Endurance Variables Research Articles

Does Combining Body Weight Support Treadmill Training with Thera-Band® Improve Hemiparetic Gait?

Introduction: The purpose of this case report was to explore the use of Thera-Band® Elastic Band in combination with body weight support treadmill training during locomotor training of a person with chronic stroke. Methods: Inclusion and exclusion criteria were established and Institutional Review Board approvals were obtained. During treadmill training, the Thera-Band® was configured around the participant’s hemiparetic leg in a figure-8 fashion and attached to the harness of the body weight support. The purpose of the Thera-Band® was to assist with hip and knee flexion and ankle dorsiflexion during swing and proper foot placement during stance, avoiding excessive inversion. The locomotor training protocol consisted of thirty minutes of training at ten-minute intervals with five-minute rest periods in between, three times per week for a total of ten weeks. Outcome measures included fast gait speed, spatiotemporal variables of gait, endurance and strength of ankle eversion. Data collection occurred at baseline, during weeks five and ten of the training protocol and at six weeks follow-up (week sixteen). Results: All 90 training trials were completed. Mean gait speed increased from .625m/s at baseline to 1.10m/s at week sixteen. Gait distance increased from 191m at baseline to 367m at week 16; ankle eversion strength increased from 4.67 ± 0.45 to 5.90 ± 0.59 force/Kg. GAITRite data demonstrated a more symmetrical gait pattern, with a more equal step length and stance time when comparing the left and right limbs, and an increased stride length bilaterally. Discussion: The results of this case report with one participant demonstrated significant improvement in the fast walking speed, gait endurance, gait symmetry and spatiotemporal gait variables and ankle eversion strength. Several limitations and suggestions for further research were identified.

Are Anthropometric, Flexibility, Muscular Strength, and Endurance Variables Related To Clubhead Velocity in Low- And High-Handicap Golfers?

The present study assessed the anthropometric profile (International Society for the Advancement of Kinanthropometry protocol), flexibility, muscular strength, and endurance of 20 male golfers. These data were collected in order to determine: a) the relationship between these kinanthropometric measures and clubhead velocity; and b) if these measures could distinguish low-handicap (LHG) and high-handicap (HHG) golfers. Ten LHG (handicap of 0.3 +/- 0.5) and 10 HHG (handicap of 20.3 +/- 2.4) performed 10 swings for maximum velocity and accuracy with their own 5-iron golf club at a wall-mounted target. LHG hit the target significantly more (115%) and had a 12% faster clubhead velocity than HHG (p < 0.01). The LHG also had significantly (28%) greater golf swing-specific cable woodchop (GSCWC) strength (p < 0.01) and tendencies for greater (30%) bench press strength and longer (5%) upper am and total arm (4%) length and less (24%) right hip internal rotation than HHG (0.01 < p < 0.05). GSCWC strength was significantly correlated to clubhead velocity (p < 0.01), with bench press and hack squat strength as well as upper arm and total arm length also approaching significance (0.01 < p < 0.05). Golfers with high GSCWC strength and perhaps greater bench press strength and longer arms may therefore be at a competitive advantage, as these characteristics allow the production of greater clubhead velocity and resulting ball displacement. Such results have implications for golf talent identification programs and for the prescription and monitoring of golf conditioning programs. While golf conditioning programs may have many aims, specific trunk rotation exercises need to be included if increased clubhead velocity is the goal. Muscular hypertrophy development may not need to be emphasized as it could reduce golf performance by limiting range of motion and/or increasing moment of inertia.

Normative Pelvic Floor Parameters in Children Assessed by Transabdominal Ultrasound

