To develop normative data from a large cohort of American school children (ages 6-18) for unscaled and allometrically scaled handgrip strength data that are uninfluenced by body size (body mass [BM] and stature [Ht]). Data (age, handgrip strength, BM, and Ht) were collected from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey databases, resulting in 4,665 cases (2,384 boys and 2,281 girls). Multiple log-linear regressions were used to determine allometric exponents for BM and Ht separately for each age and sex to satisfy the common exponent and group difference principles described by Vanderburgh. Appropriateness of the allometric model was assessed through regression diagnostics, including normality and homoscedasticity of residuals. Allometrically scaled, ratio-scaled, and unscaled grip strength were then correlated with BM and Ht to examine the effectiveness of the procedure in controlling for body size. The data did not allow for development of a common exponent across age and sex that did not violate the common exponent and group difference principles. Correlations between allometrically scaled handgrip strength with BM and Ht were not significant (p <= 0.479) and approached zero, unlike correlations of unscaled handgrip strength with BM and Ht (p < 0.001 for all), indicating that allometric scaling was successful in removing the influence of body size. Allometric scaling handgrip strength by age and sex effectively controls for body size (Ht and BM) and perhaps maturation (Ht). The allometric exponents and normative values developed can be used to compare handgrip strength within age and sex while controlling for body size.

In HIV-infected individuals, impaired mitochondrial function may contribute to cardiometabolic disease as well as to fatigue and frailty. Aerobic exercise improves total body energy reserves; however, its impact at the cellular level is unknown. We assessed alterations in cellular bioenergetics in peripheral blood mononuclear cells (PBMC) before and after a 12-week aerobic exercise study in sedentary HIV-infected subjects on stable antiretroviral therapy who successfully completed a 12-week aerobic exercise program. In this prospective study, participants underwent supervised 20-40 min of light aerobic exercise (walking or jogging) performed three times per week for 12 weeks, gradually increasing to maintain an intensity of 50%-80% of heart rate reserve. Maximal aerobic capacity (VO2MAX) was assessed by a graded exercise test on a cycle ergometer before and after completion of the study. PBMC from compliant subjects (attended at least 70% of exercise sessions) were assessed for mitochondrial respiration using the Seahorse XF24 Bio-Analyzer. Seven of 24 enrolled subjects were compliant with the exercise regimen. In these individuals, a significant increase (p = .04) in VO2MAX over 12 weeks was found with a median increase of 14%. During the same interval, a 2.45-fold increase in PBMC mitochondrial respiratory capacity (p = .04), a 5.65-fold increase in spare respiratory capacity (p = .01), and a 3.15-fold (p = .04) increase in nonmitochondrial respiration was observed. Aerobic exercise improves respiration at the cellular level. The diagnostic and prognostic value of such improved cellular respiration in the setting of chronic HIV warrants further investigation.

Subconcussive head impacts do not result in outward signs of neurological dysfunction, however they may have an effect on neurocognitive function. Limited research has indicated that negative changes in neurocognitive function occurs in high school football athletes as a result of one season of football. The purpose of this study was to prospectively evaluate the effects of one season of high school football on neurocognitive test scores. Results revealed a significant group and time interaction effect (p < .001) for the Verbal Memory composite score of the ImPACT test. Further analysis revealed a significant difference in the Verbal Memory score between groups at postseason (p < .01), with the football group scoring lower than the low contact group. It appears that one season of high school football may have a negative effect on the Verbal Memory composite score of the ImPACT test in high school football athletes.

