Resistance training and head-neck segment dynamic stabilization in male and female collegiate soccer players

Abstract

Context: Cervical resistance training has been purported to aid in reducing the severity of brain injuries in athletes.

Objective: To determine the effect of an 8-week resistance-training program on head-neck segment dynamic stabilization in male and female collegiate soccer players.

Design: Pretest and posttest control group design.

Setting: University research laboratory and fitness center.

Patients or other participants: Thirty-six National Collegiate Athletic Association Division I collegiate soccer players (17 men, 19 women).

Intervention(s): The resistance training group underwent an 8-week cervical resistance training program that consisted of 3 sets of 10 repetitions of neck flexion and extension at 55% to 70% of their 10-repetition maximum 2 times a week. Participants in the control group performed no cervical resistance exercises.

Main outcome measure(s): Head-neck segment kinematics and stiffness, electromyographic activity of the upper trapezius and sternocleidomastoid muscles during force application to the head, and neck flexor and extensor isometric strength.

Results: No kinematic, electromyographic, or stiffness training effects were seen. The posttest resistance training group isometric neck flexor strength was 15% greater than the pretest measurement. Isometric neck extensor strength in the female resistance training group was 22.5% greater at the posttest than at the pretest. Women's neck girth increased 3.4% over time regardless of training group level. Women exhibited 7% less head-neck segment length and 26% less head-neck segment mass than men.

Conclusions: Despite increases in isometric strength and girth, the 8-week isotonic cervical resistance training did not enhance head-neck segment dynamic stabilization during force application in collegiate soccer players. Future researchers should examine the effect of head-neck segment training protocols that include traditional and neuromuscular activities (eg, plyometrics) with the focus of reducing head acceleration on force application.

Figure 1. Forced extension trial setup with external force applicator

Figure 2. Stiffness calculation example. This force-displacement line was created from a trial with 3 force (B1, B2, and B3) and 3 displacement (A1, A2, and A3) data points. These points create 2 lines, and stiffness was determined from the average slope of the lines.