Effect of Sand on Knee Load and Muscle Activity During a Single Leg Landing Task

Study Overview
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Brief Summary
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This study evaluates the effect of different surfaces on the load experienced by the knee when landing from a single leg hop. A sand, pliable grass and firm (hard floor) surface will be compared when hopping from a 30 cm height. Each subject will complete 5 hops on each surface in a random order. The muscle activity in selected muscles of the lower limb will also be investigated to see how this differs in the landing leg, when landing on the different surfaces.

Detailed Description
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The aim of this study is twofold: 1) To investigate the effect of sand on landing kinematics and kinetics at the knee joint when performing a single leg jump landing task (dominant leg), comparing sand with a firm surface and pliable grass control. 2) To investigate the sEMG activity of the hamstring, quadriceps and gastrocnemius muscles of the dominant leg during the jump landing task on these different surfaces (from take off through to terminal knee flexion at the end of the landing phase).

Official Title
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Effect of Sand on Knee Load and sEMG Activity During a Single Leg Landing Task: Implications for ACL Prevention and Rehabilitation

Conditions
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Single Leg Hop Sand Surface, Single Leg Hop Grass Surface, Single Leg Hop Firm Surface

Intervention / Treatment
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* Other: Sand
* Other: artificial grass
* Other: firm ground


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Female Participate in a minimum of 3 hours sporting activity per week. Provided Informed Consent Must be over 16 years of age (16-45 years) No exclusion criteria Exclusion Criteria: Not willing to provide informed consent Pregnant History of ACL injury or other knee pathology Significant lower limb pathology Previous lower limb fracture or surgery Lower Limb injury in last 3 months. Male

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Randomised, repeated measures crossover design.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sand<br>Participants perform 5 single leg hops onto a Sand surface from a 30cm height | Other: Sand<br>* sand surface<br>|
| Active Comparator: Artificial grass<br>Participants perform 5 single leg hops onto a grass surface from a 30cm height | Other: artificial grass<br>* grass surface<br>|
| Active Comparator: Firm Ground<br>Participants perform 5 single leg hops onto a firm ground surface from a 30cm height | Other: firm ground<br>* firm surface<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| knee abduction moment (N.m) | a combination of ground force and amount of knee valgus on landing | 1 testing session (1 day) | 
| knee valgus | angle at the knee on landing | 1 testing session (1 day) | 
| surface electromyography (sEMG) activity pre and post landing | muscle activity of quadriceps (vastus medialis, vastus lateralis), hamstrings (lateral and medial), gastroc (lateral head) | 1 testing session (1 day) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anterior tibial translation | The amount of forward translation of the tibia when landing on the surface | 1 testing session(1 day) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sand, knee valgus, knee abduction moment, electromyography