Study on the Effects of Unilateral Resistance Training on Lower Limb Muscle Strength and Symmetry After Anterior Cruciate Ligament Reconstruction Surgery

NCT07271173 | Completed

• 1 other identifier: M2025001
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

Brief Summary Study type: Randomized controlled trial (interventional). Purpose: To find out whether six weeks of unilateral resistance training (URT) improves lower-limb strength and inter-limb symmetry more than traditional bilateral resistance training (BRT) after anterior cruciate ligament reconstruction (ACLR). Main questions: Does URT produce better limb-symmetry in knee flexor/extensor peak torque than BRT? Does URT lead to larger gains in feed-forward motor control, Lysholm knee score and International Knee Documentation Committee 2000 (IKDC 2000) subjective rating? Comparison: Participants will be randomly assigned to URT (each exercise done one leg at a time) or BRT (both legs work together). Training volume, frequency, session length and progression rules are identical in both groups. What participants will do: After giving consent, complete baseline tests of strength, motor control and knee questionnaires. Attend 3 supervised sessions per week for 6 weeks. Each session lasts \~70 min: 5 min warm-up on cycle ergometer 5 min core-stability work 50 min strength circuit (6 exercises, 2 min between sets, 3 min between exercises) 10 min stretching/cool-down One-repetition maximum (1RM) re-tested at week 3 to adjust load. Final assessment within 3 days after the last training session (same tests as baseline).

Conditions

Anterior Cruciate Ligament Reconstruction Rehabilitation

Outcome Measures

Primary Outcomes (1)

• muscle strength

  Isokinetic muscle strength test Before the test, the participants were instructed on the basic principles of isokinetic strength testing and were required to perform three maximum knee extensions as a warm-up. After the warm-up, the patients rested for 2 minutes, and then performed 5 repetitions at speeds of 60°/s and 180°/s. The peak torque values (PT) of the quadriceps and hamstring muscles of both limbs during the 5 attempts were recorded.

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

Secondary Outcomes (5)

• Thigh circumference measurement (unit: cm)

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

• Lysholm knee score scale

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

• Knee joint IKDC 2000 score

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

• Single-leg jump (unit: cm)

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

• Landing Error Scoring System,LESS

  Baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study)

Study Arms (2)

Control group: Bilateral resistance training group

ACTIVE COMPARATOR

Control group: Bilateral resistance training (BRT, referring to the training method where both limbs (both hands or both legs) simultaneously resist the same resistance. The force is transmitted synchronously on both sides, the center of gravity is stable, and the movements are symmetrical). The movements in the BRT group were similar to those in the URT group. Each movement was completed simultaneously by both legs. The resistance setting was based on measuring the 1RM of both lower limbs (60% of 1RM).

Behavioral: resistance training

Experimental group: Unilateral resistance training group

EXPERIMENTAL

Experimental group: Unilateral Resistance Training (URT, referring to the training method where one limb (either one hand or one leg) performs resistance movements independently, emphasizing the application of load to the target limb while activating the stabilizing muscle groups on the opposite side to maintain balance). In the URT group, each movement is performed first by the affected leg and then by the healthy leg. A set is completed when both legs have finished. After the training of the affected leg, the timing begins. The training time of the healthy leg also counts as the interval time. The resistance setting is measured separately for each side of the lower body's single side (1RM) at 60% of 1RM.

Behavioral: resistance training

Interventions

resistance training BEHAVIORAL

After signing the informed consent form, the relevant indicators for the pre-trial tests can be conducted.Outcome assessments are conducted at baseline (1 day before the intervention) and 3 days after the final training session (day 45 of the study).The entire trial period lasts for 6 weeks, with 3 training sessions per week. The entire training process includes 5 minutes of warm-up (power bike), 5 minutes of core strength training, 50 minutes of muscle strength training, and 10 minutes of stretching training. The training methods of the two groups are only different in the muscle strength training method. The experimental group (URT group) performs unilateral resistance training for both lower limbs, while the control group (BRT group) performs bilateral resistance training for both lower limbs. There are a total of 6 training actions: towel roll compression training, sitting leg-cranking training, knee extension resistance training, distant hip bridge train

Control group: Bilateral resistance training group; Experimental group: Unilateral resistance training group

Eligibility Criteria

• Age: 30 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Age 30-55 years
• ACLR performed with hamstring-tendon autograft ≥ 3 months ago
• Full extension (no loss) and ≤ 5° difference in knee-flexion range between limbs, with flexion ≥ 120°
• Able to recruit quadriceps adequately (no lag during 10 consecutive straight-leg raises on the involved side)
• Can stand pain-free on the involved leg for ≥ 5 s without support
• Has signed informed consent and can complete all study procedures

You may not qualify if:

• Previous lower-limb surgery on either leg, including revision ACLR
• Any prior knee surgery on the contralateral limb
• Associated ligament ruptures or fractures
• Severe patellar chondral damage
• Post-operative arthrofibrosis
• Professional athletes
• Cardiac disease
• Pregnant or lactating women

Sponsors & Collaborators

• Peking University Third Hospital: lead

Study Sites (1)

Peking University Third Hospital of Chongli

Zhangjiakou, Hebei, 076350, China

Location

MeSH Terms

Interventions

Resistance Training

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 20, 2025
• First Posted: December 9, 2025
• Study Start: April 6, 2025
• Primary Completion: November 1, 2025
• Study Completion: November 1, 2025
• Last Updated: December 9, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)