due to chance. No further significant differences were observed between the groups during or after cession of the intervention.

LEVEL OF EVIDENCE

Level 2.

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.

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.

Do vasomotor and genitourinary symptoms of menopause vary between sedente and migrant groups? A study on the Oraon tribal populations of Eastern India

OBJECTIVES

Human reproductive characteristics are embedded within local ecological contexts. A shift in the local ecology is likely to offer challenges in reproductive outcome. We aimed to investigate sedente-migrant variation in experiencing vasomotor and genitourinary symptoms at perimenopausal and postmenopausal stages and its concomitants.

METHODS

Four hundred Oraon tribal populations living in Eastern India (sedente [100 each from perimenopausal and postmenopausal groups] and migrants [100 each from perimenopausal and postmenopausal groups]) were studied. Data on vasomotor and genitourinary symptoms, socio-demographic and reproductive history, body compositions, lifestyle variables, and energy intake were compared between sedente and migrant independently for perimenopausal and postmenopausal groups. Principal component analysis (PCA) was used to identify the principal components (PCs) of menopausal symptoms. A two level multilevel linear regression was applied independently for perimenopausal and postmenopausal groups to identify the concomitants of menopausal symptoms and estimate sedente-migrant variance.

RESULTS

Bivariate analysis showed significant (p ≤ .05) sedente-migrant differences in socio-demographic, reproductive, body composition, energy intake, and lifestyle variables and in some of the vasomotor and genitourinary symptoms. In multilevel analyses, random effect did not show significant heterogeneity between sedente and migrant groups in experiencing menopausal symptoms; however, fixed effect showed that region from which participants were recruited (Gram Panchayat [GP]) and individual level characteristics were concomitants (p ≤ .05) for menopausal symptoms, irrespective of menopausal status.

CONCLUSION

Variability at GP levels and individual level characteristics of sedente and migrant groups predominantly determined menopausal symptoms of the study populations, but not the migration status.

The Use of Cryotherapy in Conjunction with Surgical Removal of Mandibular Third Molars: a Single-Blinded Randomized Controlled Trial

Objectives

Cryotherapy is frequently used to diminish postoperative sequelae following mandibular third molar surgery. The objective of this single-blinded randomized controlled trial was to assess the therapeutic efficiency of 30 minutes continuous cryotherapy on postoperative sequelae following surgical removal of mandibular third molars compared with no cryotherapy.

Material and Methods

Thirty patients (14 male and 16 female) including 60 mandibular third molars were randomly allocated to 30 minutes of immediately cryotherapy or no cryotherapy. Outcome measures included pain (visual analogue scale score), maximum mouth opening (trismus) and quality of life (oral health impact profile-14). Outcome measures were assessed preoperatively and one day, three days, seven days and one month following surgical removal of mandibular third molars. Descriptive and generalized estimating equation analyses were made. Level of significance was 0.05.

Results

No cryotherapy following surgical removal of mandibular third molars revealed a statistically significant lower visual analogue scale score of pain compared to thirty minutes of continuous cryotherapy after one day (P < 0.05). However, no statistically significant difference in trismus or oral health-related quality of life were revealed at any time point compared with no cryotherapy.

Conclusions

The therapeutic effect of 30 minutes continuous cryotherapy following surgical removal of mandibular third molars seem to be negligible. Thus, further randomized controlled trials assessing a prolonged application period of cryotherapy, alternative devices or use of intermittent cryotherapy are needed before definite conclusions and evidence-based clinical recommendations can be provided.

Relationship Between Interface Pressures and Pneumatic Cuff Inflation Pressure at Different Assessment Sites of the Lower Limb to Aid Soft Exoskeleton Design

OBJECTIVE

The aim was to develop a means of predicting interface pressure from cuff inflation pressure during circumferential compression at the lower limb, in order to inform the design of soft exoskeletons.

BACKGROUND

Excessive mechanical loading of tissues can cause discomfort and soft tissue injury. Most ergonomic studies on exoskeletons are of interface pressure, but soft exoskeletons apply circumferential pressures similar to tourniquet cuffs by way of cuff inflation pressure. This study details the relationship between interface and cuff inflation pressures for pneumatic tourniquet cuffs.

METHOD

Pneumatic cuffs of different widths were inflated to target pressures on (A) a rigid cylinder, (B) the dominant thigh and calf, and (C) knee of healthy participants standing still. Interface pressures were measured under the cuffs using a pressure-sensing mat. Average interface pressures were then compared to cuff inflation pressures. The influence of cuff width, cuff inflation pressure, and participants' anthropometric data on pressure transmission was assessed.

RESULTS

A strong linear relationship between cuff inflation pressures and interface pressures was observed. Interface pressures were generally higher than cuff inflation pressures. The efficiency of pressure transmission to the lower limb depended on assessment site, adipose tissue thickness, cuff size, cuff inflation pressure, and possibly limb circumference. Regression equations were developed to predict interface pressures at the thigh, calf, and knee.

CONCLUSION

Interface pressures under pneumatic cuffs are influenced by the cuff size, cuff inflation pressure, and tissue compressibility. Predicted interface pressure from cuff inflation pressure and vice versa can be used to aid the design of soft exoskeletons.

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.