BACKGROUND:Due to the high number of adolescent athletes and subsequent lower extremity injuries, improvements of injury prevention strategies with emphasis on clinic-based and practical assessments are warranted.PURPOSE:The purpose of this study was to prospectively investigate if a battery of functional performance tests (FPT) could be used as a preseason-screening tool to identify adolescent athletes at risk for sports-related acute lower extremity injury via comparison of injured and uninjured subjects.METHODS:One hundred adolescent volleyball, basketball and soccer athletes (female, n=62; male, n=38; mean age = 14.4 ± 1.6) participated. The FPT assessment included: triple hop for distance, star excursion balance test, double leg lowering maneuver, drop jump video test, and multi-stage fitness test. Composite scores were calculated using a derived equation. Subjects were monitored throughout their designated sport season(s), which consisted of a six-month surveillance period. The schools certified athletic trainer (ATC) recorded all injuries. Subjects were categorized into groups according to sex and injury incidence (acute lower extremity injury vs. uninjured) for analysis.RESULTS:Mean FPT composite scores were significantly lower for the injured compared to the uninjured groups in both sexes (males: 19.06 ± 3.59 vs. 21.90 ± 2.44; females: 19.48 ± 3.35 vs. 22.10 ± 3.06 injured and uninjured, respectively)(p < .05). The receiver-operator characteristic analysis determined the cut-off score at ≤ 20 for both genders (sensitivity=.71, specificity=.81, for males; sensitivity=.67, specificity=.69, for females)(p<.05) for acute noncontact lower extremity injuries. Significant positive correlations were found between the FPT composite score and the multi-stage fitness test in male subjects (r=.474, p=.003), suggesting a relationship between functional performance, aerobic capacity, and potential injury risk.CONCLUSION:A comprehensive assessment of functional performance tests may be beneficial to identify high-injury risk adolescents prior to athletic participation.

The direct anterior (DA) total hip arthroplasty (THA) is a minimally invasive procedure that accesses the hip joint from the anterior aspect of the hip by retracting instead of incising anterior hip musculature during surgery. During this procedure, little to no damage occurs to the hip abductors and extensors, and as a result is theorized to result in an accelerated return to normal function. PURPOSE: To prospectively investigate gait biomechanics following DA THA to identify the short term recovery and time sequence of return to normal gait. METHODS: Nine participants undergoing DA THA (64.1±9 y, 1.7±0.1 m, 72.5±10.8 kg) and nine control participants (60.7±4.3 y, 1.7±0.1 m, 71.4±5.5 kg), completed walking gait trials prior to and at three and six weeks following DA THA surgery. At each session, gait biomechanics at the hip were collected via three-dimensional motion capture system and force plates. RESULTS: Individual two-way repeated measures ANOVA revealed significant biomechanical differences in walking gait between the DA THA and the control groups at pre-surgery, and at three and six weeks following surgery. At pre operation and three weeks post operation, max hip extension (pre: p<0.001, 10.4±10.3; 3 wk post: p=0.005, 3.9±10.7), hip flexion/extension excursion (pre: p<0.001. -20.1±9.8; 3 wk post: p<0.001, -26.85±7.6), hip abduction/adduction excursion (pre: p=0.001, -2.63±2.0, 3 wk post: p=0.02, -4.65±2.24), hip extension moment (pre: p<0.001, -557.3±309.2, 3 wk post: p<0.001, -677.1±215.0) and hip internal rotation moment (pre: p<0.001, 41.89±27.6, 3 wk post: p<0.001, 54.6±31.1) were all significantly less in the DA THA group than the control group. By six weeks post operation, only hip flexion/extension excursion (p<0.001, -33.5±4.3) and hip abduction/adduction excursion (p=0.01, -3.6±2.1) remained significantly lower in the DA THA group. CONCLUSIONS: Short term analysis following DA THA revealed impairments in walking gait at pre operation, and at three and six weeks post operation. By six weeks post operation however, many improvements were made in walking gait when compared to the previous sessions. It appears that the participants began to return to normal function, but a longer follow-up time may be necessary to determine if these DA THA participants completely return to normal walking gait.

