BACKGROUND: Greater neck strength and activating the neck muscles to brace for impact are both thought to reduce an athlete's risk of concussion during a collision by attenuating the head's kinematic response after impact. However, the literature reporting the neck's role in controlling postimpact head kinematics is mixed. Furthermore, these relationships have not been examined in the coronal or transverse planes or in pediatric athletes. HYPOTHESES: In each anatomic plane, peak linear velocity (ΔV) and peak angular velocity (Δω) of the head are inversely related to maximal isometric cervical muscle strength in the opposing direction (H1). Under impulsive loading, ΔV and Δω will be decreased during anticipatory cervical muscle activation compared with the baseline state (H2). STUDY DESIGN: Descriptive laboratory study. METHODS: Maximum isometric neck strength was measured in each anatomic plane in 46 male and female contact sport athletes aged 8 to 30 years. A loading apparatus applied impulsive test forces to athletes' heads in flexion, extension, lateral flexion, and axial rotation during baseline and anticipatory cervical muscle activation conditions. Multivariate linear mixed models were used to determine the effects of neck strength and cervical muscle activation on head ΔV and Δω. RESULTS: Greater isometric neck strength and anticipatory activation were independently associated with decreased head ΔV and Δω after impulsive loading across all planes of motion (all P < .001). Inverse relationships between neck strength and head ΔV and Δω presented moderately strong effect sizes (r = 0.417 to r = 0.657), varying by direction of motion and cervical muscle activation. CONCLUSION: In male and female athletes across the age spectrum, greater neck strength and anticipatory cervical muscle activation ("bracing for impact") can reduce the magnitude of the head's kinematic response. Future studies should determine whether neck strength contributes to the observed sex and age group differences in concussion incidence. CLINICAL RELEVANCE: Neck strength and impact anticipation are 2 potentially modifiable risk factors for concussion. Interventions aimed at increasing athletes' neck strength and reducing unanticipated impacts may decrease the risk of concussion associated with sport participation.
BACKGROUND: Greater neck strength and activating the neck muscles to brace for impact are both thought to reduce an athlete's risk of concussion during a collision by attenuating the head's kinematic response after impact. However, the literature reporting the neck's role in controlling postimpact head kinematics is mixed. Furthermore, these relationships have not been examined in the coronal or transverse planes or in pediatric athletes. HYPOTHESES: In each anatomic plane, peak linear velocity (ΔV) and peak angular velocity (Δω) of the head are inversely related to maximal isometric cervical muscle strength in the opposing direction (H1). Under impulsive loading, ΔV and Δω will be decreased during anticipatory cervical muscle activation compared with the baseline state (H2). STUDY DESIGN: Descriptive laboratory study. METHODS: Maximum isometric neck strength was measured in each anatomic plane in 46 male and female contact sport athletes aged 8 to 30 years. A loading apparatus applied impulsive test forces to athletes' heads in flexion, extension, lateral flexion, and axial rotation during baseline and anticipatory cervical muscle activation conditions. Multivariate linear mixed models were used to determine the effects of neck strength and cervical muscle activation on head ΔV and Δω. RESULTS: Greater isometric neck strength and anticipatory activation were independently associated with decreased head ΔV and Δω after impulsive loading across all planes of motion (all P < .001). Inverse relationships between neck strength and head ΔV and Δω presented moderately strong effect sizes (r = 0.417 to r = 0.657), varying by direction of motion and cervical muscle activation. CONCLUSION: In male and female athletes across the age spectrum, greater neck strength and anticipatory cervical muscle activation ("bracing for impact") can reduce the magnitude of the head's kinematic response. Future studies should determine whether neck strength contributes to the observed sex and age group differences in concussion incidence. CLINICAL RELEVANCE: Neck strength and impact anticipation are 2 potentially modifiable risk factors for concussion. Interventions aimed at increasing athletes' neck strength and reducing unanticipated impacts may decrease the risk of concussion associated with sport participation.
Entities:
Keywords:
head injuries/concussion; head kinematics; injury biomechanics; neck muscle activation; neck strength
Authors: P Gunnar Brolinson; Sarah Manoogian; David McNeely; Mike Goforth; Richard Greenwald; Stefan Duma Journal: Curr Sports Med Rep Date: 2006-02 Impact factor: 1.733
Authors: Jason P Mihalik; Kevin M Guskiewicz; Stephen W Marshall; Richard M Greenwald; J Troy Blackburn; Robert C Cantu Journal: Clin J Sport Med Date: 2011-09 Impact factor: 3.638
Authors: Andrée-Anne Ledoux; Ken Tang; Keith O Yeates; Martin V Pusic; Kathy Boutis; William R Craig; Jocelyn Gravel; Stephen B Freedman; Isabelle Gagnon; Gerard A Gioia; Martin H Osmond; Roger L Zemek Journal: JAMA Pediatr Date: 2019-01-07 Impact factor: 16.193
Authors: Calvin Kuo; Jodie Sheffels; Michael Fanton; Ina Bianca Yu; Rosa Hamalainen; David Camarillo Journal: J R Soc Interface Date: 2019-05-29 Impact factor: 4.118
Authors: James T Eckner; Alireza Goshtasbi; Kayla Curtis; Aliaksandra Kapshai; Erik Myyra; Lea M Franco; Michael Favre; Jon A Jacobson; James A Ashton-Miller Journal: Am J Phys Med Rehabil Date: 2018-04 Impact factor: 2.159