Prophylactic ankle bracing reduces rearfoot motion during sudden inversion.

The purpose of this study was to evaluate the effects of ankle bracing on rearfoot angular displacement and angular velocity during a sudden inversion movement. A 1 x 3 factorial design was used. The single independent variable was ankle brace condition with three levels: semi-rigid, lace-up and control. The two dependent variables were rearfoot average angular displacement and average angular velocity. Twenty-four healthy volunteers participated in this study. A motion analysis system was used to capture, model and calculate two-dimensional rearfoot motion while the subjects' ankle/foot complex was inverted to 35 degrees on a platform device. All subjects performed five trials of each ankle brace condition, and the average of these trials was used for statistical analysis. The semi-rigid brace significantly reduced rearfoot angular displacement and angular velocity compared with the lace-up (P<0.05) and control conditions (P<0.05). Additionally, the lace-up style brace demonstrated significantly less rearfoot angular displacement and angular velocity compared with the control condition (P<0.05). These results demonstrate that a semi-rigid ankle brace is more superior then a lace-up style brace in limiting rearfoot angular displacement and angular velocity. Moreover, the lace-up style brace offers significant restriction of these measures compared with no support.

Influence of therapeutic ultrasound on skeletal muscle regeneration following blunt contusion.

Athletic trainers typically use therapeutic ultrasound to treat skeletal muscle contusion injuries. However, the structural outcomes underlying this treatment are not well understood. Our working hypothesis was that following a blunt contusion injury to the gastrocnemius muscle, ultrasound treatment would facilitate recovery, as indicated by changes in several biological markers of skeletal muscle regeneration. Eighty male Wistar rats (three-month) were studied. Following anesthetic administration, each animal received a bilateral contusion injury to the gastrocnemius muscle. Pulsed ultrasound treatment was subsequently initiated six hours post-contusion injury unilaterally on the right gastrocnemius muscle, and ultrasound treatment was continued once daily for seven days. The left (non-ultrasound treated) and right (ultrasound treated) gastrocnemius muscles of 10 animals per group were excised at 1-, 3-, 5-, 7-, 14-, 21-, 28-, and 40-days post-contusion injury. There were no differences in muscle mass, total protein concentration, or fiber cross-sectional area between the right and left gastrocnemius muscles at any post-injury time point examined. Further, when fiber cross-sectional area was normalized to muscle mass, there were no differences. Myonuclear number and cross-sectional area per myonuclei between the right and left gastrocnemius muscles were not different. These results suggest that ultrasound, as administered, does not hasten or improve the regeneration of skeletal muscle following contusion injury.

Intra- and intersession reliability of acoustic rhinometry in measuring nasal cross-sectional area.

We evaluated the intrasession and intersession reliability of acoustic rhinometry in measuring nasal cross-sectional areas in 10 subjects. Subjects were measured under three conditions: with a Breathe Right nasal strip in place, with a sham strip in place, and with no strip in place. Two sets of three measurements were taken 1 week apart. The intrasession reliability both with and without the Breathe Right strip was very good (intraclass correlation coefficient [ICC] [2,1]: 0.97 and 0.98, respectively). The intersession reliability with and without the Breathe Right strip was not nearly as good (ICC [2,1]: 0.62 and 0.67). The Breathe Right strip increased the mean nasal cross-sectional area by 0.10 cm2 (17.4%). We conclude that acoustic rhinometry is a reliable way to measure nasal cross-sectional area during a single session of multiple tests, but it is not as reliable across sessions. We also determined that the Breathe Right nasal strip significantly increases nasal cross-sectional area.

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

OBJECTIVE: To describe the relationships among muscle temperature, skin temperature, room temperature, body core temperature, time, and subcutaneous adipose thickness during cryotherapy and rewarming. DESIGN: A multiple linear regression with 5 independent variables (skin temperature, body core temperature, subcutaneous adipose thickness, room temperature, time) predicting intramuscular (IM) temperature. SETTING: A sports injury research laboratory. PARTICIPANTS: Fifteen volunteers with thigh skinfold measurements smaller than 40 mm. INTERVENTIONS: Thirty-minute cryotherapy treatment (ice bag) followed by a 120-minute rewarming period. MAIN OUTCOME MEASURES: The relationship between skin and IM temperature was described, and an equation predicting IM temperature by using room temperature, skin temperature, body core temperature, time, and adipose thickness was developed. RESULTS: Pearson's correlations between each predictor variable of IM temperature during cryotherapy were skin temperature, r = .46; skinfold, r = .37; time, r = -.59; core temperature, r =.21; and room temperature, r = -.47. During rewarming, the correlations were skin temperature, r = .71; skinfold, r = .27; time, r = .76; core temperature, r = - .05; and room temperature, r = - .21. A multiple regression equation (R(2) = .76) was developed to predict IM temperature during cryotherapy. A separate equation (R(2) =.81) was developed to predict muscle temperatures during rewarming. CONCLUSIONS: During and after ice application, no single predictor adequately explained the change in IM temperature. Skin surface temperature was a weak predictor of IM temperature during cryotherapy and should not be used as the sole dependent measure in cryotherapy efficacy studies.