BACKGROUND: The direct anterior (DA) total hip arthroplasty (THA) is a minimally invasive procedure that accesses the hip joint from the anterior aspect of the hip by retracting instead of incising muscles during surgery. The lack of soft tissue damage is thought to result in an accelerated return of strength and function. PURPOSE: The purpose of this study was to identify when participants undergoing DA regained normal strength and function. METHODS: Twenty DA and 14 controls participated in this prospective study. Maximum isometric hip strength was measured in all hip motions using a hand-held dynamometer. Function was assessed using the Timed Up and Go (TUG) test and the Trendelenburg Single-Leg Balance (SLB) test. Data were collected at pre-operation, three and six weeks, and three months post-operation. MAIN RESULTS: At three and six weeks post-operation, all strength values except for hip adduction were significantly lower than the control group. By three months, only hip external rotation remained significantly lower in the DA group (p = 0.04; DA: 0.86 ± 0.54 N/BW, Control: 1.22 ± 0.37 N/BW). At three and six weeks post-operation, all strength values except for hip extension and external rotation were more asymmetrical than the control group. By three months post operation, only hip flexion remained more asymmetrical (p = 0.03, DA: –1.11 ± 2.04, Control: 0.55 ± 2.24). There were significant time effects for Trendelenburg SLB test (p = 0.04) and TUG (p = 0.003), but post hoc testing revealed no further differences. CONCLUSIONS: The results indicate that an emphasis on improving hip flexion and external rotation strength may be valuable in regaining normal strength and function in the DA population.

BACKGROUND:Cardiovascular fitness can improve autonomic function (AF) in human immunodeficiency virus (HIV)-infected individuals.METHODS:Cross-sectional study investigating relationship between AF and cardiovascular fitness in HIV+ individuals on antiretroviral therapy. Participants' (n=29) maximal oxygen consumption (VO2MAX) were assessed by graded exercise test and scaled allometrically, then divided into tertiles by fitness level (Unfit, Low-fit, and Moderately-fit). Heart rate variability (HRV) and the Autonomic Reflex Screen were used to assess AF.RESULTS:Median VO2MAX were 104.9, 130.5, and 150.2 mL•kg-.67•min-1 for Unfit (n=10), Low-fit (n=10), and Moderately-fit (n= 9) groups respectively (p<0.05). Positive correlations were found between VO2MAX and HRV (Spearman's rho range 0.383 to 0.553) were found. Quantitative Sudomotor Axon Reflex Test (QSART) Distal Leg volumes was lower in Unfit compared to Low-fit (p=0.007) and Moderately-fit groups (p=0.018). Unfit QSART total volumes was lower than Moderately-fit (p=0.014).CONCLUSION:A positive relationship existed between AF and fitness levels. HIV+ individuals could benefit from improved fitness.

The timed up and go (TUG) test is commonly used to measure functional ability in a variety of patient populations. However, improved assessment of function could be attained with the addition of kinetics during the TUG test. A longitudinal, repeated measures evaluation of 12 osteoarthritic patients, set to undergo TKA and 12 control subjects was conducted using the TUG test pre-TKA and six months post-TKA. Kinetic variables during stance and push-off, collected from two forces plates, and time to completion for the TUG test were examined. Separate one-way, repeated measures ANOVAs were completed to examine change over time in each dependent variable. Data from both subject samples were combined, revealing significant correlation between TUG time to completion and loading rate (p=0.000, r=-0.795), anteroposterior maximum ground reaction force (p=0.000, r=-0.753) and contact time (p=0.000, r=0.882) during both time periods. There were significant increases in loading rate (p=0.023) and significant decreases in TUG time to completion (p=0.016) and contact time (p=0.013) in TKA subjects at six months. Significant main effects were reported between TKA and control subjects for loading rate (p=0.003), TUG time to completion (p=0.017), and contact time (p=0.007). Post-hoc analysis revealed TKA patients have a decreased loading rate (p<0.001), increased TUG time to completion (p=0.007), and increased contact time (p=0.004) when compared to controls prior to surgery. Based on these results, a decrease in time to completion may not only be due to an increase in walking speed post-TKA, but also the ability to load the limb more quickly upon standing. Therefore, a decrease in time to completion of the TUG test could indicate a better ability to accept weight and a greater overall function within the involved limb.

