ACL Tears
Conditions
Keywords
quadriceps strength, quadriceps voluntary activation, progressive strength program
Brief summary
Quantify differences in quadriceps function and gait biomechanics in individuals within 2 years of ACL reconstruction compared to a healthy comparison group and establish the feasibility of conducting a progressive strengthening program to improve clinical and patient-oriented outcomes in individuals who are within 2 years of ACL reconstruction
Detailed description
A maximal isometric muscle contraction of the quadriceps will be used to examine neural and peripheral contributions to quadriceps strength. Neural influences will be quantified using the interpolated twitch technique (voluntary activation) and early RTD. Peripheral influences will be quantified by examining the stimulus-evoked torque with the quadriceps relaxed (resting twitch) and late RTD. Knee joint biomechanics during treadmill walking and running will include sagittal plane (flexion, extension) movement variability (Lyapunov Exponent and approximate entropy), peak knee flexion angle, and peak external knee flexion and adduction moments. Additionally, the clinical relevance of impairments in the ACL reconstruction group will be determined by examining the relationship with performance on jumping tasks and patient function (secondary outcomes). The progressive strengthening program will be performed for 6 weeks and emphasize development of strength and power. Feasibility will be established if the researchers can recruit up to 8 participants and retain at least 80% over the 3 week intervention program. The researchers will determine effect sizes for changes outcome measures.
Interventions
OTHERProgressive strengthening program
The progressive strengthening program will be performed for 3 weeks and emphasize development of strength and power. Feasibility will be established if we can recruit up to 8 participants and retain at least 80% over the 3 week intervention program. We will determine effect sizes for changes outcome measures.
Sponsors
University of Nebraska
National Institutes of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Creighton University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Physical therapy exercises (progressive strengthening program)
Eligibility
Sex/Gender
ALL
Age
14 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Physically active * History of primary unilateral ACL reconstruction within the past 3-24 months (ACL group only)
Exclusion criteria
* History of lumbar spine or lower extremity injury or surgery (except ACL) within the past 1 year that required physician care * Concomitant knee injury (ACL group only): ligament injury that requires surgical repair (medial collateral ligament \[MCL\], posterior cruciate ligament\[PCL\]), chondral defects \>2cm, fracture, bilateral knee injury * Medial conditions that are contraindications to electrical stimulation: Cardiac Pacemaker and Pregnancy * Participants who are unable to understand procedures of experiment or provide consent (assent/parental permission)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Quadriceps Rate of Torque Development (RTD) Maximum | Change from Baseline Quadriceps RTD at 3 weeks | slope of the torque-time tracing (change in torque/change in time) (Nm/kg\*s-1) |
| Knee Joint biomechanics during gait (nonlinear) | Change from Baseline nonlinear knee joint biomechanics at 3 weeks | Sagittal plane (knee flexion) movement variability (calculated using Lyapunov Exponent and approximate entropy) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Quadriceps percent activation | Change from Baseline Quadriceps percent activation at 3 weeks | Supramaximal electrical stimulus (interpolated twitch technique) used to augment a voluntary muscle contraction |
| Knee Joint biomechanics during gait (traditional) | Change from Baseline knee joint biomechanics at 3 weeks | peak external knee flexion moment (Nm/kgm) |
| Patient reported function | Change from Baseline IKDC at 3 weeks | International Knee Documentation Committee (IKDC) subjective form |
| Jumping performance | Change from Baseline single leg hop for distance at 3 weeks | single leg hop for distance (cm) |
Countries
United States
Outcome results
None listed