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.

Ultrasound mediated destruction of multifunctional microbubbles for image guided delivery of oxygen and drugs.

We synthesized multifunctional activatible microbubbles (MAMs) for ultrasound mediated delivery of oxygen and drugs with both ultrasound and fluorescence imaging guidance. Oxygen enriched perfluorocarbon (PFC) compound was encapsulated in liposome microbubbles (MBs) by a modified emulsification process. DiI dye was loaded as a model drug. The ultrasound targeted microbubble destruction (UTMD) process was guided by both ultrasonography and fluorescence imaging modalities. The process was validated in both a dialysis membrane tube model and a porcine carotid artery model. Our experiment results show that the UTMD process effectively facilitates the controlled delivery of oxygen and drug at the disease site and that the MAM agent enables ultrasound and fluorescence imaging guidance of the UTMD process. The proposed MAM agent can be potentially used for UTMD-mediated combination therapy in hypoxic ovarian cancer.

Progression of secondary injury after musculoskeletal trauma-a window of opportunity?

CONTEXT: Acute musculoskeletal-injury management largely focuses on inhibiting secondary injury, although the data describing secondary injury and the timeline for its progression are sparse. OBJECTIVE: To describe the timeline and early progression of secondary injury in skeletal muscle over the first 5 h after blunt trauma. DESIGN: A controlled laboratory study with 2 independent variables (injury status and postinjury time point) in a 2 × 21 factorial. SETTING: University research laboratory. SUBJECTS: 168 male Sprague Dawley rats (250 to 275 g). INTERVENTIONS: Uniform blunt-contusion injury was caused to the right triceps surae using a drop-weight method; the contralateral limb served as an uninjured control. Both triceps surae were excised and flash frozen at 21 intervals across 5 h postinjury (8 animals, each 15 min). MAIN OUTCOME MEASURES: Cytochrome-c oxidase activity via reduction of triphenyltetrazolium chloride (TTC) to triphenylformazan. RESULTS: There was an interaction effect (P = .041) between and main effects for both injury status (P < .0005) and postinjury time point (P = .038). In the first 30 min after injury, uninjured tissues did not differ from injured tissues, and both displayed TTC reduction rates in the vicinity of 7.1 ± 0.94 µg × mg-1 × h-1. Statistical differences between uninjured and injured tissues became evident starting at 30 min. TTC reduction for uninjured tissues did not change, but injured tissues declined in a roughly linear fashion across the entire 5-h period to 4.8 ± 1.04 µg × mg-1 × h-1. CONCLUSIONS: Cytochrome-c oxidase activity, an indicator of oxidative phosphorylation and mitochondrial viability, is diminished by events that follow muscle trauma. Loss of this enzymatic activity becomes statistically evident at 30 min postinjury and continues linearly for at least 5 h. This suggests that secondary injury is a slowly developing problem of more than 5 h duration. A window of opportunity for intervention may lie somewhere within the first 30 min after injury.

Therapeutic ultrasound decreases mechano-growth factor messenger ribonucleic acid expression after muscle contusion injury.

OBJECTIVE: To examine the influence of nonthermal ultrasound on mechano-growth factor (MGF) messenger ribonucleic acid (mRNA) expression after blunt trauma. DESIGN: A 2x4 factorial multivariate analysis of variance design. SETTING: University research laboratory. ANIMALS: Thirty-six 3- to 4-month-old male Wistar rats (mean weight, 280.8+/-21.5g). Thirty-two received a bilateral contusion injury to the gastrocnemius via a drop mass technique. Four were control animals. INTERVENTION: Ultrasound treatment (frequency, 3MHz; intensity, 0.3W/cm(2); continuous duty cycle) was started 24 hours postinjury and delivered for 5 minutes daily on 4 consecutive days. Treatment was on the left hindlimb and the contralateral right hindlimb was the nonultrasound control. MAIN OUTCOME MEASURES: Muscle mass (in grams) and MGF mRNA expression as measured via real-time reverse transcriptase polymerase chain reaction. RESULTS: Ultrasound had no effect on muscle mass (F(1,28)=2.723, P=.110, 1-beta=.357, eta(2)=.089). Ultrasound treatments decreased MGF mRNA expression in the treated limb compared with the nontreated hindlimb (F(1,28)=6.605, P=.016, 1-beta=.699, eta(2)=.191). CONCLUSIONS: The nonthermal ultrasound treatments resulted in decreased MGF mRNA expression after blunt trauma to the gastrocnemius muscles.