This study examined population-specific allometric exponents to control for the effect of body mass (BM) on bench press, clean, and squat strength measures among Division I-A collegiate football athletes. One repetition maximum data were obtained from a university pre-season football strength assessment (bench press, n = 207; clean, n = 88; and squat n = 86) and categorized into 3 groups by positions (line, linebacker, and skill). Regression diagnostics and correlations of scaled strength data to BM were used to assess the efficacy of the allometric scaling model and contrasted with that of ratio scaling and theoretically based allometric exponents of 0.67 and 0.33. The log-linear regression models yielded the following exponents (b): b = 0.559, 0.287, and 0.496 for bench press, clean, and squat, respectively. Correlations between bench press, clean, and squat to BM were r = -0.024, -0.047, and -0.018, respectively, suggesting that the derived allometric exponents were effective in partialling out the effect of BM on these lifts and removing between-group differences. Conversely, unscaled, ratio-scaled, and allometrically scaled (b = 0.67 or 0.33) data resulted in significant differences between groups. It is suggested that the exponents derived in the present study be used for allometrically scaling strength measures in National Collegiate Athletic Association Division I-A football athletes. Use of the normative percentile rank scores provide coaches and trainers with a valid means of judging the effectiveness of their training programs by allowing comparisons between individuals without the confounding influence of BM.

This study examined the reliability and validity of the Hawaii anaerobic run test (HART) by comparing anaerobic capacity measures obtained to those during the Wingate Anaerobic Test (WAnT). Ninety-six healthy physically active volunteers (age, 22.0 ± 2.8 years; height, 163.9 ± 9.5 cm; body mass, 70.6 ± 14.7 kg; body fat %, 19.29 ± 5.39%) participated in this study. Each participant performed 2 anaerobic capacity tests: the WAnT and the HART by random assignment on separate days. The reliability of the HART was calculated from 2 separate trials of the test and then determined through intraclass correlation coefficients (ICCs). Blood samples were collected, and lactate was analyzed both pretest and posttest for each of the 2 exercise modes. Heart rate and rate of perceived exertion were also measured pre- and post-exercise. Hawaii anaerobic run test peak and mean momentum were calculated as body mass times highest or average split velocity, respectively. Intraclass correlation coefficients between trials of the HART for peak and mean momentum were 0.98 and 0.99, respectively (SEM = 18.8 and 25.7, respectively). Validity of the HART was established through comparison of momentum on the HART with power on the WAnT. High correlations were found between peak power and peak momentum (r = 0.88), as well as mean power and mean momentum (r = 0.94). The HART was considered to be a reliable test of anaerobic power. The HART was also determined to be a valid test of anaerobic power when compared with the WAnT. When testing healthy college-aged individuals, the HART offers an easy and inexpensive alternative maximal effort anaerobic power test to other established tests.

Background: Non-exercise (N-EX) questionnaires have been developed to determine maximal oxygen consumption (VO2max) in healthy populations. There are limited reliable and validated N-EX questionnaires for the HIV+ population that provide estimates of habitual physical activity and not VO2max Objectives: To determine how well regression equations developed previously on healthy populations, including N-EX prediction equations for VO2max and age-predicted maximal heart rates (APMHR), worked on an HIV+ population; and to develop a specific N-EX prediction equation for VO2max and APMHR for HIV+ individuals. Methods: Sixty-six HIV+ participants on stable HAART completed 4 N-EX questionnaires and performed a maximal graded exercise test. Results: Sixty males and 6 females were included; mean (SD) age was 49.2 (8.2) years; CD4 count was 516.0 +/- 253.0 cells.mm(-3); and 92% had undetectable HIV PCR. Mean VO2max was 29.2 +/- 7.6 (range, 14.4-49.4) mL.kg(-1).min(-1). Despite positive correlations with VO2max, previously published N-EX VO2max equations produced results significantly different than actual VO2 scores (P<.0001). An HIV+ specific N-EX equation was developed and produced similar mean VO2max values, R = 0.71, when compared to achieved VO2max (P =.53). Conclusion: HIV+ individuals tend to be sedentary and unfit, putting them at increased risk for the development of chronic diseases associated with a sedentary lifestyle. Based on the level of error associated with utilizing APMHR and N-EX VO2max equations with HIV+ individuals, neither should be used in this population for exercise prescription.

