System 4 Quick-Set™

Features a fixed-height positioning chair with 360 degree rotation and front/back travel for fast, easy patient setups that ensure maximum patient stabilization.

That event and subsequent “firsts” have made the Biodex dynamometer the choice in the most distinguished clinics and research facilities around the world.

Sports and orthopedic medicine, pediatric medicine, neurorehabilitation, older adult medicine, industrial medicine, and researchers depend on Biodex to provide consistent, accurate, objective data. Objective data that provides the best outcome for their patients… objective data that supports their research… objective data that separates their facility from the rest.

Biodex Objective Data

Communicate need, progress and outcome

Biodex Objective Data helps you communicate need, progress and outcome clearly and accurately. Easy to read and interpret color graphic reports are produced with normative data. Graphic reports and narrative letters compare patient’s status to normative data for all joints. Data legends and on-screen editing helps communicate the information in simple terms for patients, doctors, third party payers and employers.

Accuracy and Reliability

The Biodex System 4 offers a level of performance, accuracy, and safety that remains unmatched. Not surprisingly, Biodex equipment marks the highest correlation coefficients for reliability, accuracy, validity and repeatability – another reason why so many clinicians put their trust in Biodex.

Our 200 employees strive to keep Biodex at the forefront in innovation, effectiveness, efficiency and reliability. That’s why so many world class facilities depend on Biodex.

Benefits of System 4:

  • Advanced dynamometer technology for greater performance
  • Seat design accommodates athlete to pediatric applications
  • Windows® 10 Enterprise LTSC prevents intrusive update
    pop-ups and requests
  • Software interface, no other system is faster or easier to use
  • Feature rich software proves need, progress and outcome
  • Touchscreen for quick, easy operation
  • Simplified patient positioning with on-screen audio and visual aids
  • Requires only 64 sq-ft of operating space
  • Activity-specific work simulation exercises
  • Wide range of normative data, from pediatric through adults, ages 5 – 83
  • Excellent after-sale support, installation and continuing education programs

Versatility and marketability

System 4 is dependable and versatile – providing the means to take on new challenges and be adaptable to keep pace with progressive thinking and innovation.

Sports and Orthopedic Medicine

Whether your orthopedic and sports medicine practice is allowed only limited visits or you have the luxury of managing a complete recovery, Biodex is the tool that adapts to every environment. Evidence-based clinical protocols combine science with practical application to ensure that you provide the best outcomes.

Other capabilities include preseason screening, injury prevention and athletic performance enhancement.

Pediatric Medicine

Used to treat children worldwide, Isokinetic muscle testing helps clinicians by providing objective data for neuromuscular control and strength. Pediatric attachments and age-based normative data are available. View normative data for quadriceps and hamstrings in children ages 6-13 years.


For the management of persons with movement disorders, neurologic pathologies, or general deconditioning; an Integrated Protocol Using Instrument. The system helps patients build strength, endurance and coordination. Spasticity management includes objective quantification at specific contraction. Use Passive mode for repetitive exercises. Eccentric mode is useful for controlled strengthening.

Military Strength Training

Used by military special forces for injury prevention and performance optimization. Strength testing identifies residual deficits and predisposition for repeat injury.

Occupational Medicine/Workplace Health

For many industries today, poor muscular strength constitutes a risk factor for on-the-job injuries, and can predict susceptibility to many diseases.  Today’s workforce is older and more obese – characteristics expected to present increasing injury and illness challenges. Many workers display a loss of up to 30% of their muscle mass as early as age 55 – and may be unable to meet the physical demands of some jobs in as little as five years.

As a result, industry executives require objective tools to determine whether prospective employees possess the muscular strength necessary to safely meet the demands of the positions for which they’ve applied. The Biodex System 4 Dynamometer provides objective, reproducible measures that can be correlated with the physical demands of different jobs, as determined by the Department of Labor.  Such pre-employment testing enables companies to assess whether job applicants will become true assets to their workforce – or present risks of injuries, absenteeism and susceptibility to disease.

Older Adult

Biodex Fall Risk Screening & Condtioning Program has been employed by leading clinics for over ten years. It is the only fall program that incorporates a complete array of objective tests. Isokinetic testing will identify weakness; exercise will improve ankle and leg strength.