The dual roles of neutrophils and macrophages in inflammation: a critical balance between tissue damage and repair.

OBJECTIVE: To discuss the acute phase of inflammatory response with a focus on the neutrophilic response and its role in inflammation. We discuss the relative balance between the need for inflammation to stimulate repair and the need to limit inflammation because of the additional damage it causes. DATA SOURCES: We conducted a MEDLINE search from 1966 to 2005 for literature related to acute inflammation, muscle injury, and repair using combinations of the key words inflammation, neutrophil, macrophage, and cytokines. Additional literature was acquired through cross-referencing of bibliographies of articles obtained through the MEDLINE searches. DATA SYNTHESIS: We reviewed more than 200 relevant articles. Although neutrophils are an important cell population in acute inflammation, few athletic trainers are familiar with the neutrophil's actions or its dichotomous role as both perpetrator of tissue damage and initiator of repair. Neutrophils dominate the early stages of inflammation and set the stage for repair of tissue damage by macrophages. These actions are orchestrated by numerous cytokines and the expression of their receptors, which represent a potential means for inhibiting selective aspects of inflammation. CONCLUSIONS: Neutrophils infiltrate injured tissues but can also be present after noninjurious exercise. These cells have both specific and nonspecific defensive immune system functions that can cause tissue damage in isolation or as sequelae to other tissue injury. It might seem that limiting the action of neutrophils would be clinically beneficial, but these cells are also responsible for initiating the reparative process that is later managed by macrophages. Although achieving a therapeutic balance between limiting inflammation and stimulating repair is important, the duplicitous roles of neutrophils and macrophages in both the inflammation and healing processes create a physiologic paradox for clinicians whose goals are to limit inflammation and to stimulate healing after acute soft tissue injury.

Nonthermal ultrasound and exercise in skeletal muscle regeneration.

OBJECTIVE: To determine whether continuous nonthermal therapeutic ultrasound (US) and low-intensity exercise (Ex) influence skeletal muscle regeneration after a standardized contusion injury in an animal model. DESIGN: Randomized controlled trial with blinded comparisons in a 2 x 2 factorial (US by Ex) design. SETTING: Animal care facility and exercise physiology biochemistry laboratory. ANIMALS: Twenty male Wistar rats (age, 8 mo) received a reproducible bilateral contusion injury to the gastrocnemius muscles. Ten gastrocnemius muscles from 5 noninjured, nontreated rats provided baseline control data. INTERVENTIONS: US (continuous duty cycle, 3 MHz; intensity, 0.1 W/cm2 ; transducer, 1cm2 ; duration, 5 min/d; duty cycle, 100%) and exercise (20 min/d of low-intensity treadmill walking at 14 m/min). Gastrocnemius muscles from injured rats received exercise treatment alone (Ex + NoUS), exercise and US treatment (Ex + US), US treatment alone (NoEx + US), and no treatment (NoEx + NoUS). MAIN OUTCOME MEASURES: Ninety-six-hour postinjury muscle mass, contractile protein concentration, fiber cross-sectional area, number of nuclei per fiber, and myonuclear density. RESULTS: Myonuclei per fiber were statistically greater in injured than in noninjured gastrocnemius muscle (P < .05). There were no statistical differences (P > .01) among the 4 injured treatment groups for any of the outcome measures chosen as biomarkers of skeletal muscle regeneration. CONCLUSIONS: There is no evidence that the specific continuous US and Ex protocols investigated enhanced skeletal muscle regeneration after contusion injury.

