Preoperative Rehabilitation for Patient With an ACL Injury (K-POP)

Comparison of Two Programs Delivered During Rehabilitation Before an Anteriror Cruciate Ligament Reconstruction : a Randomised Controlled Trial K-POP

Muscle qualities are critical for the recovery after an anterior cruciate ligament (ACL) injury. Before ACL reconstruction (ALCR), resistance training aims to maintain patient strength and volume in order to optimize recovery. Unanswered questions remain on the modalities of resistance training before ACLR. This protocol details a pragmatic clinical trial that primary aims to increase the maximal strength of knee extensors and flexors and to induce hypertrophy before ACLR. Participants awaiting ACLR will be recruited from outpatient rehabilitation clinics and will be randomly allocated to one group to attend a 9-weeks rehabilitation program before ACLR. Participants of 'resistance training' group will perform a training program built on the principles of strength training to increase knee muscles strength and volume. Three blocks of 3 weeks will induce a progressive increase in training load, with exercises performed close to failure. Participants of 'usual group' will perform traditional exercises including: balance/proprioceptive exercises, weight-balances exercises, and body-weight resistance training exercises. Groups will be compared on muscle strength (primary outcome), clinical outcomes (muscle volume, stiffness, knee mobility, effusion) and self-reported outcomes (quality of life, perception of knee function, pain, anxiety and depression, exertion, health consumption, participations in activities) before and after ACLR. Outcomes will be collected by a blinded assessor before and after the resistance training program (before ACLR); 4 and 9 months after the ACLR.

Study Overview

• Status: Recruiting
• Conditions: Anterior Cruciate Ligament (ACL)
• Intervention / Treatment: Other: Resistance training; Other: Traditional exercises

• Study Type: Interventional
• Enrollment (Estimated): 84
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Antoine FROUIN; Phone Number: +33 02 53 48 28 35; Email: Antoine.Frouin1@univ-nantes.fr
• Study Contact Backup: Name: Guillaume LE SANT; Phone Number: +33 02 53 48 28 35; Email: Guillaume.LE-SANT@ifm3r.eu

Study Locations

• France
  • Nantes, France, 44000
    • Recruiting
    • University Hospital - Laboratoire "Motricité, Interactions, Performance" (UR 4334)
    • Contact: Antoine FROUIN; Phone Number: +33 02 53 48 28 35; Email: Antoine.Frouin1@univ-nantes.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Being over 18 years
• A first episode of an ACL injury
• An ACLR scheduled at least 10 weeks later, with a surgical technique using hamstring, gracilis, or quadriceps/patellar tendon autograft
• A minimum passive range of motion of the knee between 10° of extension deficit, and 80° of flexion
• A medical prescription for prehabilitation
• Possibility to attend prehabilitation program and post-ACLR rehabilitation in one of the 15 clinics

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Resistance training group; Participants of 'resistance training' group will perform a training program built on the principles of strength training to increase knee muscles strength and volume.	Other: Resistance training; Participants of 'resistance training' group will perform a training program built on the principles of strength training to increase knee muscles strength and volume. Three blocks of 3 weeks will induce a progressive increase in training load, with exercises performed close to failure. The exercising part for participants of 'RT group' will be composed by a progressive increase in load over the 9 weeks. For that purpose, the intensity of load will be increased each 3 weeks (i.e. on the session 1, 10, and 19), using a low-load of 25RM (W1 to W3), mid-load of 10 RM (W4 to W6), and a high-load of 8 RM (W7 to W9) at the end of the program. During each session, the exercise will be performed at an intensity of RPE 9-10 (i.e. near to failure). Based on the literature this progressivity and intensity in loads will target gains in strength and volume among strengthened muscle groups. (Schoenfeld et al., 2021).
Active Comparator: Usual group; Participants of 'usual group' will perform traditional exercises including: balance/proprioceptive exercises, weight-balances exercises, and body-weight resistance training exercises.	Other: Traditional exercises; Participants of 'usual group' will perform traditional exercises including: balance/proprioceptive exercises, weight-balances exercises, and body-weight resistance training exercises. The exercising part for participants of 'usual training group' will comport traditional exercises used in prehabilitation, including: balance/proprioceptive exercises, weight-balances exercises, and body-weight resistance training exercises. Again, the 9 weeks will be sub-divided into 3 blocks of 3 weeks for inducing a progressive increase in training load. During w1 to w3, priority will be given to gait, weight balance and knee ROM exercises. From w4 to w7, proprioceptive and jumping exercises will be introduced. During the last 3 weeks, participants will perform 2 sets of 10 repetitions of body-weight exercises.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal torque for knee extension in isometric condition	The maximal torque for KE strength, measured in MVC isometric condition, will be used to evaluate the between-group differences, at the end of prehabilitation (W9). We will use an ANCOVA (Analysis of covariance) model between strength and group, adjusted to the force measured at baseline to underline the TIME*GROUP effect.	In the week following the 9 weeks of preoperative rehabilitation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee extension and flexion torque	The maximal torque, between-leg symmetry index (injured side/contralateral side), for Knee Extension and Knee Flexion will be calculated at the different endpoints, for each condition (80° and 30°)	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)
Voluntary activation	Voluntary activation will be measured by interpolated twitch technique on knee extensor muscles.	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)
Change in muscle volume	Muscle volume will be assessed by 3D ultrasound on quadriceps and hamstring muscles	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)
KOOS questionnaire	Patient reported outcomes will be measured by the KOOS questionnaire	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)
SANE scale.	Patient reported outcomes will be measured by the SANE scale.	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)
HAD scale	Patient reported outcomes will be measured by the HAD scale	First visit, (T0), visit at 9 weeks of preoperative rehabilitation (T1), visit 4 months after surgery (T2), visit 9 months after surgery (T3)

Collaborators and Investigators

• Sponsor: Nantes University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 17, 2026
• Primary Completion (Estimated): August 15, 2027
• Study Completion (Estimated): August 15, 2027

Study Registration Dates

• First Submitted: January 30, 2026
• First Submitted That Met QC Criteria: February 6, 2026
• First Posted (Actual): February 17, 2026

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 19, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Rehabilitation; Strength; Muscle Volume; Voluntary activation; Preoperative resistance training
• Additional Relevant MeSH Terms: Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Physical Conditioning, Human; Exercise; Resistance Training
• Other Study ID Numbers: RC25_0050

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No