Self‐Reported Head Trauma Predicts Poor Dual Task Gait in Retired National Football League Players

Abstract

Objective Symptomatic head trauma associated with American‐style football (ASF) has been linked to brain pathology, along with physical and mental distress in later life. However, the longer‐term effects of such trauma on objective metrics of cognitive–motor function remain poorly understood. We hypothesized that ASF‐related symptomatic head trauma would predict worse gait performance, particularly during dual task conditions (ie, walking while performing an additional cognitive task), in later life. Methods Sixty‐six retired professional ASF players aged 29 to 75 years completed a health and wellness questionnaire. They also completed a validated smartphone‐based assessment in their own homes, during which gait was monitored while they walked normally and while they performed a verbalized serial‐subtraction cognitive task. Results Participants who reported more symptomatic head trauma, defined as the total number of impacts to the head or neck followed by concussion‐related symptoms, exhibited greater dual task cost (ie, percentage increase) to stride time variability (ie, the coefficient of variation of mean stride time). Those who reported ≥1 hit followed by loss of consciousness, compared to those who did not, also exhibited greater dual task costs to this metric. Relationships between reported trauma and dual task costs were independent of age, body mass index, National Football League career duration, and history of musculoskeletal surgery. Symptomatic head trauma was not correlated with average stride times in either walking condition. Interpretation Remote, smartphone‐based assessments of dual task walking may be utilized to capture meaningful data sensitive to the long‐term impact of symptomatic head trauma in former professional ASF players and other contact sport athletes. ANN NEUROL 2020;87:75–83

Effects of contact/collision sport history on gait in early- to mid-adulthood

“…This is consistent with a recent finding by Oldham et al 21 whereby career duration in collision and contact sports was unrelated to ST, DT, and DT cost for gait speed or stride length in a younger cohort of collegiate athletes with shorter career duration. Further, the finding that career duration, age, and BMI were unrelated to gait performance is consistent with Manor et al’s 49 finding that these factors did not influence the relationship between self-reported symptomatic head trauma and walking performance in middle-aged American football players. This finding could also be the result of any negative consequences not yet having manifested.…”

“…Indeed, self-reported head trauma is related to worse DT gait in middle-aged former professional American football players, independent of career duration, age, and BMI. 49 Furthermore, physical inactivity, which usually indicates low levels of cardiorespiratory fitness, is a risk factor for many diseases. 43 , 50 , 51 Indeed, among former professional American football players, declines in physical activity were related to increased neuropsychiatric dysfunction, 52 which has been linked to worse gait performance.…”

Gait Performance in People with Symptomatic, Chronic Mild Traumatic Brain Injury

“…56,57 Further, dual-task assessments could prove to be an important outcome in clinical evaluations in chronic, symptomatic mTBI populations, as highlighted in older adults. 58 However, the dual-task cost on gait was not different between groups herein, which suggests both groups' gait performance decreased at a similar rate as a result of the secondary task. Our results suggest it is important to measure performance with a dual-task, yet do not provide evidence that calculating dual-task cost as a separate measure will add benefit to the analysis.…”

Association Between Collision Sport Career Duration and Gait Performance in Male Collegiate Student-Athletes

“…Greater dual-task costs for stride time variability have been observed in retired professional football players, although these findings were independent of career duration. 31 The literature surrounding the association of eAFE and career duration with cognitive function remains mixed. A number of studies specific to football have suggested that earlier exposure to tackling (ie, before age 12 years) may result in greater cognitive impairments later in life.…”

“…43 Furthermore, dual-task gait represents an important component of neurological health, as it assesses the motor and cognitive domains simultaneously. 17,42,49 Dual-task gait alterations have been observed in retired professional football players, although this finding was independent of career duration 31 and the translation to a collegiate population is unknown.…”