Anterior Cruciate Ligament ReconstructionNCT05342415
Effect of Different Focused Techniques on Thigh Muscle Activation After Anterior Cruciate Ligament Reconstruction
A study testing Internally Focused Exercise and Externally Focused Exercise in people with Anterior Cruciate Ligament Reconstruction, run by Hacettepe University at 1 site in Turkey (Türkiye).
Trial summary
In recent years, it has been shown that different focuses (externally vs. internally focused) used when explaining exercises to patients after knee surgeries affect exercise performance and rehabilitation outcomes. Read more about this study
- Who is it for?
- Ages 18 to 30 years
- Conditions the study is for
- Anterior Cruciate Ligament Reconstruction
- What is being tested?
- Internally Focused Exercise and Externally Focused Exercise
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Sep 2024to 1 Jan 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- who underwent anterior cruciate ligament reconstruction with hamstring tendon autograft for the first time
- no systemic inflammation
- agreed to participate in the study
Who cannot join
- having a chronic disease/injury in the ankle, hip and knee
- contralateral knee symptoms and/or surgery history
- other surgeries in addition to the anterior cruciate ligament reconstruction (meniscus repair, chondral surgery, etc.)
- post-operative referral of the patient more than a week later
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Investigation of the Effect of Externally vs. Internally Focused Techniques on Thigh Muscle Activation After After Anterior Cruciate Ligament Reconstruction: A Randomized Assessor-Blinded Controlled Trial
In recent years, it has been shown that different focuses (externally vs. internally focused) used when explaining exercises to patients after knee surgeries affect exercise performance and rehabilitation outcomes. Quadriceps muscle inhibition after anterior cruciate ligament reconstruction is one of the primary symptoms that should be treated. This study aimed to investigate the effects of different focusing techniques during the rehabilitation exercises after anterior cruciate ligament rehabilitation.
Read the detailed description
Exercises are given for the symptoms of knee edema, knee range of motion, and quadriceps reflex inhibition in the acute period after anterior cruciate ligament surgery. In recent years it has been shown that the different focuses when explaining exercises to patients affect exercise performance and rehabilitation outcomes. It has been shown that the increase in performance of some exercises that require strength and power, such as long jump and sprint, especially with the applied external focus (the method of focusing on the result of the movement). However, it has been shown that there is an increase in muscle activation with internal focus (focusing on the muscles that reveal the movement). There is no study examining the effects of focusing differences on the exercise program given after anterior cruciate ligament reconstruction, especially on muscle activation after knee reflex inhibition.
30 individuals between the ages of 18-and 30 who had undergone anterior cruciate ligament reconstruction for the first time will be included in the study. The first evaluation will be performed and rehabilitation will begin in the first week after surgery. Patients who were taken into rehabilitation after anterior cruciate ligament surgery will be distributed into two different groups by the block randomization method. The same structured exercise program will be applied to the patients in both groups. Only the commands given during the exercise will be different.
Group 1: Internal Focused Exercise: E.g; While describing the knee pressing exercise (quadriceps isometric) in the long sitting position, the command "press your knee towards the bed by squeezing your thigh muscle" will be given by showing the muscle.
Group 2: External Focused Exercise: E.g; While describing the knee pressing (quadriceps isometric) exercise in the long sitting position, the command "press the towel/cloth that we put under your knee and compress your knee" will be given by showing the towel.
Patients will be followed under the supervision of a physiotherapist in the clinic 2 days a week and exercise progression will be provided. On the other days, the exercises will be continued as a home program. In order for the patients to comply with the exercises more easily and to be reminded easily, an exercise brochure will be given to the patients with the commands written and the exercises explained with pictures.
The last measurements will be performed at the end of one month after surgery.
- Being tested
- Internally Focused Exercise, Externally Focused Exercise
- Keywords
- external focus, internal focus, knee rehabilitation, electromyography
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Internally Focused ExerciseOther
While performing the exercises participants will be instructed to focus on the muscle itself.
Externally Focused ExerciseOther
While performing the exercises participants will be instructed to focus on the external target (towel, target line, etc.)
| Study group | Role | What they receive |
|---|---|---|
| Internally Focused | Active comparator | Focusing on the muscles that reveal the movement. Receives: Other: Internally Focused Exercise |
| Externally Focused | Experimental | Focusing on the result of the movement. Receives: Other: Externally Focused Exercise |
What is being measured
The primary outcome is the main question the study is designed to answer.