A preliminary examination of cryotherapy and secondary injury in skeletal muscle.

PURPOSE: The purpose of this study was to document the presence of secondary injury in skeletal muscle, to quantify it, and to determine whether it is altered by acute cryotherapy. METHODS: Crush injuries to the triceps surae of 19 adult male Sprague-Dawley rats were either treated continuously with ice for 5 h (N = 10) or received no ice treatment (N = 9). After treatment, tissues were assayed for the reduction of triphenyltetrazolium chloride (TTC) to triphenylformazan (formazan red). TTC reduction is indicative of oxidative function and serves as an indicator of cellular damage. RESULTS: A significantly lower TTC reduction rate was seen in both cold-treated injured tissue (6.59 +/- 1.01 microg x mg(-1) x h(-1)) and nontreated injured tissue (4.48 +/- 0.79 microg x mg(-1) x h(-1)) compared with uninjured controls (ice group = 7.94 +/- 1.49 microg x mg(-1) x h(-1), no-ice group = 6.62 +/- 0.75 microg x mg(-1) x h(-1)). These data indicate that crushing of muscle tissue produces injury measurable with the TTC reduction assay. Additionally, in crush-injured tissues, a significantly lower TTC reduction rate was seen in untreated tissues (4.48 +/- 0.79 microg x mg(-1) x h(-1)) compared with ice treated tissues (6.59 +/- 1.01 microg x mg(-1) x h(-1)), indicating that cryotherapy reduces the magnitude of secondary injury. CONCLUSIONS: From these data, it can be concluded that secondary injury occurs after primary crush injury and that secondary injury is retarded by acute treatment with 5 h of continuous cryotherapy.

Improving the treatment of colorectal cancer: the role of EUS.

The two most important factors for determining the risk of local failure and overall prognosis in colorectal carcinoma are nodal status and the depth of tumor penetration into or through the bowel wall. These features have traditionally been determined pathologically because the clinical-staging accuracy of other imaging modalities such as computed tomography (CT) has not proven sufficiently predictive of surgical staging. However, endorectal or endoscopic ultrasonography (EUS) can be used to preoperatively evaluate nodal involvement with an accuracy of up to 86% (median: 80%) and depth of tumor penetration through the bowel wall with an accuracy of up to 97% (median: 85%) for effective clinical staging. This high staging accuracy is useful in managing colorectal cancer. Through clinical evaluation of the initial stage of colorectal cancer with EUS, a patient's risk of disease recurrence can best be determined and patients stratified for the most appropriate treatment. EUS can be used to select patients with lesions that can be treated with local excision or sphincter-sparing surgery, often combined with radiation therapy, in situations otherwise requiring an abdominoperineal resection. EUS can also be used to preoperatively identify patients with locally advanced or unresectable disease. Chemoradiation can then be given preoperatively, when it appears to be better tolerated and more effective than postoperative treatment. Unresectable tumors can often be downstaged sufficiently to allow their excision. In resectable disease, EUS can also identify patients at high risk for recurrence who would benefit from adjuvant chemoirradiation. EUS for precise staging or for earlier diagnosis of recurrence will further improve the clinical outcome of patients with colorectal tumors as significant advances both in surgical techniques and in combined chemotherapy/radiotherapy continue to be made and applied selectively in a stage-dependent manner.

Morbidity after intraperitoneal insertion of saline-filled tissue expanders for small bowel exclusion from radiotherapy treatment fields: a prospective four year experience with 34 patients.

UNLABELLED: When prolonged small bowel exclusion (SBE) from external radiotherapy (RT) fields or immediate exclusion of bowel from brachytherapy sources is required for a patient without adequate omentum, there are no simple proven methods available for accomplishing these goals. We report a prospective study of SBE by intraperitoneal, saline-filled tissue expanders (TE). Thirty-four patients had exclusion of small bowel from either external radiotherapy (RT) ports (20), afterloading catheter treatment fields (5), both (5), or from intracavitary implants (4). Twenty-seven TEs were placed in the pelvis and 7 in the iliolumbar fossa. TE volume ranged from 400-1500 cc (median 550 cc). Patients had rectal (n = 15), colon (6), endometrial (4), anal (3), and vaginal (1) cancers and sarcomas (5). Fifteen patients had recurrent neoplasms, 13 of which were in previously irradiated fields. Nine patients had colorectostomies directly behind the TE, and 12 had other bowel (6) or ureteral (3) anastomoses or bladder repairs (3) adjacent to the TE. RESULTS: TEs remained in the patients from 6 to 173 days (median 95). Morbidity included three early TE withdrawals before RT was begun, one for a prolonged ileus, one for a perineal wound dehiscence, and one for an unrelated small bowel obstruction. Two patients (5.9%) early in the series had post-withdrawal complications (non-lethal small bowel fistulas requiring reoperation), although in a recent cohort of patients no post-withdrawal complications occurred using a different placement technique (0/17 vs. 2/14, P = 0.2). The patient injury complication rate was 4/34 (11.8%). None of these limited or delayed RT, but RT was limited to less than that planned in one other by TE deflation (total complication rate 14.7%). There were no clinical infections involving the prostheses, even though one patient had an abdominal wound dehiscence, 3 had pelvic abscesses, and 2 had exposure of the TE through the vagina (1 planned, 1 at dehisced vaginal cuff) after TE placement. We noted no acute and one possible late RT complication in these patients (18 months median follow-up, range 3-43 months). Small bowel was displaced from > 95 per cent of the RT treatment volume in 70 per cent and from > 75 per cent of the treatment volume in 89 per cent of 27 evaluable patients treated with external RT. CONCLUSION: Intraperitoneal placement of a saline-filled tissue expander is a simple, safe and effective means of small bowel exclusion from RT portals.

