An observational study in Aging, Athletic Injuries and Physical Inactivity, sponsored by Marquette University. Recruiting at 1 site in United States. Open to participants aged 18 Years to 64 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-25.
Sponsored by Marquette University · Observational
Competitive sport increases risk for musculoskeletal injury (e.g., traumatic knee injury) and may position former athletes for early onset of chronic diseases, chronic pain, poor health-related quality of life, and disability. Quantifying function in former athletes with and without a prior injury and non-athlete controls is critical to understanding long-term health trajectories in athletes and informing potential interventional studies. One modifiable factor that may be associated with long-term health in athletes is physical activity patterns. The purpose of this study is to evaluate strength, function, physical activity, dietary patterns, and cardiometabolic health among current and former competitive athletes and in nonathlete controls to evaluate the impact of prior knee injury and sedentary behavior as two potential determinants of later poor health and reduced function.
The overarching hypothesis is that former athletes, especially those with a prior injury, will have poorer function and health in midlife and that current and former athletes will engage in greater overall and longer bouts of sedentary behavior compared to non-athletes.
Aim 1 will compare function, strength, and cardiometabolic indicators among former athletes with and without prior knee injury and non-athlete controls in midlife (age 40-64). Hypothesis 1 is that former athletes with a prior injury will have the poorest function, muscle strength, and cardiometabolic indicators.
Aim 2 will compare sedentary behavior and physical activity patterns in current (age 18-25) and midlife former athletes to non-athlete controls. Hypothesis 2.1 is that current athletes will have greater sedentary behavior, longer sedentary behavior bouts, and higher levels of moderate-to-vigorous physical activity compared to non-athlete controls. Hypothesis 2.2 is that former athletes in midlife will have greater sedentary behavior, longer sedentary behavior bouts, and lower physical activity levels compared to non-athlete controls.
An exploratory aim will evaluate longitudinally the trajectory of physical activity patterns, cardiometabolic indicators, function, and strength annually in each cohort, comparing how these variables change over time in each subgroup.
258 studies on the registry are indexed under Athletic Injuries; 45 are open to participants now.
This study's planned enrollment of 450 is above the median of 100 across 91 observational studies indexed under Athletic Injuries.
Browse Athletic Injuries studies →Marquette University is the lead sponsor of 38 studies on the registry; 10 are open to participants now.
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Current and former collegiate varsity athletes with and without a prior history of traumatic knee injury and matched non-athlete controls.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Please see cohorts for specific inclusion/exclusion criteria
Inclusion Criteria:
Exclusion Criteria:
Inclusion Criteria: Age 40-64 years. Prior participation in a collision, contact, or jumping/cutting/pivoting sport (e.g., baseball, basketball, field hockey, football, ice hockey, lacrosse, soccer, softball, volleyball, etc.) at the collegiate varsity level for at least 1 season; history of at least 1 prior traumatic knee injury including but not limited to ACL or PCL rupture and/or reconstruction, medial and/or lateral meniscus tear or surgery, osteochondral defect, and/or intra-articular (i.e., tibiofemoral or patellofemoral) fracture. Exclusion Criteria: Neurologic (e.g., stroke, Parkinson's) and/or degenerative disease that impairs function; current pregnancy; lower extremity joint replacement (e.g., hip or knee replacement).
Inclusion Criteria: Age 40-64 years. Prior participation in a collision, contact, or jumping/cutting/pivoting sport (e.g., football, baseball, basketball, field hockey, ice hockey, lacrosse, soccer, softball, volleyball, etc.) at the collegiate varsity level for at least 1 season. Exclusion Criteria: Neurologic (e.g., stroke, Parkinson's) and/or degenerative disease that impairs function; current pregnancy; lower extremity joint replacement (e.g., hip or knee replacement); prior major lower extremity injury (e.g., ACL tear, Achilles tendon rupture, compound ankle or femur fracture, hip dislocation).
Inclusion Criteria: Age 40-64 years. Exclusion Criteria: Prior participation in a collegiate varsity sport or professional sport; neurologic (e.g., stroke, Parkinson's) and/or degenerative disease that impairs function; current pregnancy; lower extremity joint replacement (e.g., hip or knee replacement); prior major lower extremity injury (e.g., ACL tear, Achilles tendon rupture, compound ankle or femur fracture, hip dislocation).