The Effects of Age and Body Fat Content on Post-Downhill Run Recovery Following Whole Body Cryotherapy

This study explored the effects of age and body fat content on responses to whole body cryotherapy (WBC) following a downhill running bout. Forty-one male participants (mean ± SD age 42.0 ± 13.7 years, body mass 75.2 ± 10.8 kg) were allocated into WBC (n = 26) and control (CON, n = 15) groups. WBC participants were divided into old (OLD, ≥45 years, n = 10) and young (YNG, <40 years, n = 13), as well as high fat (HFAT, ≥20%, n = 10) and low fat (LFAT ≤ 15%, n = 8) groups. Participants completed a 30 min downhill run (15% gradient) at 60% VO2 max. The WBC group underwent cryotherapy (3 min, -120 °C) 1 h post-run and CON participants passively recovered in a controlled environment (20 °C). Maximal isometric leg muscle torque was assessed pre and 24 h post-run. Blood creatine kinase (CK) and muscle soreness were assessed pre, post, one hour and 24 h post-run. Muscle torque significantly decreased in both groups post-downhill run (WBC: 220.6 ± 61.4 Nm vs. 208.3 ± 67.6 Nm, p = 0.02; CON: 239.7 ± 51.1 Nm vs. 212.1 ± 46.3 Nm, p = 0.00). The mean decrease in WBC was significantly less than in CON (p = 0.04). Soreness and CK increased 24 h post for WBC and CON (p < 0.01) with no difference between groups. Muscle torque significantly decreased in OLD participants (p = 0.04) but not in YNG (p = 0.55). There were no differences between HFAT and LFAT (all p values > 0.05). WBC may attenuate muscle damage and benefit muscle strength recovery following eccentrically biased exercises, particularly for young males.

Effects of Cryotherapy on Temperature Change in Caudal Thigh Muscles of Dogs

OBJECTIVE

 The aim of the study reported here was to determine the effect of cryotherapy on the caudal thigh muscles of dogs. We hypothesized that temperature changes would be greatest in superficial tissues and decrease with tissue depth.

STUDY DESIGN

 Eight mixed-breed dogs (mean weight 21.2 kg, mean age 3.3 years) were studied. Temperature was measured at the skin surface and at depths of 1.0 and 3.0 cm below the skin using needle thermistor probes that were inserted beneath the site of cold pack application. Treatment consisted of a standard 1.0°C cold pack applied for 20 minutes. Temperature was recorded every minute for the 20 minute cold pack treatment, and for 80 minutes following treatment.

RESULTS

 Cutaneous temperatures significantly decreased (p < 0.01), with rapid rewarming of the skin following cold pack removal. Tissue cooling was less profound with increasing tissue depths, but was still significant (p < 0.05). There was no significant difference in muscle temperature between haired and clipped limbs.

CONCLUSION

 A single application of a cold pack to the caudal thigh muscles of dogs for 20 minutes resulted in significant temperature reduction at all tissue depths (p < 0.05). This decrease persisted for ∼60 minutes. The presence of hair did not have a significant effect on muscle cooling (p > 0.05).

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.

Exploring the Efficacy of a Safe Cryotherapy Alternative: Physiological Temperature Changes From Cold-Water Immersion Versus Prolonged Cooling of Phase-Change Material

PURPOSE

To evaluate the effectiveness between cold-water immersion (CWI) and phase-change-material (PCM) cooling on intramuscular, core, and skin-temperature and cardiovascular responses.

METHODS

In a randomized, crossover design, 11 men completed 15 min of 15°C CWI to the umbilicus and 2-h recovery or 3 h of 15°C PCM covering the quadriceps and 1 h of recovery, separated by 24 h. Vastus lateralis intramuscular temperature at 1 and 3 cm, core and skin temperature, heart-rate variability, and thermal comfort were recorded at baseline and 15-min intervals throughout treatment and recovery.

RESULTS

Intramuscular temperature decreased (P < .001) during and after both treatments. A faster initial effect was observed from 15 min of CWI (Δ: 4.3°C [1.7°C] 1 cm; 5.5°C [2.1°C] 3 cm; P = .01). However, over time (2 h 15 min), greater effects were observed from prolonged PCM treatment (Δ: 4.2°C [1.9°C] 1 cm; 2.2°C [2.2°C] 3 cm; treatment × time, P = .0001). During the first hour of recovery from both treatments, intramuscular temperature was higher from CWI at 1 cm (P = .013) but not 3 cm. Core temperature deceased 0.25° (0.32°) from CWI (P = .001) and 0.28°C (0.27°C) from PCM (P = .0001), whereas heart-rate variability increased during both treatments (P = .001), with no differences between treatments.

CONCLUSIONS

The magnitude of temperature reduction from CWI was comparable with PCM, but intramuscular temperature was decreased for longer during PCM. PCM cooling packs offer an alternative for delivering prolonged cooling whenever application of CWI is impractical while also exerting a central effect on core temperature and heart rate.

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.

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.

Continuous-flow cryocompression therapy penetrates to bone level in hip fracture patients in a numerical simulation

BACKGROUND

The aim of this study was to define deep tissue temperature during cryotherapy in postoperative hip fracture patients, by using measured skin temperature as input parameter for a simple numerical model. Second, an association was investigated between pain and tissue temperature distribution, to assess cryotherapy-induced analgesia of soft tissue-derived pain.

