The Effect of Upper Limbs Motion During Single-leg Jump Landing After Anterior Cruciate Ligament Reconstruction

Study Overview
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Brief Summary
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The aim of this study is to investigate the effect of upper limbs motion on lower limb biomechanics and muscle activity during single-leg jump landing after anterior cruciate ligament reconstruction.

Detailed Description
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More and more people join in different sports in recent years. But the incidence of sports injury also increases. And the most frequently occurring and debilitating knee injury in sports is rupture of the anterior cruciate ligament (ACL). Patients who aim to return to their preinjury sports should undergo anterior cruciate ligament reconstruction (ACLR) in order to maximize knee stability. The overall incidence rate of a second ACL injury within 24 months after ACLR was nearly 6 times greater than that in healthy participants. Although many studies have showed about biomechanical and neuromuscular risk factors during jump landing which were thought to associate with the secondary injury after ACLR, these studies all focused on the motion of lower extremity. But actually, people often use their upper limbs to catch or throw a ball during jump landing in playground. Whether the upper limbs motion will affect the muscle coordination of lower extremity during jump landing is still unknown. Therefore, the purpose of our study is to investigate the effect of upper limbs motion during single-leg jump landing after ACLR.

Official Title
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The Effect of Upper Limbs Motion on Lower Limb Biomechanics and Muscle Activity During Single-leg Jump Landing After Anterior Cruciate Ligament Reconstruction

Conditions
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Anterior Cruciate Ligament Reconstruction

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Only one leg has operation of ACL reconstruction At least 1 year after ACLR or have been back to sports Exercise in sports regularly. Exclusion Criteria: Other operation of lower extremity exclude ACLR Any diseases or poor condition that will affect jumping or deterioration after jumping.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Kinematics of lower-limb during landing phase | The data will be collected by VICON motion capture system, include hip, knee and ankle joint angle in three plane. (frontal plane, sagittal plane and transverse plane) | from taking off to landing, about 5 seconds. | 
| Kinetics of knee joint during landing phase | The data will be collected by VICON motion capture system and calculated by inverse dynamics, include knee flexion/extension moment, abduction/adduction moment, internal/external rotation moment. | from taking off to landing, about 5 seconds. | 
| Muscle onset time of lower-limb muscles during landing phase | The data will be collected by wireless electromyography, include rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus. | from taking off to landing, about 5 seconds. | 
| Muscle activation of lower-limb muscles during landing phase | The data will be collected by wireless electromyography, include rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus, anterior tibialis, medial gastrocnemius | from taking off to landing, about 5 seconds. | 
| Muscle activation-Hamstring and Quadriceps ratio (H/Q ratio) during landing phase | The data will use the amount of hamstring and quadriceps muscle activation to calculate H/Q ratio. | from taking off to landing, about 5 seconds. |