Determine if different focus techniques change thigh muscle activation
Vastus medialis, vastus lateralis, and rectus femoris muscle activation will be measured by superficial electromyography
Measured: Baseline and 1 month after surgery
Secondary outcomes (2)
Knee edema
The changes in the limb circumference will be measured with a tape measure (cm).
Measured: Baseline and 1 month after surgery
Knee range of motion
The changes in knee flexion and extension degree will be measured with a goniometer.
Measured: Baseline and 1 month after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Apr 2022
- Study start1 Sep 2024
- Primary completion1 Sep 2025
- Study completion1 Jan 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for Anterior Cruciate Ligament ReconstructionStudies of the same condition, open and under way.
- More trials run by Hacettepe UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hacettepe University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dilara Kara, Hacettepe University
- Investigators
- Volga Bayrakcı Tunay, PhD, Prof., Principal investigator, Hacettepe University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05342415
- Sponsor's protocol ID
- FTREK24/31
- Status last verified
- Jan 2026
- First submitted
- 3 Apr 2022
- Last updated
- 8 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Saka T. Principles of postoperative anterior cruciate ligament rehabilitation. World J Orthop. 2014 Sep 18;5(4):450-9. doi: 10.5312/wjo.v5.i4.450. eCollection 2014 Sep 18.
PubMed 25232521Kim DK, Hwang JH, Park WH. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction. J Phys Ther Sci. 2015 Sep;27(9):2693-6. doi: 10.1589/jpts.27.2693. Epub 2015 Sep 30.
PubMed 26504270Cavanaugh JT, Powers M. ACL Rehabilitation Progression: Where Are We Now? Curr Rev Musculoskelet Med. 2017 Sep;10(3):289-296. doi: 10.1007/s12178-017-9426-3.
PubMed 28791612Sonnery-Cottet B, Saithna A, Quelard B, Daggett M, Borade A, Ouanezar H, Thaunat M, Blakeney WG. Arthrogenic muscle inhibition after ACL reconstruction: a scoping review of the efficacy of interventions. Br J Sports Med. 2019 Mar;53(5):289-298. doi: 10.1136/bjsports-2017-098401. Epub 2018 Sep 7.
PubMed 30194224Halperin I, Williams KJ, Martin DT, Chapman DW. The Effects of Attentional Focusing Instructions on Force Production During the Isometric Midthigh Pull. J Strength Cond Res. 2016 Apr;30(4):919-23. doi: 10.1519/JSC.0000000000001194.
PubMed 27003451Porter JM, Anton PM, Wikoff NM, Ostrowski JB. Instructing skilled athletes to focus their attention externally at greater distances enhances jumping performance. J Strength Cond Res. 2013 Aug;27(8):2073-8. doi: 10.1519/JSC.0b013e31827e1521.
PubMed 23222082Ille A, Selin I, Do MC, Thon B. Attentional focus effects on sprint start performance as a function of skill level. J Sports Sci. 2013;31(15):1705-12. doi: 10.1080/02640414.2013.797097. Epub 2013 May 28.
PubMed 23710928Marchant DC, Greig M, Scott C. Attentional focusing instructions influence force production and muscular activity during isokinetic elbow flexions. J Strength Cond Res. 2009 Nov;23(8):2358-66. doi: 10.1519/JSC.0b013e3181b8d1e5.
PubMed 19826287Schoenfeld BJ, Vigotsky A, Contreras B, Golden S, Alto A, Larson R, Winkelman N, Paoli A. Differential effects of attentional focus strategies during long-term resistance training. Eur J Sport Sci. 2018 Jun;18(5):705-712. doi: 10.1080/17461391.2018.1447020. Epub 2018 Mar 13.
PubMed 29533715Wulf G, Dufek JS, Lozano L, Pettigrew C. Increased jump height and reduced EMG activity with an external focus. Hum Mov Sci. 2010 Jun;29(3):440-8. doi: 10.1016/j.humov.2009.11.008. Epub 2010 Apr 21.
PubMed 20409600Kal EC, van der Kamp J, Houdijk H. External attentional focus enhances movement automatization: a comprehensive test of the constrained action hypothesis. Hum Mov Sci. 2013 Aug;32(4):527-39. doi: 10.1016/j.humov.2013.04.001. Epub 2013 Jun 30.