Successful management of dysfunctional voiding in children hinges on retraining inappropriate pelvic floor muscle recruitment. Recently dynamic pelvic floor muscle activity was visualized in adults using transabdominal ultrasound. We evaluated transabdominal ultrasound for visualizing and measuring pelvic floor muscle activity in normative children. A total of 21 volunteers, including 10 boys and 11 girls 7 to 16 years old (mean age 11.6) who were free of bladder disorders consented to participate in the study. Subjects were screened and demonstrated normative bladder emptying before being imaged while supine and standing using a sagittal curved linear array 2 to 5 MHz transducer over the suprapubic region. After pelvic floor muscle contraction was explained 4 parameters were measured 3 times each, including the direction of movement/displacement from freeze-frame ultrasound images, and endurance and coordination from ultrasound movie loops. The methodology for digitizing movie data were developed, tested and found to be reliable. New variables of endurance as a percent of maximum coordination amplitude and coordination as the amplitude between maximum and minimum effort were created. Overall 66% and 71% of subjects demonstrated anterior displacement of the pelvic floor during voluntary contraction while lying and standing, respectively, with no significant difference in lying vs standing. However, coordination displacement was greater while lying than standing. During 20-second contractions pelvic floor muscle activity attained peak amplitude at 5.5 seconds, followed by a marked decay with 1 or more cycles of muscular re-recruitment. It was observed that fatigue led to repeat recruitment of the rectus and oblique abdominal muscles. In children free of voiding dysfunction pelvic floor displacement and coordination are highly variable. Noninvasive ultrasound of the pelvic floor provided visual assessment of muscular activity, a biofeedback component for the patient and measurement potential for the therapist.

Effects of an 8-Week Mat Pilates Training Program on Body Composition, Flexibility, and Muscular Endurance

PURPOSE: to examine changes in body composition, flexibility and muscular endurance after 8 wks of traditional mat Pilates. METHODS: 22 (16 Caucasian; 6 Hispanic) of the original 28 adults from the University of Miami who volunteered and gave written informed consent completed the study. Nine novice students (8 women) enrolled in the mat Pilates class were the treatment group (P), and 13 University community members (12 women) were the control group (C). Pre- and post-intervention assessments of body mass, barefoot standing height, 3-site skinfold (SKF) thickness, circumferences at 6 sites (neck, chest, waist, hip, thigh, arm), upper and lower body flexibility, as well as abdominal and lower back muscular endurance were conducted by the same experienced technician. A minimum of 2 measurements were averaged and used for subsequent data analysis for all but the muscular endurance tests. Relative body fat (%BF) was determined following calculations of body density from Jackson and Pollack equations subsequently converted into %BF using the Siri conversion formula. Pilates instruction was provided 3 d/wk for 1 hr/class by an instructor certified in traditional mat Pilates; attendance requirement for inclusion in the study was set at 85% of all classes for P. Those in C agreed to maintain their current physical activity and nutritional regimens. A 2 (group) x 2 (time) ANOVA was run for the body composition, flexibility, and muscular endurance variables of interest using SPSS-PC v. 10.1; post hoc testing was performed as needed using the Scheffe technique. Significance was set at p <.05 for all analyses. RESULTS: There was a significant main effect for time (pre v post) for %BF, sit-and-reach, shoulder reach, timed curl-ups and low back extensions, as well as circumference at 3 sites (waist, chest, and arm) (p <.05). There was a significant main effect for group (PvC) for timed low-back extensions (p <.05). Significant interaction effects were noted for %BF, sit-and-reach, shoulder reach, timed curl-ups and low back extensions, and the 3 circumference sites (p <.05). Compared to respective baseline values, P, but not C, showed significant improvement in all variables of interest with the exception of hip and thigh circumferences where changes were not significant. Body weight also did not change significantly. CONCLUSION: Significant improvements in body composition, flexibility, and muscular endurance were noted following 8-wk of traditional mat Pilates class comprised primarily of beginner and intermediate level exercises. Caution is urged in interpreting the clinical significance of some of the statistically significant changes (i.e. %BF) noted.

Etiologic factors associated with anterior knee pain in distance runners.

The objectives of this study were 1) to examine the differences between a noninjured (C) cohort of runners (N = 70) and runners afflicted with anterior knee pain (AKP) according to selected training, anthropometric, rearfoot motion, ground reaction force, and muscular strength and endurance variables; 2) to explore multivariate relationships among these measures in the well and injured groups; and 3) to develop specific hypotheses concerning risk factors for injury that will later be tested in a prospective clinical study. High speed videography (200 frames x s(-1)), a force platform (500 Hz), and a Cybex II+ isokinetic dynamometer were used to assess rearfoot motion, ground reaction forces, and knee muscular strength and endurance, respectively. A linear discriminant function was performed on each of the five categories of variables and revealed 19 significant (P < or = 0.05) predictors. These variables were then combined and a final discriminant function analysis was performed. Pronation through the first 10% of stance, arch index, shoe mileage, and extension peak torque were the best overall (P < or = 0.05) predictors. The AKP group had smaller mean values on all four significant predictors. With the exception of shoe mileage, which is likely a response to rather than a risk factor for AKP, these results should prove useful to clinicians in identifying runners at risk for anterior knee pain.

