Triathlon event distance specialization: training and injury effects.

We conducted a preliminary, questionnaire-based, retrospective analysis of training and injury in British National Squad Olympic distance (OD) and Ironman distance (IR) triathletes. The main outcome measures were training duration and training frequency and injury frequency and severity. The number of overuse injuries sustained over a 5-year period did not differ between OD and IR. However, the proportions of OD and IR athletes who were affected by injury to particular anatomical sites differed (p < 0.05). Also, fewer OD athletes (16.7 vs. 36.8%, p < 0.05) reported that their injury recurred. Although OD sustained fewer running injuries than IR (1.6 +/- 0.5 vs. 1.9 +/- 0.3, p < 0.05), more subsequently stopped running (41.7 vs. 15.8%) and for longer (33.5 +/- 43.0 vs. 16.7 +/- 16.6 days, p < 0.01). In OD, the number of overuse injuries sustained inversely correlated with percentage training time, and number of sessions, doing bike hill repetitions (r = -0.44 and -0.39, respectively, both p < 0.05). The IR overuse injury number correlated with the amount of intensive sessions done (r = 0.67, p < 0.01 and r = 0.56, p < 0.05 for duration of "speed run" and "speed bike" sessions). Coaches should note that training differences between triathletes who specialize in OD or IR competition may lead to their exhibiting differential risk for injury to specific anatomical sites. It is also important to note that cycle and run training may have a "cumulative stress" influence on injury risk. Therefore, the tendency of some triathletes to modify rather than stop training when injured-usually by increasing load in another discipline from that in which the injury first occurred-may increase both their risk of injury recurrence and time to full rehabilitation.

A tutorial review of electrical neuroimaging from group-average to single-trial event-related potentials.

This tutorial review details some of the recent advances in signal analyses applied to event-related potential (ERP) data. These "electrical neuroimaging" analyses provide reference-independent measurements of response strength and response topography that circumvent statistical and interpretational caveats of canonical ERP analysis methods while also taking advantage of the greater information provided by high-density electrode montages. Electrical neuroimaging can be applied across scales ranging from group-averaged ERPs to single-subject and single-trial datasets. We illustrate these methods with a tutorial dataset and place particular emphasis on their suitability for studies of clinical and/or developmental populations.

Early, low-level auditory-somatosensory multisensory interactions impact reaction time speed.

Several lines of research have documented early-latency non-linear response interactions between audition and touch in humans and non-human primates. That these effects have been obtained under anesthesia, passive stimulation, as well as speeded reaction time tasks would suggest that some multisensory effects are not directly influencing behavioral outcome. We investigated whether the initial non-linear neural response interactions have a direct bearing on the speed of reaction times. Electrical neuroimaging analyses were applied to event-related potentials in response to auditory, somatosensory, or simultaneous auditory-somatosensory multisensory stimulation that were in turn averaged according to trials leading to fast and slow reaction times (using a median split of individual subject data for each experimental condition). Responses to multisensory stimulus pairs were contrasted with each unisensory response as well as summed responses from the constituent unisensory conditions. Behavioral analyses indicated that neural response interactions were only implicated in the case of trials producing fast reaction times, as evidenced by facilitation in excess of probability summation. In agreement, supra-additive non-linear neural response interactions between multisensory and the sum of the constituent unisensory stimuli were evident over the 40-84 ms post-stimulus period only when reaction times were fast, whereas subsequent effects (86-128 ms) were observed independently of reaction time speed. Distributed source estimations further revealed that these earlier effects followed from supra-additive modulation of activity within posterior superior temporal cortices. These results indicate the behavioral relevance of early multisensory phenomena.

The Classification of Vitreous Seeds in Retinoblastoma and Response to Intravitreal Melphalan.

PURPOSE: To evaluate the clinical characteristics of the 3 classifications of vitreous seeds in retinoblastoma-dust (class 1), spheres (class 2), and clouds (class 3)-and their responses to intravitreal melphalan. DESIGN: Retrospective, bi-institutional cohort study. PARTICIPANTS: A total of 87 patient eyes received 475 intravitreal injections of melphalan (median dose, 30 μg) given weekly, a median of 5 times (range, 1-12 times). METHODS: At presentation, the vitreous seeds were classified into 3 groups: dust, spheres, and clouds. Indirect ophthalmoscopy, fundus photography, ultrasonography, and ultrasonic biomicroscopy were used to evaluate clinical response to weekly intravitreal melphalan injections and time to regression of vitreous seeds. Kaplan-Meier estimates of time to regression and ocular survival, patient survival, and event-free survival (EFS) were calculated and then compared using the Mantel-Cox test of curve. MAIN OUTCOME MEASURES: Time to regression of vitreous seeds, patient survival, ocular survival, and EFS. RESULTS: The difference in time to regression was significantly different for the 3 seed classes (P < 0.0001): the median time to regression was 0.6, 1.7, and 7.7 months for dust, spheres, and clouds, respectively. Eyes with dust received significantly fewer injections and a lower median and cumulative dose of melphalan, whereas eyes with clouds received significantly more injections and a higher median and cumulative dose of melphalan. Overall, the 2-year Kaplan-Meier estimates for ocular survival, patient survival, and EFS (related to target seeds) were 90.4% (95% confidence interval [CI], 79.7-95.6), 100%, and 98.5% (95% CI, 90-99.7), respectively. CONCLUSIONS: The regression and response of vitreous seeds to intravitreal melphalan are different for each seed classification. The vitreous seed classification can be predictive of time to regression, number, median dose, and cumulative dose of intravitreal melphalan injections required.