Primary Aim: Compare physiological (e.g., heart rate) and clinical responses (e.g., symptom provocation) of adolescent and adult athletes (14-35 years of age) completing either a structured treadmill running or a dynamic aerobic exertion protocol during the subacute phase of sport-related concussion recovery (3-30 days after injury). Secondary Aim: Examine potential effects of clinically-relevant factors that influence symptom responses to controlled aerobic exertion, such as age, physical activity patterns, motion sensitivities, psychological responses to injury, and sleep quality, among subjects completing controlled aerobic and dynamic exertion following sport-related concussion
Exercise testing is an emerging component of the clinical evaluation for sport-related concussion. Despite the growing empirical evidence to suggest that early activity following an initial rest period after injury is beneficial to recovery, the effects of modifiable exercise prescription factors (e.g., exercise mode, duration, and intensity) is unknown. Given that dynamic exertion, which incorporates synchronized head-body movements, may contribute greater information processing demands for the functional pathways responsible for balance and equilibrium than treadmill running, may be more likely to provoke symptoms during exertion. Thus, physically active (\>150 min/week of moderate-intensity physical activity) participants prior to a diagnosed sport-related concussion will be randomly assigned to complete either an aerobic or dynamic exercise task at 1 study visit following injury.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
6
Individuals begin walking at 5.8 km/hr. (3.6 mph) at a 0.0% incline (5.1 km/hr. \[3.2 mph\] if below 5' 10" tall), the treadmill incline is increased 1 degree each minute for the first 15 minutes, then speed increased 0.64 km/hr. (0.4 mph) each minute thereafter. Exercise will be terminated if participant a) attains 90 percent of predicted heart rate reserve (HRR=.90\*\[{208-(.7\*age)}-resting HR\]), or b) reports a symptom worsening of 3 or points (0-10 scale) for headache, dizziness, or nausea, d) a rapid progression of complaints with continued exercise, or e) a rating of perceived exertion (RPE) greater than 18.5.
Participants will begin in a center circle with equidistant cones 2.5 meters away. After the administrator presents a card, the participant touches a corresponding cone and returns to the starting position. Cards will be presented in increasing frequency in synchrony with a metronome application until exercise termination criteria are identified. Exercise will be terminated if participant a) attains 90 percent of predicted heart rate reserve (HRR=.90\*\[{208-(.7\*age)}-resting HR\]), or b) reports a symptom worsening of 3 or points (0-10 scale) for headache, dizziness, or nausea, d) a rapid progression of complaints with continued exercise, or e) a rating of perceived exertion greater than 18.5.
Neuromuscular Research Laboratory-Warrior Human Performance Research Center
Pittsburgh, Pennsylvania, United States
Changes in Concussion Symptoms From Pre to Post Exercise
Concussion symptoms will be measured with the Post-concussion Symptom Scale (PCSS), a patient-report survey of 22 concussion-associated symptoms on a 0-6 Likert scale (0 'none' to 6 'severe'). Number of reported symptoms (range: 0- 22) and total symptom severity (range: 0-132) whereby greater scores indicate worse symptom burden will be examined. The survey takes approximately 5 minutes to complete
Time frame: At 1 study visit within 30 days following concussion, and within 15 minutes of initiating exercise until approximately 15 minutes after exercise cessation
Heart Rate
Actual and percent of age-estimated heart rate, measured in beats per minute , will be recorded prior to (approximately 5 min), during, and following (approximately 5 min) exercise via a noninvasive heart rate monitor. Heart rate at rest, exercise cessation, and their difference (maximum heart rate - resting heart rate) will be recorded.
Time frame: At 1 study visit within 30 days following concussion, and within 15 minutes of initiating exercise until approximately 15 minutes after exercise cessation
Systolic and Diastolic Blood Pressure
Systolic and diastolic blood pressure, measured in mmHg with a non-invasive blood pressure cuff, will be recorded prior to and following exercise intervention.
Time frame: At 1 study visit within 30 days following concussion, and within 15 minutes of initiating exercise until approximately 15 minutes after exercise cessation
Exercise duration
Exercise duration, the time interval between exercise initiation and cessation, will be recorded in seconds (range: 0-900)
Time frame: Completed during the 1 study visit within 30 days following concussion
Clinical recovery
Duration of clinical recovery, measured in days, is the interval between injury onset until medical clearance to resume unrestricted sport participation.
Time frame: Through study completion, approximately between 3 and 30 days following concussion
Changes in vestibular ocular motor screening (VOMS) symptoms from pre-exercise to post-exercise
The vestibular/ocular motor screening (VOMS) tool is a brief (approximately 5 minutes) patient-reported assessment to screen for vestibular and ocular motor impairments after concussion. Participants report on a 0-10 Likert scale (0 'none' to 10 'severe') prior to and following each of the 7 VOMS sub-tests: smooth pursuits, horizontal saccades, vertical saccades, near-point of convergence, horizontal vestibular-ocular reflex, vertical vestibular-ocular reflex, visual motion sensitivity; and near point of convergence (NPC) distance. Symptoms will be totaled across all symptoms and sub-tests (maximum=240) whereby greater scores indicate worse symptom burden.
Time frame: At 1 study visit within 30 days following concussion, and within 15 minutes of initiating exercise until approximately 15 minutes after exercise cessation
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