METHODS

Data from 35 participants in an ongoing trial was used. In three subjects who consented on optional measurements, skin temperature was measured in 3 days during and after cryotherapy. A simple numerical model was developed to calculate tissue temperature distribution during cryotherapy.

RESULTS

Inter and intrasubject skin temperature displayed high variation: trochanter 11-27 °C, mid-femur 11-24 °C, distal femur 10-16 °C. Predicted temperatures decreased to 20 °C at 1 cm, 26 °C at 2 cm, and 30 °C at 3 cm tissue depth. Smallest soft tissue layer was measured at the trochanter; 42% had less than 30 mm and 21% had less than 20 mm. Numeric rating scale pain varied (mean = 2.14; SD = 1.92), and no association was found between pain and decrease in temperature (r = 0.064; p = 0.204).

CONCLUSIONS

Cryotherapy was predicted to reduce temperature up to 3 cm; in cachectic patients, this reaches the bone, where it might have implications for bone tissue healing when treated for a prolonged period of time. Cryotherapy-induced analgesia is likely to originate from skin analgesia rather than analgesia of muscle or bone-derived pain.

Effectiveness of Salted Ice Bag Versus Cryocompression on Decreasing Intramuscular and Skin Temperature

CONTEXT

Rest, ice, compression, and elevation are commonly recommended immediately after injury. Traditionally, ice bag (IB) with elastic wrap compression has been utilized; however, recently intermittent cryocompression units are being used. Limited research has evaluated tissue temperature decreases with intermittent cryocompression units.

OBJECTIVE

Evaluate magnitude of muscle and skin cooling.

DESIGN

Repeated-measures counterbalanced study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Twelve healthy college-aged participants (4 males and 8 females; age = 23.08 [1.93] y; height = 171.66 [9.47] cm; mass = 73.67 [13.46] kg; subcutaneous thickness = 0.90 [0.35] cm) without compromised circulation or injury.

INTERVENTION(S)

Salted IB, GameReady (GR), and PowerPlay-ice bag (PP-ice) were applied to the posterior aspect of the nondominant calf for 30 minutes; participants underwent each treatment in counterbalanced order.

MAIN OUTCOME MEASURE(S)

Muscle temperature measured via 21-gauge catheter thermocouple; skin temperature measured via a surface thermocouple. Temperatures were recorded at baseline and during a 30-minute treatment. Correlations were evaluated between muscle and skin temperatures.

RESULTS

Nonsignificant treatment × time interaction and nonsignificant main effect of treatment for intramuscular cooling. Mean Decrease From Baseline: IB, 6.4°C (±2.8); GR, 5.4°C (±1.1); PP-ice, 4.8°C (±2.8). Nonsignificant treatment × time interaction for skin cooling (F_20,200 = 1.440, P = .65, ηp2=.346 , and observed β = 0.773), but significant main effect for treatment (F_10,100 = 5.279, P = .03, ηp2=.883 , and observed β = 1.00). Mean Decrease From Baseline: IB, 17.0°C; GR, 16.4°C; PP-ice, 14.6°C. No significant correlation between intramuscular and skin temperatures in any condition at any time point. No significant correlation between adipose tissue thickness and maximum temperature decrease with any modality.

CONCLUSIONS

Salted IB with elastic wrap compression, GR, and PP-ice produced equivalent intramuscular temperature decreases during the treatment period.

The effectiveness of self-care and lifestyle interventions in primary dysmenorrhea: a systematic review and meta-analysis

Background

Menstrual pain is very common amongst young women. Despite the significant impact that menstrual pain has on academic attendance and performance, social activities and quality of life, most young women do not seek medical treatment but prefer to use self-care; commonly OTC analgesic medications and rest. Many women do not get significant pain relief from these methods, therefore other low cost, easy to learn self-care methods may be a valuable approach to management.

This review and meta-analysis examines the evidence for participant lead self-care techniques.

Methods

A search of Medline, PsychINFO, Google Scholar and CINAHL was carried out in September 2017.

Results

Twenty-three trials including 2302 women were eligible and included in the meta-analysis. Studies examined self-delivered acupressure, exercise and heat as interventions. Risk of bias was unclear for many domains. All interventions showed a reduction in menstrual pain symptoms; exercise (g = 2.16, 95% CI 0.97 to 3.35) showed the largest effect size, with heat (g = 0.73, 95% CI 0.06 to 1.40) and acupressure (g = 0.56, 95% CI 0.10 to 1.03) showing more moderate effect sizes. Exercise (g = 0.48, 95% CI 0.12 to 0.83) and heat (g = 0.48, 95% CI 0.10 to 0.87), were more effective than analgesics in reducing pain intensity, whereas acupressure was significantly less effective (g = − 0.76, 95% CI -1.37 to − 0.15).

Conclusion

Exercise showed large effects, while acupressure and heat showed moderate effects in reducing menstrual pain compared to no treatment. Both exercise and heat are potential alternatives to analgesic medication. However, difficulties in controlling for non-specific effects, along with potential for bias, may influence study findings.

