Biomedical subjects

Mitchell L Cordova

Publications and source records attributed to Mitchell L Cordova.

12 recordsLinked to original sources

PubMed2006

Certified athletic trainers' knowledge and perception of professional preparation involving eating disorders among athletes.

The perceived adequacy of professional preparation about eating disorders and disordered eating has not been evaluated in certified athletic trainers (ATCs). This study was intended to establish how ATCs perceive their professional preparation and educational background in identifying and managing eating disorders. A 42-item Web-based survey was specifically created for this study and disseminated to certified 14,477 members of the National Athletic Trainers' Association (NATA), of whom 13.6% (n = 1,966) responded (mean age of respondents, 31.87 +/- 7.82 yrs). The survey consisted of an 11-question demographic section, 13 Likert-scale statements, five "check all that apply" questions, 10 yes/no questions, two "fill in the best answer" questions, and one "check one that applies" question. Statistical analysis focused on qualitative and descriptive analysis of survey items. Our results suggest that ATCs believe that they do not receive enough professional preparation or education in dealing with eating disordered athletes. Despite this finding, they also believe it is their responsibility to identify and deal with eating disordered athletes. The overall findings indicate a need and desire for continuing education about eating disorders.

Adult↗

PubMed2005

Effects of ankle support on lower-extremity functional performance: a meta-analysis.

UNLABELLED: Clinicians surmise that the application of external ankle support reduces the ability to perform functional skills and movements, but the outcomes from some of these studies have been inconclusive. PURPOSE: To meta-analyze studies regarding the effects of external ankle support on lower-extremity functional performance measures. METHODS: A total of 93 effects from 17 randomized controlled trials utilizing predominantly crossover designs with recreationally active participants and competitive athletes were subjected to a random-effects meta-analysis. The treatment variable was external ankle support with three levels: adhesive tape, lace-up style, and semirigid style. Differences between mean changes in treatment and control groups were computed as standardized effect sizes for sprint, agility, and vertical jump performance with their 90% confidence intervals (CI). Effect sizes >0.20 were considered substantial. RESULTS: The greatest effect of ankle support on performance was a negative effect of lace-up style brace on sprint speed (effect size -0.22, 90% CI -0.47 to 0.03), equivalent to approximately 1% impairment of speed. The other effects of external ankle support on performance were insubstantial, though most were negative, and their lower confidence limits allowed for realistic chances of impaired performance. Substantial true variation between studies, although poorly defined, was also present for some effects, further increasing the likelihood of performance impairment in some settings. CONCLUSIONS: More research is needed to reduce the uncertainty in the effects of external ankle support on performance. In the meantime, it is our opinion that the benefit in preventing injury outweighs the possibility of substantial but small impairment of performance when athletes use external ankle support.

Ankle↗

PubMed2004

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.

Journal Article↗

PubMed2003

The effect of a simulated knee joint effusion on postural control in healthy subjects.

OBJECTIVE: To determine the effects of a simulated knee joint effusion on center of pressure (COP) path and mean power frequency (MPF) during standing. DESIGN: Quasi-experimental design. SETTING: Sports injury research laboratory in a university setting. PARTICIPANTS: Twenty healthy volunteers, 10 of whom (age, 20.1+/-2.4y; height, 168.0+/-8.1cm; weight, 70.4+/-13.3kg) were assigned to an effusion group and 10 of whom (age, 25+/-3.8y; height, 169.4+/-8.9cm; weight, 74.7+/-7.7kg) were assigned to a control group. INTERVENTIONS: COP data were collected before and after a 60-mL injection of sterile saline into the knee joint space. MAIN OUTCOME MEASURES: COP path and mediolateral and anteroposterior MPF. RESULTS: COP path decreased after the effusion (pre-effusion mean, 92.2+/-21.9cm; posteffusion mean, 77.27+/-23.0cm). No change was found within the control group for COP path (P>.05). No differences were detected before or after joint effusion when the MPF was examined (P>.05). CONCLUSIONS: Possible explanations for the improved postural control after the effusion include additional somatosensory feedback, an augmented neural drive to the soleus, and/or increased capsular tension.

Adult↗

PubMed2003

Arthrogenic muscle inhibition is not present in the limb contralateral to a simulated knee joint effusion.

