Effect Of Age Category Research Articles

The impact of menopausal status on auditory brainstem responses

ObjectiveTo determine the effect of decreased estrogen levels due to menopause on auditory brainstem response measurements (ABR). Study designRetrospective chart review. SettingAcademic. PatientsPre- and post-menopausal females (pre-M, post-M) and age-matched males. MethodsABR measurements of wave I, III, and V latencies, and interpeak latencies; amplitudes of waves I, III, V, and V/I ratio. Outcome measureDifferences in ABR measurements between pre-M and post-M. Results164 subjects (101 female and 64 male) were included. Post-M had significantly greater latencies (msec) than pre-M of wave V. Post-M had a significantly smaller wave I amplitude (uV) than pre-M. Post-M had a significantly higher wave V/I amplitude ratio than pre-M. Pre-M had significantly shorter latencies than young males for wave III, and wave V. Post-M had significantly shorter latencies than older males at wave III, and wave V. A two-way ANOVA revealed a significant interaction between the effects of age category and gender on V/I amplitude. ConclusionPost-M group showed a significant drop in wave I amplitude compared with pre-M group, even in the absence of hearing loss, suggesting that the gender differences in hearing are related to estrogen signaling along the auditory pathway. If wave I amplitude changes between older and younger groups resulted from decreased peripheral hearing sensitivity, we would expect larger drops in amplitude in males since rates of presbycusis are higher. We observed much larger drops in wave I amplitude in females, which cannot be attributed to peripheral hearing loss. These results may assist in understanding gender differences in presbycusis and a possible protective effect of estrogen on the auditory system. Knowledge of gender differences in wave I may be important when ABR is used to assess possible synaptopathy.

Technical skills in complex tennis situations: Dutch talented players U15 compared to players U17.

Technical skills in complex situations appear crucial for progress towards elite tennis performance. However, it is unknown how these skills develop in different age categories in a group of talented youth players. The aim of this study is to evaluate possible differences in technical skills among Dutch talented youth tennis players U15 compared to U17. A total of 19 players (12 males, 7 females; age 14.6 ± 1.4 years) were tested on ball speed, accuracy, percentage errors and spin rate using the on-court Dutch Technical-Tactical Tennis Test. With a ball machine, four games were simulated which were either fixed (game 1 and game 2) or variable (game 3 and game 4), depending on the complexity of the task. Each game consisted of two offensive, two neutral and two defensive rallies, representing different tactical situations. A two-way ANOVA revealed a statistically significant interaction between the effects of age category and sex for ball speed (F(1,15) = 5.472, p = 0.034, η 2 = 0.267), indicating that males U17 produced higher ball speed compared to males U15, whereas no differences were found between females U15 and U17. A one-way ANCOVA showed that, regardless of sex, players U17 scored significantly higher on accuracy than players U15 (F(1,16) = 5.021, p = 0.040, η 2 = 0.239). No differences were found between players U15 and U17 for spin rate and percentage errors (p > .05), although there was a medium to large effect size for males U17 to produce higher spin rates compared to males U15. A closer examination of accuracy revealed that players U17 scored significantly higher compared to players U15 in game 4 (F(1,17) = 6.358, p = .022, η 2 = .272) and in defensive situations (F(1,17) = 9.602, p = .007, η 2 = .361). In conclusion, the results of the current study suggest that technical skills, especially ball speed for males and accuracy in complex situations for both males and females, continue to develop in adolescence in talented tennis players. There is an increased understanding about underlying technical skills that contribute to progress towards elite tennis performance. To effectively develop technical skills, coaches are encouraged to design specific practices where these skills are performed in complex situations under high cognitive and temporal pressure.

Bilateral Strength Asymmetry in Elite Youth Soccer Players: Differences between Age Categories

The strength asymmetry of athletes as a negative health and performance factor is increasingly being researched in sports with a high load on the dominant limb when some specific unilateral movements, such as passing, jumping, and tackling, are required. This study aimed to determine the level of isokinetic strength bilateral asymmetry (BA) among knee extensors (KEs) and knee flexors (KFs) of elite youth soccer players. The sample (n = 87) consisted of three age categories of under 13 (U13), under 15 (U15), and under 17 (U17) years old. Isokinetic dynamometry was used to obtain the maximum peak torque of the KEs and KFs in the dominant and non-dominant lower limbs during concentric muscle contraction. The analysis revealed significantly lower values (p < 0.05) of BA in KEs in U17 than in younger categories, U13 and U15, and higher values (p < 0.05) of BA in KFs in the U15 category than in the U17category. The majority of the players in the U15 category (68%) reached KFs BA higher than 10% in comparison with U13 players (50%) and U17 players (28% of players) (p < 0.05). Our results showed a significant effect of age category on BA levels in young soccer players. High incidences of increased BA in the lower limbs occurred in the younger categories (U13, U15) and subsequently decreased in the later adolescent stages.

