Knee Isokinetic Strength Measurement and Training System

Developed by Jizhi Medical, this knee isokinetic strength measurement and training system represents the company’s first commercial rehabilitation robot incorporating proprietary DDR (Direct Drive Robot) motor technology. The device provides quantitative assessment and targeted training for patients recovering from knee injuries or surgeries.

Product Overview

The system addresses a clinical need for precise, reproducible knee rehabilitation exercises with objective measurement capabilities. Traditional rehabilitation approaches rely heavily on therapist judgment and patient-reported outcomes, while isokinetic systems provide standardized force application and quantitative data collection throughout the range of motion.

By utilizing direct-drive motor technology rather than conventional geared actuators, the system achieves smoother torque delivery and eliminates mechanical backlash that can compromise measurement accuracy. This technical approach enables both diagnostic assessment and therapeutic training within a single platform.

Key Features

At NMPA Class II approval (2019), Jizhi Medical’s knee isokinetic system uses DDR direct-drive motors for backlash-free torque measurement across isokinetic, isotonic, and isometric protocols, with bilateral limb comparison for objective rehabilitation benchmarking.

• DDR Direct-Drive Motor: Proprietary motor technology provides precise torque control without gear reduction, enabling accurate force measurement across the full range of motion
• Real-Time Force Feedback: Continuous monitoring of patient-applied force with visual feedback for both clinician and patient
• Quantitative Assessment: Generates objective strength metrics including peak torque, average power, and fatigue indices
• Bilateral Comparison: Enables comparison between affected and unaffected limbs to establish rehabilitation targets
• Adjustable Resistance Modes: Supports isokinetic, isotonic, and isometric exercise protocols
• Data Recording: Stores session data for longitudinal tracking of patient progress

Technical Specifications

At NMPA Class II certification (2019), this DDR direct-drive knee rehabilitation system generates peak torque, average power, and fatigue index data using self-developed motor, controller, and encoder components across full flexion-extension range.

Clinical Applications

The system serves multiple clinical scenarios within rehabilitation medicine:

Post-Surgical Rehabilitation: Following ACL reconstruction, meniscus repair, or total knee arthroplasty, the device provides controlled strengthening exercises with quantifiable progress metrics.

Sports Medicine: Athletes recovering from knee injuries benefit from objective strength assessment to guide return-to-play decisions, with bilateral comparison establishing when the affected limb has achieved adequate recovery.

Neurological Rehabilitation: Patients with central nervous system injuries affecting lower limb function can use the system for targeted knee strengthening as part of full rehabilitation programs.

Orthopedic Assessment: Pre-operative strength baselines and post-operative recovery tracking provide objective data for clinical decision-making.

Regulatory Status

Frequently Asked Questions

What conditions can be treated with this system?

The knee isokinetic system is indicated for rehabilitation of knee joint dysfunction from various causes including post-surgical recovery (ACL, meniscus, arthroplasty), sports injuries, and neurological conditions affecting lower limb strength. It is also used for pre-operative assessment and sports performance testing.

How does DDR direct-drive technology differ from conventional systems?

DDR direct-drive motors connect directly to the joint mechanism without gear reduction, eliminating mechanical backlash and providing smoother, more accurate force control. This enables more precise strength measurements and a more natural feel during exercise compared to geared systems.

Is the system suitable for home use?

The current system is designed for use in medical facilities under clinical supervision. The device requires proper setup and interpretation of assessment data by trained rehabilitation professionals.