Inclusion Criteria: Age 18-25 years. Participation in a collision, contact, or jumping/cutting/pivoting sport (e.g., baseball, basketball, field hockey, football, ice hockey, lacrosse, soccer, softball, volleyball, etc.) at the varsity collegiate level. Exclusion Criteria: Neurologic (e.g., stroke, Parkinson's) and/or degenerative disease that impairs function; current pregnancy; lower extremity joint replacement (e.g., hip or knee replacement).
Inclusion Criteria: Age 18-25 years. Exclusion Criteria: Prior or current participation in any collegiate varsity sport; prior major lower extremity injury or surgery (e.g., ACL tear, Achilles tendon rupture, compound ankle or femur fracture, hip dislocation); current participation in competitive sport (e.g., collegiate club sport) more than 3x/week; joint replacement in the lower extremity (i.e., knee or hip replacement); current pregnancy; or neurologic condition (e.g., stroke, Parkinson's) and/or degenerative condition that impairs function.
30-Second Chair Stand Test (primary outcome for Aim 1)
Physical function (functional performance) will be evaluated using the 30-Second Chair Stand Test, 6-Minute Walk Test, and Stair Climb Test. The 30-Second Chair Stand Test uses a standard height chair and requires the participant to stand up and sit down as many times as possible in 30 seconds. More completions indicate better physical function.
Time frame: Baseline
Sedentary Behavior (primary outcome for Aim 2)
Physical activity will be monitored continuously using an accelerometer worn for 2 weeks. Physical activity will be classified throughout the day as sedentary, light, moderate, or vigorous using established algorithms. The primary outcome for aim 2 is the mean percentage of waking hours in sedentary behavior.
Time frame: Baseline
Strength
Isometric quadriceps and hamstring strength will be assessed using a standardized strength testing machine (i.e., electromechanical dynamometer).
Time frame: Baseline
Body Composition
Body composition (i.e., percent body fat) will be assessed via dual-energy x-ray absorptiometry (DXA).
Time frame: Baseline
Step Counts
Average daily step counts will also be recorded using an objective physical activity monitor.
Time frame: Baseline
Cardiovascular Disease Risk
The American College of Cardiology/American Heart Association Atherosclerotic Cardiovascular Disease Risk Estimator will be used in the midlife participants to estimate 10-year cardiovascular disease risk.
Time frame: Baseline
6-Minute Walk Test
The 6-Minute Walk Test evaluates the distance participants can walk in 6 minutes and is a widely used indicator of function and aerobic capacity. The 6-minute walk test will be evaluated in the midlife participants only.
Time frame: Baseline
Stair Climb Test
The Stair Climb Test assesses the time it takes the participant to ascend and descend a flight of stairs. Faster times on the Stair Climb Test are associated with better strength and function. The Stair Climb Test will be evaluated in the midlife participants only.
Time frame: Baseline
Sedentary Behavior (follow-up)
Physical activity will be monitored continuously using an accelerometer worn for 2 weeks. Physical activity will be classified throughout the day as sedentary, light, moderate, or vigorous using established algorithms. Mean percentage of waking hours in sedentary behavior and each physical activity classification will be assessed.
Time frame: Follow-up (an average of 1 year post-baseline)
30-Second Chair Stand Test (follow-up)
The 30-Second Chair Stand Test uses a standard height chair and requires the participant to stand up and sit down as many times as possible in 30 seconds. More completions indicate better physical function.
Time frame: Follow-up (an average of 1 year post-baseline)
Strength (follow-up)
Isometric quadriceps and hamstring strength will be assessed using a standardized strength testing machine (i.e., electromechanical dynamometer).
Time frame: Follow-up (an average of 1 year post-baseline)
Body Composition (follow-up)
Body composition (i.e., percent body fat) will be assessed via dual-energy x-ray absorptiometry (DXA).
Time frame: Follow-up (an average of 1 year post-baseline)
Step Counts (Follow-up)
Average daily step counts will also be recorded using an objective physical activity monitor.
Time frame: Follow-up (an average of 1 year post-baseline)
6-Minute Walk Test (follow-up)
The 6-Minute Walk Test evaluates the distance participants can walk in 6 minutes and is a widely used indicator of function and aerobic capacity. The 6-minute walk test will be evaluated in the midlife participants only.
Time frame: Follow-up (an average of 1 year post-baseline)
Stair Climb Test (follow-up)
The Stair Climb Test assesses the time it takes the participant to ascend and descend a flight of stairs. Faster times on the Stair Climb Test are associated with better strength and function. The Stair Climb Test will be evaluated in the midlife participants only.
Time frame: Follow-up (an average of 1 year post-baseline)
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