Now the Unloader One OA knee brace is even simpler to fit and easier to wear!

A new design incorporates color-coded buckles , more intuitive strapping, and denser Sensil® lining for increased patient comfort.

The flexible, perforated shells conform easily to individual anatomy, giving Unloader One OTS an excellent out-of-the-box fit. This brace combines a streamlined, flexible upright with Dual Dynamic Force Straps to generate more unloading leverage than any Unloader to date. Quick fit buckles and breathable liners help ensure better patient compliance.

New! Plus model for larger patients features a wider thigh strap, a gastroc strap and a sturdier frame and upright.

Unloader One: An effective treatment option for knee pain

Many people choose to treat their OA symptoms,  such as pain in the knees when walking, stiffness and swelling of the knee joints, with oral medications, injections and surgery. However, there is another option. Knee bracing for knee OA is less invasive and can be less costly than these other treatments. Plus, it is simple, safe and clinically proven to work.

Light-weight and unobtrusive

Unloader One® combines a streamlined, flexible upright with Dual Dynamic Force Straps to generate more unloading leverage than any Unloader to date.

Dual Dynamic Force Straps provide greater unloading leverage with a racheting Dynamic Force Control System enables on-the-spot self-dosing. Liners are coated with Össur Sensil® Silicone Technology eliminate migration. The flexible perforated shells conform easily to patient anatomy, giving Unloader One OTS an excellent out-of-the box fit.


Indications for Use

  • Mild to severe unicompartmental osteoarthritis (OA)
  • Unicompartmental knee conditions requiring load reduction, such as Articular Cartilage Defect Repair, Meniscal Cartilage Repair, Avascular Necrosis, or Tibial Plateau Fracture.
  • Thigh circumferences of 13.5" (34.3cm) to 33" (83.8cm) and calf circumferences of 9.8" (25cm) to 24" (61.5cm)
  • All non contact activities
Unloader One OTS Short - Medial
Part# Leg Compartment Size Measuring*
B-241519711 Right Medial X-Small 9.8 - 12.2"
B-241619711 Left Medial X-Small 9.8 - 12.2"
B-241519712 Right Medial Small 12.2 - 14"
B-241619712 Left Medial Small 12.2 - 14"
B-241519713 Right Medial Medium 14 - 16.75"
B-241619713 Left Medial Medium 14 - 16.75"
Circumference: 6" below mid-patella

Unloader One OTS Short - Lateral
Part# Leg Compartment Size Measuring*
B-241529711 Right Lateral X-Small 9.8 - 12.2"
B-241629711 Left Lateral X-Small 9.8 - 12.2"
B-241529712 Right Lateral Small 12.2 - 14"
B-241629712 Left Lateral Small 12.2 - 14"
B-241529713 Right Lateral Medium 14 - 16.75"
B-241629713 Left Lateral Medium 14 - 16.75"
Circumference: 6" below mid-patella

Unloader One OTS Standard - Medial
Part# Leg Compartment Size Measuring*
B-240519712 Right Medial Small 12.2 - 14"
B-240619712 Left Medial Small 12.2 - 14"
B-240519713 Right Medial Medium 14 - 16.75
B-240619713 Left Medial Medium 14 - 16.75
B-240519714 Right Medial Large 16.75 - 20"
B-240619714 Left Medial Large 16.75 - 20"
B-240519715 Right Medial XLarge 20 - 24"
B-240619715 Left Medial XLarge 20 - 24"
Circumference: 6" below mid-patella

Unloader One OTS Standard - Lateral
Part# Leg Compartment Size Measuring*
B-240529712 Right Lateral Small 12.2 - 14"
B-240629712 Left Lateral Small 12.2 - 14"
B-240529713 Right Lateral Medium 14 - 16.75
B-240629713 Left Lateral Medium 14 - 16.75
B-240529714 Right Lateral Large 16.75 - 20"
B-240629714 Left Lateral Large 16.75 - 20"
B-240529715 Right Lateral XLarge 20 - 24"
B-240629715 Left Lateral XLarge 20 - 24"
Circumference: 6" below mid-patella