The Influence of the Cervical Spine on Chronic Headache in Women: A Pilot Study

This study compares selected posture, mobility, strength and endurance variables in subjects with chronic headaches to the same features in asymptomatic subjects. Two convenience samples of 10 female subjects were obtained: 1) those who experience chronic headache, mean age of 34.2 years (SD=11, range=23-57), and 2) a group not experiencing headache mean age of 30 years (SD=9.6, range=21-50). Measurements compared: 1) cervical range of motion in flexion, extension, rotation, and lateral flexion, 2) cervical strength in flexion and extension, 3) forward head posture (FHP), 4) forward shoulder posture (FSP), and 5) endurance testing of the anterior cervical musculature between the two groups.Statistical analysis was completed using the Kruskal-Wallis test. The headache group was found to have significantly less cervical extension ROM (p<0.05) and lower strength for both the cervical flexor (p=0.001) and cervical extensor (p<0.01) muscle groups; in addition the endurance of the anterior cervical musculature was significantly decreased (p=0.001) as compared to the controls. Forward head and forward shoulder posture measurements did not differ between the two groups.

Electromyographic and neuromuscular variables in unstable postpolio subjects, stable postpolio subjects, and control subjects

Objective: To compare strength and endurance variables obtained in the quadriceps muscles of postpolio and control subjects over a 7-year interval with macro and single fiber electromyography (EMG) variables. Design: A controlled inception cohort study. Setting: Neuromuscular research laboratory of a university hospital. Subjects: A cohort of 23 postpolio and 14 control subjects. All postpolio subjects had a history, physical examination, and EMG consistent with previous poliomyelitis, and had greater than antigravity strength in the quadriceps muscle tested. Unstable postpolio subjects acknowledged new quadriceps weakness over the 7-year period of the study ( n = 11), and stable postpolio subjects denied new weakness of the quadriceps over the same period ( n = 12). Main Outcome Measures: All subjects had tests of neuromuscular function of the quadriceps muscles at the onset of this study and yearly over a 7-year period. EMG variables were determined on a separate day after the seventh year of neuromuscular measurements. Neuromuscular variables measured were isometric knee extension peak torque, isometric endurance (time to inability to maintain knee extensor contraction at 40% of maximal torque), tension time index (TTI) (product of isometric endurance time and 40% of maximal torque), and recovery of torque at 10 minutes after the endurance test. EMG variables were macro EMG and single fiber EMG (jitter, fiber density, and percent blocking). Results and Conclusions: Unstable postpolio subjects did not lose strength more rapidly than stable postpolio subjects or control subjects. Unstable postpolio subjects were significantly weaker, had decreased TTI, larger macro EMG amplitude, greater jitter, blocking, and fiber density in comparison with stable postpolio subjects (all p < .05). Strength was negatively correlated with macro EMG amplitude in the stable postpolio group ( p < .05). The slope of the regression line of strength over 7 years did not correlate ( p > .05) with neuromuscular or EMG variables in control, stable, or unstable postpolio subjects.

The relationship of aerobic and anaerobic power to distance running performance

The purpose of this study was to examine the relationship of various measures of aerobic and anaerobic metabolism to 10 km run time. Subjects were 14 trained and experienced female distance runners whose mean (±SD) age, mass, percent body fat, and VO2 max were 31.3 ± 2.8 yr, 58.5 ± 6.7 kg, 17.5 ± 3.9 percent, and 48.9 ± 4.9 ml· min−1 · kg−1 respectively. Results indicated that ventilation threshold (VT), velocity at VO2 max (vVO2 max), V02max, 50 m sprint time, and peak knee extension torque at 400 deg· sec−1 were significantly correlated with 10 km run time (p ≤ .05). Stepwise multiple regression indicated that VT was the strongest single predictor explaining 48% of the variance while 50 m sprint time increased the explained variance to 67.2% (SEE = 1.40 min). The regression equation developed was: Y' = 48.65 ‐ .270 (VT ml· min−1 · kg−1 + .90 (50m in sec). The results of this investigation provide evidence that distance running performance may be attributed to individual variables such as VT and anaerobic power as measured by a 50 m sprint. Therefore, some measure(s) of anaerobic power in combination with endurance variables should be included in predicting distance running performance from a regression equation. It is concluded that a combination of aerobic and anaerobic factors (VT and 50 m sprint time, respectively) best explain the variance in 10 km run time.