PubMed 24054892Ogrodzka-Ciechanowicz K, Glab G, Slusarski J, Gadek A. Quadriceps muscle strength recovery with the use of high tone power therapy after anterior cruciate ligament reconstruction: a randomized controlled trial. BMC Musculoskelet Disord. 2021 Nov 23;22(1):975. doi: 10.1186/s12891-021-04862-w.
PubMed 34814896
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Effect of Externally vs. Internally Focused Techniques on Thigh Muscle Activation After After Anterior Cruciate Ligament Reconstruction: A Randomized Assessor-Blinded Controlled Trial
- ClinicalTrials.gov ID
- NCT05342415
- Acronym / sponsor ID
- FTREK24/31
- Keywords
- external focus, internal focus, knee rehabilitation, electromyography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Hacettepe UniversityUniversity, hospital or other
- Study start
- 1 Sep 2024 (actual)
- Primary completion
- 1 Sep 2025 (actual)
- Study completion
- 1 Jan 2026 (actual)
- First posted
- 22 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In recent years, it has been shown that different focuses (externally vs. internally focused) used when explaining exercises to patients after knee surgeries affect exercise performance and rehabilitation outcomes. Quadriceps muscle inhibition after anterior cruciate ligament reconstruction is one of the primary symptoms that should be treated. This study aimed to investigate the effects of different focusing techniques during the rehabilitation exercises after anterior cruciate ligament rehabilitation.
Detailed description
Exercises are given for the symptoms of knee edema, knee range of motion, and quadriceps reflex inhibition in the acute period after anterior cruciate ligament surgery. In recent years it has been shown that the different focuses when explaining exercises to patients affect exercise performance and rehabilitation outcomes. It has been shown that the increase in performance of some exercises that require strength and power, such as long jump and sprint, especially with the applied external focus (the method of focusing on the result of the movement). However, it has been shown that there is an increase in muscle activation with internal focus (focusing on the muscles that reveal the movement). There is no study examining the effects of focusing differences on the exercise program given after anterior cruciate ligament reconstruction, especially on muscle activation after knee reflex inhibition.
30 individuals between the ages of 18-and 30 who had undergone anterior cruciate ligament reconstruction for the first time will be included in the study. The first evaluation will be performed and rehabilitation will begin in the first week after surgery. Patients who were taken into rehabilitation after anterior cruciate ligament surgery will be distributed into two different groups by the block randomization method. The same structured exercise program will be applied to the patients in both groups. Only the commands given during the exercise will be different.
Group 1: Internal Focused Exercise: E.g; While describing the knee pressing exercise (quadriceps isometric) in the long sitting position, the command "press your knee towards the bed by squeezing your thigh muscle" will be given by showing the muscle.
Group 2: External Focused Exercise: E.g; While describing the knee pressing (quadriceps isometric) exercise in the long sitting position, the command "press the towel/cloth that we put under your knee and compress your knee" will be given by showing the towel.
Patients will be followed under the supervision of a physiotherapist in the clinic 2 days a week and exercise progression will be provided. On the other days, the exercises will be continued as a home program. In order for the patients to comply with the exercises more easily and to be reminded easily, an exercise brochure will be given to the patients with the commands written and the exercises explained with pictures.
The last measurements will be performed at the end of one month after surgery.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Internally Focused | Active comparator | Other: Internally Focused ExerciseFocusing on the muscles that reveal the movement. |
| Externally Focused | Experimental | Other: Externally Focused ExerciseFocusing on the result of the movement. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- who underwent anterior cruciate ligament reconstruction with hamstring tendon autograft for the first time
- no systemic inflammation
- agreed to participate in the study
Key exclusion criteria (4 listed)
- having a chronic disease/injury in the ankle, hip and knee
- contralateral knee symptoms and/or surgery history
- other surgeries in addition to the anterior cruciate ligament reconstruction (meniscus repair, chondral surgery, etc.)
- post-operative referral of the patient more than a week later
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Internally Focused ExerciseWhile performing the exercises participants will be instructed to focus on the muscle itself. | Other | Internally Focused |
| Externally Focused ExerciseWhile performing the exercises participants will be instructed to focus on the external target (towel, target line, etc.) | Other | Externally Focused |
Primary outcome
Determine if different focus techniques change thigh muscle activation
Time frame: Baseline and 1 month after surgery
Vastus medialis, vastus lateralis, and rectus femoris muscle activation will be measured by superficial electromyography
2 secondary outcomes
Knee edema
Time frame: Baseline and 1 month after surgery
Knee range of motion
Time frame: Baseline and 1 month after surgery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2026.
