Isometric Cervical Muscular Strength in Pediatric Athletes With Multiple Concussions

Objective: To compare maximal cervical muscle strength among athletes with a history of 2 or more concussions relative to athletes with no history of a previous concussion. Design: Athletes in the 2 groups were frequency-matched. Linear mixed models were used to test for differences in peak isometric flexion, extension, left lateral flexion, and right lateral flexion cervical muscle torque between groups. Setting: Pediatric sports medicine clinic. Participants: Athletes with a history of multiple concussions (n = 16) and athletes with no previous concussion history (n = 17). Interventions (or Assessment of Risk Factors or Independent Variables): Concussion history (group), age, sex, neck girth, and height. Main Outcome Measures: Peak isometric torque measured with a stationary isokinetic dynamometer during a 3-second isometric hold. Results: There was no significant difference in peak flexion [mean difference: 21.2%, 95% confidence interval (CI): -6.6% to 57.4%, P = 0.1413], extension (mean difference: 17%, 95% CI, -6.8% to 47.1%, P = 0.1667), left lateral (mean difference: 4.4%, 95% CI, -16.9% to 31.1%, P = 0.7011), or right lateral (mean difference: 9.3%, 95% CI, -14.5% to 39.8%, P = 0.4627) isometric torque in the concussion group relative to the control group. Across all muscle actions, neck torque was significantly (P < 0.05) higher in male compared with female athletes. Increasing neck girth was also associated with a significant (P < 0.05) increase in neck torque. Conclusions: There was no evidence of a consistent cervical muscle strength deficit among athletes with a history of 2 or more concussions relative to athletes with no previous history of a concussion. Age, neck girth, and sex were significantly associated with cervical muscle strength. Clinical Relevance: Isometric cervical muscle strength testing may not be a reliable test for differentiating athletes with a history of multiple concussions relative to athletes with no history of concussions in the pediatric and adolescent population. Our study presents a reliable methodology for testing cervical muscle strength among young athletes.

Automated summary

This study compared maximal cervical muscle strength between athletes with a history of multiple concussions and those with no history of concussions, finding no significant differences. Neck girth and male gender were significantly associated with cervical muscle strength.