Neurocognitive Loading Following Anterior Shoulder Stabilization: A Randomized Controlled Trial

Effects of Neurocognitive Loading on Neuromuscular Control, Kinesiophobia, and Clinical Outcomes Following Anterior Shoulder Stabilization Surgery: A Randomized Controlled Trial

The goal of this randomized controlled clinical trial is to learn if adding neurocognitive loading to standard shoulder rehabilitation improves physical and psychological recovery in adults who have undergone arthroscopic anterior shoulder stabilization surgery (such as Bankart repair, Latarjet, or remplissage procedures).

The main questions it aims to answer are:

Does adding neurocognitive loading exercises improve shoulder proprioception, muscle strength, and functional performance compared to standard therapy alone? Does this integrated training approach reduce the kinesiophobia? Does it lead to better overall clinical outcomes and improve psychological readiness to return to sports? Researchers will compare a group receiving standard shoulder exercises combined with dual-task neurocognitive loading (using light-based reaction systems and cognitive tasks) to a control group receiving standard shoulder rehabilitation alone. Participants will:Undergo supervised physical therapy sessions starting 10 days after surgery up to the 16th postoperative week (twice a week for the first 12 weeks, and once a week for weeks 13-16) alongside an assigned home exercise program. Complete neurocognitive loading tasks (if assigned to the intervention group) that challenge attention, quick decision-making, and visual reactions while executing physical movements. Attend detailed clinical evaluation sessions lasting about 60 minutes before the treatment starts, and at 6, 12, and 24 weeks after surgery. These assessments include neurocognitive, functional and clinical tests, and questionnaires.

Background and Rationale Traumatic anterior shoulder dislocation frequently compromises mechanical tissue stability and alters the sensorimotor pathways by damaging mechanoreceptors and articular proprioceptors. While surgical stabilization methods (e.g., arthroscopic Bankart repair, Latarjet, or remplissage techniques) restore structural integrity, residual deficits in glenohumeral proprioception and neuromuscular rotator cuff control often persist long after surgery. Standard postoperative rehabilitation paradigms primarily emphasize repetitive, single-task motor exercises in highly predictable clinical settings. However, when patients transition back to real-world environments or competitive sports where cognitive and visual demands are high, optimal motor control can fail, escalating the risk of re-injury.

This study utilizes an innovative neurocognitive rehabilitation model designed to bridge the gap between isolated motor performance and complex real-world demands. By adding dual-task training that pairs motor stabilization exercises with explicit cognitive and visual-reactive tasks, this intervention aims to optimize neural resource allocation, enhance motor learning retention, and accelerate safe return-to-sport preparation.

Randomization and Stratification Participants are assessed at the 10th postoperative day and randomly assigned via sequentially numbered, opaque, sealed envelopes to either the experimental group (Neurocognitive Loading) or the control group (Standard Shoulder Rehabilitation). Randomization is stratified based on biological sex and the specific surgical technique used by the orthopedic surgeon to ensure balanced group distributions.

Rehabilitation Framework Both groups undergo an aligned, progressive exercise protocol structured into specific postoperative phases. Following 10 days of absolute joint immobilization, supervised treatment sessions are conducted twice weekly for the first 12 weeks, and once weekly from weeks 13 through 16, supplemented by a structured 4-day-a-week home exercise program. Progression within the physical therapy timeline balances tissue healing constraints with the incremental advancement of mechanical load, moving from passive and active-assisted range of motion to targeted rotator cuff strengthening and scapular stabilization.

Neurocognitive Progression Model

The experimental group executes the exact same physical protocol as the control group but integrates simultaneous neurocognitive loading during all proprioceptive and dynamic stabilization exercises. The cognitive load is applied via a multi-pod wireless reaction light system (BlazePod) and structured cognitive tasks using the healthy, uninjured limb to interact with the stimuli. The progression of the cognitive workload is directly mapped to Aleksandr Luria's "Functional Units of the Brain" model and the Fitts & Posner motor learning stages to systematically shift neurological processing from primitive attention to higher-order executive functioning:

Weeks 3-4 (Cognitive Stage / Unit I - Arousal & Selective Attention): Focuses on basic visual-reactive triggers. Participants respond to a single random light pod to reinforce alert orientation and basic motor planning.

Weeks 5-6 (Associative Stage / Unit II - Information Processing & Inhibition): Introduces selective multi-color triggers. Participants are instructed to react strictly to a designated target color while actively ignoring a distractor color (Response Inhibition).

Weeks 7-8 (Associative Stage / Unit II - Visuospatial Mapping): Integrates color-position rules where participants must process the physical location of the stimulus and match it to an abstract response rule.

Weeks 9-12 (Transition to Autonomous Stage / Unit III - Working Memory & Go/No-Go Executive Processing): Incorporates sequential memory strings (reproducing a multi-pod lighting pattern in correct serial order) and rapid executive Go/No-Go switching rules.

Weeks 13-16 (Autonomous Stage / Unit III - Complex Cognitive Conflict Resolution): Focuses on high-tier hierarchical decisions under environmental conflict (e.g., instructions requiring a response to a specific target color unless it appears in a forbidden physical zone) to simulate complex athletic scenarios.

Progress Management Rules

To safeguard healing tissues and manage neurological adaptation, progression is strictly monitored. Exercises are adjusted using explicit performance error metrics:

Optimal Progression: Achieving a cognitive/motor task accuracy rate of age 80% with only 1 to 2 minor coordination faults justifies advancing the exercise difficulty.

Regressive Calibration: Committing 3> coordination faults or demonstrating a single severe compensatory movement failure requires an immediate step down to a simpler stimulus level (e.g., reducing lighting colors, slowing target velocity, or stabilizing the physical support base).

Inclusion Criteria:

• Age: Participant must be between 18 and 45 years of age.
• Diagnosis: Must have undergone arthroscopic anterior shoulder stabilization surgery (e.g., Bankart repair, Latarjet, or remplissage techniques) within the past month due to traumatic, unilateral anterior shoulder instability.
• Postoperative Timeline: Currently within postoperative days 10 to 28.
• Baseline Activity Level: Pre-injury physical activity level must be a score of 3 or higher on the Tegner Activity Scale.
• Consent: Participant must be willing and give voluntary informed consent to participate in the study.

Exclusion Criteria:

• Hypermobility: Diagnosed generalized joint hypermobility syndrome, defined as a Beighton Score of 5 or higher.
• Neurological or Systemic Conditions: Presence of any systemic, rheumatic, or neurological disorders.
• Previous Surgical History: History of prior shoulder surgery or revision surgery on the affected side, with the exception of the primary anterior shoulder stabilization and an accompanying SLAP lesion repair.
• Concomitant Structural Pathology: Concomitant rotator cuff tear larger than 1 centimeter. History of osteochondral lesions or acromioclavicular separation injuries.
• Contralateral Limb Status: History of shoulder instability, shoulder surgery, or any shoulder injury within the past 6 months on the uninjured (contralateral) side.
• Cognitive Impairment: A score of 24 or below on the Standardized Mini-Mental State Examination (MMSE).
• Visual/Sensory Impairments: Any severe visual or sensory deficit that prevents interaction with visual-reactive training equipment.
• Pregnancy: Current pregnancy.

Non-compliance/Withdrawal:

• Refusal to participate or withdrawal of consent at any stage of the study.
• Attendance of less than 80% of the scheduled supervised rehabilitation sessions.
• Missing two consecutive clinical follow-up assessment sessions.