Changes in balance and gait can be an indication of incipient neurologic disease, such as Alzheimer’s disease or Parkinson’s disease. But there is evidence that there can be subtle changes in balance, and thus concern about neurologic injury, in young adults who engage in sports that involve blows to the head.

A study authored by Dr. John Jeka of the University of Delaware found that soccer players who moved the ball more often by heading it were more likely to have problems with balance than those players who did not.

This study was part of research presented at the American Academy of Neurology’s Sports Concussion Conference in Indianapolis July 20-22.

Jeka reported that, "Soccer headers are repetitive subconcussive head impacts that may be associated with problems with thinking and memory skills and structural changes in the white matter of the brain," he continued, "But the effect of headers on balance control has not been studied."

The study included 20 soccer players with an average age of 22. They completed questionnaires regarding the frequency of heading the ball. The reported range of number of heading plays during the season was between 16 and 2,100. The average was 451.

The study found that the players having the largest number of headers had the greatest problems with a standardized balance test of foot and hip movement and vestibular processing of balance. The research found that for every 500 headers, there was an increasing deviation of foot movement and hip placement response.

Monitoring deviations from normal or deviations from the baseline are means to better understand how the habits and practice of play in soccer are impacting health. This can be difficult.

Interestingly, the Food and Drug Administration (FDA) approved a simple test for balance assessment of athletes and a clinical population this spring. It is an application in a smartphone called K-D Balance. It is an FDA 510(K)-cleared mobile application, and the company suggests it be used by athletic trainers, physical therapists, physicians, and other healthcare professionals to assess vestibular dysfunction.

The product uses an iPhone secured to the athlete’s chest directly below the athlete’s chin with a static device holder (included with the product). The baseline balance administration is performed using the type of footwear specific to the athlete’s sport.

For instance, hockey players complete their K-D Balance assessments wearing skates on a non-ice hard surface. The test can be used to determine a baseline and then the information can be utilized to determine if there is decrease in balance functioning.

There are some more common tests of balance used in sports and clinical applications. One is the single-leg stance. Research has shown the single-leg stance to be highly variable even in healthy patients, resulting in unreliable and time-consuming evaluations.

Dr. Danielle Leong, the chief scientific officer of King-Devick Technologies, raises concerns about the utility of the single-leg stance in the evaluation of concussions. This is based on the results of a Mayo Clinic study, which "demonstrated that, at baseline, the single-leg stance in a commonly used subjective balance test accounted for 74% of all errors and 21% of subjects had the maximum possible error score at baseline."

K-D Balance does not require, nor does it allow for measurement of single-leg stances, which saves clinical time and reduces the number of false positives by focusing on the three balance stances of highest value to healthcare professionals, team physicians and athletic trainers.

Since the product is new, there is little information about its practical application. But having means to measure vulnerable young athletes and their brain functioning is critical to prevent lifelong health issues.

Optimum performance is often the primary objective of competitive athletes, and if the game is not only impacting quality of health but performance, this needs to be identified.

"Soccer players must have good balance to play the game well, yet our research suggests that headers may be undermining balance, which is key to all movement, and yet another problem now linked to headers," said Fernando V. Santos, another study author at the University of Delaware. "It is important that additional research be done to look more closely at this possible link with balance and to confirm our findings in larger groups of people."

Furthermore, there is need to understand how subtle a brain injury can impact neurologic function later in life. Balance dysfunction at an early age may be contributing to greater risk of serious disease such as Alzheimer’s and Parkinson’s.

If preventing and limiting head blows means mitigating such problems, it is critical to understand this and institute safe practices for youth and young adults involved in sports.