Three-MHz Ultrasound Heats Deeper Into the Tissues Than Originally Theorized.

OBJECTIVE: To measure muscle temperature of ultrasound at 1-MHz and 3-MHz frequencies at a depth of 2.5 cm and to compare treatment durations for vigorous heating (increase of 4 degrees C) and for heating to 40 degrees C. DESIGN AND SETTING: A counterbalanced, repeated-measures design with 1 fixed, independent variable, 1.5-W/cm(2) ultrasound treatment (1 MHz, 3 MHz, or control [sham]) using a Theratouch 7.7 ultrasound device. Dependent variables were end-treatment temperature at 2.5 cm, time to vigorous heating, and time to reach 40 degrees C. SUBJECTS: Eighteen healthy volunteers (age = 24.6 +/- 2.3 years, height = 173.0 +/- 9.7 cm, mass = 72.0 +/- 16.3 kg) without a history of lower leg injury. MEASUREMENTS: The medial triceps surae intramuscular temperature at 2.5 cm was measured every 10 seconds using an implantable thermocouple. Each of the 3 ultrasound frequencies was applied in counterbalanced order at 24-hour intervals. RESULTS: Ultrasound of 3 MHz produced both vigorous heating (at 3.4 minutes) and an absolute temperature of 40 degrees C (at 4 minutes). CONCLUSIONS: Our results suggest that 3-MHz ultrasound heats 0.5 cm deeper than suggested by others. With our machine, 3-MHz ultrasound was more effective in heating muscle at this depth than 1-MHz ultrasound.

Pre-athletic training students perform better on written tests with teacher-centered instruction.

There are many different methods of instruction used in the academic setting. Little experimental research exists examining which mode is more effective in educating students. The purpose of this study was to compare scores obtained on the written and the practical examinations of students on a single topic taught through either a teacher-centered format or a student-centered format. A 2 x 2 x 6 factorial design was used in this study. Independent variables were teaching style (teacher-centered instruction and student-centered instruction), order (first or second), and learning style (competitive, collaborative, participant, avoidant, dependent, and independent). The dependent variables were the scores obtained on a written and a practical examination of gait and crutch fitting. Forty pre-athletic training students in their first semester of their first year (16 males, 24 females) participated in this study. The Grasha-Reichmann Student Learning Style Scale was used to determine the learning styles of the subjects. The total subject pool was divided randomly into two groups, one taught by teacher-centered instruction and the other by student-centered instruction. Both groups took the same written and practical examinations, and scores were recorded. A 2 x 2 x 6 fixed model multivariate analysis of variance was performed. A difference was observed for teaching style (F2,21 = 5.35, p = 0.01), on the combination of written and practical exam scores. A difference also was observed on the written examination scores with the teacher-centered format producing better results (p < 0.05); but teacher-centered format scores did not differ from student-centered scores on the practical examination (p > 0.05). Teacher-centered instruction improves written test performance compared with student-centered instruction. When initially teaching a skill, direct teacher involvement may help students learn and perform better.

The effects of land vs. aquatic plyometrics on power, torque, velocity, and muscle soreness in women.

The purpose of this study was to compare changes in performance indicators (power, torque, and velocity) and muscle soreness between plyometric training on land and in water. Thirty-two college age women were randomly assigned to 8 weeks of an identical plyometric training program on land or in an aquatic setting. Performance indicators were assessed pretraining, midtraining, and posttraining. Muscle soreness (ordinal scale) and pain sensitivity (palpation) were assessed after a training bout (0, 48, and 96 hours) during the first week of training and when training intensity was increased (weeks 3 and 6). Performance indictors increased for both groups (pretraining < midtraining < posttraining, p < or = 0.001). Muscle soreness was significantly greater in the land compared to the aquatic plyometric training group at baseline and each time training intensity was increased, p = 0.01. Aquatic plyometrics provided the same performance enhancement benefits as land plyometrics with significantly less muscle soreness.

