An observational study in Knee Hyperextension, sponsored by National Yang Ming Chiao Tung University. Completed at 1 site in Taiwan. Open to participants aged 20 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-04-10.
Sponsored by National Yang Ming Chiao Tung University · Observational
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.
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.
college athletes in Yang-Ming University and University of Taipei
Exclusion Criteria:
athletes who has knee hyperextension
athletes who doesn't have knee hyperextension
Injury type
Record injury type
Time frame: 4 months
Injury duration
time loss during the game or training (days)
Time frame: 4 months
Lower extremity alignments-pelvic tilt on sagittal plane
pelvic tilt on sagittal plane in degree
Time frame: 1st day
Lower extremity alignments-hip anteversion
hip anteversion in degree
Time frame: 1st day
Lower extremity alignments-tibiofemoral angle
tibiofemoral angle in degree
Time frame: 1st day
Lower extremity alignments-knee hyperextension angle
knee hyperextension angle in supine and standing posture in degree
Time frame: 1st day
Lower extremity alignments-tibial rotation angle
tibial rotation angle in degree
Time frame: 1st day
Lower extremity alignments-hip external rotation angle
hip external rotation angle in degree
Time frame: 1st day
Lower extremity alignments-hip internal rotation angle
hip internal rotation angle in degree
Time frame: 1st day
Lower extremity alignments-navicular drop
navicular drop normalized with foot length in %
Time frame: 1st day
Rectus femoris flexibility
measure knee angle in prone knee bend position
Time frame: 1st day
Hamstrings flexibility
measure knee angle in 90-90 straight leg raise test
Time frame: 1st day
Gastrocnemius flexibility
measure ankle dorsiflexion angle in standing position without rearfoot lift off the floor
Time frame: 1st day
Soleus flexibility
measure ankle dorsiflexion angle in knee flex standing position without rearfoot lift off the floor
Time frame: 1st day
Iliotibial band flexibility
use Ober's test to measure the angle below horizontal level
Time frame: 1st day
Dynamic task parameters-acceleration and angle
anteroposterior acceleration and angle changes at knee joint
Time frame: 1st day
Dynamic task parameters-ground reaction force
ground reaction force
Time frame: 1st day
Dynamic task parameters-Electromyography (EMG)
use EMG to detect muscle firing during jump task
Time frame: 1st day
knee extensors muscle strength
knee extensors by hand held dynamometer
Time frame: 1st day
knee flexors muscle strength
knee flexors by hand held dynamometer
Time frame: 1st day
This study is completed, as verified in Apr 2019. You cannot join it, but the record below documents what was studied.
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National Yang Ming Chiao Tung University