Intermittent wetting clothing as a cooling strategy for body heat strain alleviation of vulnerable populations during a severe heatwave incident

Many documented studies have demonstrated the human mortality rate increases during severe heatwaves. There remains a need for further explore ecologically valid cooling strategies to alleviate body heat strain during extreme heatwaves. The main aim of this work was to explore whether intermittent wetting clothing can be served as an ecologically valid cooling strategy to mitigate heat stress on inactive vulnerable populations not having access to air-conditioning during a severe heatwave. Ten young male subjects underwent two 90-min separate trials: a dry clothing trial (i.e., CON) and a wetted clothing cooling trial (i.e., WEC). A set of light summer wear was chosen and intermittently wetted by tap water at intervals of every 30 min. Physiological and perceptual responses of subjects were examined and compared. All trials were performed in a chamber with an air temperature of 43 ± 0.5 °C, RH= 57 ± 5% and an air velocity of 0.15 ± 0.05 m/s (WBGT=37.35 °C). Results demonstrated that WEC, compared with CON, could significantly reduce both the mean skin temperature and the core temperature throughout the 5-90th min and 25-90th min of the trial, respectively (p < 0.05). Besides, WEC could also remarkable reduce local skin temperatures at those body sites covered by wet clothing (p < 0.05). In comparison, no significant difference was found between WEC and CON on perceptual responses. Further, it was also found from PHS simulations that conditions with a partial water vapour pressure ≤ 3.1-3.5 kPa would not induce pronounced core temperature rises at 43 °C. Finally, it may be concluded that intermittent wetting clothing could be served as an ecologically valid cooling strategy to reduce thermophysiological strain of vulnerable populations while seating during humid heatwaves and thereby improve their health and safety.

A Numerical Model of Blood Flow Velocity Measurement Based on Finger Ring

Aiming to measure the blood flow velocity in a finger, a novel noninvasive method, i.e., a ring with a heat source chip and a temperature sensor, is designed in this paper. The heat source chip is used to heat the finger and generate heat diffusion between the chip and the temperature sensor. And the temperature sensor is designed to measure the temperature difference. Since the blood flow is the main medium of heat diffusion in bodies, part from the heat energy in the tissue will be taken away by the flowing blood. Therefore, the blood flow velocity can be acquired via its relationship with the temperature difference. Compared to the ultrasound Doppler method and the laser Doppler method, the proposed method guarantees a more convenient operation in more flexible work sites. We also analyze the theory between heat transfer and laminar flow. Finally, several simulations are conducted, and the influence of the relevant factors (i.e., the number of blood vessels, the radius, etc.) corresponding to the simulation results is also discussed.

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.

Modification of therapeutic temperature range in cryotherapy could improve clinical efficacy in tension type headache

BACKGROUND

Cold pack therapy is not used frequently in clinics in spite of its effectiveness in clinical reports. Low compliance due to cold intolerance may be a disturbance factor that hinders patients from using the modality.

OBJECTIVE

To demonstrate the improved compliance and clinical efficacy as new devised cold modality with a different composition is applied to target different therapeutic temperature range in tension-type headache (TTH) patients.

METHODS

A randomized, controlled, comparative trial involving 53 patients with tension-type headache was conducted. A new cold modality that targets upper normal therapeutic temperature range was devised and applied to one group (n= 27) and ice pack was applied to the other group (n= 26).

RESULTS

After application of two modalities for 4 weeks, the amount of analgesics intake, modality use per week, and Likert survey of cold intolerance were significantly different between the two groups.

CONCLUSIONS

Rather than focusing on lowering the skin temperature indefinitely, optimizing tolerability by targeting the temperature at the upper therapeutic range could be more effective in cold modality application.

Obesity and thermoregulation

Excised fat tissue has a lower thermal conductivity than excised lean tissue. In theory then subcutaneous fat might serve as a barrier to heat loss and influence thermoregulatory abilities. In some aquatic mammals and animals from severely cold habitats subcutaneous adipose tissue has evolved into a continuous sheet that envelopes the organs and acts as a thermal insulation layer. This layer can comprise more than half of the cross-sectional area of the body. In most mammals however, the distribution of fat is less continuous. It has been suggested that in tropical animals this distribution may in fact allow animals to still store energy while not impeding heat loss. Studies of humans immersed in cool water convincingly demonstrate that obesity in humans also serves an insulation function. Humans with obesity cool less rapidly and have to elevate their metabolism less significantly than lean individuals when immersed in water. Although obesity provides an advantage in cold conditions it conversely impedes heat loss and makes obese people susceptible to heat stress more than lean individuals. In small mammals like mice the role of subcutaneous (or intradermal) fat for providing thermal insulation is less clear. In theory variations in thermoregulatory capacity may allow individuals different capabilities to burn off excess consumption. Hence, thermoregulatory variations may cause obesity differences. Thermoregulatory capacity is related to ambient temperature. Yet, levels of obesity are only weakly related to ambient temperature and this effect disappears when confounding factors like poverty and race are taken into account. Hence we conclude that obesity may have a significant impact on thermoregulatory physiology, but the converse is much less likely.

Postoperative continuous-flow cryocompression therapy in the acute recovery phase of hip fracture surgery-A randomized controlled clinical trial

BACKGROUND

The acute recovery phase after hip fracture surgery is often complicated by severe pain, postoperative blood loss with subsequent transfusion, and delirium. Prevalent comorbidity in hip fracture patients limit the use of opioid-based analgesic therapies, yielding a high risk for inferior pain treatment. Postoperative cryotherapy is suggested to provide an analgesic effect, and to reduce postoperative blood loss. In this prospective, open-label, parallel, multicentre, randomized controlled, clinical trial, we aimed to determine the efficacy of continuous-flow cryocompression therapy (CFCT) in the acute recovery phase after hip fracture surgery.