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This case study reports a 5-year follow-up of a 32-year-old male service member who suffered polytrauma in 2007 following a Humvee rollover in Afghanistan. The service member's injured left lower extremity was salvaged, but severe damage to the lumbosacral plexus and significant injuries to the pelvis, hip, and femur resulted in near total paralysis and foot drop of the left lower limb. Two years of multiple substandard ankle-foot orthotic devices pushed him to investigate a dynamic ankle-foot orthotic (DAFO) with energy storing capability, which allowed him to remain on active duty and deploy for a second tour while wearing the device. The anecdotal improvements described by this service member prompted a biomechanical analysis of walking and running gait, comparing a shoes only condition to the DAFO. Results of gait analysis demonstrated an improvement in spatial-temporal parameters in both walking and running, improved sagittal angles and moments at the ankle, knee, and hip, greater ankle stability through decreased dorsiflexion excursion, and a marked increase in ankle power while running. Most notably, the service member credits this device for substantial improvement in quality of life including total cessation of pain medication and return to regular vigorous activity.

CONTEXT:The effectiveness of education in modifying hydration behaviors in adolescent athletes is unclear. OBJECTIVE:To assess the hydration status and behaviors of female athletes before and after a 1-time educational intervention and prescribed hydration intervention in a warm, humid, tropical environment. DESIGN:Cohort study. SETTING:Non-air-conditioned gymnasium in a tropical environment (indoor wet bulb globe temperature = 24.0 ± 0.2°C). Patient or Other Participants: Thirty-six female adolescent elite volleyball players (age = 14.8 ± 0.8 years, height = 168.2 ± 8.2 cm, mass = 60.8 ± 9.0 kg, body mass index = 21.7 ± 2.7, body surface area = 1.65 ± 0.14 m(2), body surface area to mass ratio = 2.71 ± 0.18 m(2)·kg(-1)·10(-2)) participated. INTERVENTION(S):Four observational periods consisting of 3 practices per observational period separated by 48 hours. The 4 periods included a control period, educational intervention, prescribed hydration intervention (PHI), and observational follow-up (OF-U). After the control period, an educational intervention consisting of a slide presentation was provided to the participants, followed by a week of observation. In the PHI, a precalculated volume of water based on individual sweat rate was consumed every 20 minutes during each 2-hour practice. During all other periods, participants consumed their fluid of choice ad libitum. The order of the treatment periods was not randomized and was the same for all participants. MAIN OUTCOME MEASURE(S):Prepractice to postpractice changes in body mass (ΔBM), percentage of body mass lost (%BML), urine specific gravity, urine color, urine osmolality, sweat rate, and volume of fluid consumed (F(vol)). RESULTS:The PHI was the only period during which participants maintained body mass (ΔBM = 0.05 ± 1.3%); F(vol) consumed was greatest during this time (F(vol) = 1.3 ± 0.4 L; F(1,3) = 34.869, P ≤ .001). TheΔBM was less for the PHI (ΔBM = 0.05 ± 0.9 kg, %BML = 0.04 ± 1.3%) than the OF-U period (ΔBM = -0.7 ± 1.1 kg, %BML = -1.2 ± 1.9%; F(1,3) = 6.220, P = .01). The F(vol) (1.3 ± 0.4 L) and percentage of fluid consumed (143.7 ± 110.8%) to restore sweat loss for the PHI period were higher than for any other period (F(1,3) = 34.869, P ≤ .001). None of the participants experienced serious dehydration in any of the conditions. CONCLUSIONS:A 1-time education session alone was not successful in changing hydration behaviors. However, prescribing individualized hydration protocols improved hydration for adolescents exercising in a warm, humid environment.

