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CompletedNCT05342415Updated Jan 8, 2026

Effect of Different Focused Techniques on Thigh Muscle Activation After Anterior Cruciate Ligament Reconstruction

An interventional study of Internally Focused Exercise and Externally Focused Exercise in Anterior Cruciate Ligament Reconstruction, sponsored by Hacettepe University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 30 Years. Per ClinicalTrials.gov, last updated 2026-01-08.

Sponsored by Hacettepe University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
24
Allocation
Randomized
Ages
18 Years to 30 Years
Sex
All
01

Study 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. 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.

02

Conditions studied

  • Anterior Cruciate Ligament Reconstruction

Keywords

  • external focus
  • internal focus
  • knee rehabilitation
  • electromyography
03

In context

Lead sponsor

Hacettepe University is the lead sponsor of 983 studies on the registry; 212 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 30 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • who underwent anterior cruciate ligament reconstruction with hamstring tendon autograft for the first time
  • no systemic inflammation
  • agreed to participate in the study

Exclusion criteria

Exclusion Criteria:

  • 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
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
24 participants (actual)

Study arms

  • Active comparator
    Internally Focused

    Focusing on the muscles that reveal the movement.

    Other: Internally Focused Exercise

  • Experimental
    Externally Focused

    Focusing on the result of the movement.

    Other: Externally Focused Exercise

Interventions

  • OtherInternally Focused Exercise

    While performing the exercises participants will be instructed to focus on the muscle itself.

  • OtherExternally Focused Exercise

    While performing the exercises participants will be instructed to focus on the external target (towel, target line, etc.)

06

What researchers measure

Primary outcomes

  1. Determine if different focus techniques change thigh muscle activation

    Vastus medialis, vastus lateralis, and rectus femoris muscle activation will be measured by superficial electromyography

    Time frame: Baseline and 1 month after surgery

Secondary outcomes

  1. Knee edema

    The changes in the limb circumference will be measured with a tape measure (cm).

    Time frame: Baseline and 1 month after surgery

  2. Knee range of motion

    The changes in knee flexion and extension degree will be measured with a goniometer.

    Time frame: Baseline and 1 month after surgery

07

Study locations

1 site
  • Hacettepe University
    Ankara, Turkey (Türkiye)
08

References and documents

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 25232521 ↗
  • Kim 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 26504270 ↗
  • Cavanaugh 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 28791612 ↗
  • Sonnery-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 30194224 ↗
  • Halperin 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 27003451 ↗
  • Porter 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 23222082 ↗
  • Ille 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 23710928 ↗
  • Marchant 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 19826287 ↗
  • Schoenfeld 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 29533715 ↗
  • Wulf 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 20409600 ↗
  • Kal 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 24054892 ↗
  • Ogrodzka-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 ↗

Individual participant data

Plan to share: No

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jan 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT05342415
Lead sponsor
Hacettepe University
Responsible party
Dilara Kara (Principal Investigator, Hacettepe University) — Principal investigator
First posted
Apr 22, 2022
Start date
Sep 1, 2024
Primary completion
Sep 1, 2025
Completion
Jan 1, 2026
Last update
Jan 8, 2026

Study contacts

Volga Bayrakcı Tunay, PhD, Prof.
principal investigator · Hacettepe University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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