METHODS

Patients with an intra or extracapsular hip fracture scheduled for surgery were included. Subjects were allocated to receive postoperative CFCT or usual care. The primary endpoint was numeric rating scale (NRS) pain the first 72 postoperative hours. Secondly, analgesic use; postoperative haemoglobin change and transfusion incidence; functional outcome; length of stay; delirium incidence; location of rehabilitation; patient-reported health outcome; complications and feasibility were assessed.

RESULTS

Sixty-one subjects in the control group, and 64 subjects in the CFCT group were analysed. Within the CFCT group, post treatment NRS pain declined 0.31 (p=0.07) at 24h, 0.28 (p=0.07) at 48h, and 0.47 (p=0.002) at 72h relative to pre treatment NRS pain. Sensitivity analysis at 72h showed that NRS pain was 0.92 lower in the CFCT group when compared to the control group (1.50 vs. 2.42; p=0.03). Postoperative analgesic use was comparable between groups. Between postoperative day one and three haemoglobin declined 0.29mmol/l in the CFCT group and 0.51mmol/l in controls (p=0.06), and transfusion incidence was comparable. The timed up and go test and length of stay were also comparable between both groups. Complications, amongst delirium and cryotherapy-related adverse events were not statistically significantly different. Discharge locations did not differ between groups. At outpatient follow-up subjects did not differ in patient-reported health outcome scores. Subjects rated CFCT satisfaction with an average of 7.1 out of 10 points.

CONCLUSIONS

No evidence was recorded to suggest that CFCT has an added value in the acute recovery phase after hip fracture surgery. If patients complete the CFCT treatment schedule, a mild analgesic effect is observed at 72h.

Evaluating the Physiological and Perceptual Responses of Wearing a Newly Designed Cooling Vest for Construction Workers

Construction workers are subjected to heat stress because of the hot environment, physically demanding tasks, and/or personal protective equipment. A tailor-made cooling vest that protects construction workers from heat-related injuries was developed. The purpose of the study is to examine a newly designed cooling vest's effectiveness in alleviating physiological and perceptual strain in a hot and humid environment. Twelve male participants performed two trials, i.e., cooling vest (VEST) and control (CON) in a climatic chamber controlled at 37°C temperature, 60% relative humidity, 0.3 m/s air velocity, and 450 W/m2 solar radiation to simulate the summer working environment of construction sites. Two bouts of treadmill exercise intermitted with 30-minute passive recovery were designed to simulate the practical work-rest schedule of the construction industry. The cooling vest was used during the passive recovery period in the VEST condition, and the results were compared with that of no cooling vest in the CON condition. The results revealed that the newly designed cooling vest can significantly alleviate heat strain and improve thermal comfort, based on the decrease in body temperature, heart rate, and subjective perceptions (including perceived exertion, thermal, wetness, and comfort sensation) of the participants. It can also prolong work duration in the subsequent exercise. The cooling countermeasures proposed in this study will be able to provide an effective solution in situations that involve repeated bouts of outdoor construction work.

Individualising the exposure of -110°C whole body cryotherapy: The effects of sex and body composition

The purpose of this study was to investigate the effects of whole body cryotherapy (WBC) on a range of thermoregulatory measures. We also sought to examine the influence of sex and body composition. A convenience sample of 18 healthy participants (10 males and 8 females) (27±6yr) volunteered for this study. Temperature (core, tympanic, skin and mean body), heart rate, blood pressure, and thermal comfort and sensation were recorded pre- and post- (immediately and every 5min until 35min post) exposure to a single bout of WBC (30s at -60°C, 150s at 110°C). Anthropometric data (height, weight, body surface area, body mass index, fat mass and fat free mass) were also recorded. No significant differences in temperature (core, tympanic, skin and mean body), heart rate, blood pressure, or thermal comfort / sensation were observed between male and females at baseline. Immediately post WBC mean body (male:31.9±0.8°C; female:31.0±0.9°C; ∆ mean body temperature:0.9±0.1°C; P≤0.05, d=0.64) and mean skin (male:22.1±2.2°C; female:19.6±2.8°C; ∆ mean skin temperature:-2.5±0.6°C; d=0.99, P≤0.05) temperature was significantly different between sexes. Sex differences were also observed in regional skin temperature (male thigh, 20.8±1.1°C; female thigh, 16.7±1.1°C, ∆ mean thigh skin temperature:-4.1°C; d=3.72; male calf, 20.5±1.1°C; female calf, 18.2±1°C, ∆ mean calf skin temperature:-2.3±0.1°C; d=3.61; male arm, 21.7±1°C; female arm, 19±0.4°C, ∆ mean arm skin temperature: -2.7±0.3°C; d=3.54; P≤0.05). Mean arterial pressure was significantly different over time (P≤0.001) and between sexes (male 0mins:94±10mmHg; female 0mins:85±7mmHg; male 35mins:88±7mmHg; female 35mins:80±6mmHg; P≤0.05). Combined data set indicated a strong negative relationship between skin temperature and body fat percentage 35min' post WBC (r=-0.749, P≤0.001) and for core temperature and body mass index in males only (r=0.726, P≤0.05) immediately after WBC. There were no significant differences between sexes in any other variables (heart rate, tympanic and perceptual variables). We observed sex differences in mean skin and mean body temperature following exposure to whole body cryotherapy. In an attempt to optimise treatment, these differences should be taken into account if whole body cryotherapy is prescribed.