To date, the only studies conducted on skateboarding have been injury studies. The increased popularity of this sport suggested that further study was warranted. PURPOSE The purpose of this study was to compare the oxygen uptake of skateboarding and running on a treadmill; and to use oxygen pulse data from the metabolic analysis of treadmill skateboarding and heart rate data from a skateboard field test to estimate the metabolic responses to skateboarding in the field. METHODS Five skateboarders of varying levels of experience were studied, two females and three males (age = 23.4±2.6 yrs, ht = 173.3±5.9 cm, wt = 70.0±6.3 kg) with a mean VO2max of 55.1±4.3 ml/kg/min. VO2max was assessed using the Bruce protocol. Subjects then participated in two treadmill tests and one field test. The treadmill protocol consisted of ten stages, the first at 0% elevation at 5.0 mph, then 9 subsequent stages at 1.5% elevation starting at 5.0 mph and increasing 0.5 mph per stage. Subjects skated and ran the same treadmill protocol. The field test consisted of 30 minutes of skateboarding on a flat concrete surface while wearing a Polar heart rate monitor. A regression equation for each individual was created using the O2 pulse and heart rate from the skateboard treadmill test. The heart rate data collected from each field test were entered into the equation and used to estimate VO2. RESULTS Oxygen uptakes were significantly greater across the workloads for the running treadmill tests when compared to the skateboard treadmill tests (p < 0.05). The mean VO2 for 30 minutes of skateboarding was estimated to be 62.4±9.4 L. The mean caloric expenditure, assuming a mixed diet, was 302.6±45.9 kcal and mean kcal/min was 10.1±1.5. CONCLUSION Across a progressively increasing workload on a treadmill, these results indicated that skateboarding was more efficient than running. The average estimated caloric expenditure of 10.1±1.5 kcal/min, indicated that skateboarding could provide similar health benefits compared to other modes of moderately intense aerobic exercise.

Cleary, MA, Hetzler, RK, Wages, JJ, Lentz, MA, Stickley, CD, and Kimura, IF. Comparisons of age-predicted maximum heart rate equations in college-aged subjects. J Strength Cond Res 25(9): 2591-2597, 2011—This study investigated the accuracy of age-predicted equations to predict heart rate maximum (HRmax) in a college-age sample and establish efficacy of short-duration anaerobic capacity tests to determine the actual HRmax. A criterion HRmax (CHRmax) was obtained from 96 (52 men and 44 women, age = 22.0 ± 2.8 years, height = 163.9 ± 9.5 cm, 70.6 ± 14.7 kg, resting HR = 68.9 ± 11.2 b·min−1) healthy volunteers during 2 200-m sprint trials on a standard track. Maximal effort was confirmed via plasma lactate ≥7 mmol·L−1 and rating of perceived exertion ≥17 points. The CHRmax was compared to 7 age-predicted HRmax equations: Fox et al., 3 equations from Gellish et al., Tanaka et al., and gender-specific equations from Fairbarn et al., and Hossack et al. Descriptive statistics and standard errors of estimate (SEEs) were calculated. One-way analysis of variance was used to assess differences between the criterion HRmax and the age-predicted HRmax from the 7 equations. The predicted HRmax from the Fox equation and those of Gellish3, Tanaka, and Hossack were all significantly higher (p ≤ 0.05) than the CHRmax. The Fox equation resulted in overpredicting HRmax in 88.5% of the cases compared to the CHRmax. Compared to the CHRmax, the age-predicted HRmax equations resulted in the following percentages of the CHRmax: Fox = 104.8%, SEE = 12.7; Gellish1 = 95.2%, SEE = 12.2; Gellish2 = 99.6%, SEE = 8.3; Gellish3 = 101.8%, SEE = 9.1; Tanaka = 102.0%, SEE = 9.3; Fairbarn = 100.1%, SEE = 8.5; and Hossack = 105.2%, SEE = 13.9 of CHRmax. It was concluded that the Gellish2 and Fairbarn equations were the most accurate of the age-predicted HRmax equations in a college-age population. In practical application, 2 200-m sprint trials provide a reasonable estimate of HRmax compared to a graded exercise test.

