Background The long-term effect of repeated head impacts during purposeful heading in football is largely unknown. However, evidence suggests that head acceleration during purposeful heading may be reduced by players having strong neck musculature.

Objective To investigate the relationship between neck strength and head acceleration during purposeful heading in football.

Design This systematic review included a comprehensive search of five electronic databases: EMBASE, MEDLINE, CINAHL, SportsDiscus and Web of Science.

Setting All competitive levels of football regardless of setting (high school, football club or academy) were included.

Patients (or Participants) All football players regardless of age, sex, health status or playing level were included.

Interventions (or Assessment of Risk Factors) Only original research reporting on the relationship between neck strength and head acceleration during purposeful heading in football were included. For experimental research designs, studies were included if neck strengthening was the intervention of interest.

Main Outcome Measurements Neck strength measurement using hand-held dynamometry and head acceleration captured during purposeful heading using accelerometry or video analysis.

Results From an initial search of 1174 potentially eligible papers, five cross-sectional studies met the eligibility criteria for inclusion in this review. A total of 190 participants (67% Female) with a mean age of 19 years (range 15–24 years) were recruited across the five studies. Playing level ranged from high school football to division I and II collegiate level. Evidence from four level IV studies supported a statistically significant relationship between higher neck strength and lower head acceleration during purposeful heading in football (p=<0.05; r<-0.5). The fifth study showed a weak association (r=-0.10).

Conclusions Data available from cross-sectional research supports that higher neck strength may lower head acceleration during purposeful heading in football. Further evidence is required to determine the most effective method to strengthen the neck musculature in football players and the impact this may have on the long-term health of players.