Presenting and simulating an innovative model of liver phantom and applying two methods for dosimetry of it in neutron radiation therapy

AIM

A new model of liver phantom is defined, then this model is simulated by MCNPX code for dosimetry in neutron radiation therapy. Additionally, an analytical method is applied based on neutrons collisions and mathematical equations to estimate absorbed doses. Finally, the results obtained from two methods are compared to each other to justify the approach.

BACKGROUND

The course of treatment by neutron radiation can be implemented to treat cancerous tissues, although this method has not yet been widespread. The MIRD and the Stylized Family Phantom were the first anthropomorphic phantoms, although the representation of internal organs was quite crude in them. At present, a water phantom is usually used for clinical dosimetry.

MATERIALS AND METHODS

Each of the materials in an adult liver tissue including water and some organic compounds is decomposed into its constituent elements based on mass percentage and density of every element. Then, the accurate mass of every decomposed material of human liver tissue is correlated to masses of the phantom components.

RESULTS

The absorbed doses are computed by MCNPX simulation and analytical method in all components and different layers of this phantom.

CONCLUSIONS

Within neutron energy range of 0.001 eV-15 MeV, the calculated doses by MCNPX code are approximately similar to results obtained by analytical method, and the derived graphs of both methods approve one another. It is also concluded that through increasing the incident neutron energy, water receives the largest amounts of absorbed doses, and carbon, nitrogen and sulfur receive correspondingly less amounts, respectively.

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.

The hybrid personal cooling system (PCS) could effectively reduce the heat strain while exercising in a hot and moderate humid environment

This study aimed to examine the effectiveness of a hybrid personal cooling system (PCS) in mitigating body heat stain while exercising in a hot environment. Eight subjects underwent two trials: PCS and CON (i.e. no cooling). All trials were conducted at an air temperature of 36 ± 0.5 °C and RH = 59 ± 5%. The key findings demonstrated that the PCS could significantly reduce the core temperature, mean skin temperature, heart rate and physiological strain index during both exercise and recovery periods (p < 0.05). Subjective perceptions were also significantly alleviated in PCS at the end of the exercise and during the recovery (p < 0.05). Besides, the PCS could also bring remarkable benefits in lowering local skin temperatures and in improving perceptual sensations in both upper and lower body during both exercise and recovery periods (p < 0.05). It was thus concluded that the hybrid PCS is effective in mitigating body heat strain while exercising in a hot environment. Practitioner Summary: In hot and humid environments, body heat dissipation through sweating is greatly restricted. Our newly developed hybrid PCS could effectively alleviate heat strain while exercising in hot environments. The findings contribute to the body of knowledge in improving the health and well-being of sportsmen while exercising in hot environments.

Cold applications for recovery in adolescent athletes: a systematic review and meta analysis

Recovery and regeneration modalities have been developed empirically over the years to help and support training programmes aimed at maximizing athletic performance. Professional athletes undergo numerous training sessions, characterized by differing modalities of varying volumes and intensities, with the aim of physiological adaptation leading to improved performance. Scientific support to athletes focuses on improving the chances of a training programme producing the largest adaptive response. In competition it is mainly targeted at maximizing the chances of optimal performance and recovery when high performance levels are required repeatedly in quick succession (e.g. heats/finals). In recent years, a lot of emphasis has been put on recovery modalities. In particular, emphasis has been placed on the need to reduce the delayed onset of muscle soreness (DOMS) typically evident following training and competitive activities inducing a certain degree of muscle damage. One of the most used recovery modalities consists of cold-water immersion and/or ice/cold applications to muscles affected by DOMS. While the scientific literature has provided a rationale for such modalities to reduce pain in athletes and recreationally active adults, it is doubtful if this rationale is appropriate to aid training with adolescent athletes. In particular, since these methods have been suggested to potentially impair the muscle remodeling process leading to muscle hypertrophy. While this debate is still active in the literature, many coaches adopt such practices in youth populations, simply transferring what they see in elite sportspeople directly; without questioning the rationale, safety or effectiveness as well as the potential for such activity to reduce the adaptive potential of skeletal muscle remodeling in adolescent athletes. The aim of this review was to assess the current knowledge base on the use of ice/cold applications for recovery purposes in adolescent athletes in order to provide useful guidelines for sports scientists, medical practitioners, physiotherapists and coaches working with such populations as well as developing research questions for further research activities in this area. Based on the current evidence, it seems clear that evidence for acute benefits of such interventions are scarce and more work is needed to ascertain the physiological implications on a pre or peri-pubertal population.

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.

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.

Blood flow after exercise-induced muscle damage

CONTEXT

The most common modality used to address acute inflammation is cryotherapy. Whereas pain decreases with cryotherapy, evidence that changes occur in perfusion of skeletal muscle is limited. We do not know whether ice attenuates the increases in perfusion associated with acute inflammation.