- Background: PubMed 25232521Saka T. Principles of postoperative anterior cruciate ligament rehabilitation. World J Orthop. 2014 Sep 18;5(4):450-9. doi: 10.5312/wjo.v5.i4.450. eCollection 2014 Sep 18.
- Background: PubMed 26504270Kim DK, Hwang JH, Park WH. Effects of 4 weeks preoperative exercise on knee extensor strength after anterior cruciate ligament reconstruction. J Phys Ther Sci. 2015 Sep;27(9):2693-6. doi: 10.1589/jpts.27.2693. Epub 2015 Sep 30.
- Background: PubMed 28791612Cavanaugh JT, Powers M. ACL Rehabilitation Progression: Where Are We Now? Curr Rev Musculoskelet Med. 2017 Sep;10(3):289-296. doi: 10.1007/s12178-017-9426-3.
- Background: PubMed 30194224Sonnery-Cottet B, Saithna A, Quelard B, Daggett M, Borade A, Ouanezar H, Thaunat M, Blakeney WG. Arthrogenic muscle inhibition after ACL reconstruction: a scoping review of the efficacy of interventions. Br J Sports Med. 2019 Mar;53(5):289-298. doi: 10.1136/bjsports-2017-098401. Epub 2018 Sep 7.
- Background: PubMed 27003451Halperin I, Williams KJ, Martin DT, Chapman DW. The Effects of Attentional Focusing Instructions on Force Production During the Isometric Midthigh Pull. J Strength Cond Res. 2016 Apr;30(4):919-23. doi: 10.1519/JSC.0000000000001194.
- Background: PubMed 23222082Porter JM, Anton PM, Wikoff NM, Ostrowski JB. Instructing skilled athletes to focus their attention externally at greater distances enhances jumping performance. J Strength Cond Res. 2013 Aug;27(8):2073-8. doi: 10.1519/JSC.0b013e31827e1521.
- Background: PubMed 23710928Ille A, Selin I, Do MC, Thon B. Attentional focus effects on sprint start performance as a function of skill level. J Sports Sci. 2013;31(15):1705-12. doi: 10.1080/02640414.2013.797097. Epub 2013 May 28.
- Background: PubMed 19826287Marchant DC, Greig M, Scott C. Attentional focusing instructions influence force production and muscular activity during isokinetic elbow flexions. J Strength Cond Res. 2009 Nov;23(8):2358-66. doi: 10.1519/JSC.0b013e3181b8d1e5.
- Background: PubMed 29533715Schoenfeld BJ, Vigotsky A, Contreras B, Golden S, Alto A, Larson R, Winkelman N, Paoli A. Differential effects of attentional focus strategies during long-term resistance training. Eur J Sport Sci. 2018 Jun;18(5):705-712. doi: 10.1080/17461391.2018.1447020. Epub 2018 Mar 13.
- Background: PubMed 20409600Wulf G, Dufek JS, Lozano L, Pettigrew C. Increased jump height and reduced EMG activity with an external focus. Hum Mov Sci. 2010 Jun;29(3):440-8. doi: 10.1016/j.humov.2009.11.008. Epub 2010 Apr 21.
- Background: PubMed 24054892Kal EC, van der Kamp J, Houdijk H. External attentional focus enhances movement automatization: a comprehensive test of the constrained action hypothesis. Hum Mov Sci. 2013 Aug;32(4):527-39. doi: 10.1016/j.humov.2013.04.001. Epub 2013 Jun 30.
- Background: PubMed 34814896Ogrodzka-Ciechanowicz K, Glab G, Slusarski J, Gadek A. Quadriceps muscle strength recovery with the use of high tone power therapy after anterior cruciate ligament reconstruction: a randomized controlled trial. BMC Musculoskelet Disord. 2021 Nov 23;22(1):975. doi: 10.1186/s12891-021-04862-w.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Volga Bayrakcı Tunay, PhD, Prof. principal investigator
Hacettepe University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Internally Focused Exercise and Externally Focused Exercise in people with Anterior Cruciate Ligament Reconstruction, run by Hacettepe University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Determine if different focus techniques change thigh muscle activation (time frame: Baseline and 1 month after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05342415, which also lists 12 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jan 2026.