Intercollegiate student athlete use of nutritional supplements and the role of athletic trainers and dietitians in nutrition counseling.

A survey of university student athletes was conducted to determine supplement use, perceived efficacy of supplements, availability and use of nutrition services, and perceived nutrition knowledge of athletic trainers. Results from 236 athletes showed that 88% used one or more nutritional supplements, yet perceived efficacy was moderate (2.9 or less; 5-point scale). Classes (69.4%), brochures (75%), and individual counseling (47%) were available and were used by 29.9%, 33.2%, and 17.9% of athletes, respectively. Primary sources of nutrition information were athletic trainers (39.8%), strength and conditioning coaches (23.7%), and dietitians (14.4%). Athletes perceived athletic trainers to have strong nutrition knowledge (mean=3.8+/-0.9; 5-point scale). Many (23.5%) did not know whether a dietitian was available. Dietitians must accelerate their marketing efforts to student athletes, work closely with athletic trainers to provide sound nutrition information, and provide services that meet the needs of a diverse population of student athletes.

Identical 3-MHz ultrasound treatments with different devices produce different intramuscular temperatures.

STUDY DESIGN: A counterbalanced, repeated-measures design with ultrasound device (Omnisound 3000C, Dynatron 950, Excel Ultra III) as the independent variable. The 2 dependent variables were intramuscular (IM) temperature at 6 minutes and at the end of a 10-minute treatment. OBJECTIVE: To compare IM temperatures produced by identical 3-MHz ultrasound treatments between 3 different ultrasound devices. BACKGROUND: Most recent studies prescribing intensity and duration parameters for thermal ultrasound treatments have been performed using an Omnisound device, but have not been verified in other common ultrasound devices. METHODS AND MEASURES: Six uninjured volunteers (mean age +/- SD, 22 +/- 3.4 y; mean height +/- SD, 171.9 +/- 11.0 cm; mean mass +/- SD, 66.1 +/- 11.1 kg) gave informed consent and served as subjects. Separate ultrasound treatments using identical parameters (3 MHz, 1.5 W/cm2, 10 minutes, treatment area equal to twice transducer surface area) were administered at 24 or 48 hours intervals using a different ultrasound device for each treatment. Left medial calf IM temperature was recorded every 20 seconds using implantable thermocouples at a depth of 1.6 cm below the treatment surface. Data were analyzed using MANOVA with Sidak adjusted multiple comparisons post hoc. RESULTS: Tissue heating using the Omnisound device was greater than with either the Dynatron or the Excel. The results of treatments using Dynatron or Excel devices did not differ. The Omnisound was the only device to consistently produce IM temperatures above the 40 degrees C therapeutic threshold and did so in less than 6 minutes. The other devices did not reach this threshold within the 10-minute treatment session. Subjects routinely reported heating sensations approaching discomfort when the IM temperature reached the 40 degrees C therapeutic threshold. CONCLUSIONS: Because there are differences in thermal effects between ultrasound devices, our results suggest that recently published parameters for ultrasound intensity and duration parameters will not produce equally therapeutic effects for all ultrasound devices.

Cold Modalities With Different Thermodynamic Properties Produce Different Surface and Intramuscular Temperatures.