Anthropometric, physiological characteristics and rugby-specific game skills of schoolboy players of different age categories and playing standards

BackgroundRugby is increasingly gaining popularity among school-aged male junior players in countries hardly known for dominating international rugby, such as Zimbabwe. Given rugby combativeness, participating adolescents should possess qualities or skills commensurate with the physical demands of the sport for effective participation. This study investigated the independent and interactive effects of age category and playing standard on anthropometric, physiological characteristics and rugby-specific game skills among Zimbabwean athletes.MethodsTwo hundred and eight elite, sub-elite and non-rugby players competing at Under 16 and Under 19 age categories were assessed using the School Clinical Rugby Measure (SCRuM) test battery. Participants underwent height, sitting height, mass, skinfolds, speed, agility, upper-and-lower muscular strength and power, prolonged high-intensity intermittent running ability, tackling, passing and catching assessments in a cross-sectional experimental design.ResultsAge categories had significant main effect on all SCRuM test items except sum of seven skinfolds (p = 0.45, η2p = 0.003). Playing standard had significant main effects for all variables except height (p = 0.40, η2p = 0.01) and sum of seven skinfolds (p = 0.11, η2p = 0.02). Specifically, upper-and-lower muscular strength and power, prolonged high-intensity intermittent running ability, tackling, passing and catching improved with increasing playing standards. However, two-way analysis of variance only demonstrated significant interactions between the effects of age category and playing standards for vertical jump height (VJ) test, 2-kg medicine ball chest throw (2-kg MBCT) test, Yo-Yo intermittent recovery test level 1 (Yo-Yo IRT L1), and tackling and catching tests. Yo-Yo IRT L1, VJ, tackling and catching tests demonstrated greater discriminative ability among Under 16 s, whereas the 2-kg MBCT test showed better ability in Under 19 s.ConclusionAll SCRuM variables except skinfolds improved with age, highlighting relative sensitivity in differentiating older from younger athletes. However, the discriminative ability by playing standards for VJ, 2-kg MBCT, Yo-Yo IRT L1, tackling and catching ability tests was age-dependent. These findings informs on general attribute development in junior rugby players with age and on specific players attributes in need of monitoring for attainment of elite status at U16 or U19 level.

Measurement of Prevertebral Cervical Soft Tissue Thickness on Lateral Digital Radiographs

Widening of the prevertebral soft tissues is one of several significant indirect signs of cervical spine trauma. This paper provides pediatric radiographic reference measurements for prevertebral soft tissues at C2 and C6, and for the ratio of soft tissue to vertebral width at C6. We reviewed 327 radiographs of consecutive patients under 14 years of age presenting at a trauma unit and obtained the relevant measurements using a software tool. Patients included in the study had no clinical features of cervical spine injury. Interobserver reliability of the measurements was assessed using the intraclass correlation coefficient of reliability. The effect of age category on the measurements was tested. Interobserver reliability was high for all measurements. The mean soft tissue width at C6 was significantly different across 3 age categories, whereas there was no significant difference for the soft tissue at C2 or the C6 ratio. The highest C2 soft tissue measurement was 10.6 mm, whereas the mean was 4.3 mm. The highest ratio at C6 was 1.2, with a mean ratio of 0.69. We present prevertebral soft tissue measurements from a larger sample of subjects than published previously, which allows our values to be used with more confidence as a tool in screening for cervical spine injury.

The inclusion of adult vehicle occupants in matched cohort studies of child restraint effectiveness: a study of potential bias

ObjectiveTo determine whether either the inclusion of adults in matched cohort studies of passenger vehicle occupants or modification of age effects by collision severity biases child restraint risk ratios biases...

Transurethral prostatectomy: Differential effects of age category and presurgery sexual functioning on postprostatectomy sexual adjustment

Sexual functioning and adjustment of 72 aging married males who had undergone transurethral prostatectomy were examined retrospectively according to their pre- and postsurgery status. Results indicate that although transurethral prostatectomy was generally associated with deterioration in various aspects of sexual expression, grouping subjects according to age and presurgery sexual adjustment qualified these general findings dramatically. For example, more younger than older males retained or attained good sexual adjustment after surgery. Furthermore, while older males with good presurgery sexual adjustment maintained good couple sexual functioning, they manifested greater loss of sexual self-confidence and individual sexual capacity than did their younger counterparts. In addition, the findings suggest that the question "Does transurethral prostatectomy affect sexual function?" must be rephrased to take into account changes in the cognitive, capacity, and affective domains as well as in the couple behavior and adjustment dimensions of sexual expression.