Unloader One OTS Plus - Standard, Medial
Part# Leg Compartment Size Thigh circ.* Calf circ.*
B-245510004 Right Medial Large 21 - 25" 14 - 16.75"
B-245610004 Left Medial Large 21 - 25" 14 - 16.75"
B-245510005 Right Medial XLarge 25 - 29" 16.75 - 20"
B-245610005 Left Medial XLarge 25 - 29" 16.75 - 20"
  • Standard Length = 15.5"
  • Thigh Circumference: 6" above mid-patella
  • Calf Circumference: 6" below mid-patella

Unloader One OTS Plus - Standard, Lateral
Part# Leg Compartment Size Thigh circ.* Calf circ.*
B-245520004 Right Lateral Large 21 - 25" 14 - 16.75"
B-245620004 Left Lateral Large 21 - 25" 14 - 16.75"
B-245520005 Right Lateral XLarge 25 - 29" 16.75 - 20"
B-245620005 Left Lateral XLarge 25 - 29" 16.75 - 20"
  • Standard Length = 15.5"
  • Thigh Circumference: 6" above mid-patella
  • Calf Circumference: 6" below mid-patella

Unloader One OTS Plus - Long, Medial
Part# Leg Compartment Size Thigh circ.* Calf circ.*
B-244510004 Right Medial Large 21 - 25" 14 - 16.75"
B-244610004 Left Medial Large 21 - 25" 14 - 16.75"
B-244510005 Right Medial XLarge 25 - 29" 16.75 - 20"
B-244610005 Left Medial XLarge 25 - 29" 16.75 - 20"
  • Long Length = 16.5"
  • Thigh Circumference: 6" above mid-patella
  • Calf Circumference: 6" below mid-patella

Unloader One OTS Plus - Long, Lateral
Part# Leg Compartment Size Thigh circ.* Calf circ.*
B-244520004 Right Lateral Large 21 - 25" 14 - 16.75"
B-244620004 Left Lateral Large 21 - 25" 14 - 16.75"
B-244520005 Right Lateral XLarge 25 - 29" 16.75 - 20"
B-244620005 Left Lateral XLarge 25 - 29" 16.75 - 20"
  • Long Length = 16.5"
  • Thigh Circumference: 6" above mid-patella
  • Calf Circumference: 6" below mid-patella

Why the Unloader One Stands Above the Others

At the heart of the Unloader One is a highly sophisticated 3-Point Leverage System. This maximizes stability and support for knee osteoarthritis, providing an unparalleled level of comfort and range of motion.

The effectiveness of this system is further enhanced by two diagonal Dynamic Force Straps, which significantly increase the unloading potential of the knee brace. Adjusting these straps enables you to modify the amount of relief needed to alleviate joint pain.

Product Highlights

  • Dual Dynamic Force Straps increase unloading capabilities and prevent rotation of the brace on the leg 
  • Tool-free,  racheting Dynamic Force Control System enables self-dosing for easier pain management 
  • Quick Fit Buckles with leverage arms enable easy application and removal without the need for cumbersome strap adjustment 
  • Breathable liners featuring Össur Sensil® Silicone Technology on an Aerospacer base material eliminate migration
  • Flexible, low-profile, hinged upright contours to individual anatomy and allows use underneath clothing
  • Quick Connect Strapping for tool-free removal and replacement
  • Lightweight frame is perforated for flexibility and ventilation

Ossur AcademyÖssur Academy now offers the Unloader One Competency Program. The program is an online training intended to enhance the successful clinical outcomes for the practitioner. This program offers key information and direction on the proper technique in measurement for and fitting of the Unloader One osteoarthritis knee orthosis.

Get more information on the Unloader One Competency Program and other online education resources made available by Össur Academy