This study examined the appropriate magnitude of allometric scaling of the Wingate anaerobic test (WAnT) power data for body mass (BM) and established normative data for the WAnT for adult men. Eighty-three men completed a standard WAnT using 0.1 kg·kg(-1) BM resistance. Allometric exponents and percentile ranks for 1-second peak power (PP), 5-second PP, and mean power (MP) were established. The Predicted Residual Sum of Squares (PRESS) procedure was used to assess external validity while avoiding data splitting. The mean 1-second PP, 5-second PP, and MP were 1,049.1 ± 168.8 W, 1,013.4 ± 158.6 W, and 777.9 ± 105.0 W, respectively. Allometric exponents for 1-second PP, 5-second PP, and MP scaled for BM were b = 0.89, 0.88, and 0.86, respectively. Correlations between allometrically scaled 1-second PP, 5-second PP, and MP, and BM were r = -0.03, -0.03, and -0.02, respectively, suggesting that the allometric exponents derived were effective in partialling out the effect of BM on WAnT values. The PRESS procedure values resulted in small decreases in R² (0.03, 0.04, and 0.02 for 1-second PP, 5-second PP, and MP, respectively) suggesting acceptable levels of external validity when applied to independent samples. The allometric exponents and normative values provide a useful tool for comparing WAnT scores in college-aged females without the confounding effect of BM. It is suggested that exponents of b = 0.89 (1-second PP), b = 0.88 (5-second PP), and b = 0.86 (MP) be used for allometrically scaling WAnT power values in healthy adult men and that the confidence limits for these allometric exponents be considered as 0.66-1.0 for PP and 0.69-1.0 for MP. The use of these exponents in allometric scaling of male WAnT power values provide coaches and practitioners with valid means for comparing power production between individuals without the confounding influence of BM.

Ankle sprains are among the most common athletic injuries. The prophylactic use of ankle taping and various braces is widely practiced in an effort to prevent ankle injuries. The impact of ankle support devices on athletic performance including vertical jump, running speed, agility, and sport specific skills has been widely evaluated; however, the effect of ankle support devices on running economy has received less attention. PURPOSE: The purpose of this study was to compare the metabolic cost while running at a self-selected speed wearing ankle tape or ankle braces compared to control (no tape or brace). METHODS: Metabolic data were collected on 18 healthy young adult subjects (9 male: mean age=25.4 yrs; ht=177.8 cm; mass= 76.5 kg; 9 female: mean age=24.1 yrs; ht=163.7 cm; mass=64.2 kg) running (males: mean=5.1 mph; females: mean=4.6 mph) for 30 minutes on a motor driven treadmill set at 1% grade in each of four conditions: control, ankles taped bilaterally, wearing bilateral semi-rigid lace-up braces or bilateral hinged braces. The ankle taping was performed by the same certified athletic trainer using the closed basket-weave technique. RESULTS: Mean oxygen uptake (VO2) was significantly higher when wearing the semi-rigid ankle braces compared to control (mean VO2 control: 30.9±3.9 ml/kg/min vs mean VO2 brace: 31.8±4.3 ml/kg/min; p<0.05). Mean oxygen uptake was also significantly higher when wearing the hinged ankle braces compared to control (mean VO2 hinged brace: 31.6±3.7 ml/kg/min; p<0.05). No differences in VO2 were found between the control and the ankle taping condition (mean VO2 ankle taping: 31.9±4.5 ml/kg/min; p=0.08). Our study supports the results of the study by MacKean et al. (1995) (n=7) who had previously reported that VO2 during fixed-speed running (6 mph) was affected by the type of ankle support with tape having the lowest VO2 of the ankle support devices, followed by hinged braces and semi-rigid lace-up braces. CONCLUSION: It was concluded that when running at a self-selected speed, the ankle braces resulted in a small but significantly greater VO2 compared to the control condition. Therefore, running economy was negatively impacted by ankle bracing but not taping.