OBJECTIVE

To examine the effects of repeated applications of ice bags on perfusion of the gastrocnemius muscle after an eccentric exercise protocol.

DESIGN

Controlled laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Eighteen healthy participants (3 men, 15 women; age = 22.2 ± 2.2 years, height = 166.0 ± 11.9 cm, mass = 69.4 ± 25.0 kg).

INTERVENTION(S)

To induce eccentric muscle damage, participants performed 100 unilateral heel-lowering exercises off a step to the beat of a metronome. A randomized intervention (cryotherapy, sham, control) was applied to the exercised lower extremity immediately after the protocol and again at 10, 24, and 34 hours after the protocol.

MAIN OUTCOME MEASURE(S)

Baseline perfusion measurements (blood volume, blood flow, and blood flow velocity) were taken using contrast-enhanced ultrasound of the exercised leg. Perfusion was reassessed after the first intervention and 48 hours after the protocol as percentage change scores. Pain was measured with a visual analog scale at baseline and at 10, 24, 34, and 48 hours after the protocol. Separate repeated-measures analyses of variance were used to assess each dependent variable.

RESULTS

We found no interactions among interventions for microvascular perfusion. Blood volume and blood flow, however, increased in all conditions at 48 hours after exercise (P < .001), and blood flow velocity decreased postintervention from baseline (P = .041). We found a time-by-intervention interaction for pain (P = .009). Visual analog scale scores were lower for the cryotherapy group than for the control group at 34 and 48 hours after exercise.

CONCLUSIONS

Whereas eccentric muscle damage resulted in increased blood flow, ice did not decrease muscle perfusion 48 hours after exercise. Therefore, ice does not seem to decrease muscle perfusion when blood flow is elevated, as it would be during inflammation.

Anthropometric characteristics and sex influence magnitude of skin cooling following exposure to whole body cryotherapy

This study explored whether anthropometric measures influence magnitude of skin cooling following exposure to whole body cryotherapy (WBC). Height, weight, body fat percentage, and lean mass were measured in 18 male and 14 female participants. Body surface area, body surface area to mass ratio, body mass index, fat-free mass index, and fat mass index were calculated. Thermal images were captured before and after WBC (−60°C for 30 seconds, −110°C for 2 minutes). Skin temperature was measured at the chest, arm, thigh, and calf. Mean skin temperature before and after WBC and change in mean skin temperature (ΔT_sk) were calculated. ΔT_sk was significantly greater in females (12.07 ± 1.55°C) than males (10.12 ± 1.86°C; t(30) = −3.09, P = .004). A significant relationship was observed between body fat percentage and ΔT_sk in the combined dataset (P = .002, r = .516) and between fat-free mass index and ΔT_sk in males (P = .005, r = .622). No other significant associations were found. Skin response of individuals to WBC appears to depend upon anthropometric variables and sex, with individuals with a higher adiposity cooling more than thinner individuals. Effects of sex and anthompometrics should be considered when designing WBC research or treatment protocols.

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.

Cold-water immersion and other forms of cryotherapy: physiological changes potentially affecting recovery from high-intensity exercise

High-intensity exercise is associated with mechanical and/or metabolic stresses that lead to reduced performance capacity of skeletal muscle, soreness and inflammation. Cold-water immersion and other forms of cryotherapy are commonly used following a high-intensity bout of exercise to speed recovery. Cryotherapy in its various forms has been used in this capacity for a number of years; however, the mechanisms underlying its recovery effects post-exercise remain elusive. The fundamental change induced by cold therapy is a reduction in tissue temperature, which subsequently exerts local effects on blood flow, cell swelling and metabolism and neural conductance velocity. Systemically, cold therapy causes core temperature reduction and cardiovascular and endocrine changes. A major hindrance to defining guidelines for best practice for the use of the various forms of cryotherapy is an incongruity between mechanistic studies investigating these physiological changes induced by cold and applied studies investigating the functional effects of cold for recovery from high-intensity exercise. When possible, studies investigating the functional recovery effects of cold therapy for recovery from exercise should concomitantly measure intramuscular temperature and relevant temperature-dependent physiological changes induced by this type of recovery strategy. This review will discuss the acute physiological changes induced by various cryotherapy modalities that may affect recovery in the hours to days (<5 days) that follow high-intensity exercise.

Precooling methods and their effects on athletic performance : a systematic review and practical applications

BACKGROUND

Precooling is a popular strategy used to combat the debilitating effects of heat-stress-induced fatigue and extend the period in which an individual can tolerate a heat-gaining environment. Interest in precooling prior to sporting activity has increased over the past three decades, with options including the application (external) and ingestion (internal) of cold modalities including air, water and/or ice, separately or in combination, immediately prior to exercise. Although many studies have observed improvements in exercise capacity or performance following precooling, some strategies are more logistically challenging than others, and thus are often impractical for use in competition or field settings.

OBJECTIVE

The purpose of this article was to comprehensively evaluate the established precooling literature, which addresses the application of cooling strategies that are likely to enhance field-based sports performance, while discussing the practical and logistical issues associated with these methods. We undertook a narrative examination that focused on the practical and event-specific application of precooling and its effect on physiological parameters and performance.

DATA SOURCES

Relevant precooling literature was located through the PubMed database with second- and third-order reference lists manually cross matched for relevant journal articles. The last day of the literature search was 31 January 2012.

