Sex Differences in Multidirectional Neck Muscle Strength Characteristics in High School Soccer Athletes

Abstract

Weaker neck strength has been suggested as a potential risk factor of sport related concussion in female soccer athletes. The purpose of this study was to examine sex differences in neck muscle strength characteristics in multiple directions. A total of 52 high school soccer players (17 Females/35 Males) with no history of concussion participated. Subjects were instructed to perform three maximum voluntary isometric contractions for eight directions: flexion, right / left diagonal flexion, right/left lateral flexion, right/left diagonal extension, and extension. Peak force, normalized peak force, force steadiness, force ratio, and rate of force development were calculated and used for statistical analyses. Based on the normality test on each dependent variable, either independent t-tests or Mann-Whitney U-tests were used to compare sex differences (P < 0.00625: Adjusted for multiple comparisons). Males had significantly higher peak force in right lateral flexion and extension directions and rate of force development in left diagonal flexion and left lateral flexion direction compared to females (P < 0.00625). After values were normalized to body mass, significant sex differences were only observed with peak force in right lateral flexion. Significant sex differences were found mostly in secondary directions. Continued research efforts are needed to determine how neck strength characteristics may influence sport related concussion risk in soccer athletes.