What is the Effect of Vision on Movement Control in Anterior Cruciate Ligament Reconstructed Patients 7 Months Post-surgery?

Study Overview
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Brief Summary
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The anterior cruciate ligament (ACL) is thought to have two main roles within the body: (1) providing a physical restraint to excessive rotation and forwards translation within the knee and (2) providing sensory information to the sensorimotor cortex (contributes to motor planning and motor task execution). Therefore, an ACL injury is thought to be not just a physical injury but also one which affects an individual's ability to plan and execute motor tasks. It has been suggested in previous research that following an ACL injury and even post-ACL reconstruction, individuals may become reliant on the visual-motor system when planning and executing movements. Therefore, this study aims to compare an ACLR population against healthy controls to see if it is possible to identify those who may be visually-motor reliant by accessing movement control in the absence of vision

Detailed Description
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This study will compare a male ACLR cohort against matched healthy controls. The study population will be between 18-35 year old males who are competing multi-directional field sport. The ACLR cohort will be 7 months post-surgery. The main outcome measure will be time to stability during the stepdown task (from a 20cm step). The stepdown task will be completed first with their eyes open and then with their eyes closed, thereby allowing for the creation of an index reporting how time to stability changes following the obstruction of vision. Strength and lower limb power measures will be collected as potential confounding factors. The testing battery that participants complete are: visual processing ability via a sensory station which contains neurocognitive and visual acuity testing 3D biomechanical tests: double leg countermovement jump single leg countermovement jump double leg drop jump single leg drop jump stepdown test (eyes open and eyes closed) joint position sense test single leg balance (eyes open and eyes closed) isokinetic strength testing of quadriceps and hamstrings at 60deg/sec. 3 sets of 5 questionnaires: international knee documentation committee tampa scale of kinesiophobia ACL- return to sport after injury

Official Title
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What is the Effect of Vision on Movement Control in Anterior Cruciate Ligament Reconstructed Patients 7 Months Post-surgery?

Conditions
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ACL

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18-35 years old Playing club level Gaelic football or hurling They must report that they intend on returning to sport at the same or higher level Able to give written informed consent and to participate fully in the interventions At 7 months biomechanical testing, individuals would need to have 70% symmetry of both quadriceps and hamstring peak torque as measured on our isokinetic dynamometer with the angular velocity set to 60°/s Individuals should have already commenced linear running and double leg jumping tasks as part of their rehabilitation They are currently attending a gym or can attain gym access for the duration of intervention period Exclusion Criteria: They have not commenced running or jumping in their rehabilitation Revision ACL They underwent concurrent meniscal repair, chondral repair or extra-articular augmentation Serious medical conditions preventing them from completing high intensity resistance exercise Any previous: injuries to the visual system, concussion, head injury, unexplained seizures or epilepsy Any previous ankle or knee injuries Those who are uncomfortable or do not want to hop with their eyes closed (one of the assessment tasks will involve hopping on one leg with their eyes open and followed by another set in which their eyes are closed