Acute and chronic effect of aspirin on selected endurance variables

The purpose of the study was to determine the influence of acute and chronic ingestion of aspirin on selected endurance variables during maximal exercise. Eleven moderately trained men (19 to 30 years old) participated in three blind graded maximal treadmill tests for each of two different aspirin doses and a placebo condition. The treatments consisted of the following: an acute dose of 975 mg of aspirin 1 hour prior to exercise; a chronic dose of 975 mg of aspirin 3 times a day for 4 consecutive days; and a placebo of three comstarch‐filled capsules, 3 times a day for 4 consecutive days. Maximal performance was not significantly different among the treatments. However, chronic treatment resulted in significantly higher 5‐minute postexercise lactate levels (p < 0.001), a decrease in time to reach ventilatory threshold (Tvent), and a shorter time to exhaustion (p < 0.01) compared with the acute and placebo treatment Acute treatment also resulted in significantly higher 5‐minute postexercise lactate concent...

Relationships among selected attributes and three measures of upper body strength and endurance in elementary school children.

The purpose of this investigation was to assess (a) proportions of children unable to perform each of three measures of upper body strength and endurance--pull-up, flexed-arm hang, and modified pull-up; (b) relationships among selected attribute variables of age, weight, percent body fat, and body mass index, and the three measures of upper body strength and endurance; and (c) the attribute variables which best predict scores for the three measures of upper body strength and endurance. Subjects were 104 elementary school children in Grades 1 through 6. Percentages of children obtaining zero scores were computed. Intercorrelations among the attribute and upper body strength and endurance variables were examined for significance and effect size. For each of the three measures of upper body strength and endurance, a max R2 forward stepwise, multiple regression analysis was performed to identify which attribute variables best predict the score of that particular measure. Analyses indicated that age and percent body fat were the best predictors of pull-up and flexed-arm hang scores, whereas age and body mass index best predicted the modified pull-up score.

239 ETIOLOGIC FACTORS ASSOCIATED WITH PATELLOFEMORAL PAIN IN RUNNERS

The purpose of this study was to extend our knowledge of running related injuries by determining whether relationships exist between selected anthropometric, biomechanical, muscular strength and endurance, and training variables and runners afflicted with patellofemoral pain (PFP). Specifically, the objectives of this study were to examine differences in selected measures between a non-injured control group (C) of runners (N = 20) and a group of injured runners (INJ) diagnosed by an orthopedic surgeon as having PFP (N = 16). High speed photography, a force platform, and isokinetic dynamometry were used to determine rearfoot motion, ground reaction forces, and knee muscular strength and endurance. Stepwise discriminant function analyses were performed on the anthropometric, biomechanical, and muscular strength and endurance variables. Q angle was a significant discriminator (P less than 0.01) between the INJ and C groups. The muscular endurance data revealed several significant discriminators with the INJ subjects being weaker in knee extension endurance. Kinetic analysis revealed several significant discriminators whereas rearfoot movement variables were not good discriminators between the groups. The training data revealed that the INJ group ran significantly less (P less than 0.01) miles.wk-1 than the C group. Our results suggest that Q angle is a strong discriminator between runners afflicted with PFP and non-injured runners. In addition, several muscular endurance and kinetic variables may also be important components of the etiology of PFP.