OBJECTIVE: To compare surface cooling and deep cooling produced by 3 common forms of cryotherapy. DESIGN AND SETTING: We used a 3 x 4 x 4 factorial with repeated measures on measurement depth and treatment. Independent variables were measurement depth (surface, fat + 1 cm, and fat + 2 cm), treatment (ice bag, Wet-Ice, Flex-i-Cold, and control), and treatment order (first, second, third, and fourth). The lowest temperature recorded was the dependent variable. The treatment order was counterbalanced using a Latin square. Data were analyzed with a repeated-measures analysis of variance. SUBJECTS: Fifteen collegiate volunteers who were free of lower extremity abnormalities. MEASUREMENTS: Thigh skin and thigh intramuscular temperatures (1- and 2-cm subadipose) were measured at 30-second intervals both before and during the 30-minute treatments using fine-wire implantable and surface thermocouples. The coldest recorded temperatures were analyzed. RESULTS: Statistical differences were observed for the depth-by-treatment interaction as well as for the depth and treatment main effects. During cold treatments, superficial depths were colder than deeper depths, and all cold treatments were colder than controls at all depths. For the interaction effect at both the skin surface and at 1-cm subadipose, the ice-bag and Wet-Ice treatments were colder than the Flex-i-Cold treatment. For the interaction at 2-cm subadipose, the cold treatments did not differ from each other. Order of treatments did not produce a significant effect. CONCLUSIONS: During a 30-minute cryotherapy treatment, modalities that undergo a phase change caused lower skin and 1-cm intramuscular temperatures than cold modalities that do not possess these properties. These differences were not seen at 2-cm subadipose but may become apparent with longer treatments.

Preliminary comparison of bromelain and Ibuprofen for delayed onset muscle soreness management.

OBJECTIVE: The purpose of this study was to determine whether a common bromelain regimen or common ibuprofen regimen are effective in resolving pain and muscle dysfunction associated with delayed onset muscle soreness of the elbow flexors. DESIGN: A randomized, double-blinded, repeated measures design was used for this study. SETTING: The study was performed in the Sports Injury Research Lab at an NCAA Division I university. PARTICIPANTS: Forty subjects who had not participated in an upper body resistance-training program 3 months prior to the study, suffered pain or injury in the nondominant arm, or experienced an adverse response to nonsteroidal anti-inflammatory drugs or pineapple (bromelain source) were recruited. Thirty-nine subjects finished the study. INTERVENTIONS: Active range of motion (ROM), perceived pain, and peak concentric torque measurements of the nondominant arm were taken prior to and 24, 48, 72, and 96 hours following an eccentric exercise protocol of the elbow flexors. Subjects were assigned to one of four treatment groups (bromelain 300 mg t.i.d., ibuprofen 400 mg t.i.d., placebo t.i.d., and control) and began treatment immediately following the exercise protocol. MAIN OUTCOME MEASURES: No differences among treatments were observed for any of the dependent variables at any time. ROM deficits and pain peaked between 48 and 72 hours. Peak torque deficiencies were observed between 24 and 72 hours. CONCLUSIONS: Ingestion of bromelain and ibuprofen had no effect on elbow flexor pain, loss of ROM, or loss of concentric peak torque as a result of an eccentric exercise regimen.

Subcutaneous adipose tissue thickness alters cooling time during cryotherapy.

OBJECTIVE: To determine if differing subcutaneous adipose thickness alters the treatment duration required to produce a standard cooling effect during cryotherapy. DESIGN: A 4-group, between-groups comparison in which the independent variable was skinfold thickness (0-10mm, 11-20mm, 21-30mm, 31-40mm) and the dependent variable was cooling time, defined as the treatment duration required to decrease intramuscular (IM) temperature 7 degrees C from baseline. SETTING: A sports injury research laboratory. PARTICIPANTS: Forty-seven volunteers with anterior thigh skinfold measurement of less than 40mm. INTERVENTION: Topical cryotherapy (750g crushed-ice bag) to the anterior thigh to produce a typical cooling effect, defined as IM temperature at 1cm subadipose declining by 7 degrees C. MAIN OUTCOME MEASURE: Cryotherapy treatment duration required to produce a standardized cooling effect in subjects with differing subcutaneous adipose thickness. RESULTS: Analysis of variance revealed that mean time to cool IM tissues by 7 degrees C differed across all groups, with cooling time increasing as adipose thickness increased. The mean +/- standard deviation cooling times were as follows: 31-40mm (58.6+/-11.7min), 21-30mm (37.8+/-9.6min), 11-20mm (23.3+/-6.7min), and 0-10mm (8.0+/-3.4min). CONCLUSIONS: During cold application, there is a clinically important direct relationship between adipose thickness and required cooling time. This relationship necessitates dramatic adjustments to cryotherapy duration to produce similar IM temperature changes. A 25-minute treatment may be adequate for a patient with a skinfold of 20mm or less; however, a 40-minute application is required to produce similar results in a patients with skinfolds between 21 and 30mm, whereas a 60-minute application is required for patients with skinfolds of 30 to 40mm.

