Eccentric or Concentric Contralateral Training in Rehabilitation After Shoulder Surgery With Elbow Immobilization

This clinical study investigates whether contralateral training (exercising the non-immobilized arm) can help preserve muscle strength and mass in patients recovering from shoulder surgery with elbow immobilization. Immobilization is often necessary to prevent further injury, but it can lead to significant muscle loss and reduced strength, delaying recovery and increasing healthcare costs. Recent studies suggest that training the non-immobilized arm may help maintain muscle function in the immobilized arm, particularly when using eccentric exercises (where muscles lengthen under tension). This study aims to compare the effects of eccentric and concentric (shortening) contralateral training versus standard care (no training) in patients undergoing shoulder surgery.

The study involves 4 visits: pre-surgery assessments, a 4-6 weeks' immobilization period with or without training, and follow-ups at the end of immobilization, 6 weeks' post-immobilization, and 17 weeks' post-immobilization. Participants will be randomly assigned to one of three groups: a control group receiving standard care, a group performing eccentric training, or a group performing concentric training. Muscle strength, mass, and function will be measured using tests such as isometric strength, ultrasound imaging, and functional scores.

The hypothesis is that eccentric contralateral training will better preserve neuromuscular function and muscle mass in the immobilized arm compared to both standard care and concentric training. This could lead to faster recovery and improved outcomes for patients. The study will provide valuable insights into optimizing rehabilitation strategies for patients recovering from shoulder surgery.

The study is structured into four visits:

* Inclusion Visit (V0): During the pre-surgical consultation, patients are informed about the study and provided with an information sheet and consent form.
* Pre-Surgery Visit (V1, PRE): Conducted within 7 days before surgery, this visit includes baseline measurements on both arms (immobilized and non-immobilized). Assessments include:

  * Isometric maximal voluntary strength of elbow flexors and extensors using an isokinetic dynamometer.
  * 1-RM (one-repetition maximum) for elbow flexors and extensors.
  * Arm circumference at 5, 10, and 15 cm from the elbow crease.
  * Anatomical cross-sectional area of arm muscles using ultrasound.
  * Forearm circumference at 5 cm from the elbow crease.
  * Handgrip strength (finger flexors).
  * Functional scores: DASH (Disabilities of the Arm, Shoulder, and Hand), Constant-Murley, joint position sense (proprioception), and muscle stiffness.
* Following surgery, patients enter a 4-6 weeks' immobilization period, during which they are randomly assigned to one of three groups:

  * Control Group (CTRL): Receives standard care, including rehabilitation sessions three times per week.
  * Eccentric Training Group (EXC): Performs standard care plus eccentric training of the non-immobilized arm.
  * Concentric Training Group (CON): Performs standard care plus concentric training of the non-immobilized arm.

The training protocol involves 3 sessions per week, separated by 24-48 hours. Each session includes 4-6 sets of 10 repetitions of elbow flexion/extension exercises on the non-immobilized arm at 60-90% of 1-RM, depending on the week. Eccentric or concentric actions are performed based on group assignment, with controlled contraction duration (4 seconds) using a metronome. Rest periods of 2 seconds between repetitions and 2 minutes between sets are provided.

• Follow-Up Visits:

* V2 (POST): At the end of immobilization, the same measurements as V1 are repeated
* V3 (POST + 6 weeks): Measurements are repeated again.
* V4 (POST + 17 weeks): Measurements are repeated again.

Eligibility Criteria:
Inclusion Criteria:

* Adult patient (≥ 18 years old) undergoing shoulder surgery (i.e., Bankart procedure, rotator cuff repair, arthroplasty)
* With an indication for immobilization, expected to last 4 to 6 weeks
* Free from any neurological pathology
* Having provided their informed consent before any participation in the research

Exclusion Criteria:

* Having a medical contraindication to the practice of physical and sports activities
* Presenting an expected modification of their physical activity of the non-immobilized limb
* Having suffered an injury to the upper limbs in the last 6 months
* Having already undergone surgery on the upper limbs
* Pregnant, parturient, and breastfeeding women
* Presenting a medically established alteration of their cognitive functions
* Subject under guardianship, curatorship, family empowerment, or judicial safeguard
* Not affiliated or beneficiary of health insurance coverage
* Any other reason that, in the investigator's opinion, could interfere with the evaluation of the study objectives