Altered Vestibular Balance Function in Combat Sport Athletes

Area of Science:

• Neuroscience
• Sports Medicine
• Biomechanics

Background:

• Combat sports carry risks for cumulative nervous system injuries.
• Fighters represent an understudied population regarding neurological effects of their sport.

Purpose of the Study:

• To investigate the effect of repetitive head impacts on vestibular balance reflexes in combat sports athletes.
• To compare vestibular responses between fighters and non-fighter controls.

Main Methods:

• Electrical vestibular stimulation (EVS) was used to evoke lower-limb muscle responses.
• Surface electromyography recorded responses from medial gastrocnemius and soleus muscles.
• Participants included boxers, Muay Thai athletes, and healthy controls.

Main Results:

• Fighters exhibited significantly delayed short and medium latency responses (SLR/MLR) compared to controls.
• Fighters showed significantly lower SLR and MLR peak amplitudes.
• Cumulative head impacts positively correlated with SLR/MLR peak timing and negatively with MLR amplitude and response gain.

Conclusions:

• Evidence suggests progressive vestibular impairment in combat sports athletes due to head impacts.
• EVS may serve as a clinical diagnostic tool for assessing vestibular function in athletes.
• Findings can inform return-to-play and career-length decisions for athletes at risk of repetitive head impacts.