The Biodex Multi-Joint System has been used in over 1,000 published studies. Unique capabilities include:

  • Integrated Analog/EMG Output Signal Scaling provides real time analog voltage outputs of torque, position and velocity from the dynamometer. Perfect for integration with EMG devices.
  • Export Data Parser produces .csv files with preformatted header.
  • Curve Analysis allows the user to conduct complete neuromuscular evaluation. Available with Advantage Software v4.63. Coming soon to Advantage BX™.

Combine the art and science of rehabilitation

Based on accepted science, backed by independent studies, supported by clinical protocols and normative data
Featuring six modes of operation, the Biodex System 4 continues to offer pioneering breakthroughs in neuromuscular testing and rehabilitative technology. Biodex assessments of physical impairments provides patients a fast, effective, documented return to function. The Biodex System 4 is unusually sensitive to your patient’s limits. Progressive and interactive features keep you in complete control. Dynamic and static muscle loading environments provide unlimited combinations of technique and application.

Isokinetic Resistance Mode
  • The Isokinetic Resistance mode for testing and rehabilitation is totally accommodating throughout the entire range of motion. Biodex’s unique impact-free acceleration and deceleration eliminates joint trauma, allowing patients to exercise and be tested at more functional speeds. Resistance continuously matches effort, accommodating to variations in patient force output due to weakness, pain or fatigue at specific points in the individual’s range of motion.
  • Research along with over 30 years of clinical application has demonstrated that isokinetic resistance is a safe, objective means to quantify physical impairments with a high correlation to function. Isokinetic testing is the standard for muscle and joint assessment.
  • Applied torque response ensures that the patient’s limb velocity increases or decreases in proportion to the torque applied during acceleration and deceleration, enabling neuromuscular control measurements.
  • Choose concentric and eccentric contractions to perform isolated polymetric exercises.
      • Concentric torque up to 500 ft-lb (680 Nm) and eccentric torque up to 400 ft-lb (542 Nm) accommodates the demands of high performance athletes and sports medicine researchers.
Reactive Eccentric Mode
  • The Reactive Eccentric mode for submaximal neuromuscular re-education in the early phases of rehabilitation
  • The System 4 responds only to the patient’s force output. To initiate movement, the patient must produce and maintain a pre-determined minimum amount of force. This loads the muscles surrounding the joint, producing a pre- load, thus stabilizing and protecting the joint.
  • Eccentric torque up to 400 ft-lb (542 Nm)
      • Accommodates the demands of today’s athletes and sports medicine researchers.
Passive Motion Mode
  • The Passive Motion mode is a multi-function modality. Unique control properties allow for early intervention in all patients throughout all phases of rehabilitation.
  • Torque limits can be set as low as .5 ft-lb (.7 Nm). If a torque limit is exceeded during an eccentric contraction, the System stops. Once the patient’s torque output drops below the prescribed limit, movement is allowed. This unique capability allows patients to work safely at definitively prescribed sub-maximal force levels while combining isometric, concentric and eccentric contractions for:
    – decreasing joint effusion
    – increasing range of motion
    – developing strength
  • Passive speeds can be set as low as .25 degree per second and as fast as 300 degrees per second. The very slow speeds allow for overcoming the natural stretch reflex.
  • Biodex software includes specific protocols for active and passive joint repositioning.
  • Higher speeds in passive mode are ideal for active assistive exercise.
Isometric Mode
  • The Isometric mode is commonly used pre and post operatively or when pain associated with motion is a factor. Isometric contractions are effective at developing strength and decreasing joint effusion while avoiding painful points in the range of motion.
  • Biodex software automates the rehab process with automated multiple angle isometric protocols. Work the agonist, antagonist or both muscles at specified joint angles.
Isotonic Mode
  • The Isotonic mode allows velocity to vary while providing inertia-free constant force and concentric or eccentric muscular contractions.
  • Higher performance:
      • Isotonic force to as low as .5 ft-lb (.7 Nm) = 6 inch pound; and as high as 400 ft-lb (542 Nm)
  • Allows for functional task simulation when using work simulation tools, e.g. turning a doorknob.
  • Because the force is selected, the Isotonic mode also provides protective pre-loading of the joint prior to movement.
  • Ideal for work simulation. Constant force muscle loading is considered functional, as natural activities normally involve moving a constant weight object at varying velocities.

