ABSTRACT
The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90 degrees to 60 degrees , 60 degrees to 30 degrees , and 30 degrees to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception.
ABSTRACT
This study examined the effects of aspartate supplementation (ASP) on plasma ammonia concentrations ([NH4+]) during and after a resistance training workout (RTW). Twelve male weight trainers were randomly administered ASP or vitamin C in a crossover, double blind protocol, each trial separated by 1 wk. ASP and vitamin C were given over a 2-hr period beginning 5 hr prior to the RTW. The RTW consisted of bench, incline, shoulder, and triceps presses, and biceps curls at 70% of one repetition maximum (1-RM). After the RTW a bench press test (BPT) to failure at 65% of 1-RM was used to assess performance. [NH4+] was determined preexercise, 20 and 40 min midworkout, immediately postexercise, and 15 min postexercise. Treatment-by-time ANOVAs, paired t tests, and contrast comparisons were used to identify mean differences. No significant differences were observed between treatments for [NH4+] or BPT. [NH4+] increased significantly from Pre to immediately postexercise for both the ASP and vitamin C trials. Acute ASP supplementation does not reduce [NH4+] during and after a high intensity RTW in weight trained subjects.
Subject(s)
Ammonia/blood , Exercise/physiology , Potassium Magnesium Aspartate/pharmacology , Adolescent , Adult , Analysis of Variance , Ascorbic Acid/administration & dosage , Ascorbic Acid/pharmacology , Cross-Over Studies , Double-Blind Method , Food, Fortified , Humans , Lactates/blood , Male , Potassium Magnesium Aspartate/administration & dosageABSTRACT
Underlying mechanisms of prepubescent strength gains following resistance training are speculative. The purpose of this investigation was to determine the effects of 8 wk of resistance training on muscular strength, integrated EMG amplitude (IEMG), and arm anthropometrics of prepubescent youth. Sixteen subjects (8 males, 8 females) were randomly assigned to trained or control groups. All subjects (mean age = 10.3 yr) were of prepubertal status according to the criteria of Tanner. The trained group performed three sets (7-11 repetitions) of bicep curls with dumbbells three times per week for 8 wk. Pre- and posttraining measurements included isotonic and isokinetic strength of the elbow flexors, arm anthropometrics, and IEMG of the biceps brachii. Planned comparisons for a 2 x 2 (group by test) ANOVA model were used for data analysis. Significant isotonic (22.6%) and isokinetic (27.8%) strength gains were observed in the trained group without corresponding changes in arm circumference or skinfolds. The IEMG amplitude increased 16.8% (P < 0.05). The control group did not demonstrate any significant changes in the parameters measured. Early gains in muscular strength resulting from resistance training prepubescent children may be attributed to increased muscle activation.
Subject(s)
Adaptation, Physiological , Muscle Contraction/physiology , Muscles/physiology , Neuromuscular Junction/physiology , Weight Lifting/physiology , Anthropometry , Arm , Child , Elbow , Electromyography , Female , Humans , Isotonic Contraction/physiology , Male , Muscles/anatomy & histology , Muscles/innervation , Physical Education and Training , Puberty , Skinfold ThicknessABSTRACT
A generalizability study was conducted to determine the percentage of variance associated with observers and trials when assessing movement control in children with mild mental retardation. One group of observers received competency-based training and another group experienced informal training. A series of decision studies employing the variance component estimates indicated that different conditions of observation need to be employed based on the type of training received in movement control analysis. Observers receiving informal training needed to observe twice as many trials of the kick, jump, and overband throw compared to competency-trained observers to reach an acceptable level of reliability.
Subject(s)
Competency-Based Education , Curriculum , Intellectual Disability/diagnosis , Motor Skills , Adolescent , Child , Child, Preschool , Generalization, Psychological , Humans , Physical Education and TrainingABSTRACT
This study investigated the influence of catch trial (CT) occurrence and foreperiod variation on reaction time and movement time of children of different ages. 48 children were randomly assigned to a CT group or a no-CT group. All received randomly ordered foreperiods. The presence of CTs and varying foreperiods played an inhibitory role in the motor performance of children.