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

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 |
| --- | --- |
| ACLR group<br>Individuals who are 7 months post primary ACLR | |
| healthy control group<br>Healthy uninjured individuals who are actively playing sport and have not sustained any knee injuries, ankle injuries or concussions. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to stability during stepdown task (eyes open versus eyes closed) | Participants will stepdown from a 20cm box and land on one leg. Participants will be advised to achieve stability as quickly as possible and then to remain in that position for 20 seconds. Participants will complete 3 trials on each leg first with their eyes open and then a further 3 trials on each leg whilst blindfolded. Participants will perform this test in the 3D lab utilising using an eight-camera motion analysis system (200Hz: Bonita-B10, Vicon, UK) | at 7 months post-ACLR | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Joint position sense testing | Participants will be seated and blindfolded. Participants will perform this test in the 3D lab utilising using an eight-camera motion analysis system (200Hz: Bonita-B10, Vicon, UK). The assessor will active extend the participant's knee to between 0-30 degrees and hold it there. The participant will then be asked to replicate that angle 5 times for each leg | at 7 months post-ACLR | 
| single leg balance (eyes closed versus eyes open) | Participants will perform this test in the 3D lab utilising using an eight-camera motion analysis system (200Hz: Bonita-B10, Vicon, UK) and integrated force plates (1000Hz BP400600, AMTI, USA). Participants will stand on one leg with less than 15 degrees knee flexion. They will be asked to balance for 20 seconds. 3 trials will be taken for each leg with participants' eyes open and 3 trials of each leg whilst they are blindfolded | at 7 months post-ACLR | 
| Quadriceps and hamstrings strength | isokinetic dynamometry conducted on each leg between 0-100 degrees at 60 deg/sec. 3 sets of 5 completed for each leg | at 7 months post-ACLR | 
| Countermovement jump- double leg and single leg | Participants will be instructed to jump as high as they can. This will be conducted 3 times with double leg and then 3 trials single legged (for each leg) | at 7 months post-ACLR | 
| Drop jump- double leg and single leg | participants will drop off 30cm step (double leg) and 15cm step (single leg) and be instructed to quickly jump off the ground and as high as they can. 3 trials of each will be taken | at 7 months post-ACLR | 
| anterior cruciate ligament return to sport after injury (ACL-RSI) questionnaire | Questionnaire utilised to assess for participants' readiness to return to sport and identify if there are any potential psychological factors impacting their return to sport. Minimum score 0% and maximum score 100%. Lower score indicates less fear regarding return to sport | at 7 months post-ACLR | 
| International knee documentation committee (IKDC) Questionnaire | Questionnaire utilised to assess participants' self-reported function. Minimum score 0 and maximum score 100. A higher score indicates higher levels of function | at 7 months post-ACLR | 
| Tampa scale of kinesiophobia | Questionnaire utilised to assess participants' fear of movement or reinjury. Minimum score 17 and maximum score 68. A lower score indicates better outcome or reduced kinesiophobia | at 7 months post-ACLR | 
| Near far quickness score (as part of visual processing software) | sensory tablet (Senaptec, USA) with preloaded assessment tasks to across multiple visual processing domains including near far quickness task. The task requires the participants to correctly answer a task on a screen 3 metres away. Upon entry of the correct answer, a task appears on a device 70-100cm from the participant. The task will then continue to move between the 2 screens over a 30 second period, with the number of correct responses and time taken to input a response being calculated. The number of correct responses over 30 second test period is reported with a higher score indicating better function | at 7 months post-ACLR | 
| Near far quickness reaction time to target (as part of visual processing software) | sensory tablet (Senaptec, USA) with preloaded assessment tasks to across multiple visual processing domains including near far quickness task. The task requires the participants to correctly answer a task on a screen 3 metres away. Upon entry of the correct answer, a task appears on a device 70-100cm from the participant. The task will then continue to move between the 2 screens over a 30 second period, with the number of correct responses and time taken to input a response being calculated. Average response time is calculated for individual to input correct response for a far target and a near target. A lower value indicates quicker reaction time and hence better function. | at 7 months post-ACLR | 
| Perception span (as part of visual processing software) | sensory tablet (Senaptec, USA) with preloaded assessment tasks to across multiple visual processing domains including perception span task. The task involves recalling which circles were filled following a pattern being flashed for 1 second. Total score is calculated by the software with a higher score indicating better function | at 7 months post-ACLR | 
| multiple object tracking score (as part of visual processing software) | sensory tablet (Senaptec, USA) with preloaded assessment tasks to across multiple visual processing domains including multiple object tracking task. In the task, a set of circles are highlighted to the participant. The circles then spin around the screen in conjunction with other circles before coming to a stop. The participant is then tasked with correctly identifying the circles that were initially highlighted.The software provides a proportional and composite score. A higher score indicates better function | at 7 months post-ACLR | 
| Reaction time (as part of visual processing software) | sensory tablet (Senaptec, USA) with preloaded assessment tasks to across multiple visual processing domains including reaction time task. In the task, the participant places both index fingers on the screen, a flashing red image indicates which finger needs to be removed from the screen. The participant is advised to remove their finger from the screen as quickly as possible. Reaction times are provided by the software for each side (dominant hand and non-dominant hand) and also as an average between the two sides. A lower time indicates better function | at 7 months post-ACLR |