Training neck muscles in such a way as to improve responsiveness to head acceleration forces, and to help prevent concussion and/or screen subjects who are at high risk of concussion, especially from contact sports, the neck muscles may be trained to improve strength and responsiveness to head acceleration. This may be accomplished by a device and/or method of training that incorporates an adjustable centripetal force about a fixed axis on the head. The centripetal force may be adjusted through varying the weight and/or length of a force arm. Neck muscle performance may be measured by the number of revolutions of the force arm completed over a pre-determined time period or the time required to complete a pre-determined number of revolutions of the force arm.