A two-dimensional analysis of limb symmetry in the trot of Labrador retrievers.

Sixteen sound Labrador retriever and Labrador retriever cross-breed adult dogs were evaluated for symmetry while in a trot gait using a two-dimensional motion analysis system. Reflective markers were placed at selected joint centers. Each dog had the right side and then the left side videotaped while in the trot gait. The markers on the videotape were then digitized for analysis. There was no significant difference (p less than 0.05) between the movements of the two sides. It was concluded that the trot gait is symmetrical and that a two-dimensional system can be used to analyze gait in the dog.

Acute L-glutamine ingestion does not improve maximal effort exercise.

BACKGROUND: L-glutamine (GLN) may have an ergogenic effect during exercise considering its base generating potential. We attempted to determine whether GLN ingestion influences acid-base balance and improves high intensity exercise performance. METHOD: Ten trained males performed five exercise bouts on a cycle ergometer at 100% of VO2 peak. The first four bouts were 60 sec in duration, while the fifth bout was continued to fatigue. Each bout was separated by 60 sec of recovery. The exercise bouts were initiated 90 min after ingesting 0.03 g.kg body mass-1 of either GLN or placebo (PLC). Venous blood samples were collected pre-ingestion (PRE-IN), pre-exercise (PRE-EX), and following bouts four (B4) and five (B5) and analyzed for pH, bicarbonate concentration (HCO3), and lactate concentration (La-). Time to fatigue for B5 was used as a performance measure. RESULTS: pH, [HCO3], and [La-] were not significantly different (p > 0.05) between conditions for PRE-IN, PRE-EX, B4, and B5. Time to fatigue was not significantly different between conditions and averaged 263.4 +/- 24.5 sec and 263.2 +/- 19.4 sec for the GLN and PLC trials, respectively. CONCLUSIONS: These data indicate that acute ingestion of L-glutamine does not enhance either buffering potential or high intensity exercise performance in trained males.

Metabolic and biomechanical variables of two incline conditions during distance running.

The purpose of this experiment was to examine the effects of an incline during distance running on selected metabolic and biomechanical variables. Six (4 males, 2 females) trained distance runners (age 27.2 +/- 7.8 yr; VO2max 63.7 +/- 7.5 mL x kg-1 x min-1) performed three 35-min runs at speeds corresponding to each individual's anaerobic threshold. The first run (Control) was performed at 0% grade. The remaining two runs were randomly assigned and included a 5% incline during min 5-15 (Run A) or 20-30 (Run B). Heart rate via telemetry (HR), and oxygen consumption (VO2), minute ventilation (VE), RER, and tidal volume (TV) were measured by indirect calorimetry. High speed videography was used to measure time in support phase, time in swing phase, step length, trunk lean, vertical oscillation of the hip, knee flexion in support, shank angle during toe-off, and ankle flexion at heel strike during the runs. Significant increases (P < or = 0.05) were found during the incline conditions of Run A for VO2 (+18%) HR (+11%), VE (+24%), and RER (+8%) and Run B for VO2 (+19%) HR (+10%), and VE (+25%) compared with the Control. No significant differences (P > 0.05) were noted between Run A and Run B during incline running in the physiological variables. No significant differences (P > 0.05) were observed in any of the biomechanical variables among the runs. These data indicate that the energy expenditure required during incline running is the same regardless of incline location during a 35-min run, and running mechanics are not significantly altered during a 5% incline lasting 10 min. In addition, following a 5% incline for 10 min, runners experience no significant physiological or biomechanical changes during subsequent level running at anaerobic threshold pace.

Prevention of injuries in excessive pronators through proper soccer shoe fit.

OBJECTIVE: Properly fitting shoes are important in the prevention of injuries. When it involves the lower extremity and pronation, proper fitting of shoes is considered as a treatment for gender variations in shoe fit and excessive pronators. The purpose of the study therefore, is to compare static and dynamic foot tracings in excessive pronators to determine if there were differences between right and left feet of male and female soccer athletes. DESIGN AND SETTING: Multivariate analysis with static and dynamic foot tracing measurements of foot length, first metatarsal length, fifth metatarsal length, metatarsal width, and heel width as the dependent variables and male and female (gender) as the effect. Interscholastic soccer players who were excessive pronators were used in the study. SUBJECTS: Volunteers were solicited from a boys and girls interscholastic soccer team (level C to varsity). From this pool of 40 subjects, a group of 20 (10 males and 10 females, n = 40 feet), with excessive pronation were used in the study. Criteria for selection was based on navicular height (? 10 mm) and arch index (? .26). MEASUREMENTS: Static and dynamic foot tracings were determined. From these tracings, foot length, first metatarsal length, fifth metatarsal length, metatarsal width, and heel width were determined. Multivariate analysis of variance (MANOVA; p < .05), one-way repeated measures analysis of variance (ANOVA; p < .05), and pairwise comparisons (p < .05) were performed to determine significance, as well as intraclass correlation coefficients for intraclass reliability of the measurements. RESULTS: For between genders, male foot tracings for static and dynamic right and/or left feet were statistically greater in all foot parameters except heel width. Comparison of same side static and dynamic measurements for the right or left foot indicated differences for foot length, metatarsal width, and heel width for males, and foot length, fifth metatarsal width, metatarsal width, and heel width for females. There were no significant differences between static and dynamic foot measurements for either foot between genders and within genders. CONCLUSIONS: Foot length should not be the only consideration used for determining proper shoe fit. Static and dynamic measurements for the right or left foot, as well as metatarsal width, fifth metatarsal length, and heel width should also be included.

Musculoskeletal injuries in a college-age population during a 1-semester term.

The authors' retrospective survey assessed the incidence and causes of sport- and exercise-related injuries in college students participating in intramural, recreational, and club sports. For their survey, they examined clinical screening forms and medical charts of 300 students (160 men and 140 women) to determine the type of injury, the body part affected, loading behavior of tissues involved, and mechanism of the injuries. Sprains resulting from tensile forces accounted for most of the injuries, with the knee the most frequently injured body part. The occurrence of injuries was equally divided between injuries from overuse, caused primarily by improper body mechanics, and acute injuries resulting from collisions with the ground or floor or from falls. The study suggests a need for programs in sport-injury prevention for college students.

Physiological and psychological correlates of success in track and field athletes.

Twenty-four collegiate distance runners and 20 power athletes (sprinters and jumpers) of various success levels were tested on a number of physiological and psychological parameters. Multiple regression analysis indicated that physiological factors could explain over 81% of the variance related to successful distance running while physiological and psychological factors could explain over 80% of the of the variance related to successful sprinting and jumping. Body weight, fibre type, low density lipoprotein-cholesterol, and hamstring strength were significant singular correlates to successful distance running. Year in school, percent body fat, quadriceps strength, and leg muscle balance were significant single correlates to successful sprinting and jumping performance.