Exploration of Mechanical and Electromyographic Responses of Trunk Muscles to High-Intensity Resistive Exercise

The purposes of this study were to determine the effects of high intensity exercise on fatigue of the trunk muscles within a test session, and on multiple kinetic and electromyographic (EMG) variables over a 6-week training period. Fourty-five normal men and women (20-40 years of age) completed the study. The KIN/COM trunk testing unit (Chattecx Corporation, Chattanooga, Tennessee) was used for both testing and training. The results of the study follow: 1) The KIN/COM trunk testing system was very accurate, and the method used was highly reproducible for the kinetic variables. Reproducibility for the endurance variables was mixed, and isolated EMG variables were poor. 2) Kinetic and EMG decrements associated with fatigue did occur in the trunk muscles with ten continuous cycles of maximal concentric and eccentric contractions. 3) Trunk muscle strength gains were highest for the same mode of exercise used in training (specificity), but significant strength gains also were seen in different modes of muscle contraction (transfer of training). For the trunk extensors, the eccentric form of exercise was superior. 4) The rate of isometric torque development and decay was increased by exercise in men. 5) Trunk muscle endurance was retained when gains in strength occurred. 6) The majority of variables reflecting strength and endurance were retained. The methods and results can serve as guidelines for the evaluation of trunk muscle function and resistive exercise in the clinic.

Assessment of abdominal and back extensor function. A quantitative approach and results for chronic low-back patients.

A method was developed to obtain static and dynamic measures of trunk flexor and extensor strength and endurance. The method was evaluated using 32 normal subjects. Variables of trunk strength and endurance were used to compare 24 normals (12 men and 12 women) and 24 patients (16 men and eight women) with chronic low-back dysfunction. The Iowa Trunk Dynamometer is acceptably reliable and provides for assessment of isolated function of the abdominal and back muscles. For peak abdominal and back extensor strength, the range of superiority of men over women was 39-57%, and the range of superiority of normals over patients with chronic low-back dysfunction was 48-82%. Using time to percent decrement of peak strength as a criterion, the abdominals were more susceptible to fatigue than the back extensors, women demonstrated more endurance than men, and the endurance for normals was less than those patients who were able to perform dynamic reciprocal trunk movements.

Psychological test findings on pathological gamblers in treatment.

A sample of 23 veterans entering the Pathological Gambling Treatment Program at the Veterans Administration Medical Center in Miami, Florida, were administered a battery of tests including the following: Wechsler Adult Intelligence Scale (WAIS), Minnesota Multiphasic Personality Inventory (MMPI), Edwards Personal Preference Schedule (EPPS), and the Personal Orientation Inventory (POI). Findings on the intelligence testing indicated that on the average the pathological gamblers were of bright normal intelligence with a mean WAIS Full Scale IQ of 116.78, mean Verbal IQ of 119.30, and a mean Performance IQ of 111.30. Group profile results on the MMPI showed significant mean clinical scale elevations on two of the nine clinical scales: Scale 2, Depression; and Scale 4, Psychopathic Deviate. Group profile results on the EPPS indicated relatively high scores on the variables of achievement, exhibition, autonomy, dominance, and heterosexuality; and relatively low scores on the variables of deference, order, and endurance. Group profile results on the POI were essentially within normal limits with a tendency toward time incompetency noted, suggesting difficulty living fully in the present here and now.

Individual differences in coalitional behavior.

Individual differences in coalitional behavior were investigated in an experimental setting. Variables representing the choice of partner and bargaining on payoff were correlated with one another and with some personality variables. The findings indicate that partner power preference is significantly related to initial bargaining demands and bargaining endurance. The bargaining variables of initial demands, final demands, concessions, and endurance were found to be significantly related to one another. The findings indicate that the personality variable of external control is significantly related to partner power preference and bargaining concessions. The results suggest that differences in coalitional behavior that occur independently of situational variation have a significant systematic component. The findings indicate that an analysis of these differences could enhance prediction of coalitional behavior. Prediction linkages between variables are proposed.

Effects of Time, Endurance, and Scoring Variables on Tennis Results

Abstract Comparisons were made between match results using the traditional method of scoring tennis matches and match results using the Van Alen Simplified Scoring System (VASSS). Fourteen players from the Florida State University tennis team and 14 students from an intermediate tennis class at the Florida State University participated in the study. Each group of subjects, advanced and intermediate, played two separate round robin tournaments, one using traditional scoring and the other using VASSS. There was no significant difference between the mean match times of the two scoring systems. The variability of match times in the traditional method, however, was significantly greater than the variability of match times in the VASSS method at both ability levels. The same relationship held true for the mean number of points played per match except for a significant difference between the mean number of points played per match at the advanced level. Internal consistency within each tournament was above 90% in...