An Investigation of Risk Factors for Concussion in Japanese American Football: Associations with Helmet Structure and Neck Muscle Strength

A Multifaceted Investigation of Concussion Risk in Japanese American Football Players: Associations with Helmet Structure and Neck Muscle Strength - Multifactor Concussion Risk Study : Helmet Structure & Neck Strength

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

JPRN

Registry ID

JPRN-UMIN000060585

Enrollment

150

Registered

2026-02-08

Start date

2026-02-09

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Concussion

Interventions

None listed

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: 1. University students (years 1 to 4) who belong to the Senshu University American football team and have provided written informed consent. 2. Healthy participants who can undergo neck circumference measurement, neck muscle strength testing, and neck muscle hardness assessment without injury and with normal performance of all measurements.

Exclusion criteria

Exclusion criteria: 1. Participants will be excluded if written informed consent cannot be obtained. 2. Participants who become unable to continue measurements due to progression of any disease or medical condition. 3. Participants for whom the participating physicians determine that measurements should be discontinued. 4. Any other participants deemed inappropriate for the study by the participating physicians.

Design outcomes

Primary

Measure	Time frame
1. Helmet Type: manufacturer, model name, fit 2. Neck Measurement: measurement of neck circumference. 3. Neck Muscle Strength and Muscle Hardness Measurement: measurement of maximum neck muscle strength (flexion, extension, lateral flexion) using a dedicated dynamometer (Mutus F1), and measurement of muscle hardness using an ultrasound device (Canon Apria).	—

Secondary

Measure	Time frame
Age, height, weight, athletic history, medical history (including head injuries and concussions - mandatory items), position, helmet fit sensation, SCAT6 results (Sport Concussion Assessment Tool 6). For concussion patients: SCAT6 retest, date and time of injury, and detailed circumstances of injury.	—

Countries

Japan

Contacts

Public ContactSHU SOMEMURA

St. Marianna University School of Medicine Department of Sports Medicine

s3somemura@marianna-u.ac.jp0449778111

Outcome results