A comparison of intramuscular temperatures during ultrasound treatments with coupling gel or gel pads.

STUDY DESIGN: A repeated-measures design was used. The independent variable was ultrasound coupling medium with 2 levels: gel pad and traditional gel. The dependent variable was peak intramuscular (IM) tissue temperature. OBJECTIVE: To compare changes in IM temperature during similar ultrasound treatments with 2 different coupling media. BACKGROUND: Gel pads are gaining popularity as an ultrasound coupling medium. Intramuscular temperatures during ultrasound with gel pads and standard gel have not been compared. METHODS AND MEASURES: Subjects were 13 student volunteers (21.3 +/- 1.4 years of age) without lower-extremity pathology. Ultrasound treatments were administered in a laboratory on two separate occasions 48 hours apart, each with a different coupling medium (standard ultrasound gel or gel pad). One-MHz continuous ultrasound was administered for 7 minutes at 1.5 W/cm2 with the transducer head moving 3 to 4 cm/s over an area approximately twice the size of the transducer head. Tissue temperature was measured every 10 seconds using implantable thermocouples inserted at a 3-cm depth to the surface of the right medial calf. Data were analyzed using an ANCOVA with pretreatment temperature as the covariate. RESULTS: Tissue temperatures increased during both treatments, with the mean and standard deviation peak temperature during the gel pad treatment reaching 39.40 +/- 1.5 degrees C compared to 39.20 +/- 2.4 degrees C during the normal gel treatment. Statistical analysis revealed no difference in temperature between ultrasound treatments using gel and those performed using gel pads. CONCLUSIONS: Because temperature changes were similar with both treatments, we conclude that these coupling methods are equivalent under the ultrasound application parameters tested.

Secondary injury after musculoskeletal trauma: a review and update.

OBJECTIVES: To revisit the secondary injury model, to incorporate several current pathophysiologic theories into the model, and to show the need for more direct research examining the model. DATA SOURCES: I searched MEDLINE and CINAHL from 1976 to 2001 for literature related to acute injury pathology and pathophysiology and selected classic articles and pathology, pathophysiology, and immunology texts. DATA SYNTHESIS: Acute musculoskeletal injury management is based on a pathophysiologic model, often referred to as the secondary injury model, which was originally developed more than 25 years ago. In this model, acute trauma is referred to as primary injury, whereas secondary injury refers to damage to otherwise uninjured cells that was a direct consequence of the physiologic response to primary injury. In the original model, mechanisms for secondary injury were hypothesized based on then-contemporary understandings of immunology and cellular pathology. These mechanisms were broadly categorized as either enzymatic or hypoxic. Since this time, the pathologic paradigms for cell death from trauma have evolved, and the secondary injury model requires some updating. Some controversy now exists regarding the categorization of injury as primary or secondary, specifically whether posttraumatic damage is actually secondary injury in previously uninjured tissue or delayed death of primary injured cells. Similarly, the postulated mechanisms that lead to secondary injury now appear to be considerably more complex than originally anticipated. CONCLUSIONS/RECOMMENDATIONS: The secondary injury model has been reconciled with our contemporary understanding of pathophysiology. Specifically, secondary hypoxic injury has been clarified to be secondary ischemic injury, and several specific mechanisms for ischemic injury have been identified. Similarly, secondary injury from mitochondrial failure and other potential mechanisms has been identified, and the role and interaction of these mechanisms in relation to total secondary injury have been expanded.