Enjoy complete freedom in planning the mode and level of clinician interaction that works best for each patient. Touch panel controls give clinicians the hands-on ability to adjust torque, speed, range of motion and other clinical parameters in real time.

The Biodex System 4 also allows clinicians the option to select automated test and exercise sessions. Any sequence of modes can be employed automatically.


The Biodex Multi-Joint System has been used in over 1,000 published studies. Unique capabilities include:

  • Integrated Analog/EMG Output Signal Scaling provides real time analog voltage outputs of torque, position and velocity from the dynamometer. Perfect for integration with EMG devices.
  • Export Data Parser produces .csv files with preformatted header.
  • Curve Analysis allows the user to conduct complete neuromuscular evaluation.


System 4 Quick-Set Patient Positioning System with fixed seat height, fully assisted Dynamometer height adjustment, front-to-back chair adjustment.

  • Dimensions:
    Base with Dynamometer and Positioning Chair: 33″ w x 61″ d x 56″ h (84 x 155 x 142 cm)
  • Clinical Data Station: 25″ w x 19″ d x 41″ h (64 x 48 x 104 cm)
  • Accessory Cart: 33″ w x 20″ d x 40″ h (85 x 51 x 102 cm)
  • Total Operating Floor Space Required: 32 sq. ft. (3 sq. m)
  • Clinical Data Station:
    – PC with Windows 10 Enterprise LTSC, Advantage BX™ Software, 22″ flat panel touchscreen with integrated speakers.
    – HP InkJet printer (US only).
  • Included accessories: ankle, knee, shoulder, elbow and wrist attachments, accessory cart and wall chart.
  • Performance:
    – Concentric speed up to 500 deg/sec
    – Eccentric speed up to 300 deg/sec
    – Concentric torque up to 500 ft-lb (680 Nm)
    – Eccentric torque up to 400 ft-lb (544 Nm)
    – Passive speed as low as .25 deg/sec
    • Passive torque as low as .5 ft-lb
    • Isotonic torque as low as .5 ft-lb
  • Total Weight: 1,350 lb (612 kg)
  • Power: 230 VAC, 50-60 Hz, 8 amps
  • Standards:
    IEC 60601-1:2005 (Third Edition) + CORR. 1:2006 + CORR. 2:2007 + A1:2012 (or IEC 60601-1: 2012 reprint)
    ANSI/AAMI ES60601-1:2005 + A1:2012 + C1:2009 and A2:2010
    CAN/CSA-C22.2 No. 60601-1:2014
    IEC 60601-1-2:2014
  • Warranty: one year parts and labor

To order, call 1-800-224-6339

850-000System 4 Pro™
852-000System 4 MVP™
840-000System 4 Quick-Set™

Export models available.


830-450Attachment, Back, Dual Position Ex/Flex
Includes docking clamp for PRO configuration
830-520Attachment, Closed Chain
830-269Attachment, Work Simulation Tools
830-540Attachments, UE Hemiparetic
830-315Attachment, Hip
Standard on PRO configuration
830-260Attachment, Anti-Shear, Left Pivot
830-261Attachment, Anti-Shear, Right Pivot
830-474Attachment, Pediatric Left Knee
830-475Attachment, Pediatric Right Knee
821-321Attachment, Pediatric Shoulder
830-550Attachment, Hamstring (set)
For use with Multiple Angle Comparison (Lengthened State) Test
830-316Attachment, Pediatric Hip
830-113Chair Wedge
830-120Wide Seat
830-451Attachment, Back, Docking Clamp, Quick-Set

Use with Quick-Set configuration. Order docking clamp with 830-450.


830-322Shoulder Input Tube
Standard on Pro, MVP and Quick-Set configuration
830-332Ankle Attachment (for System 3 and 4)
Standard on Pro, MVP and Quick-Set configuration
831-332Ankle Attachment (for System 2)

The Biodex Find a Clinic Directory

Help Patients and
Physicians Find You


ACL Return To Play

Recent Advances in the Treatment of the Shoulder & Knee

Course Presented by
Dr. Kevin E. Wilk