Profiling of translational and rotational head accelerations in youth BMX with and without neck brace

Abstract

1Objectives 2 To investigate the influence of BMX helmets and neck braces on translational and 3 rotational accelerations in youth riders. 4 Design 5Mixed model, repeated measure and correlation. 6 Methods 7Twenty three competitive youth BMX riders classified by age group (6-9 yrs, 10-13 yrs 8 and 14-18 yrs) completed 6 laps of an indoor BMX track at race pace, 3 laps without a 9 neck brace (NB) and 3 without brace (WB). A triaxial accelerometer with gyroscope was 10 placed behind the right ear to determine the mean number of accelerations, translational 11 and rotational, of the head between conditions and by age group. 12 Results 13Significant reductions by condition (p = 0.02) and by age (p = 0.04) were found for the 14 number of accelerations, though no interactions (condition x age) were revealed. 15Significant increases by age (p = 0.01) were revealed for translational accelerations, whilst 16 significant increases by condition (p = 0.02) were found for rotational accelerations. In 17 addition, significant correlations were revealed between relative helmet mass and age (r 18 = 0.83; p 0.001) and relative helmet mass and number of accelerations (r = 0.46; p = 0.03). 19 Conclusions 20Accelerations at the head decreased with increased age, possibly due to the influence of 21 greater stabilising musculature. Additionally, neck braces also significantly reduced the 22 number of accelerations. However, the magnitude of accelerations may be influenced by 23 riding dynamics. Therefore, the use of neck braces combined with strength work to 24 2 develop neck strength, could aid in the reduction of head accelerations in youth BMX 25 riders. 26 27

The magnitude of translational and rotational head accelerations experienced by riders during downhill mountain biking

“…However, as with BMX, mean peak translational loads were greater than those reported for contact sports 10,11,18,[26][27][28] . Though maximum peak translational loads were not reported for BMX 9 , the present study found these to average ~80 g over the two course, with individual values being recorded up to the 160 g cut off. Whilst the majority of translational accelerations were sub-concussive (10-20 g), 2.3 % of all accelerations recorded were above the reversible threshold for brain injuries 16 .…”

“…displacements of the head following impulsive neck loads 29 . This is further supported by data from youth BMX riders, which found that those in the eldest of the youth groups were generally had greater neck musculature, resulting in reduced neck loads 30 . This might be the case for Senior and Masters rider, who potentially spend less time on muscular conditioning.…”

“…However, DHI values were almost double those reported for BMX when not using a protective neck brace. However, they were comparable to BMX when BMX A C C E P T E D M A N U S C R I P T riders wore neck braces 9 . This again, may be a result of course demands and the tighter radius corners DHI riders have to negotiate compared to BMX.…”

“…The magnitude of head accelerations resulting from trail vibrations has not yet been established. However, research on head accelerations in youth BMX riders between 6-18 years of age found mean rotational loads were between 1440.7 and 1951.8 rads/s 2 , whilst mean peak translational load was between 23.2 and 29.6 g across the age ranges 9 . Individual peak translational loads between 70 and 133 g and…”

Miedo y depresión en la práctica del BMX en jóvenes deportistas de la liga Tunja-Boyacá, Colombia

“…La salud es un tema controversial que interesa a distintas áreas del conocimiento, por lo que este estudio quiso conocer estados del ánimo de sujetos que se enfrentan a potenciales presiones deportivas y que por ende pueden ser vulnerables a desarrollar algún tipo de trastorno, razón por la cual es fundamental conocer el riesgo al que se enfrentan los jóvenes en cuanto a la presencia de la depresión como un trastorno que afecta significativamente la vida del sujeto(Bohórquez, Delgado, & Fernández, 2017).Investigaciones como las de Stucchi(2017), logran demostrar al igual que este estudio que la depresión ha aumentado los últimos años convirtiéndose en una patología juzgada como normal, algunos criterios puestos en evidencia en los corredores del BMX pueden ser alerta para prevenir un suicidio, por ejemplo. Sin embargo, se han venido ignorando a favor de un incremento de tendencia actual(Hurst, et al, 2018).En cuanto a las limitaciones del estudio, se encontró que el número de personas que pertenecen al grupo de corredores de la liga de Tunja de BMX es muy baja, por lo tanto, la muestra es un poco escasa. Sin embargo, se considera la totalidad para la región en cuanto a la práctica oficial del deporte en cuestión.…”