STUDY SELECTION

Relevant studies were included on the basis of conforming to strict criteria, including the following: (i) cooling was conducted before exercise; (ii) cooling was conducted during the performance task in a manner that was potentially achievable during sports competition; (iii) a measure of athletic performance was assessed; (iv) subjects included were able bodied, and free of diseases or disorders that would affect thermoregulation; (v) subjects were endurance-trained humans (maximal oxygen uptake [[Formula: see text]O(2max)] >50 ml/kg/min for endurance protocols); (vi) cooling was not performed on already hyperthermic subjects that were in immediate danger of heat-related illnesses or had received passive heating treatments; (vii) drink ingestion protocols were used for the intended purpose of benefiting thermoregulation as a result of beverage temperature; and (viii) investigations employed ≥ six subjects. Initial searches yielded 161 studies, but 106 were discarded on failing to meet the established criteria. This final summary evaluated 74 precooling treatments, across 55 studies employing well trained subjects.

STUDY APPRAISAL AND SYNTHESIS METHODS

Key physiological and performance information from each study was extracted and presented, and includes respective subject characteristics, detailed precooling methods, exercise protocols, environmental conditions, along with physiological and performance outcomes. Data were presented in comparison to respective control treatments. For studies that include more than one treatment intervention, the comparative results between each precooling treatment were also presented. The practical benefits and limitations of employing each strategy in the field and in relation to sports performance were summarized.

RESULTS

Clear evidence of the benefits for a range of precooling strategies undertaken in the laboratory setting exists, which suggest that these strategies could be employed by athletes who compete in hot environmental conditions to improve exercise safety, reduce their perceived thermal stress and improve sports performance.

LIMITATIONS

This review did not include a systematic assessment of the study quality rating and provided a subjective assessment of the pooled outcomes of studies, which range in precooling methodologies and exercise outcomes. The wide range of research designs, precooling methods, environmental conditions and exercise protocols make it difficult to integrate all the available research into single findings.

CONCLUSION

Most laboratory studies have shown improvements in exercise performance following precooling and the emergence of strategies that are practically relevant to the field setting now allow scientists to individualize relevant strategies for teams and individuals at competition locations. Future research is warranted to investigate the effectiveness of practical precooling strategies in competition or field settings.

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.

Comparing the analgesic effect of heat patch containing iron chip and ibuprofen for primary dysmenorrhea: a randomized controlled trial

BACKGROUND

Primary dysmenorrhea is a common and sometimes disabling condition. In recent years, some studies aimed to improve the treatment of dysmenorrhea, and therefore, introduced several therapeutic measures. This study was designed to compare the analgesic effect of iron chip containing heat wrap with ibuprofen for the treatment of primary dysmenorrhea.

METHODS

In this randomized (IRCT201107187038N2) controlled trial, 147 students (18-30 years old) with the diagnosis of primary dysmenorrhea were enrolled considering the CONSORT guideline. Screening for primary dysmenorrhea was done by a two-question screening tool. The participants were randomly assigned into one of the intervention groups (heat Patch and ibuprofen). Data regarding the severity and emotional impact of the pain were recorded by a shortened version of McGill Pain Questionnaire (SF-MPQ). Student's t test was used for statistical analysis.

RESULTS

The maximum and minimum pain severities were observed at 2 and 24 hours in both groups. The severity of sensual pain at 8, 12, and 24 hours was non-significantly less in the heat Patch group. There was also no significant difference between the groups regarding the emotional impact of pain at the first 2, 4, 8, 12 and 12 hours of menstruation.

CONCLUSIONS

Heat patch containing Iron chip has comparable analgesic effects to ibuprofen and can possibly be used for primary dysmenorrhea.

TRIAL REGISTRATION

IRCT201107187038N2.

Microvascular perfusion and intramuscular temperature of the calf during cooling

PURPOSE

The study's purpose was to examine how the microvascularity of the gastrocnemius changed after a cryotherapy intervention based on subcutaneous tissue thickness. A secondary purpose was to compare intramuscular temperature change to subcutaneous tissue thickness.

METHODS

This was a single-blinded crossover study; each subject received both conditions (cryotherapy or sham). Subjects had baseline measurements of blood flow, blood volume, and intramuscular temperature recorded at 1 cm into the muscle belly of the medial gastrocnemius. The randomized condition was applied for 10, 25, 40, or 60 min, depending on subcutaneous tissue thickness. Immediate posttreatment microvascular measures were taken. After a designated rewarming period, again based on subcutaneous tissue thickness, measurements were retaken. At least 48 h separated the two conditions.

RESULTS

There were significant condition × time interactions for blood flow (P = 0.01), blood volume (P = 0.022), and intramuscular temperature (P < 0.001). For blood flow and volume, the cryotherapy condition maintained baseline levels, whereas the sham condition increased immediately after treatment and rewarming. For intramuscular temperature, the cryotherapy condition caused a decrease in intramuscular temperature from baseline compared with no change in the sham condition from baseline. Intramuscular temperature change was significantly correlated to subcutaneous tissue thickness (r = 0.49, P = 0.05).

CONCLUSIONS

Cryotherapy did not decrease blood flow and blood volume from resting levels, although the intramuscular temperature decreased. An intramuscular change of 7°C-9°C may not be cold enough to cause local vasoconstriction.