OBJECTIVE: The purpose of this investigation was to estimate bilateral neuromuscular activity in the vastus medialis on induction of a unilateral knee joint effusion. DESIGN: Eight subjects each were assigned to effusion or control groups. The effusion group had 60 ml of sterile saline injected into their superolateral knee joint capsules. The control group rested for 8 mins. Bilateral recruitment curves for the Hoffmann reflex (H-reflex) and muscle response (M-wave) were obtained before and 10, 20, and 30 mins after the effusion or rest. The maximum H-reflex (Hmax), maximum M-wave (Mmax), and the Hmax/Mmax ratio were utilized for data analysis. RESULTS: Both Hmax and Hmax/Mmax ratios decreased from the baseline measure in the effused vastus medialis, whereas no changes were detected on the contralateral side. Effused subjects demonstrated decreased motoneuron pool excitability in the effused limb, whereas control subjects did not differ from baseline. CONCLUSIONS: Knee joint effusion results in ipsilateral but not contralateral impairment of quadriceps function. Rehabilitation protocols after knee joint injury should focus on ipsilateral neuromuscular and mechanical alterations that occur as the result of joint damage.

Adult↗

PubMed2003

A single dose of Ginkgo biloba does not affect soleus motoneuron pool excitability.

EGb 761 has been shown to increase acetylcholine synthesis and release and increase cholinergic receptors leading to an increase in cholinergic neurotransmission. These effects may be observed in the neuromuscular system, manifested by changes in motoneuron pool excitability as measured by the Hoffmann reflex to motor response (H/M) ratio. The objective was to determine whether a single dose of EGb 761 affects motoneuron pool excitability of the soleus muscle as measured by the H/M ratio. Following initial soleus H/M measurements, 20 healthy volunteers were randomly assigned to 1 of 3 treatment groups (control, 180 g cellulose placebo, and 180 g EGb 761). H/M ratios were recorded 1, 2, and 3 hours post treatment. A 3 x 4 repeated-measures analysis of variance was used to analyze differences in H/M ratio between treatments. No differences were observed between treatments (p = 0.75) or over time (p = 0.17), and there was not a treatment by time interaction (p = 0.27). A single dose of 180 g of EGb 761 does not affect soleus motoneuron pool excitability.

Adult↗

PubMed2002

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.

Adipose Tissue↗

PubMed2002

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.

Adult↗

PubMed2002

Efficacy of Prophylactic Ankle Support: An Experimental Perspective.

OBJECTIVE: To provide a comprehensive review of the literature regarding the role of external ankle support on joint kinematics, joint kinetics, sensorimotor function, and functional performance. DATA SOURCES: We searched MEDLINE and SPORT Discus databases from 1960-2001 for the key words ankle bracing, ankle support, ankle taping, and ankle prophylaxes. We also used personal libraries based on our own research to complement the existing literature. DATA SYNTHESIS: The effects of external ankle support have been studied on a plethora of dependent measures. Here, we specifically discuss the role of external ankle support on joint kinematics, joint kinetics, sensorimotor function, and functional performance and present a general consensus regarding the overall effects of these prophylactic devices. CONCLUSIONS/RECOMMENDATIONS: The effects of ankle support on joint kinematics during static joint assessment and on traditional functional-performance measures (ie, agility, sprint speed, vertical jump height) are well understood. However, the potential effects of ankle support on joint kinetics, joint kinematics during dynamic activity (eg, a cutting maneuver), and various sensorimotor measures are not well known. Future research investigating the role of external ankle bracing needs to focus on these areas.

Journal Article↗

PubMed2002

The Spectral Qualities of Postural Control are Unaffected by 4 Days of Ankle-Brace Application.

OBJECTIVE: To determine if the spectral qualities of medial-lateral (ML) and anterior-posterior (AP) center of pressure during a 1-legged stance are affected by 4 days of ankle-brace application. DESIGN AND SETTING: The study, which consisted of a pretest-posttest randomized group design, took place in the Sports Injury Research Laboratory at Indiana State University. SUBJECTS: Twenty-eight Indiana State University students, who had not suffered from any ankle injuries within the past 2 years and were free of any neurologic or vestibular disorders, participated in the study. MEASUREMENTS: The effects of 3 independent variables on mean frequency amplitude for both ML and AP center of pressure were examined: (1) treatment (brace, control), (2) frequency bin (0%-20%, 20%-40%, 40%-60%, 60%-80%, and 80%-100% of area), and (3) time (pretest, immediately after brace application, and after 1, 2, 3, or 4 days of brace wear). RESULTS: We detected no difference (P >.05) for the ML or AP mean frequency when comparing the brace and control groups. CONCLUSIONS: Application of an ankle brace may not require modifications in the postural-control strategies during a 1-legged stance in subjects with healthy ankles.

