This Study Evaluates the Use of a Data-driven Lower Limb Exoskeleton Controller for Stroke Rehabilitation.

• Unified Control Framework for Lower-Limb Powered Orthosis (Device): An AI-driven, machine learning-based control software integrated into a wearable lower-limb powered orthosis. The system utilizes a Bayesian Neural Network (BNN) to analyze a user's pathological walking patterns (kinematics) in real-time via onboard sensors. Based on this real-time performance, the device dynamically modulates its physical assistance along a seamless continuum. It automatically transitions between stiff corrective guidance (position-based gait training) when the user struggles, and compliant, volitional torque support (torque-based assistance) as the user's independent walking ability improves.
• Conventional Robotic Controller (Device): A standard control paradigm for lower-limb powered orthoses that provides non-adaptive physical assistance during gait training. Depending on the trial block, the device operates in one of two static modalities: either rigid position-based gait training (GT) that physically guides the patient's limbs through a fixed, predetermined trajectory regardless of effort, or torque-based volitional augmentation (VA) that proportionally amplifies existing muscle output or ground reaction forces. Unlike the experimental intervention, this controller cannot interpret kinematics in real-time or dynamically modulate assistance along a continuous spectrum based on the user's instantaneous performance.

Primary outcomes

• Walking Speed [Baseline (Week 0), Post-Intervention Phase 1 (Week 4), Post-Washout / Pre-Intervention Phase 2 (Week 8), and Post-Intervention Phase 2 (Week 12).]: A standardized clinical assessment used to determine short-distance walking speed over a 10-meter course. This metric evaluates the preliminary clinical efficacy of the unified control framework compared to the conventional controller in chronic stroke survivors.
• Functional Mobility and Balance [Baseline (Week 0), Post-Intervention Phase 1 (Week 4), Post-Washout / Pre-Intervention Phase 2 (Week 8), and Post-Intervention Phase 2 (Week 12).]: A clinical performance-based measure used to assess dynamic balance, turning agility, and functional mobility. The test measures the time (in seconds) taken for a participant to rise from a chair, walk 3 meters, turn around, walk back, and sit down.

Secondary outcomes

• Acute Within-Session Changes in Spatial Gait Symmetry [Baseline (Week 0) and weekly during the 12 training sessions across each 4-week intervention period.]: Gait symmetry evaluated using the step length symmetry index (SI), calculated from lower-limb kinematics recorded by the exoskeleton's onboard joint encoders and/or motion capture data. This metric evaluates the immediate corrective effects on walking patterns. An SI of 0% represents perfect symmetry.
• Acute Within-Session Changes in Ground Reaction Force Symmetry [Baseline (Week 0) and weekly during the 12 training sessions across each 4-week intervention period.]: Force symmetry evaluated using the peak vertical ground reaction force ratio between the paretic and non-paretic limbs, measured via the exoskeleton's instrumented insoles and/or force plates. This evaluates the immediate impact of the control framework on weight-bearing symmetry. Data are expressed as a dimensionless ratio, where a value of 1.0 indicates perfect symmetry between limbs. Force is measured in units of Newtons.
• Acute Within-Session Changes in Joint Range of Motion [Baseline (Week 0) and weekly during the 12 training sessions across each 4-week intervention period.]: Measurement of the peak angular displacement of the knee, hip and ankle joints (in degrees) during the sagittal plane gait cycle, captured by the exoskeleton's onboard joint encoders and/or a motion capture system.

Sex: All, ages: 18 Years to 80 Years, accepts healthy volunteers

Inclusion Criteria:

* Cohort 1: Able-Bodied Participants (Initial Validation)
* Healthy young adults.
* No history of neurological, orthopedic, or cardiovascular impairments affecting gait or balance.
* Able to walk independently without assistive devices.

Cohort 2: Stroke Survivors (Clinical Efficacy Pilot)

* Individuals with a documented history of chronic stroke.
* Persistent unilateral lower-limb motor impairment resulting in a pathological gait pattern (heterogeneous gait deficits).
* Stable medical condition allowing for participation in intensive physical rehabilitation tasks.
* Able to provide informed consent.

Exclusion Criteria:

* Severe cognitive or communication impairments that prevent the participant from following safety instructions or reporting discomfort.
* Co-existing neurological conditions (other than stroke) that independently impair locomotion (e.g., Parkinson's disease, Multiple Sclerosis).
* Severe lower-limb joint contractures or orthopedic conditions that mechanically restrict the safe range of motion of the robotic orthosis.
* Skin breakdowns, open wounds, or severe unhealed lesions at the contact points where the powered orthosis interfaces with the lower limbs.
* Any medical contraindication to intensive walking exercise or treadmill training (e.g., unstable angina, severe unmanaged cardiovascular disease).