Lower Extremity Alignment and Dynamic Control With Associated Injury Risk in College Athletes With Knee Hyperextension

Study Overview
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Brief Summary
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Knee hyperextension, also called genu recurvatum or back knee, is commonly seen in women, people with ligamentous laxity, stroke and cerebral palsy patients. This faulty posture would result in excessive tension of the passive tissues such as anterior cruciate ligament (ACL) and posterior capsule of the knee. Subjects may also develop compensations at hip and ankle joint, as well as lower extremity malalignment. Muscles surrounding the knee could also become dysfunctional when performing functional tasks requiring stability during terminal knee extension, during which uncontrolled knee hyperextension could easily be utilized to lock the joint for stability in gait and stair climbing. In athletes, landing from a jump on an extended knee is one of the common reasons resulting in ACL injury. Little is known about the injury rate of athletes with knee hyperextension who participate in sports involving jump-landing activities. The aim of the study is to explore if knee hyperextension is associated with poor lower extremity alignment and dynamic control and injury rate in athletes requiring jump-landing activities. One of the study hypothesis is that athlete with knee hyperextension can find more compensatory lower extremity alignments and poor control in dynamic movement than control group. The other hypothesis is with or without knee hyperextension, the parameter of lower extremity alignment and dynamic control can predict injury rate in jump landing athlete.

Detailed Description
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Investigators expect to recruit 100 subjects into 2 group- control group and knee hyperextension group (KH group). In knee hyperextension group, investigators will include college athletes having knee hyperextension alignment, no lower extremity injuries in past three months, and participating in jump-landing activities. Control group will match the gender, age, height, weight and sports to KH group. Inclusion criteria is the same as KH group, except the knee hyperextension angle is <5⁰ in control group. Every subjects will receive the first time assessment and follow up by filling the injury-follow-up form every months for about four months. At the first assessment, investigators will measure lower extremity alignments include pelvic angle in sagittal plane, hip anteversion, tibiofemoral angle, knee hyperextension angle in supine and standing position, tibial rotation angle, and navicular drop; lower extremity muscle flexibility include rectus femoris, hamstrings, gastrocnemius, soleus, iliotibial band; lower extremity muscle strength include hip, knee, muscle group; dynamic control task will record tibio-femoral acceleration, angle change ground reaction force and EMG muscle firing during vertical jump and drop jump.

Official Title
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Lower Extremity Alignment and Dynamic Control With Associated Injury Risk in College Athletes With Knee Hyperextension

Conditions
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Knee Hyperextension

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age ≥ 20 years old knee hyperextension ≥ 5⁰ participate in jump- landing sports training at least 3 days per week no lower extremity injury last 3 months Exclusion Criteria: having knee surgery before In the past three months have occurred lower extremity musculoskeletal injury leading the person can't participate in training or competition for at least three days

Ages Eligible for Study
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Minimum Age: 20 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Knee hyperextension group<br>athletes who has knee hyperextension | |
| Control group<br>athletes who doesn't have knee hyperextension | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Injury type | Record injury type | 4 months | 
| Injury duration | time loss during the game or training (days) | 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lower extremity alignments-pelvic tilt on sagittal plane | pelvic tilt on sagittal plane in degree | 1st day | 
| Lower extremity alignments-hip anteversion | hip anteversion in degree | 1st day | 
| Lower extremity alignments-tibiofemoral angle | tibiofemoral angle in degree | 1st day | 
| Lower extremity alignments-knee hyperextension angle | knee hyperextension angle in supine and standing posture in degree | 1st day | 
| Lower extremity alignments-tibial rotation angle | tibial rotation angle in degree | 1st day | 
| Lower extremity alignments-hip external rotation angle | hip external rotation angle in degree | 1st day | 
| Lower extremity alignments-hip internal rotation angle | hip internal rotation angle in degree | 1st day | 
| Lower extremity alignments-navicular drop | navicular drop normalized with foot length in % | 1st day | 
| Rectus femoris flexibility | measure knee angle in prone knee bend position | 1st day | 
| Hamstrings flexibility | measure knee angle in 90-90 straight leg raise test | 1st day | 
| Gastrocnemius flexibility | measure ankle dorsiflexion angle in standing position without rearfoot lift off the floor | 1st day | 
| Soleus flexibility | measure ankle dorsiflexion angle in knee flex standing position without rearfoot lift off the floor | 1st day | 
| Iliotibial band flexibility | use Ober's test to measure the angle below horizontal level | 1st day | 
| Dynamic task parameters-acceleration and angle | anteroposterior acceleration and angle changes at knee joint | 1st day | 
| Dynamic task parameters-ground reaction force | ground reaction force | 1st day | 
| Dynamic task parameters-Electromyography (EMG) | use EMG to detect muscle firing during jump task | 1st day | 
| knee extensors muscle strength | knee extensors by hand held dynamometer | 1st day | 
| knee flexors muscle strength | knee flexors by hand held dynamometer | 1st day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Injury rate