Journal Article↗

PubMedDate not supplied

Exercise and quadriceps muscle cooling time.

CONTEXT: Cryotherapy is commonly used for a variety of purposes; however, the body's response to cryotherapy immediately postexercise is unknown. OBJECTIVE: To investigate the effect of prior exercise on crushed-ice-bag treatment of a large muscle group. DESIGN: 2 x 3 repeated-measures design on depth (1 cm and 2 cm below adipose tissue) and treatment (exercise followed by ice, exercise followed by no ice, and no exercise followed by ice). SETTING: Sports Injury Research Laboratory. PATIENTS OR OTHER PARTICIPANTS: Six physically active, uninjured male volunteers. INTERVENTION(S): For the 2 exercise conditions, subjects rode a stationary cycle ergometer at 70% to 80% of their age-predicted maximum heart rate, as calculated by the Karvonen method. For the no-exercise condition, subjects lay supine on a treatment table. The cryotherapy treatment consisted of a 1-kg ice bag applied to the anterior mid thigh. For the no-ice condition, subjects lay supine on a treatment table. MAIN OUTCOME MEASURE(S): Time required for the intramuscular temperatures at the 1-cm and 2-cm depths below adipose tissue to return to pre-exercise baseline and time required to cool the 1-cm and 2-cm depths to 10 degrees C below the pre-exercise temperature. RESULTS: The time to cool the rectus femoris to the pre-exercise temperature using a crushed-ice-bag treatment was reduced by approximately 40 minutes (P < .001). The ice bag cooled the 1-cm and 2-cm depths to the pre-exercise temperature within 7 minutes (P = .38), but the 2-cm tissue depth took nearly 13.5 minutes longer to cool than the 1-cm depth when no ice was applied (P = .001). The 1-cm depth cooled to 10 degrees C below the pre-exercise temperature about 8 minutes sooner than the 2-cm depth, regardless of whether the tissue was exercised or not (P < .001). Exercise shortened the cooling time to 10 degrees C below the pre-exercise temperature by approximately 13 minutes (P = .05). CONCLUSIONS: Exercise before cooling with a crushed-ice bag enhanced the removal of intramuscular heat.

Journal Article↗

PubMedDate not supplied

Local ice-bag application and triceps surae muscle temperature during treadmill walking.

CONTEXT: Ice bags "to go" are a common practice in athletic training. OBJECTIVE: To determine the effect of submaximal exercise on tissue temperatures during a common ice-bag application. DESIGN: 2 X 5 fully repeated-measures design with treatment (cooling while resting, cooling while walking) and time (pretreatment, immediately after ice application, and at 10, 20, and 30 minutes during treatment) as the independent variables. SETTING: Laboratory setting. PATIENTS OR OTHER PARTICIPANTS: Sixteen healthy, physically active volunteers (age = 21.63 +/- 2.63 yrs, height = 68.97 +/- 4.00 cm, mass = 80.97 +/- 18.18 kg, calf skinfold = 21.1 +/- 9.3 mm). MAIN OUTCOME MEASURE(S): Left triceps surae intramuscular and skin temperatures, as measured by thermocouples to the nearest 0.1 degrees C, served as dependent measures. INTERVENTION(S): After collecting baseline temperatures, we secured a 1.0-kg ice bag to the calf using plastic wrap before the subject either rested prone or walked on a treadmill at 4.5 km/h for 30 minutes. RESULTS: Treatment did not (P < 0.10) affect the approximately 15 degrees C (P < 0.0001) surface temperature decrease, which remained depressed immediately upon ice-bag application (P < 0.05). Conversely, intramuscular temperature continually cooled (34 to 28 degrees C), while subjects rested (P < 0.0001), whereas no change took place during walking (P = 0.49). Moreover, at the 20- and 30-minute treatment intervals, the resting intramuscular temperatures were, respectively, 3.9 degrees C and 5.4 degrees C cooler than the walking intramuscular temperatures (P < 0.01). CONCLUSIONS: The current trend of wrapping "to go" ice bags to the leg is not likely to achieve deep tissue cooling despite surface temperature decreases.

Journal Article↗