The effects of ice and compression wraps on intramuscular temperatures at various depths.

While ice and compression wraps are commonly used to treat musculoskeletal injuries, the literature describing intramuscular temperatures has not addressed the combination of ice and compression wraps. The purpose of this study was to evaluate intramuscular temperatures at three sites on the anterior thigh (skin surface, 1 cm below the fat layer, and 2 cm below the fat layer) using both ice and compression wraps. Temperatures were recorded in 11 subjects with an isothermex, using implantable and surface thermocouples. Each subject was tested under four conditions: control, compression only, ice only, and ice + compression according to a balanced Latin square. Surface and intramuscular temperatures were recorded at 30 second intervals during 5 minutes of preapplication, 30 minutes application, and 20 minutes postapplication. A repeated measures ANOVA and Duncan post hoc tests were used to evaluate peak temperature differences between the treatment conditions and the depths of measurement. Both ice alone and ice + compression produced significant cooling at all three depths (F(6,60) = 168.5, p<.0005). Likewise, during the 20-minute postapplication period, these temperatures did not return to their preapplication levels. The compression-only condition produced significant warming at the skin surface, but did not have any effect on intramuscular temperature. At all depths, the ice + compression condition produced significantly cooler temperatures than ice alone. We suggest that compression increases the effectiveness of ice in reducing tissue temperatures. Therefore, ice combined with compression should be more effective than ice alone in reducing the metabolism of injured tissue. This provides an additional rationale for combining ice with compression in treating acute musculoskeletal injuries.

Frequent p53 mutations in head and neck cancer.

Squamous cell carcinomas of the head and neck (SCCHN) are associated strongly with the use of tobacco and alcohol, but little is known about the molecular pathogenesis of these tumors. In the present study, we analyzed SCCHN for mutations in the tumor suppressor gene p53 by immunocytochemistry and complementary DNA sequencing. Overexpression of p53 protein was detected in 13 (100%) of 13 SCCHN cell lines and in tumor cells cultured directly from 10 (77%) of 13 patients with SCCHN. Direct evidence for p53 mutations was obtained by sequencing p53 complementary DNA from eight SCCHN cell lines and two tumor xenografts. The genetic alterations included seven missense mutations resulting in single amino acid substitutions, a mutation encoding a stop codon, one 10-base pair deletion, and one 2-base pair addition. All seven missense mutations were G to T transversions, five of which were clustered at codons 245 and 248. A similar high frequency of G to T transversions predominates in lung cancer, another tobacco-related disease. Mutation of the p53 gene is the most common genetic alteration detected in SCCHN and implicates this gene locus as a critical site of specific damage by mutagenic carcinogens in tobacco, one of the important risk factors in the etiology of this disease.

Sensory perception of the foot and ankle following therapeutic applications of heat and cold.

Many athletes are treated with hot and cold modalities prior to therapeutic exercise, but the effects of these treatments on sensory perception are not clear. The purpose of this study was to examine the effects of hot and cold treatments on sensory perception. We recruited 21 volunteer subjects, who reported for testing on three separate occasions. One of three treatments was applied to the left ankle and foot each day for 20 minutes: cold immersion, hot immersion, or quiet sitting (control). Three variables were measured following treatment: topagnosis, two-point discrimination, and one-legged balance. We assigned treatments and the testing order according to a Greco Latin square. Data were analyzed using a multivariate analysis of variance (MANOVA). No significant differences were detected for the three dependent measures, suggesting that therapeutic applications of heat and cold do not affect sensory perception. These findings indicate that heat and cold applications can be used prior to therapeutic exercise programs without interfering with normal sensory perception as do other analgesic and anesthetic agents. For example, the hypalgesic effect of cold, which is essential to cryokinetics, can be realized without fear of altered sensory perception.