Contralateral Resistance Training During Immobilization in Patients With Acromioclavicular Joint Injury

NCT07628361 | Recruiting DMC

• 4 other identifiers: DI-03-CBC/2221261279DI-07-25/INI24 010884 01
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized controlled trial aims to compare the effects of contralateral eccentric and concentric resistance training performed during the immobilization period following acromioclavicular joint injury. Immobilization is commonly prescribed after injury but may lead to reductions in muscle mass, neuromuscular function, force production, and upper-limb functionality. Contralateral resistance training, also known as cross-education training, involves exercising the non-injured limb to induce beneficial adaptations in the immobilized limb through neural mechanisms. While both eccentric and concentric exercise may produce contralateral effects, their relative effectiveness in a clinical population remains unclear. Participants with acute acromioclavicular joint injury requiring sling immobilization will be randomly assigned to either a contralateral eccentric training group or a contralateral concentric training group. During immobilization, participants will perform supervised resistance training with the non-injured upper limb. Following immobilization, all participants will receive the same standardized rehabilitation program. Neuromuscular function, muscle morphology, force production, upper-limb function, and quality of life will be assessed before immobilization, after immobilization, and following rehabilitation. The findings may contribute to the development of more effective rehabilitation strategies for patients recovering from upper-limb injuries requiring temporary immobilization.

Conditions

Acromioclavicular Joint Dislocation; Acromioclavicular Joint Injury

Keywords

Cross-Education; Contralateral Training; Eccentric Exercise; Concentric Exercise; Resistance Training; Immobilization; Shoulder Rehabilitation; Acromioclavicular Joint Injury; Neuromuscular Function; Muscle Strength; Transcranial Magnetic Stimulation; Electromyography; Upper Limb Function; Physical Therapy; Rehabilitation

Outcome Measures

Primary Outcomes (2)

• Maximal Voluntary Isometric Contraction

  Maximal voluntary isometric force of the injured upper limb assessed using a calibrated dynamometer. Force values will be recorded during standardized maximal isometric contractions and used to evaluate changes in muscle performance throughout immobilization and rehabilitation. Unit: Newtons (N)

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

• Rate of Force Development

  Rate of force development (RFD) of the injured upper limb assessed during maximal voluntary isometric contractions using a calibrated dynamometer. RFD will be calculated from the force-time curve and used as an indicator of explosive force production and neuromuscular performance. Unit: N·s-¹ (N/s)

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

Secondary Outcomes (12)

• Elbow Flexors Voluntary Activation

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

• Biceps Brachii Motor Supramaximal Response Amplitude

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

• Biceps Brachii Motor Evoked Potential Amplitude

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

• Biceps Brachii Silent Period Duration

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

• Biceps Brachii Short-Interval Intracortical Inhibition

  Baseline, post-immobilization (2-4 weeks), and post-rehabilitation (6-8 weeks)

Study Arms (2)

Contralateral Eccentric Training

EXPERIMENTAL

Participants will perform supervised contralateral eccentric resistance training with the non-injured upper limb during the period of physician-prescribed sling immobilization following acute acromioclavicular joint injury, with or without surgical repair. The immobilization period is expected to last approximately 2 to 4 weeks depending on clinical management. Following immobilization, participants will complete a standardized 4-week rehabilitation program.

Behavioral: Contralateral Eccentric Resistance Training

Contralateral Concentric Training

ACTIVE COMPARATOR

Participants will perform supervised contralateral concentric resistance training with the non-injured upper limb during the period of physician-prescribed sling immobilization following acute acromioclavicular joint injury, with or without surgical repair. The immobilization period is expected to last approximately 2 to 4 weeks depending on clinical management. Following immobilization, participants will complete the same standardized 4-week rehabilitation program.

Behavioral: Contralateral Concentric Resistance Training

Interventions

Contralateral Eccentric Resistance Training BEHAVIORAL

Supervised unilateral eccentric elbow flexor training performed with the non-injured limb during sling immobilization (2-4 weeks). Training is performed 3 times/week, 5 sets of 8-12 repetitions at 60-90% 1RM, with 4-second contractions and 3-minute rest intervals between sets.

Contralateral Eccentric Training

Contralateral Concentric Resistance Training BEHAVIORAL

Supervised unilateral concentric elbow flexor training performed with the non-injured limb during sling immobilization (2-4 weeks). Training is performed 3 times/week, 5 sets of 8-12 repetitions at 60-90% 1RM, with 4-second contractions and 3-minute rest intervals between sets.

Contralateral Concentric Training

Eligibility Criteria

• Age: 18 Years - 36 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Men and women aged 18 to 36 years.
• Diagnosis of acute acromioclavicular joint injury confirmed by an orthopedic surgeon.
• Physician-prescribed upper-limb immobilization using a sling for approximately 2 to 4 weeks, with or without surgical repair.
• Ability to understand study procedures and provide written informed consent.
• Medical clearance to participate in the rehabilitation and resistance training program.

You may not qualify if:

• Previous surgery or severe musculoskeletal injury affecting either upper limb within the previous 12 months.
• Neurological disorders affecting motor function or neuromuscular performance.
• Contraindications to transcranial magnetic stimulation according to established safety guidelines.
• Current participation in another clinical trial or structured upper-limb rehabilitation program.
• Cognitive impairment or inability to comply with study procedures.
• Pregnancy.
• Any medical condition that, in the opinion of the investigators, may compromise participant safety or study participation.

Sponsors & Collaborators

• Universidad Nacional Andres Bello: lead

Study Sites (1)

Clínica Indisa

Santiago, Providencia, Chile

RECRUITING

Study Officials

• Claudio Chamorro Lange, PhD

  Universidad Nacional Andres Bello

  STUDY DIRECTOR

• Luis Peñailillo Escaráte, PhD

  Universidad Nacional Andres Bello

  STUDY DIRECTOR

Central Study Contacts

Omar E Valdés Tapia, PT, MSc, PhD(c)

CONTACT

+569 74082822; o.valdestapia@uandresbello.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Outcome assessors and data analysts will be blinded to group allocation throughout data collection and statistical analysis.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Participants with acute acromioclavicular joint injury requiring a period of upper-limb immobilization with a sling, either following conservative management or surgical repair, will be randomly assigned to one of two parallel intervention groups: contralateral concentric resistance training or contralateral eccentric resistance training. Both interventions will be performed with the non-injured upper limb during the immobilization period. Following immobilization, all participants will receive the same standardized rehabilitation program. Outcomes will be assessed at baseline, after immobilization, and after completion of rehabilitation.

Study Record Dates

• First Submitted: May 29, 2026
• First Posted: June 5, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2027
• Last Updated: June 8, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Data will become available beginning 6 months following publication of the primary study results and will remain available for a period of 5 years.
• Access Criteria: Researchers who provide a methodologically sound proposal and whose intended use of the data has been approved by the study investigators may access the data. Requests should be directed to the Principal Investigator. Data will be shared through a secure institutional repository or encrypted electronic transfer following execution of an appropriate data-sharing agreement.

Locations

CL (1)